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Cardiorespiratory and metabolic responses to treadmill versus water immersion to the neck exercise in… Frangolias, Despina Daisy 1993

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CARDIORESPIRATORY AND METABOLIC RESPONSES TO TREADMILL VERSUS WATERIMMERSION TO THE NECK EXERCISE IN ELITE DISTANCE RUNNERSbyDespina Daisy FrangoliasB.P.E., The University of British Columbia, 1985A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THEDEGREE OF MASTER OF PHYSICAL EDUCATIONinTHE FACULTY OF GRADUATE STUDIES(School of Physical Education)We accept this thesis as conforming to the required standardTHE UNIVERSITY OF BRITISH COLUMBIASeptember 1993Despina Daisy Frangolias, 1993In presenting this thesis in partial fulfilment of the requirements for an advanceddegree at the University of British Columbia, I agree that the Library shall make itfreely available for reference and study. I further agree that permission for extensivecopying of this thesis for scholarly purposes may be granted by the head of mydepartment or by his or her representatives. It is understood that copying orpublication of this thesis for financial gain shall not be allowed without my writtenpermission.Department of \k\c\ &\ c\:—\ csThe University of British ColumbiaVancouver, CanadaDate(Signature)DE.6 (2/88)ABSTRACTThe purpose of this study was to compare the following: a) thecardiorespiratory responses, in elite endurance runners familiar withwater immersion to the neck non—weight bearing (WI) running, atventilatory threshold (Tvent) and at maximal effort (ie. VO2m) fortreadmill and WI running performance to exhaustion and b) thecardiorespiratory and metabolic responses to prolonged performance (42mm.) at exercise intensities reflecting the treadmill and WI Tvent.Thirteen endurance trained runners familiar with water running completedcomparable treadmill and WI VO2max tests. Oxygen consumption (V02),ventilation (ye), heart-rate (HR), respiratory exchange ratio (RER),ratings of perceived exertion (RPE) and stride frequency (SF) weremeasured at Tvent and VO2max. Blood lactate [BLa] samples were obtained30 seconds and 5 minutes post—test. Correlated t—tests revealedsignificantly (p<O.05) higher VO2max (59.7 vs 54.6 mlkgmin), HRmax(190 vs 175 bpm), RERmax (1.20 vs 1.10), V02 at Tvent (46.3 vs 42.8mlkgmin), HR at Tvent (165 vs 152 bpm) for the treadmill vs WI,respectively. Similar values were recorded for Vemax (109.0 vs 105.8lmin), Ve at Tvent (66.4 vs 65.7 lmin), RER at Tvent (0.99 vs0.89) and post—test [BLaJ at 30 sec (10.4 vs 9.8 mmoll) and 5 mmpost—test (9.7 vs 9.2 mmoll1) for the two conditions. Wilcoxonsmatched pairs signed—ranks test revealed no differences in RPE at Tventand VO2max level for the two conditions. Significantly higher SF valuesover time were recorded (88 vs 54 stridesmin, averaged over time) oniithe treadmill. The lower WI VO2max with similar peak [BLa) and lower SFsuggests that the active musculature and muscle recruitment patternsdiffer in WI running due to the high viscocity friction of water, andthe non—weight bearing nature of WI running.During steady state exercise at treadmill and WI Tvent nodifferences in Ve response to exercise were noted in the treadmill andWI conditions. [BLa] response exhibited a decreasing trend over time inthe WI condition both during the treadmill and WI Tvent intensity tests.Similar HR values were exhibited for exercise at WI Tvent in bothconditions, confirming that the lower HR exhibited at Tvent from the WIVO2max test was related to the lower V02 at WI Tvent and not the WIcondition. Significantly lower HR values were exhibited for exercise attreadmill Tvent in the WI versus the treadmill condition suggesting thatHR is lower only at workloads corresponding to and above 84.8 % of WIVO2max. Results suggest that exercise in the water immersion to theneck condition affects (reduces) HR and [BLa) response over time, withthe intensity of exercise being a factor. The WI condition, howeverdoes not affect Ve and RPE responses.iiiTABLE OF CONTENTSAbstract__________ iiList of Tables____ viii.List of Figures --Acknowledgement xiiChapter 1.1.0________1.1_____________________________________1.2__________________________1.3__ _____2.0 Review of Literature 202.1 Cardiovascular responses to water immersion tothe neck________________________________________________2.1.1 Heart—rate_______________________________________2.1.2 Preload, Contractility and Afterload________________2.1.3 Cardiac output and Stroke volume_____________________2.2 Respiratory responses to water immersion to theneck2.2.1 Static Lung volumes_______________________________2.2.2 Exercise Respiratory responses2.3 Water immersion exercise studies________________________2.3.1 VO2max and short duration submaximal effort__________Introduction__________Definition of Terms_Statement of Problem1.41.5157Hypotheses 8Delimitations 15Assumptions 151.6 Limitations_1.7 Significance_Chapter 2.16•2 02125262828_3 03 131iv2.3.2 Submaximal prolonged duration exercise in waterimmersion 402.3.3 Comparison of the specificity of training: WIversus land—based training 402.4 Ventilatory threshold (Tvent) performance 42Chapter 3.3.0 Methods and Procedures 443.1.0 Sample 443.2.0 Physiological test equipment 483.3.0 Underwater film assessment apparatus and procedures_523.4.0 Treadmill and WI VO2max and Tvent performance testprotocols and procedures 533.4.1 Treadmill and VO2max common procedures 533.4.2 Treadmill VO2max test protocol and procedures 543.4.3 WI VO2max test protocol, procedures and equipment 553.4.4 Ventilatory threshold determination 613.4.5 Tvent performance tests 613.5.0 Experimental design 633.6.0 Statistical analysis 65Chapter 4.664.0 Results4.1.0 Physical characteristics of the sample 664.2.0 Maximal oxygen consumption (VO2max) test results 674.2.1 Maximal responses 674.2.2 Ventilatory threshold (Tvent) responses 694.3.0 Tvent steady state performance test results 764.3.1 Heart-rate 76V4.3.2 Oxygen consumption 824.3.3 Ventilation 874.3.4 Blood lactate concentration 934.4 Hypothesis verification 984.4.1 Test of hypothesis 1 984.4.2 Test of hypothesis 2 984.4.3 Test of hypothesis 3 994.4.4 Test of hypothesis 4 994.4.5 Test of hypothesis 5 1004.4.6 Test of hypothesis 6 1004.5 Summary of hypothesis results 102Chapter 55.0 Discussion 1035.1 Maximal and Tvent responses from VO2max test results 1045.2 Comparison of the treadmill and WI steady stateTvent performance tests 1125.2.1 Heart-rate 1155.2.2 Ventilation 1165.2.3 Blood lactate concentration 1175.2.4 Respiratory exchange ratio 1195.2.5 Ratings of perceived exertion 120Chapter 66.0 Conclusions 1236.1 Recommendations for future research 1246.2 Training implications 1266.3 Bibliography 130AppendicesviSubjects Raw Data 136Repeated measures analysis for HR, V02, yeand [BLa] 162Stride frequency 172Repeated measures analysis for RER and RPE 175Quality of workouts 190Laboratory temperature and barometric pressureover test sessions 192Determination of Tvent from Ventilatoryparameters 194Appendix H: Subject Informed Consent form 196Appendix A:Appendix B:Appendix C:Appendix D:Appendix E:Appendix F:Appendix G:viiLIST OF TABLESTable 1.0. Physical Characteristics and Treadmill MaximalOxygen Consumption of the Sample 66Table 2.0 VO2max Results : Maximal ResponsesTable 3.0 VO2max Results : Results at Tvent 70Table 4.0 2 X 2 X 7 Repeated Measures analysis Results forHeart—rate 163Table 4.1 2 X 2 X 7 Repeated Measures analysis ResultsTrTrTVent VS WlTrTvent for Heart-rate 164Table 4.2 2 X 2 X 7 Repeated Measures analysis ResultsTrwITVeflt V5 WIWITvent for Heart—rate 164Table 5.0 2 X 2 X 7 Repeated Measures analysis Results forOxygen Consumption 165Table 5.1 2 X 2 X 7 Repeated Measures analysis ResultsTrTrTVent ‘s WITrTvent for Oxygen Consumption 166Table 5.2 2 X 2 X 7 Repeated Measures analysis ResultsTrWITVeflt V5 WIwITvent for Oxygen Consumption 166Table 6.0 2 X 2 X 7 Repeated Measures analysis Results forVentilation 167Table 6.1 2 X 2 X 7 Repeated Measures analysis ResultsTrTrTVent V5 WITrTvent for Ventilation 168Table 6.2 2 X 2 X 7 Repeated Measures analysis ResultsTrwITVeflt VS WIWITvent for Ventilation 168Table 7.0 2 X 2 X 7 Repeated Measures analysis Results forBlood Lactate Concentration 169Table 7.1 2 X 2 X 7 Repeated Measures analysis ResultsTrTrTVent VS WlTrTvent for Blood LactateConcentration 170Table 7.2 2 X 2 X 7 Repeated Measures analysis ResultsTrwITVeflt VS WIwITvent for Blood LactateConcentration 170Table D1.0 2 X 2 X 7 Repeated Measures analysis Results forRespiratory Exchange Ratio 181Table D1.1 2 X 2 X 7 Repeated Measures analysis ResultsTrTrTVent vs WITrTVent for Respiratory ExchangeviiiRatio 182Table Dl.2 2 X 2 X 7 Repeated Measures analysis ResultsTrwlTveflt VS WIWITvent for Respiratory ExchangeRatio 182Table D2.O 2 X 2 X 7 Repeated Measures analysis Results forRatings of Perceived Exertion 188Table D2.1 2 X 2 X 7 Repeated Measures analysis ResultsTrTrTVent VS WlTrTvent for Ratings of PerceivedExertion 189Table D2.2 2 X 2 X 7 Repeated Measures analysis ResultsTrWITVent VS WIwITvent for Ratings of PerceivedExertion 189ixLIST OF FIGURESFigure 1.0. Hypotheses Summary Chart 14Figure 2.0. Underwater photograph of a subject WI running 47Figure 3.0. WI running; an above and below surface picture 50Figure 4.0 WI running set-up 51Figure 5.0 Treadmill and WI VO2max Protocol description 59Figure 6.0 VO2max and Tvent tests schematic representationof procedures 60Figure 7.0 Diagram of the factors and levels of the experimentaldesign 64Figure 8.0. Mean V02 (+1 std) at maximal effort and Tvent fromthe treadmill and WI VO2max tests 71Figure 8.1. Mean HR and ye (+1 std) at maximal effort and Tventlevel from the treadmill and WI tests 72Figure 8.2. Mean RER and RPE (+1 std) at maximal effort andTvent level from the treadmill and WI VO2max tests 73Figure 8.3. Mean post-test [BLa) and VO2max test duration atmaximal effort and at Tvent level from the treadmilland WI VO2max tests 74Figure 8.4. Comparison of the treadmill and WI VO2max and Tventresponses and the %age of the respective VO2max thateach Tvent represents, compared to their respectiveVO2max responses 76Figure 9.0. Mean HR response for condition and Tvent main effectsand Condition X Tvent interaction 79Figure 9.1. Mean HR response over the steady state performancetests over time 80Figure 9.2. Mean HR response for Condition X Time and Tvent XTime interactions 81Figure 10.0 Mean V02 (in mlkg min) response for Conditionand Tvent main effects and Condition X Tventinteraction 84Figure 10.1 Mean V02 (in mlkg min) response over thesteady state performance tests over time 85xFigure 10.2 Mean V02 (in mlkg1in)response forCondition X Time and Tvent X Time interactions 86Figure 11.0 Mean ye response for Condition and Tvent maineffects and Condition X Tvent interaction 90Figure 11.1 Mean ye response over the steady state performancetests over time 91Figure 11.2 Mean ye response for Condition X Time and Tvent XTime interactions 92Figure 12.0 Mean (BLa] response for Condition and Tvent maineffects and Condition X Tvent interaction 95Figure 12.1 Mean BLa) response over the steady stateperformance tests over time 96Figure 12.2 Mean [BLa] response for Condition X Time and TventX Time interactions 97Figure C1.0 Comparison of stride frequency (strides/mm) duringthe treadmill vs the WI VO2maX tests 174Figure 01.0 Mean RER response for Condition and Tvent maineffects and Condition X Tvent interaction 179Figure 01.1 Mean RER response over the steady state performancetests over time 180Figure D2.0 Mean RPE response for Condition and Tvent maineffects and Condition X Tvent interaction 186Figure 02.1 Mean RPE response over the steady state performancetests over time 187Figure E1.0 Comparison of the quality of the subjects’ WIrunning workouts compared to the magnitude of thedifference in WI and treadmill VO2max (in mlkg1min1) 190Figure F1.0 Laboratory temperature and barometric pressure overthe test sessions 192Figure G1.0 Determination of Tvent from ventilatory parameters(ExCO2 and Ve/V02) 194xiAcknowledgementsTo Mr. and Mrs. Steve Frangolias:Dear Mom and Dad,For the person you created,For the person 1 have become,I dedicate this to you.I would like to express my sincere gratitude and appreciation to mysubjects who volunteered their precious time and gave their personalbest to make this investigation possible, and to my fellowcolleagues, friends, workstudy students and family who assisted inthe data collection and were simply there for me.I extend my sincere appreciation to my committee members: Drs. AngeloBelcastro, Ken Coutts, Igor Mekjavic, Jack Taunton and thesis advisorDr. Ted Rhodes, for their guidance, patience and support.I am indebted to Dr. J.R. Ledsome and Mr. Jim Potts (Ph.D student)and his father for their technical support in this investigation.xiiCHAPTER 11.0 INTRODUCTIONWater immersion to the neck (WI) has been used as a method ofsimulating various aspects of the aerospace environment. Theapplication of knowledge attained from this area of research hasexpanded beyond the aeronautical sciences (Epstein, 1976). The non—weight bearing nature of water immersion exercise has made this form ofexercise popular among populations of low fitness levels and thoseexperiencing muscle and joint problems (Vickery et al, 1983; Evans etal, 1978). It has also become popular among special needs populations,such as during pregnancy among women (McMurray et al, 1988) and withindividuals affected by chronic soft tissue degeneration andneurological disease (eg. rheumatoid arthritis, multiple sclerosis)(Danneskiolt-SamSoe et al, 1987; Compton et al, 1989).WI running has gained popularity among runners. WI running has beenused by runners and has been prescribed by athletes’ doctors and coachesas an alternative to land based running. It is currently being usedboth as a rehabilitative treatment for lower trunk injury (Koszulta,1986), and as a supplement to the runners’ land based training regimen(Town and Bradley, 1991; Richie and Hopkins, 1991; Yaxnaji et al, 1990;Bishop et al, 1989). The non-weight bearing nature of WI running makesthis form of exercise popular among runners experiencing muscle andjoint problems, or trying to avoid such injuries by proportioning theirweekly ‘mileage’ between land and WI running.1The non—weight bearing nature of WI running and the viscosityfriction experienced in WI, however, also raises the question of howsimilar these two activities are. Johnson et al (1977) noted a higheroxygen consumption for similar leg exercise in WI versus land. Theynoted that, whereas, more energy is required on land to lift a greatermass, a similar effect is present in the WI condition related to thefrictional resistance and turbulence of the water. The longer thelever, the larger the girth of the legs and the greater the speed of themovement, the greater will be the frictional resistance and turbulenceexperienced during WI exercise.The goal with WI running is to simulate land—based running motionwhile immersed to the neck in water and non—weight bearing. Theassumption is made that the same muscle groups and recruitment patternsare involved in WI running as are with land—based running. Studiescomparing land and WI cycling have found no differences in VO2maX(Christie et al, 1990; Connelly et al, 1990; Shedahi et al, 1987;Dressendorfer et al, 1976), however, studies which have comparedtreadmill and WI running have reported lower VO2max responses in WIcompared to treadmill running (Svedenhag and Seger, 1992; Town andBradley, 1991; Butts et al, 1991; Welsh, 1988). WI running style andfamiliarity with WI running may be factors responsible for the lower WIVO2max reported by WI running studies.Responses during submaximal exercise on the treadmill and WI runninghave also been investigated recently (Svedenhag and Seger, 1992; Richie2and Hopkins, 1991; Yamaji et al, 1990; Bishop et al, 1989). Theauthors comment that although their subjects were familiarized with WIrunning, they were ‘less conditioned’ in the WI compared to the land(treadmill) condition. These studies have compared the physiologicalresponses of WI and treadmill running among runners with limited WIrunning familiarity and at absolute workloads, which most likelyrepresent in the WI condition a higher metabolic requirement. This hasbeen demonstrated by the WI running studies comparing treadmill and WIVO2max, which have found lower WI responses.Static lung volumes have been reported to be reduced in WI (Withersand Hamdorf, 1989; Hong et al, 1969; Agostoni et al, 1966). Exerciseminute ventilation (ye) (in relation to V02) has been reported to remainunaffected (Svedenhag and Seger, 1992; Sheldahl et al, 1987; and Welsh,1988), or reduced (Butts et al, 1991; Dressendorfer et al, 1976) in theWI condition.Lower maximal HR has been reported for WI running and ergometercycling (Svedenhag and Seger, 1992; Butts et al, 1991; Town andBradely, 1991; Connelly et al, 1990; Christie et al, 1990; Welsh, 1988;Sheldahl et al, 1987; Dressendorfer et al, 1977). However, there is noclear consensus on resting and submaximal HR responses. Resting HR inupright WI compared to land has been reported to remain unchanged(Connelly et al, 1990; Christie et al, 1990; Arborelius et al, 1972) orto decrease (Risch et al, 1978; Fahri and Linnarsson, 1977; Lollgen etal, 1976). Similarly, submaximal exercise HR response (matched for V02)has been reported to remain unchanged (Christie et al, 1990; Sheldahl et3al, 1987; Evans et al, 1978; McArdle et al, 1976) or to decrease(Conrielly et al, 1990; Christie et al, 1990; Welsh, 1988; Johnson et al,1977; Rennie et al, 1971) in WI compared to land exercise.Cardiorespiratory mechanics are altered by WI at rest and possiblyin exercise. It is therefore important to distinguish thephysiological differences which can be attributed to the WI conditionversus differences which are attributed to limitations of these studies.Studies comparing treadmill and WI running have predominately usedrunners untrained in WI running (who are not incorporating WI running intheir training regimen) and have compared physiological responses toexercise at dissimilar workloads in the two conditions. Ventilatorythreshold (Tvent) is representative of one’s aerobic capacity (Andersonand Rhodes, 1991; Loat and Rhodes, 1991; Anderson and Rhodes, 1989;Wiley and Rhodes, 1986; Caiozzo et al, 1982; Rusko et al, 1980; Volkovet al, 1975) and is highly correlated with long distance performance(Coen at al, 1991; Maffulli et al, 1991; Rhodes and McKenzie, 1984).The purpose of this study was twofold: a) to compare the physiologicaland metabolic responses to treadmill and WI running at ventilatorythreshold (Tvent) and at maximal effort among a group of elite distancerunners familiar with WI running, and b) to compare the physiologicaland metabolic responses to treadmill and WI running during prolongedexercise at Tvent (WI and treadmill Tvent). It was postulated thatstudies to date had not controlled adequately for WI running style andthe extent of the runners’ familiarity with WI running.41.1 DEFINITION OF TERMSExcess CO2. The non-metabolic CO2 has been calculated by Issekutz andRodahl (1961) by the following formula: Excess CO2 = — (RQrest *V02), with RQrest = 0.70—0.80). It is the non-metabolic CO2 (and water)generated by the bicarbonate buffering system of the hydrogen ionsproduced within exercising muscle from the dissociation of lactic acid.The chemical reactions are as follows HLa + NaHCO3 = NaLa + H2C03 =CO2 + H20 (Wasserman et al, 1973).Lactate. Also referred to as lactic acid or blood lactate. It is themetabolic by—product of anaerobic energy production (Brooks and Fahey,1985).Respiratory Exchange Ratio (RER). Different amounts of oxygen (V02) arerequired for the catabolism (oxidation) of carbohydrate, fat and proteinto carbon dioxide (C02), water and energy. The ratio of CO2produced/V02 consumed is defined as the RER and varies depending uponthe substrate metabolized (Brooks and Fahey, 1985).Runner Trained in WI Running. A runner trained in WI running is definedby this study as the runner who utilizes WI running on a regular basisin their training regimen. It is the runner who performs a minumum 6sessions of WI running per month, of at least 45 minute duration persession, for the previous 6 months prior to participation in the presentstudy.5Steady State Exercise. The intensity of exercise that can be performedfor a prolonged period of time without appreciable elevations in V02,HR, Ve, RER, (BLa] etc.Ventilatory Threshold (Tvent). Characterized by the non—linear increasein excess CO2. It is the intensity of exercise just below the point ofthe abrupt increase in excess CO2. The abrupt increase in excess CO2 isrelated to increased reliance on anaerobic processes for energy becauseaerobic energy sources are unable to meet tissue requirements (Loat,1991; Anderson and Rhodes, 1991; Anderson and Rhodes, 1989).Maximal Oxygen consumption (VO2max). Defined as the point where V02plateaus and exhibits no further increase (or increases only slightly)with additional workiads (Brooks and Fahey, 1985).Water Immersion to the Neck Running (WI Running). The simulation ofland-based running motion in deep (non-weight bearing) water. The WIrunner is immersed in water to the neck and propels herself in the waterby simulating land-based running motion. There is no weight bearing,consequently no push—off phase on a stable immoveable surface. Theindividual propels herself through the water working against theresistance of the water. A flotation devise may be worn to provideminimum boyancy and facilitate the simulation of land—based runningmotion.61.2 STATEMENT OF PROBLEMThe purpose of this study was to investigate the cardiorespiratory andmetabolic responses during maximal effort and during prolongedperformance at the ventilatory threshold (Tvent) during treadmill andwater immersion to the neck (WI) running in a group of elite endurancerunners familiar with WI running.1.2.1 SubproblemsThe subproblems were:1) To utilize elite endurance runners who regularly include WI runningin their training regimen.2) To compare the cardiorespiratory and metabolic responses totreadmill and WI running at Tvent and maximal effort (ie. VO2max) amonga group of elite endurance runners familiar with WI running.3) To compare the cardiorespiratory and metabolic responses totreadmill and WI running during prolonged exercise at Tvent (WI andtreadmill Tvent) among a group of elite endurance runners familiar withWI running. That is the subjects would be asked to performed four Tventprolonged performance (42 minute) tests and they were the following:TrTrTVent (treadmill Tvent intensity performed on the treadmill).TrwlTvent (WI Tvent intensity performed on the treadmill).WlTrTvent (treadmill Tvent performed in the WI condition).7WIWITvent (WI Tvent performed in the WI condition).1.3 HYPOTHESES1. The VO2max values determined during the treadmill versus the WIrunning VO2max test for WI running trained endurance runners would besimilar at the 0.05 level of significance.Specific hypothesis was: TrvO2max = WIVO2max at >O.O5.RATIONALE: The runners would be simulating land—based running mechanicsin an aqueous environment and since VO2max is unaffected by this medium,performance in both environmental conditions should be similar asexhibited with land versus WI ergometer cycling studies (Connelly et al,1990, Christie et al, 1990, Sheldahi et al, 1986, Avellini et al, 1983,Dressendorfer et al, 1976). Welsh (1988) reported lower treadmillversus WI VO2max values. He attributed these findings to increasedblood flow to the upper body musculature, a greater proportion of workperformed by the upper body and a reduced ability of the upper bodymusculature to extract oxygen as possible factors. Lower VO2max valuesfor WI versus treadmill running have been reported by Svedenhag andSeger (1992), Butts et al (1991) and Town and Bradley (1991). These WIrunning studies utilized runners unexperienced to WI running. Therunners were given one to two sessions of instruction and thenclassified as runners trained in WI running. The authors suggest intheir discussions that less familiarity with WI running may have been afactor for the lower WI VO2max values (Svedenhag and Seger, 1992; Butts8et al, 1991; Town and Bradley, 1991). If the upper torso is utilized toa greater extent in WI versus treadmill running, in an attempt to remainafloat, then WI VO2max values will be lower than treadmill values. Itis postulated that the control measures set in this study, regarding WIrunning experience and acceptable WI running style will prevent thistrend.2. The treadmill Tvent will be significantly higher than the WI Tvent,at the 0.05 level of significance.Specific hypothesis is: TrTveflt > WlTvent at pO.O5.RATIONALE: The assumption was made here that there would be nosignificant differences in treadmill and WI VO2max values. It washypothesized that the absolute and relative treadmill and WI Tventvalues would be different. The upper body musculature would beperforming a proportionately greater quantity of work in WI versustreadmill running. Arm crank versus cycle exercise elicits a loweranaerobic threshold due to the smaller muscle mass available forrecruitment (Sawka, 1986) and a proportionately higher ratio ofglycolytic to oxidative muscle fibers, and so increasing lactateproduction and facilitating exhaustion. It was postulated that WIrunning motion would simulate treadmill (or land—based) running motion,however, the resistance of the water would result in increased workperformed by the back and shoulder muscles as the arms swing back duringthe running cycle. This would result in a lower WI versus treadmillTvent value.93. Cardiorespiratory and metabolic (HR, vo2, ye, and BLa]) responsesduring prolonged exercise at Tvent (determined from the WI and treadmillVO2max protocols, ie. WITvent and TrTvent respectively) would differsignificantly for the (WI running trained) runners during treadmillversus WI running tests at treadmill and WI Tvent at the 0.05 level ofsignificance.i) Heart—rate (HR) response during prolonged performance at treadmilland WI Tvent would differ significantly during treadmill versus WIrunning. The specific hypotheses were:TrHRWITVent > WIHRw,y andTrHkTrTvent > orTrHRTVent > WIHR ( WlTventTrTvent) at pO.O5.RATIONALE : Lower WI HR values have been reported at maximal effort(Svedenhag and Seger, 1992; Christie et al, 1991; Connelly et al, 1991;Welsh, 1988; Sheldahl et al, 1987; Dressendorfer et al, 1977; Arboreliuset al, 1972), and at Tvent (Welsh, 1988). Lower WI running HR valueshave been reported during 5 minute exercise intervals at 65 % VO2max andabove (Svedenhag and Seger, 1992). Lower submaximal WI HR values havealso been noted by studies comparing WI versus land ergometer cyclingexercise (5 minute intervals) at 60%, 80% and 75% VO2max and above,respectively (Connelly et al, 1991; Christie et al, 1991; Sheldahl etal, 1987). Similar WI HR values were reported during exercise, by thesefour studies below these exercise levels (Svedenhag and Seger, 1992;10Connelly et al, 1991; Christie et al, 1991; Sheldahl et al, 1987).Middle distance runners commonly reach Tvent at approximately 80%(Davis et al, 1984), thus lower WI HR values would be expected for theWI tests at TrTvent and WlTvent. The hydrostatic pressure gradient andconsequent cephalad redistribution of blood volume are suggested to beresponsible for the lower WI HR values (Svedenhag and Seger, 1992;Christie et al, 1991; Connelly et al, 1991; Sheldahi et al, 1987; Lin,1984).ii) Oxygen consumption (V02) during the Tvent prolonged performancetests would be significantly greater in WI versus treadmill running.The specific hypotheses were:WIVO2ITvent > TrVO2WITvent andWIVOTrTvent > TrVO2rT ent orWIVO2Tvent > TrVO2,1 (if WlTventTrTvent) at p<O.O5.RATIONALE: WI running would utilize a larger muscle mass than treadmillrunning and therefore would require a higher V02 for the activity overtime. WI work would result in a greater energy expenditure, andtherefore, V02 compared to the same work performed on land. This wouldbe related to the viscocity friction and turbulance of the aqueousenvironment (Evans et al, 1978, Johnson et al, 1977, Costill, 1971). IfTvent was not affected by the condition (ie. treadmill vs WI), the V02would still be expected to be higher during the WI versus treadmillprolonged performance tests, due to these properties of the aqueousenvironment.11iii) Ve during the Tvent prolonged performance tests would besignificantly greater in WI versus treadmill running. Specifichypotheses were:WIVeITvent > TrveWlTvent andWIVeTrTVent > orWIVeTVent < TrVe (if WlTvent=TrTvent) at p<OO5.RATIONALE: Similar maximal ye values have been reported by WI runningstudies (Svedenhag and Seger, 1992; Town and Bradley, 1991, Butts et al,1991; Welsh, 1988) and by Sheldahl et al (1987) for WI cycling.Dressendorfer et al (1977) noted lower maximal Ve reponse in WI cycling.Similar Ve and ventilatory equivalent for V02 has been reported at Tventfor WI versus treadmill running (Welsh, 1988). Svedenhag and Seger(1992) reported similar Ve responses during 5 minutes of WI versustreadmill running at submaximal exercise intensities. Similarsubmaximal Ve have also been reported for five minute exercise intervalsin WI versus land cycling (Sheldahi et al, 1987; Sheldahi et al, 1984).This study hypothesized that ye during the Tvent prolonged performancetests would be higher in the WI condition. This would be related to thehigher relative intensity of the exercise in the WI versus the treadmillcondition. This hypothesis was based on the assumption that WlTvent <TrTvent. If WI and treadmill Tvent are similar, then no differences inVe would be expected for the prolonged performance tests at Tvent in the2 conditions.12iv) Blood lactate concentration BLa] during the Tvent prolongedperformance tests would be significantly higher in the WI versustreadmill running. Specific hypotheses were:WI[BLa]WITVent > Tr[BLajWITveflt andWI[BLa)TrTveflt > Tr[BLa]TrTvent orWI[BLa]Tveflt = Tr[BLaITveflt (if WlTventTrTvent) at pO.O5.RATIONALE: The greater metabolic demands of WI running, due to thehigher relative intensity of the WI prolonged performance tests comparedto the same absolute intensity performed on the treadmill would resultin higher blood lactate accumulation in the WI (ie. WlTrTvent andWIWITvent) versus the treadmill (ie. TrTrTVent and TrWITveflt) prolongedperformance tests. If the Tvent did not differ in the two conditions(ie. WlTventTrTvent), then no differences in blood lactateconcentration would have been expected.See figure 1 for a summary hypotheses diagram.13LuiiwTv.nt>Tro2wTventjjWITvent>TrVeWITveJFigure 1. Hypotheses Summary Chart.TventjjWITventErTVentTrTv.ntLiiTrTvent>T02TrTveJvent>jrvJbvent<TrvejjjrTvent>TTrTventEa1TtTrtBLa1w1TvJaTvent=BLaITvJjaTrTvent>TrcBLaTrTveJ141.4 DELIMITATIONS1) The study was delimited to male and female distance runners, 20-35years—old, who were trained on land, treadmill and WI running, and whocould demonstrate WI running style during high intensity exercise as setby this study (see sampling section).2) The sample size was restricted to 13 elite runners trained in WIrunning.3) The study was delimited to subjects with a minimum treadmill VO2maxof 50 and 60 mlkg 1min, for female and male runners respectively.This was to ensure that the subjects had enhanced cardiorespiratory andmetabolic abilities comparable in level to top—level varsity andnational caliber distance runners.4) The study was delimited to examine only one intensity of exercise(Tvent intensity), with WI and treadmill Tvent performed and compared onthe treadmill and WI condition.1.5 ASSUMPTIONS1) The subjects’ measured VO2max values were a true reflection of theiraerobic capacity.2) The subjects would be able to run on the treadmill and simulate landrunning motion with WI running.153) The trial sessions for familiarization to the equipment andenvironmental test conditions would be adequate.4) Running in the water immersed to the neck requires activation ofpredominantly similar skeletal muscle groups which are activated duringland—based running. Land—based running motion is simulated during WIrunning motion.5) Subjects would perform maximally to exhaustion in both conditions(ie treadmill and WI running). Use of the Borg scale for ratings ofperceived exertion during the VO2m8X tests and post—test [BLa] measureswould provide additional evidence that VO2max was achieved.6) Hydration and cooling provided for the laboratory treadmill testswould be adequate for the subjects.1.6 LIMITATIONS1) The investigation was limited by the WI running ergometer and WIrunning VO2max protocol used to assess VO2max and Tvent in WI running.2) The investigation was limited by the WI running ergometer which withincreasing load facilitated a foward lean due to the harness pulling thesubjects’ trunk in a backward direction.163) The investigation was limited by the functioning of the Beckmanmetabolic cart and the accuracy of its readings.4) The study was limited by the laboratory environmental conditions andthe inability to control laboratory temperature and humidity for thecomfort of the subjects during testing. Attempts were made to maintaina comfortable environment for the subjects by providing them with waterto maintain adequate hydration and some cooling by use of an electricfan.5) The investigation was limited by the subjects’ ability andmotivation to perform maximally to exhaustion on the WI and treadmillVO2max tests.6) The study was limited by the water turbulence in the pooi caused byactivities ongoing during WI test times. This increased turbulence ofthe water, would work to reduce or increase the subject’s workload.7) The investigation was limited by the subjects’ ability to correctlyand consistantly simulate WI running motion. Subjects were to remainalmost vertical in the pooi immersed to the neck with the arms followingnormal running motion; the hands would not ‘cup’ the water. Normalrunning motion of the lower trunk would include flexion of the hipfollowed by hip and leg extension.8) The study was limited by the ability of the investigator toobjectively evaluate the subjects’ running style during testing from17videotape of the sagital view of the subjects’ performance against thescaling grid.9) The investigation was limited by the minimum requirements set for arunner to be trained in WI running, which were neccesary for inclusionin this study. That is the regular WI running training sessions and thequality of the work-outs completed by the subjects during the six monthsprior to participation in the present study.10) The investigation was limited by the ability of the unbiasedreseachers to extrapolate the Tvent levels from the ExCO2 over timecurve (and Ve/V02 over time curve and RER around 1.00).1.7 SIGNIFICANCENumerous studies have examined the cardiorespiratory responses ofexercise in WI compared to exercise on land. These studies, however,have been limited to the investigation of maximal responses and shortduration submaximal exercise at similar absolute intensities. Morerecently WI running at submaximal intensities of a prolonged nature havebeen examined and compared with treadmill responses, however, theexercise intensity has not been objectively controlled. Studiescomparing treadmill and WI running have utilized predominately runnersuntrained in WI running, as their subjects. Could differences inphysiological responses reported for WI and treadmill running be relatedto the subjects’ unfamiliarity with WI running? Since WI VO2maX valueshave been reported to be lower than treadmill values, could the18responses then, exhibited during submaximal exercise be related to thehigher relative intensity of the exercise in the WI condition.HR response during submaximal exercise has been reported to besimilar, or lower in the WI versus land (treadmill) condition. WI HRresponse seems to be exercise intensity dependent, but there is noagreement as to what intensity of exercise (% of VO2max) results inlower WI HR values. Determination of Tvent and comparison of exerciseat similar relative exercise intensities (at and above WI Tvent) wouldprovide new information on HR response in WI.WI running is often used by runners. The incorporation of WIrunning in the training regimens of elite runners is justified as eithera preventative measure to avoid the occurrence of sports—relatedinjuries, or as a form of maintenance training following injury. Thetraining regimens of runners incorporate the principle of specificity oftraining, which requires that one’s training regimen overload themetabolic system and muscles which support his activity (Brooks andFahey, 1985). If WI running requires a very similar muscle recruitmentpattern, then one should expect the runner to be able to sustain theactivity at a specific intensity (ie. Tvent) eliciting similarcardiovascular and metabolic responses as during running on land. Ifthis is the case then WI running can also provide training benefitswhich can be transfered to land—based running and can serve to enhance arunner’s training regimen.19CHAPTER 22.0 REVIEW OF THE LITERATUREDuring the last 30-35 years water immersion to the neck (WI) hasbeen used to simulate weightlessness. Recently, exercise in WI hasgained popularity due to its non-weight bearing nature. Running isbecoming a common activity in the WI condition. It is being usedextensively by competitive runners and other athletes not only duringrehabilitation but also to complement their regular training. Thisliterature review will present research pertaining to cardiovascular andrespiratory responses to the WI condition, WI exercise studies and theventilatory threshold concept with respect to steady state exercise.2.1.0 CARDIOVASCULAR RESPONSES TO WATER IMMERSION TO THE NECKThe four major determinants of cardiac performance are heart—rate(HR), preload, contractility and afterload. Preload is defined as theextent of ventricular filling before contraction. Preload is determinedby the venous return of blood to the heart, and venous return isdirectly affected by cardiac output (CO) (Brooks and Fahey, 1985).Afterload is defined as the resistance to ventricular emptying, that isthe force against which the heart muscle must contract during theejection phase of systole. Increased afterload increases the workloadfor the heart. Increased afterload is characterized by reducedventricular—ejection fraction, shortening velocity and increased20ventricular end—diastolic and end—systolic volumes (Brooks and Fahey,1985). Contractility is described as the quality of ventricularperformance. Enhanced contractility enables the heart to increasestroke volume (Brooks and Fahey, 1985). HR is described as the majordeterminant of CO, especially during moderate to maximal exercise(Brooks and Fahey, 1985).During upright water immersion to the neck (WI) a mean hydrostaticpressure of 20 cm water is exerted on the thoracic cavity and abdominalarea. Atmospheric air pressure of 1 atm is exerted on the unimmersedhead and neck and is transmitted through the airways into the alveoli.An imbalance is created between the air pressure in the alveaolar spacesand the greater pressure exerted on the thoracic cavity (Epstein, 1976).A redistribution of blood volume to the central circulation by 700 ml isinduced. The heart accepts approximately 200 ml of this blood volume(Arborelius et al, 1972).2.1.1 Heart-rateResting and submaximal HR responses have been reported to remainunchanged or to decrease in WI. Although there is agreement thatmaximal HR is lower in WI (Svedenhag and Seger, 1992; Town and Bradley,1991; Butts et al, 1991; Connelly et al, 1991; Christie et al, 1991;Welsh, 1988; Sheldahl et al, 1987; Sheldahl et al, 1984; Dressendorferet al, 1976), there is no clear consensus on the mechanisms responsiblefor the lower HR responses in WI at higher exercise intensities. Thecephalad shift in blood volume which causes the redistribution of 700 ml21of blood from the lower extremities and abdomen to the centralcirculation is implicated (Lin, 1984; Fahri and Linnarsson, 1977;Arborelius et al, 1972). The heart accepts 200 ml of this blood (Fahriand Linnarsson, 1977; Arborelius et al, 1972). It is suggested that theincrease in atrial blood volume with WI could result in a reflexincrease in HR at rest and up to moderate exercise, offsetting a cardiacdecelerating reflex (Christie et al, 1991; Sheldahl et al, 1987;Sheldahi et al, 1984). This is suggested to occur through theBainbridge reflex (Sheldahl et al, 1987; Lin, 1984).Bainbridge reported HR to increase with infusions of blood orsaline. This was observed when central venous pressure increased to theextent to distend the right side of the heart. In this case cardiacfilling rose resulting in increases in HR (Berne and Levy, 1988).It has also been postulated that CO may be regulated at a higherlevel in WI in order to maintain an ‘appropriate’ arterial bloodpressure response (Christie et al, 1991; Sheldahl et al, 1987; Lin,1984). Sheldahi et al (1987) proposes that since similar systolic bloodpressure responses are exhibited during WI and land exercise (Sheldahiet al, 1987; Arborelius et al, 1972) and if systemic vascular resistanceremains lower during exercise in WI, a greater CO would be neccessary tomaintain the same blood pressure response as exhibited on land.Arborelius et al (1972) has noted lower (by 30%) systemic vascularresistance in resting WI.22Lower sympathetic neural outflow in WI has also been suggested toexplain the lower HR response to heavy exercise (Christie et al, 1991;Connelly et al 1991; Sheldahi et al, 1987). Lower plasma norepineprineand epineprine concentrations have been noted during heavy and maximalexercise in WI compared to land responses (Connelly et al, 1991). Anexercise intensity dependent response of plasma catecholamine levels inWI is suggested (Connelly et al, 1991; Christie et al, 1991).HR response in WI is also affected by temperature. Similar HRvalues have been reported during rest and submaximal exercise inthermoneutral WI (29°-35° C) compared to land values (Sheldahl et al,1987; Fahri and Linnarsson, 1977; McArdle et al, 1976; Arborelius et al,1972; Craig and Dvorak, 1966). Lower HR values have been reportedduring rest and exercise in WI at 250 C compared to thermoneutral water(Craig and Dvorak, 1966). McArdle et al (1972) noted lower HR valuesfor exercise at oxygen consumption (V02) values of 1.5 and 2.8 lminin WI at 18—25° C. Consequently V02 was higher (by 250-700 mlmin) inWI at 18-25° C compared to V02 values on land and WI at 33° C (McArdleet al, 1972). Lower maximal HR (HRmax) values, however, were reportedfor similar VO2max values for WI exercise at 18_250 C compared tothermoneutral WI exercise (Dressendorfer et al, 1976; McArdle et al,1972).Rennie et al (1971) reported lower resting HR values, (a-v02)difference (15%) and CO in WI at 28-32° C. During exercise, however, nodifferences in CO—V02 relationship were noted, although HR and strokevolume (SV) were lower and higher respectively from land values. The23authors concluded that the decline in skin blood flow, CO, HR at rest inWI were related to water temperature. Any differences, however, in COduring WI exercise were minimized by the higher perfusion of muscle inexercise. They postulated that the reduced HR and increased SV duringexercise were the result of negative feedback control frombaroreceptors.Resting heart—rate (HR) has been reported to remain unchanged(Connelly et al, 1990; Christie et al, 1990; Arborelius et al, 1972) orto decrease in water immersion to the neck (WI) in water temperaturesranging from 27_310 C compared to resting HR values reported on land(Risch et al, 1978; Farhi and Linnarsson, 1977; Loilgen et al, 1976).Similarily submaximal exercise HR responses (matched for oxygenconsumption) have been reported to remain unchanged (Christie et al,1990; Sheldahl et al, 1987; Evans et al, 1978; McArdle et al, 1976) orto decrease (Connelly et al, 1990; Christie et al, 1990; Johnson et al,1977; Rennie et al, 1971) with upright exercise in WI compared to onland.Connelly et al (1990) and Christie et al (1990) reportedsignificantly lower WI HR responses at exercise intensities (on cycleergometer) corresponding to 60 % VO2max or above and 80 % VO2maxrespectively. Svedenhag and Seger (1992) reported significantly lowerHR responses elicited in WI running at intensities over 80 % VO2maxcompared to treadmill running. Welsh (1988) reported significantlylower WI HR responses at ventilatory threshold (Tvent) compared to TventHR determined from the treadmill VO2max protocol, among endurance24trained runners. The HR responses at Tvent in the WI and treadmillcondition corresponded to 83 and 86 percent of their respective VO2max.Sheldahi et al (1987) compared WI and land stationary ergometer cyclingand reported lower exercise HR responses at 80 % VO2max in WI. Inanother study Sheldahi et al (1984) noted lower HR values during WIexercise at 76 % VO2max and above.Although differences in WI and land-based HR’s at rest and atsubmaximal exercise intensities are still being debated, there isagreement that HR response to maximal exercise is lower in WI comparedto maximal exercise on land. Lower HRmax values have been reported bystudies comparing WI and land stationary ergometer cycling (Connelly et,1990; Christie et al, 1990; Sheldahl et al, 1987; Sheldahi et al, 1984;Dressendorfer et al, 1977) and by studies comparing WI and treadmillrunning (Svedenhag et al, 1992; Butts et al, 1991; Town and Bradley,1991; Welsh, 1988).2.1.2 Preload, Contractility and AfterloadSheldahl et al (1984) noted increases in ventricular end-diastolicvolume and end—systolic diameter during exercise at 37% and 47% VO2maxin WI versus land cycle exercise. The authors concluded that preloadmay be enhanced in WI and suggest that preload may be under—utilizedduring exercise on land. The decline in the ratio of systolic bloodpressure and end—systolic diameter during WI exercise may indicate lowermyocardial contractility in the WI condition. The greater leftventricular end—diastolic volume during WI exercise suggests that the25left ventricular wall tension is greater at a given left ventricularpressure. This is suggested to result in increased afterload (Sheldahiet al, 1984). Christie et al (1991) also noted higher left ventricularend—diastolic volume during WI exercise, coupled with similar systolicblood pressure and concluded that afterload is increased in WI, but thatcontractility, most likely, is reduced.2.2.3 Cardiac Output and Stroke VolumeCardiac output (CO) has been reported to increase during resting WI(Christie et al, 1991; Farhi and Linnarsson, 1977; Begin et al, 1976;Arborelius et al, 1972;). Decline in CO has also been reported (McArdleet al, 1976; Rennie et al, 1971; Hood et al, 1968), but this decline hasbeen attributed to water temperature (below thermoneutrality) (Farhi andLinnarsson, 1977; Rennie et al, 1971).Farhi and Linnarsson (1977) noted a progressive increase in CO fromland (5.1 lmin1) to water immersion to the hip (5.7 lmin1), xiphoid(7.4 lmin1) and neck level (8.3 lmin1). HR decreased during hip andxiphoid level water immersion, but increased during immersion to theneck (WI). Stroke volume (SV), on the other hand, increased at eachwater immersion stage. The authors concluded that in the first twowater immersion stages atrial baroreceptors played the dominant role andnoted that as CO increases and blood pressure rises, HR is ref lexlylowered. During neck immersion atrial stretch receptors are responsiblefor the increase in HR (Farhi and Linnarsson, 1977). Increase in26resting SV during the WI compared to land condition have been noted byChristie et al (1991) and Sheldahi et al (1987).The 30-35% increase in CO during resting WI has been attributed tothe increase in SV (up to 77% increase) (Lin, 1984; Farhi andLinnarsson, 1977) related to enhanced diastolic filling (enhancedpreload) (Farhi and Linnarsson, 1977; Begin et al, 1976; Arborelius etal, 1972).Higher SV has been reported during graded intensities of exercise inthe WI versus land condition (Christie et al, 1991; Sheldahi et al,1987; Arborelius et al, 1972; Rennie et al, 1971). Higher CO at a givenV02 has been noted during submaximal exercise (Christie et al, 1991;Sheldahi et al, 1987; Bonde-Peterson et al, 1980), although the patternof increase was similar in the WI and land condition (Christie et al,1991).Submaximal (above 40% VO2max) to maximal exercise does not result infurther increases in SV, although SV has been reported to be higher atany given submaximal and maximal exercise intensity when compared toland values (Christie et al, 1991). Possible explanations for the lackof further increase in SV with WI exercise is attributed to: a) thecephalad shift of blood volume during resting WI has reduced the amountof blood available to be centrally shifted with exercise, or b) theleft—ventricular diastolic volume during resting WI is near maximal,consequently there is limited ability to increase SV further withexercise (Christie et al, 1991; Farhi and Linnarsson, 1977).27Cold stress in WI also affects CO and SV. McArdle et al (1976)reported SV values to increase in cold WI, with SV greater at 18° Cversus 250 C and versus thermoneutral water. When SV and HR wereplotted over V02, the increase in SV observed parallelled the decreasesin HR in cold stress.In summary CO and SV increase with WI. The majority of the increasein CO and SV occurs with initial WI in rest. SV does not exhibitfurther increases with exercise beyond the increase exhibited withresting WI, but compared to land exercise values WI SV values are stillhigher. CO increases by 30-35% with resting WI and during gradedexercise a similar in magnitude increase occurs as during similar landexercise (similar CO—V02 slope). HR response during resting WI remainsmost likely similar to land—based values, as a consequence of atrialstretch receptor activity which increases HR to land resting values.There is no clear consensus on HR response during submaximal exercise,although there is agreement that maximal HR is lower in the WI versusland condition.2.2.0 RESPIRATORY RESPONSES TO WATER IMMERSION TO THE NECK2.2.1 Static Lung VolumesVital capacity is reduced (3-9%) with WI (Withers and Hamdorf, 1989;Hong et al, 1969, Agostoni et al, 1966). The reduction in vitalcapacity is attributed to the rise of the diaphragm and the increase in28intrapulmonary blood volume (Risch et al, 1978; Hong et al, 1969).Dalback (1975) attributes the reduction in VC solely due tointrathoracic blood accumulation.Tidal volume during resting WI is unaltered (Withers and Hamdorf,1989; Sheldahl et al, 1987; Hong et al, 1969). Breathing frequency alsoremains unaltered during resting WI (Withers and Hamdorf, 1989; Sheldahiet al, 1987; Dressendorfer et al, 1976; Hood et al, 1968). Reduction inmaximal voluntary ventilation (MW) (12%) with no change in breathingfrequency during WI compared to air was reported by Dressendorfer et al(1976).Decreases have also been reported during WI for expiratory reservevolume (ERV) (62—70%) (Withers and Hamdorf, 1989; Hong et al, 1969;,Agostoni et al, 1966), functional residual capacity (FRC) (30—54%)(Withers and Hamdorf, 1989; Fahri and Linnarson, 1977; Hong et al, 1969;Agostoni et al, 1966), residual volume (RV) (16%) (Withers and Hamdorf,1989; Hong et al, 1969;, Agostoni et al, 1966). The preceeding lungfunction reductions are attributed to the hydrostatic pressure of thewater counteracting the forces of the inspiratory muscles, therebycompressing the abdomen and raising the diaphragm to a positionapproaching full expiration (when the respiratory muscles are relaxed)(Agostoni et al, 1966). This results in a restriction of the forcerequired for inspiration by reducing total lung capacity (TLC) and VC(Withers and Ha.mdorf, 1989; Dahiback et al, 1978a; Dahlback et al,1978b).29The hydrostatic pressure of the water also causes a redistributionof blood volume from the lower extremities to the thoracic cavity (Honget al, 1969;, Agostoni et al, 1966). This increase in thoracic bloodvolume results in a reduction in lung compliance, and to spacecompetition between thoracic air and redistributed thoracic blood(Dahiback et al, 1978a; Dahlback et al, 1978b; Arborelius et al, 1972;Agostoni et al, 1966). These events are also responsible for thereduction in lung compliance (Dahlback et al, 1978b). The reduction inlung compliance results in an increase in RV, however the net effect ofthe hydrostatic chest compression and centrally redistributed bloodvolume produces a net reduction in RV (Withers and Hamdorf, 1989).Hong et al (1969) calculated the work of breathing at resting WI andreported an increase with WI by 39 %, of which 29 % was ascribed to anincrease in elastic work and 10 % to an increase in dynamic work. Theincrease in dynamic work was attributed to increased flow resistance ofthe airways functioning at reduced lung volumes (reduced ERV).2.2.2 Exercise Respiratory Responses.Exercise ye is not affected by the WI condition. Similar Ve(matched for V02) responses have been noted by Sheldahl et al (1987) atrest and during exercise at 44%, 60% and 80% VO2max. Greater increasesin Bf and lower TV values were noted during WI versus land exercise(Sheldahi et al, 1987). This is in agreement with the findings of Welsh(1988) for Ve at Tvent and VO2max for treadmill and WI running. Welsh30(1988) also noted higher Bf and lower TV at Tvent and VO2max during WIversus treadmill running.In summary respiratory mechanics are altered by the externalapplication of hydrostatic pressure. The cephalad shift in blood volume(700 ml) is partly accomodated by the heart (which accepts 200 ml) andthe remainder is accomodated by the pulmonary circulation. WI resultsin changes in static lung volumes, but does not seem to affect Ve.2.3.0 WATER IMMERSION EXERCISE STUDIESThis section will review literature from an exercise scienceperspective.2.3.1 VO2max and Short Duration SubKaximal Effort.Svedenhag and Seger (1992) compared treadmill and WI running VO2max andshort duration (5 minute bout) submaximal exercise responses in a groupof middle and long distance runners (N=9). Seven of the subjects hadprevious WI running experience and the two remaining were familiarizedwith WI running once before testing. A wet vest was worn during WIrunning testing. Four minute submaximal exercise bouts (with one minutepause) of progressive intensity were performed at exercise intensitieseliciting HRs of 115, 130, 145 and 155—160 bpm. The subjects WI ranlengths alongside the pool deck and expired air was collected in Douglasbags during the last 1-1.5 minutes of each exercise bout. At the end of31each exercise bout blood lactate sample (from the earlobe) and RPE wereobtained.Following completion of the fourth exercise bout, the subjects wereasked to increase their exercise intensity to maximal effort within 1—2minutes and to maintain this intensity for as long as possible (2minutes). HR and expired air were collected during the last minute ofexercise (3_4th minute) at maximal effort and blood lactate obtained 30seconds post—test. The treadmill protocols for the submaximal exercisetests were matched to the V02’s determined from the WI tests. Thetreadmill protocol for determination of VO2m did not match the WIVO2max protocol. A treadmill VO2max protocol of set velocity andincreasing grade over time was utilized.Lower VO2max values were reported for WI compared to treadmillrunning (4.03 vs 4.60 lmin). Significantly lower HR8 were reportedat a V02 of 3.5 l’min (155 vs 165 bpm) and maximal effort (172 vs 188bpm) for the WI compared to the treadmill condition. Submaximal andmaximal Ve responses were similar for the two conditions. [BLa] valueswere higher in the WI condition at a V02 of 3.5 lmin’ (5.01 vs 1.33mmo11) and 70 % VO2maX (4.6 vs 1.5 mmol11). Peak [BLa] values(12.4 vs 10.0 mmo11) were also higher in the WI condition compared totreadmill values. Higher RER values were noted for WI versus treadmillrunning at a V02 3.5 lmin’ (0.98 vs 0.95). RERmax was lower for WIversus treadmill running (1.10 vs 1.20). Similar RPE values werereported for breathing and legs separately for treadmill and WI running.Higher RPE values were reported during exercise at a V02 of 3.5 lmin32(14.6 vs 12.6) and for a HR of 150 bpm (14.2 vs 10.4) in the WI versusthe treadmill condition.The authors concluded that the higher anaerobic metabolismassociated with WI running is likely related to the reduced perfusionpressure in the legs with a consequent reduction or maldistribution intotal muscle blood flow. The authors also noted that although thesubjects were familiarized with WI running, they were less conditionedto WI running (Svedenhag and Seger, 1992). Consequently the lower WIrunning conditioning may be directly responsible for the RPE, [BLa] andRER behaviour exhibited during submaximal and maximal exercise and notthe WI condition.Butts et al (1991) compared treadmill and WI running responses(N=24). A wet vest was worn for WI running. For WI testing thesubjects were tethered to the side of the pool. Stride frequency wasused to produce a progressive incremental test to exhaustion for WIrunning. The subjects WI ran initially at 100 strides per minute andwere told to increase their stride frequency every two minutes by 20strides per minute. The subjects were encouraged to ‘go all out’ whenthey were unable to maintain the specific stride frequency for anadditional minute. Lower WI values for VO2max, ye, HR and RER werenoted. The lower WI VO2max values were attributed to the hydrostaticpressure and mechanical constraints imposed on WI running related to thewater resistance. Restrictions to maximal limb movement and a decreasein active muscle mass in WI running were also suggested as possibleexplainations. The authors note that antigravity muscles active during33land—based running are not neccessary in WI running, consequently themetabolic cost of WI running may be reduced.Town and Bradley (1991) compared VO2max values from distance runners(N=9) familiarized with water running in WI running, shallow water (SW)running (1.3 meters in depth and arms above the water level) andtreadmill running. VO2maX tests for water running (SW and WI) were 4minute duration tests and the subjects were asked to increase theireffort each minute resulting in exhaustion by the fourth minute. Thetreadmill test produced higher VO2max values compared to SW running(representing 90 % of the mean treadmill VO2maX value). Both modesproduced higher VO2maX values than WI running (representing 73.5 % ofthe treadmill VO2maX). HR was lower in the WI running test. Similaroxygen pulse (HR/V02) values were noted for treadmill (2.66 beatsml)and SW (2.63 beats ml1) running. Lower HR/V02 was reported for WIrunning (3.40 beatsml) and the authors attribute this relationship togreater left ventricular end—diastolic and end—systolic dimensionsobserved during WI. RER and [BLa] were similar in all three protocols,but treadmill running showed a trend toward higher (ie. 19 %) [BLa)levels than the WI and SW running tests.Welsh (1988) compared treadmill and WI running Tvent and VO2maXresponses in middle distance runners (t4=16) who regularly performed WIrunning workouts. Lower V02, and HR values were exhibited at Tvent andVO2max in WI compared to treadmill running. Similar Ve values werenoted at Tvent and VO2max in the two conditions, but higher ventilatoryequivalent for V02 (Ve/V02) values were noted in WI versus treadmill34running. Tidal volume (TV) and breathing frequency (Bf) were measuredat Tvent and maximal effort on a subsample (N=4). Bf at Tvent values(37.9 vs 37.1 breaths per minute (brpm)) were similar and slightlyhigher at maximal effort (54.6 vs 48.7 brpm) in WI versus treadmillrunning. TV values were lower at Tvent (2.17 vs 2.28 liters) andmaximal effort (2.32 vs 2.56 liters) in WI versus treadmill running.TC-99 2—methyloxy isobutyl isonitrile was injected in two subjects tomonitor blood flow distribution in the lower trunk during WI andtreadmill running at Tvent. Although leg blood flow decreased in onesubject, it increased in the other subject during WI running. Theintersubject differences in blood flow distributions were suggested tobe related to WI running styles.Dressendorfer et al (1976) reported similar VO2max values for WI andland (3.18 vs 3.92 1min) ergometer cycling (N=7). Similar RER (1.08vs 1.12) and lower HR (169 vs 130 bpm) and Ve (130.2 vs 145.9 lmin)values were also reported for WI compared to land cycling at maximaleffort.Sheldahl et al (1987) compared WI and land ergometer cycling HR,V02, CO, SV, Ve, TV and Bf responses (N=19). Similar VO2max values werenoted in both conditions. Exercise responses were compared during 5minute exercise bouts at 40, 60, 80 % VO2max. In both conditionsworkloads were matched for V02. Lower HR values were noted only duringexercise at 80 % VO2max. SV values were greater in WI at rest andexercise at 40 % VO2max. A linear increase in CO values with V02 werereported for both conditions, however CO was higher at rest and during35exercise at 40 and 60 % VO2max in the WI condition. The authorsobserved, however, some variability (lower) in Co with WI exercise, ye,TV and Bf were not altered at rest by the WI condition. Ve responseswere similar during exercise in both the WI and land conditions. HigherBf values were reported during WI exercise at 40 and 80 % VO2max.Decline in TV response were noted in the WI condition during exercise at80 % VO2max.Connelly et al (1991) compared V02, HR, RER, blood lactate andplasma catecholamine responses to upright graded WI and land cycleergometer exercise (N=9). Similar VO2max values were reported for WIand land cycling. Five minute exercise bouts were performed at 43, 61,78-82, and 100 % VO2max. Similar RER and blood glucose values werenoted at each exercise intensity and at maximal effort. V02 values ateach exercise intensity were similar. HR values were lower duringexercise at and above 61 % VO2max. [BLa] values were lower in the WIcondition only at maximal effort. Plasma norepinephrine values werelower at and above 78—82 % VO2max, whereas plasma epinephrine valueswere lower only at maximal effort in the WI condition.Connelly et al (1991) concluded that plasma catecholamine responsesare altered by WI. It was, however, unclear whether the decrease innorepinephrine was the result of reduced sympathoadrenal activity, ordue to an increase in the clearance of epinephrine, or to an alterationin metabolic response to exercise. The lower plasma epinephrineexhibited during maximal effort was suggested that it may have served toreduce muscle glycogenolysis and thus [BLa]. It was also suggested that36there may be an increase in muscle blood flow in WI, which may increaseaerobic metabolism and reduce [BLa] resulting in a lower increase inplasma epinephrine. It was also suggested that plasma epinephrine andlactate clearance may be increased during maximal exercise.The effect of the redistribution of blood volume in WI wasinvestigated by Christie et al (1991). Land and WI VO2max tests werecompleted on cycle ergometers (N=l0). Five minute exercise bouts(matched for V02) were completed in the two conditions at 40, 60, 80 and100 % VO2max. No differences in resting HR, systolic blood pressure,V02 and VO2max (43.5 vs 42.5 mlkg1in) were noted on land and WI.Similar V02 values were reported for each exercise bout in bothconditions. Lower HR values were noted for exercise at 80 and 100 %VO2max.Christie et al (1991) reported cardiac index to be higher in WI andto increase in a linear fashion with increasing V02. Centralhypervolemia was suggested to alter the cardiac output-V02 relationshipwith upright WI exercise. The authors believe that the additionaloxygen delivered by the heart may not be utilized by the exercisingmuscles. Stroke index increased during resting WI, with no furtherincreases noted with WI exercise. The increase in stroke index wasattributed to enhanced preload. The lower WI HR’s at higher intensityworkloads were suggested to be the result of reduced sympathetic neuraloutflow. It was suggested that reduced sympathetic neural outflow couldbe the result of altered baroreceptor activity caused by increasedcentral blood volume, or increased muscle blood flow. Similar resting37and submaximal HR’S were suggested to be indicative of cardiopulmonarymediated vascular dilation.In summary it appears that differences in WI and treadmill VO2maXand Tvent may be attributed to less familiarity of the runners to WIrunning and possibly not to the WI condition. HR is lower at maximaleffort in WI, however, there is no clear consensus regarding submaximalHR response in WI versus land exercise. ye is not affected by the WIcondition, however Bf is higher and TV reduced during WI exercise.There is no consensus on [BLa] and RER response to WI versus landexercise, however, could familiarity to the activity soley have dictatedthe patterns exhibited.2.3.2 Submaximal Prolonged Duration Exercise in Water IRmersion.Responses during submaximal exercise on the treadmill and WI runninghave also been investigated recently. Bishop et al (1989) compared V02,HR, Ve, RER, and RPE during a 45 minute subject selected pace on thetreadmill and WI running (utilizing a bouyancy vest). The runners wereasked to select a running pace which they could comfortably sustain for45 minutes. The authors state that the runners were ‘familiarized’ withWI running and they concurrently determined their 45 minute WI runningpace following only two practice trials. V02 in the WI run was 36percent lower than treadmill values (ie. W1v02=29 mlkgmin vsTrVO2=4O.6 mlkg1in) for similar RPE responses (WIRpE=l2.4 vsTrRpE=ll.7). Lower Ve and RER were also noted for WI versus treadmillrunning (ie. WIv5=58.l 1’min and WIRER=O.92 vs Trve=79 lmin andTrRER=O.9S). It was concluded that the metabolic cost for WI running at38a preferred intensity was less than for treadmill running at a preferredintensity (Bishop et al, 1989).Richie and Hopkins (1991) suggest that the bouyancy vest Bishop etal (1989) utilized may itself have been a limitation to simulating landrunning style in the WI condition, but may also have reduced the needfor the runners to exercise maximally to remain afloat. However, themain contributing factors for the differences may be related to theunfamiliarity of the runners to WI running and the bouyancy vest.Richie and Hopkins (1991) compared WI running to treadmill and roadrunning at a hard and normal training pace in distance runners who weretrained’ in WI running technique. WI running training consisted of twosessions with instruction in WI running technique. The subjects werethen asked to complete a 30 minute WI running session with V02, RER, HRand RPE measured and compared to 30 minutes of subject determined normaltraining pace and 30 minutes at a hard training pace on the treadmilland to 30 minutes of road running at their normal training pace. HigherV02, RER, and RPE were reported for WI running compared to normaltraining pace running on the treadmill. Similar HR responses werereported by the authors for WI running and normal training pacetreadmill and road running. However examination of the V02 during thesesessions reveals a higher V02 and RER for the WI compared to the normaltraining pace treadmill run, therefore HR was lower in WI relative tov02.Yamaji et al (1990) compared the HR-V02 relationship for WI andtreadmill running in a group of runners (N=10) with varying WI runningabilities. Although they found no differences between the twoconditions, they suggest that the (low) WI running skill level of the39runners may have produced the higher HR for similar V02 in the WIcompared to the treadmill condition. They noted that runners who hadutilized WI running extensively did demonstrate lower HR values thanthose runners less familiar with the activity. It was noted thatrunners less familiar with WI running tended to utilize their uppertorso to a greater degree to remain afloat.Commonality in all three of these studies (ie. Richie and Hopkins,1991; Yamaji et al 1990; Bishop et al. 1989), is the use of runners whowere untrained in WI running. Comparisons of the physiologicalresponses to WI and treadmill running were made at dissimilarintensities of exercise in the two activities. Consequently it isunclear from these studies whether the responses exhibited were relatedto the WI condition or to the samples utilized.In summary it appears that WI running studies have compared thephysiological responses of WI and treadmill running among runners withlimited WI running familiarity and at absolute workloads, which mostlikely represent in the WI condition a higher metabolic requirement, ashas been demonstrated by the WI running studies comparing treadmill andWI VO2max.2.3.3 Comparison of the specificity of training: WI versus land-basedtraining.Avellini et al (1983) and Sheldahi et al (1986) investigated thecardiorespiratory adaptations in males to ergometer cycling whileimmersed in water at shoulder and neck level respectively versus landcycling. Subjects were assigned to either the WI cycling or the land40based cycling training group. In Avellini et al (1983) the subjectstrained for one hour per day, 3 times per week for 12 weeks. InSheldahi et al (1986) the subjects trained for one hour per day, 5 daysper week for 4 weeks. The intensity of training in both studies was setbetween 60—80% and controlled for the dampened HR responses withWI (trained at a 10 bpm lower HR in WI). Training resulted in increasedVO2max of the same magnitude in both the WI and land training groups inboth studies. Pre and post testing VO2maX tests were completed on thetreadmill. Submaximal HR, systolic and diastolic BP were lower andsubmaximal SV higher at the same exercise V02 following training, inboth the WI and land training groups.The authors concluded that differences in physiological responses toWI versus land exercise do not alter cardiovascular adaption to exercise(Sheldahl et al, 1986; Avellini et al, 1983). The ability to stabilizethe body on a cycle ergometer therefore permits central and possiblyperipheral adaptations which may facilitate land-based cyclingperformance.In summary it appears that the WI condition used as the trainingenvironment for cycling training does not hinder cardiovascularadaptations. Target training HR for WI exercise of 10 bpm lower thanland training HR appears to have produced equivalent WI and landtraining programs. Consequently, it appears that submaximal HR responseis lower in the WI versus land condition.412.4 VENTILATORY THRESHOLD (Tvent) PERFORMANCETvent during incremental exercise to exhaustion provides anindication of lactate steady-state (Yamamoto et al, 1991). Tvent hasbeen identified as the point where there is a non—linear increase inexcess CO2 (Anderson and Rhodes, 1991; Loat, 1991; Rhodes and McKenzie,1984). Ve (Davis et al, 1976), RER (Wasserman et al, 1973) and Ve/V02(Ciaozzo et al, 1982; Davis et al, 1979) have also been used to identifyTvent. The use of excess CO2 to identify Tvent has been suggested as abetter indicator of metabolic acidosis in the exercising muscles,because excess CO2 is the direct result of metabolic buffering (Loat,1991; Anderson and Rhodes, 1991; Rhodes and McKenzie, 1984).Tvent intensity level has been used to predict distance runningperformances. Rhodes and McKenzie (1984) reported a high correlation(r=O.94, p<O.O1) between predicted and actual marathon times. They usedthe excess CO2 curves from progressive incremental VO2max tests toidentify the velocity at Tvent. The runners then completed aninternational marathon and their completion times were compared to thepredicted time from Tvent velocity. It was concluded that the velocityat Tvent represented the optimal pace to complete a marathon for trainedmarathoners.Other studies have also used Tvent velocity to predict runningperformance for 3.2 km to 42.2 km runs (Hearst, 1982; LaFontane et al,1981; Farrell et al, 1979). Tvent has also been used to predict steady—state cycling velocity (Loat, 1991) and Ironman triathlon performance by42predicting swim, cycle and run time from Tvent pace (Langill and Rhodes,1993).Loat (1991) determined individual Tvent workload levels from excessCO2 curves and then had the cyclists cycle at their determined Tventworkload for 60 minutes in the laboratory. The cyclists completed thetest without significant elevations in ye, V02, HR and [BLa). Hearst(1982) noted low [BLa] maintained over time during exercise at Tvent,but elevated [BLa) (and HR, vo2, ye, excess C02) levels noted whenexercising one kilometer (and 2 km) above Tvent.In summary Tvent determined from the excess CO2 curve representsthe maximal steady state exercise intensity. Exercising at Tventintensity appears to allow prolonged exercise without elevations in[BLa], V02, ye and HR.43CHAPTER 33.0 METHODS AND PROCEDURESThis study examined and compared maximal oxygen consumption (VO2max)and ventilatory threshold (Tvent) responses on treadmill and waterimmersion to the neck (WI) running in a group of elite distance runners,trained in deep water running. Forty two minute performance tests ateach runner’s treadmill and WI Tvent values were thereafter completedand minute ventilation (ye), oxygen consumption (V02), heart—rate (HR)and blood lactate concentration ([BLa)) values were measured. Subjectscompleted all testing within a 2.5-4 week period with 02max testsseparated by at least 5 days. Tvent performance tests were completedwith a minimum one day rest period.3.1.0 SAMPLEThirteen elite distance runners ‘trained in WI running’ with aminimum VO2max of 50 mlkgmin and 60 mlkgmin for the female(5) and male (8) runners, respectively participated in the study. Tenof thirteen elite distance runners 20 to 35 years of age who volunteeredcompleted all testing required for the study. This sample consisted of4 female and 6 male runners. Complete results for only the treadmilland WI VO2max tests are available on the three remaining subjects (N=3)and they have been included for the VO2max section of the studyanalysis. The subjects ranged in age from 21 to 35 years of age. Theycompeted in distance events which ranged from 800 meters to marathon and44ultramarathon distances and were trained in WI running. The goal ofthis study was to utilize runners who regularly incorporated WI runningin their training regimens and simulated in their WI running stylecertain key land—based running motions.This study defined an elite distance runner trained in WI running asone who incorporates in their training regimen a minimum of 6 sessions(approximately 45—60 minutes per session) per month of WI running forthe former 6 months prior to their participation in this study. Onlyrunners who practiced non—weight bearing WI running were accepted in thestudy. WI running style was assessed during a WI running session withthe investigator and during the WI VO2max test. An underwater videocamera was used to videotape each subject’s WI running style, initiallyunattached to the pulley system and then during the WI VO2max test. Thevideotaped WI running performances were assessed for comparability toland—based running motion. Subjects who met WI running style andtraining criteria were kept in the study. It was not the intention ofthis study to do a biomechanical analysis, but only to maintain similarbasic running styles in WI as on the treadmill.Three criteria were set to evaluate WI running style which had to bemet by each subject to participate in the study. If the criteria werenot met the runner was excluded. The 3 criteria were the following:i) The trunk remained upright with respect to the scaling grid. Afoward lean of up to 45 degrees was deemed acceptable.45ii) Unilateral foward motion of the arms and legs was followed,specifically:a) The lower right knee was brought foward and upward, in the recoveryphase of the right leg cycle. When the thigh reached a horizontal ornear horizontal position the lower leg swung forward. The right legbegan to descend and the left leg began to move forward.b) The arms were flexed at approximately right angles with the elbows.The left arm was swung foward as the right knee swung foward andbackward and the right leg descended.iii) The hands were not used to significantly propel the runner. Toprevent cupping of the water and thus excessive use of the upper bodymusculature and excessive foward lean, the subjects were instructed tohold small sponges in either hand during the water tests.46Figure 2. Underwater photograph of a subject WI running. The subject runs in deep waterand there is no weight bearing involved. The subject is instructed to simulate land-basedrunning motion and remain in an upright posture, while WI running. The grid board, situatedbehind the runner serves to assess his forward lean. A maximum lean of 45 degrees isdeemed acceptable and is depicted by the diagonal lines on the board. The water ski beltcan be seen worn by the subject around his waist. Worn underneath the water ski belt isthe waist harness. The attachment ropes connect to the waist harness and lead to thepulley system of the WI ergometer.473.2.0 PHYSIOLOGICAL TEST EQUIPMENTThe following equipment were used for physiological testing:1) Beckman Metabolic Cart was utilized to measure expiratory gases andvolumes (V02, VCO2, Ve, tidal volume (TV), breathing frequency (Bf)).The Hewlett Packard 3052 A Data Aquisition system was used to processthe metabolic data collected and obtain Ve (in STPD), ExCO2 and Ve/V02calculations. Expired gases were sampled at 30 second intervals by themetabolic cart.2) Two HR monitor models were utilized for HR sampling. The POLARACCUREX and the POLAR FAVOR HR monitors were utilized. The POLARACCUREX was utilized for all treadmill tests. The POLAR ACCUREX wasused in conjuction with the POLAR FAVOR for WI tests, when possible (the2 HR monitors transmitted at different frequencies). The POLAR ACCUREXHR monitor was worn at the level of the sternoxiphoid junction (fortreadmill and WI testing) and the POLAR FAVOR was worn at the level ofthe third rib (for WI testing) (see Figure 3 for HR monitor placementfor WI testing.A nylon spandex sports top was worn by the male subjects during WItesting. These latter two steps were taken primarily to avoid loosingHR values during WI testing. This occurred often with the male subjectsand was due to water moving freely between the subjects’ sternum and theHR monitor belts. This inhibited continuous contact of the HR monitorbelt with the subjects’ chest and therefore the HR signal would be lost.483) Water ski belt was worn by the subjects around the waist for the WIrunning tests. This was a limited buoyancy devise providing enoughbuoyancy to limit upper body musculature involvement during WI runningfor the purpose of remaining afloat. The buoyancy section was worn inthe front (on the abdominal region) versus the back, which caused thesubjects to lean foward excessively due to the belt rising up their back(see Figure 2 and 3).3) Kontron Medical LA640 Blood Lactate Analyzer was used to analyze[BLa] samples. Twenty microliter blood samples were drawn from thefingertip and immediately haemolyzed. The blood samples were thenplaced in the refrigerator and later analyzed for lactate content (inmmol/l blood) with the lactate analyzer.4) Quinton 24-72 treadmill was used for treadmill tests.5) A modified tethered swimming apparatus (ie. WI ergometer) was usedfor the WI tests (see section 3.4.3 for description and Figure 4 forpicture).6) Underwater film assessment recorder was used for underwatervideotaping of WI running.49Figure 3. WI running; an above and below surface picture. A. Underwater picture of asubject WI running. The waist harness is shown in this picture. During testing the waterski belt would be worn on top of this harness (see Figure 2). Also shown are the positionsof the 2 HR monitors worn for WI running testing. B. Mouthpiece apparatus assembly forWI running testing is shown. The mouthpiece is secured on the subject with head supportfor VO,ak. testing.050_:-.iFigure 4. WI running set-up. A. Picture of the WI running set-up from behind the WIergometer. The WI ergometer is a simple frame equipped with 2 pulley systems and ispositioned at the edge of the pool. The rope which attaches to the waist harness runsthrough the lower and upper pulley systems of the WI ergometer and finally attaches to theloading bucket. The position of the subject and metabolic equipment are visible in the fardistance. The position of the video operator relative to the subject is also shown in thispicture. B. This picture provides a forward view of the WI set-up. In this picture theinvestigator can be seen obtaining the final blood lactate sample from a subject following asteady state test. The mouthpiece apparatus and metabolic measurement equipment arevisible. The WI ergometer position is also visible in the background. Note the differentorientation of the mouthpiece for the steady state Tvent tests versus the VO2max tests (seeFigure 2 B). This was to allow for ease of insertion and removal during these tests.Rope to PulleyI513.3.0 UNDERWATER FILM ASSESSMENT APPARATUS AND PROCEDURESA grid board and an underwater video recorder were utilized tomonitor WI running motion. The grid board measured 1.2 X 2.4 meters andwas immersed, longest side across, along the pool wall. Vertical andhorizontal lines (2.5 cm in width, vertical lines were spaced 15 cmapart, and horizontal lines were spaced 30 cm apart) were painted on theboard. A 2.5 cm tape in bold colours was placed along the grid board at45 degree angles with their point of initiation 0.76 meters from the topof the grid board. This level was determined to approximate on averagethe location of the pelvis area. Hooks attached the grid board to thepool deck and weights attached to the lower end of the board preventedexcessive movement of the immersed grid board due to water turbulence(see Figure 2 and 3 for a schematic presentation).The underwater video camera was used to tape the WI VO2max tests.The subject was positioned at the center of the grid board and there wasrelatively little motion of the subject in relation to the grid boardduring the WI VO2max test. The video operator videotaped from astationary position 6 feet in front of the grid board (ie. the sagitalview was videotaped) (see Figure 4). The video operator was instructedto videotape the whole grid board and the limbs of the subject. Thevideo operator was thus filming a 2.4 X 1.7 meter area. Filming began30 seconds prior to test initiation. Test initiation was signalled onthe videotape by the investigator waving her arm or a small board acrossthe grid board under the water.523.4.0 TREADMILL AND WI VO2max AND Tvent PERFORMANCE TEST PROTOCOLS ANDPROCEDURES3.4.1 Treadmill and WI VO2m Common ProceduresSubjects were asked to refrain from eating 2 hours prior to testtime and from heavy training on test day. Subjects reported to thelaboratory and following the subjects’ self selected warm—up (withrespect to pace and duration), height and weight measurements weretaken. Expired gases were sampled by a Beckman Metabolic Cart duringthe VO2max tests every 30 seconds. Heart—rates were recorded during thelast 5 seconds of each minute utilizing the HR monitors. Subjects wereinstructed to point to their percieved exertion rating (Borg scale fromBorg, 1970) every 2 minutes 45 seconds into the workload.At test termination a blood lactate sample was obtained within thefirst minute post—test (within 30 seconds post-test). At 5 minutespost—test an additional blood lactate sample was obtained. The sameprocedures were followed for the treadmill and WI tests. In the case ofthe WI VO2max test the subject was instructed to come out of the poolafter the first lactate sample was obtained and the second [BLaJ samplewas obtained on the pool deck (see Figure 6 for a schematic diagram ofVO2max test procedures).533.4.2 Treadmill VO2max Test Protocol and ProceduresThe treadmill VO2max protocol followed a continuous progressiveregimen. The treadmill speed commenced at 5 mph and was increased every60 seconds by 0.5 mph. If the treadmill speed reached 12 mph at minute15 of the test, the speed was no longer increased instead the treadmillgrade was increased every following minute by 2 percent untilphysiological or volitional fatigue (see Figure 5). The increase inpercent grade was introduced to ensure that a true maximum was achievedand to prevent the treadmill speed exceeding the runner’s running skillor capabilities before achieving a true VO2fflaX. The duration of theprotocol ranged from 12 to 19 minutes (mean test duration was 14.5minutes, Table 2).A 5-25 minute warm-up preceeded the test and the intensity of thewarm—up was subject selected. Height and weight were then assessed andthe HR monitor, nose clip and mouthpiece secured on the subject. Thesubject was then instructed to run on the treadmill (treadmill speed=5mph) and the test commenced within 2 to 3 minutes following finaladjustments to mouthpiece position (see Figure 6 for VO2maxprocedures).Termination of the test was defined by exhaustion characterized bythe point when the subject experienced at least two of the followingcriteria: 1) volitional fatigue, 2) a plateau in V02, 3) an RER 1.10.543.4.3 WI VO2max Test Protocol, Procedures and EquipmentThe WI VO2max protocol followed a continuous progressive model andwas designed to resemble the treadmill protocol in loading progressionand duration. The goal was to produce a linear progression of Ve, V02with a distinct ‘breakaway’ point in order to establish the Tvent, butalso to ensure that the duration of the test was similar to thetreadmill protocol (that is 12 to 19 minutes). Thoden et al (1987)suggest that measurement of cardiorespiratory parameters begin frompower outputs which represent 20 % of a subject’s VO2m8X. The protocolwhich was originally proposed to be utilized for the WI VO2maX test wasby Welsh (1988). This protocol, however, produced initial power outputswhich would represent 45 to 52 % of the present study’s subjects’ VO2maxvalues. The protocol was revised to meet this study’s goals and toaccount for sex differences in size, muscle mass and possibly the lowerfitness level of this study’s population of runners from which thesample was drawn.The water immersion running ergometer (IRE) utilized by Welsh (1988)was used in this study with slight modifications. The IRE was amodified tethered swimming apparatus. It was a rectangular shaped 2.5meter high frame which sat at the edge of the pool. At the topextension rod a pulley system of low resistance was attached and marinerope of 1.5 cm diameter passed through. Another pulley system (this onewas a double pulley system) was secured on the bottom rod, which was 1 min front of the top rod, and the marine rope was passed through thissystem. The rope finally attached to a 6 cm flat waist harness which55was worn by the subject (see figure 2 to 4) and reached the center ofthe grid board. The rope at the other end of the pulley system wasattached to a bucket, which was loaded with weights for the WI tests.For all WI tests the subjects were immersed to the neck and wore awater ski belt around their waist (with the flotation segment situatedaround the abdominal area, see Figure 2 and 3). This belt was wornabove the waist harness. The IRE was placed by the end of the pool withthe lower pulley rod extending over and into the pooi surface. Fourmeters of rope was passed through the pulley system, in order toposition the subject in the middle of the grid board. The subjects wererequired by correct running motion to maintain the bucket 6 cm from thetop pulley system for the duration of the test. A ± 4 cm variation inthe position of the bucket was allowed.The WI VO2m test required the subject to maintain his/her positionin the water (and thus the bucket position stationary) with progressiveincreased loading. A point of reference was placed 1 m in front of thesubject as a point of reference for the subject. With increasing loadper minute the subject would be forced to run faster and faster (ie.increase their cadence, length and power) to displace more water inorder to maintain his/her position. The protocol and subject would thusbe simulating treadmill performance which forces the subject to runfaster and faster with increasing velocity until fatigue.The bucket on the IRE was initially loaded with 500 gram (g) and 750g weights, respectively, for the females and males. After minute 1 the56load was increased by 400 g/min for both females and males until minute15. On minute 15 and until exhaustion the load was increased by 500 and750 g/min respectively for the females and males, with the goal being tosimulate the change to increasing grade on the treadmill protocol (seefigure 5 for comparison of the treadmill and WI VO2max protocols).Termination of the test was defined as the point of exhaustioncharacterized by the following: 1) the subject was no longer capable ofmaintaining his position, and thus the position of the bucket relativeto the top pulley system was greater than 11 cm, 2) volitional fatigue,3) a plateau in V02 for more than 1.5 minutes, 4) RER > 1.10. Meetingthe first criterion and at least two of the other criteria wereneccessary to establish VO2max. Post—test evaluation of maximal effortincluded the comparison of post—test peak BLaJ values to treadmillvalues. The test protocol was approximately 12 to 19 minutes induration (mean test duration was 15.0 minutes, see Table 2).WI running motion was also subjectively monitored during the test bythe investigator to ensure acceptable running motion (discussed insection 3.1) in addition to underwater videotaping. A foward leangreater than 45 degrees relative to the grid board and excessive use ofthe upper body musculature also resulted in early termination of thetest. Underwater videotaping was used to assess WI running motion post—test and if the subject’s running motion deviated from the study’s setcriteria, the test and subject were not used in the study’s results.57Deviation of WI running motion from the set criteria during the last2 to 3 minutes of the test with an RER between 1.10-1.20, resulted inconsideration that VO2max was reached prior to deviation in acceptableWI running style. The V02 prior to running style deviation was acceptedas the subject’s VO2max. The rationale for this exception was based onthe premise that when on the treadmill and the subject reachesexhaustion he/she can no longer maintain the treadmill pace and musteither step off or risk falling on the treadmill. The subject,however, does not580.5 mph/mm 400 g/mmn750 g/minFigure 5. Treadmill and WI VO2max Protocol description. WI VO2m test loadingdiffered by gender. The loadings were higher for male runners.Initial Load 5 mphMinute 15 grade by 2%Immn750g 500g500 g/minUntil Volitional Fatigue59VO2maxPROCEDURESTventPROCEDURESSUBJECTSELECTEDWARM-UP(5-25MIN)TIME(MIN)HGTANDWGTDETERMINATIONEQUIPMENTHOOK-UP-13TESTSTARTWARM-UPTEST-8-30TESTCOMPLETION[BLa]SAMPLING+0.5+5SUBJECTSELECTEDWARM-UP(5-25MIN)WGTEQUIPMENTHOOK-UPTIME(MIN)TESTWARM-UP-16-11-8STARTTESTMOUTHPIECEONIAI0AAIITESTTERMINATIONII——******42TiT2T3T4T5T6T7*-Expiredgasesand—-[BLa]collection.HRcollection.Figure6.VO2maxandTventtestsschematicrepresentationofprocedures.experience the same fear with WI running. When the subject can nolonger maintain his/her position in the water, the subject is eitherpulled back as the bucket goes down or begins utilizing non—fatiguedmusculature to remain afloat and maintain their position. In the lattercase the subject increases arm and shoulder contribution. The elbowsare pushed out to the sides, in line with the shoulders and the handsused to cup the water. This action also results in increasing fowardlean of the subject beyond 45 degrees.3.4.4 Ventilatory Threshold DeterminationExcess CO2 (ExCO2) was plotted against time for the treadmill and WIVO2max test for each subject. Tvent was determined as the point wherethe slope of ExCO2 increased disproportionately (Anderson and Rhodes,1991; Loat and Rhodes, 1991; Anderson and Rhodes, 1989; Rhodes andMcKenzie, 1984; Volkov et al, 1975) and was established independently bytwo to three reseachers. The corresponding minute V02 values werecalculated at Tvent. The treadmill velocity and WI loading at the Tventlevels were used to approximate the woakloads for the Tvent performancetests. The Ve/V02 plotted over time (to locate the break—away’ point)and an RER near 1.00 were also used to substantiate Tvent (see AppendixG).3.4.5 Tvent Performance TestsFour Tvent performance tests were completed by each subject andthese were:61TrTrTVent (treadmill Tvent performed on the treadmill)TrWITveflt (WI Tvent performed on the treadmill)WIWITvent (WI Tvent performed in WI)WlTrTvent (treadmill Tvent performed in WI)The minute V02 (in mlkgmin) values from the treadmill and WITvent extrapolations were used to determine the test workloads for alltest conditions. Similarily to the VO2max tests, the subjects completedtheir self selected warm-up (5-25 minute duration) and then had theirbody weight measured and equipment fitted, except for the mouthpiece.During the Tvent test warm—up the subjects were progressively loaded, orthe treadmill velocity increased with HR monitored. Once a HR wasachieved just below the anticipated HR at Tvent the subject was asked toput the mouthpiece on (with assistance). While continuing to run,expired V02 was monitored and treadmill velocity (or WI loading)manipulated until the desired minute V02 at Tvent was obtained. Oncethe workload at the respective Tvent was obtained expired gases weremonitored for 2—3 more minutes to ensure that the minute VO2 wasmaintained within the acceptable range. Minute VO2 values ± 0.5ml/kg/min of the V02 at Tvent were deemed acceptable and data collectedduring this period signaled commencement the of the Tvent test and wasidentified as collection interval Ti. The total process for reachingTvent workload was established within 4-5 minutes.HR, V02, Ve were monitored and collected for 1.5 minutes at testinitiation (Ti) and at 6.5—8.0 mm (T2), 13.5—15.0 mm (T3), 20.5—22.0mm (T4), 27.5—29.0 mm (T5), 34.5—36.0 mm (T6) and 40.5—42.0 mm (T7).62Blood lactate samples were drawn during collection periods T2 throughT7. Blood lactate samples were obtained following the last expired gascollection for the interval by the metabolic cart. Expired gases (andHR) were continously sampled every 30 seconds during the stated timeintervals for the treadmill and WI Tvent performance tests (see figure 6for schematic diagram of Tvent steady state prolonged performance testprocedures).3.5.0 EXPERIMENTAL DESIGNThe independent variables in this study were Condition(environmental) (factor 1) and Tvent (factor 2), with 2 levels each.The two levels of factor 1 were the treadmill and WI (to the neck)conditions. The two levels of factor 2 were treadmill Tvent (TrTveflt)and WI Tvent (WlTveflt), determined from the treadmill and WI VO2maxtests, respectively.The experimental design for the VO2max test data for hypotheses 1and 2 can be treated as a one way within subject comparison (of VO2maxand Tvent) under two different conditions (treadmill versus WI). VO2m&xand Tvent were treated as the main dependent variables.The dependent variables for the Tvent steady state prolongedperformance tests were exercise HR, V02, Ve and [BLa]. The experimentaldesign for the Tvent test data, for hypotheses 3, 4 and 5 (ie. HR, V02and ye), were treated as a 2 X 2 X 7 within subject design with repeatedmeasures on all 3 factors (ie. Condition, Tvent, and Time).63The experimental design for the Tvent test data for hypothesis 6(ie. [BLa)), were treated as a 2 X 2 X 6 within subject design withrepeated measures on all 3 factors (see Figure 7).A counterbalanced single factor design with 4 treatments wasemployed. The treatments were the 4 Tvent intensity steady stateprolonged performance tests, that is TrTrTvent, TrwITvent, WlTrTvent andWIWITvent.TRT_,.Figure 7. Diagram of the factors and levels of the experimental design. Thestudy examined whether the Condition (WI vs treadmill), Tvent (WI vstreadmill) and Time (over the 42 minute tests) factors, were responsible for thedifferences in physiological and metabolic function. The contribution of eachfactor separately and in combination with the other two factors were exploredwith repeated measures analysis of variance and trend analysis (see section3.6.0).- 6 levels for [BLaJ, starting at T2.FACTOR 1Levels=2 I CONDITIONTRPDM ILL IwilFACTOR 2:LeIs=2FACTOR 3:LeveI=7 TIME___I I______I IT1T2T3jIT4T5JIT6I T71643.6.0 STATISTICAL ANALYSISThe data collected was analyzed as follows:1) Correlated T—Tests were conducted to test Hypotheses 1 and 2regarding the comparison of treadmill versus WI VO2max and treadmillversus WI Tvent (V02 at Tr and WI Tvent). Differences in HR, Ve, RER,RPE, test duration at VO2max and Tvent and post—test [BLa) at 30 secondsand 5 minutes from the VO2max tests were also analyzed in the twoconditions using correlated T—Tests.2) 2 X 2 X 7 within subject repeated measures analysis of variance withtrend analyses were utilized to test hypotheses 3 to 5 regardingdifferences in V02, HR, and ye over Condition, Tvent and Time. Two 2 X7 within subject repeated measures analysis of variance with trendanalysis were used to specifically compare TrTrTvent V5 WlTrTvent andTrWITveflt vs WIWITvent.3) 2 X 2 X 6 within subject repeated measures analysis of variance andtrend analysis was used to test hypothesis 6 regarding differences in[BLa] over Condition, Tvent and Time. Two 2 X 6 within subject repeatedmeasures analysis of variance with trend analysis were used tospecifically compare TrTrTvent VS WlTrTvent and TrwlTveflt vs WIWITvent.65CHAPTER 44.0 RESULTS4.1.0 Physical Characteristics of the SampleThe sample consisting of five (5) female and eight (8) maleendurance runners trained in water immersion running to the neck (WI)(ie. simulating land—based running style and with minimum WI runningexperience of 6 months) were selected for this study. Three subjects(one female and two males) have complete data on only the two maximaloxygen consumption tests (VO2max) (ie the treadmill and the WI VO2maxtests) due to technical difficulties in completing the remaining steadystate performance tests and have only been used for the VO2max resultsanalysis. The female and male subjects had to demonstrate a minimumtreadmill VO2max of 50 and 60 mlkg min respectively for inductioninto the study. Table 1 contains the mean physical characteristics ofthe subjects and mean treadmill VO2max by gender.Table 1.0. Physical Characteristics and Treadmill Maximal Oxygen Consumptionof the Sample.; VARIABLE FEMALE (N=5) MALE (N=8).,Mean (std) Range Mean (std) RangeAge (yrs) 242 (6 7) 18 0 35 0 273 (4 1) 22 0 340Height (cm) 1656 (43) 1597 1709 1825 (50) 1747 1910Weight (kg) 542 (4 9) 49 2 61 1 71 5 (4 6) 67 7 79 4VO2max (I/mm) 2.91 (0.29) 2.60 . 3.17 4.56 (0.36) 4.18 . 5.03VO2max (mI/kg/mm) 53.7 (4.2) 50.5 - 61.0 63.4 (4.2) 60.0- 72.7664.2.0 Maximal Oxygen Consumption (VO2max) Pest ResultsThe purpose of the first part of this study was to compare maximaland Tvent responses from the progressive incremental loading toexhaustion (ie. VO2max) tests on the treadmill and WI. The 3 maincriteria set to control subject selection a priori were a) WI runningstyle, b) familiarity with WI running and c) minimum treadmill VO2m(of 50 and 60 mlkg min’ for female and male runners respectively)for classification as an ‘elite distance runner familiar with WIrunning’ (see Methods and Procedures chapter). The thirteen subjectsincluded in the present study met the above set a priori criteria.4.2.1 Maximal ResponsesThe treadmill running (Tr) VO2max was significantly higher, bothexpressed in lmin (p<O.O5) and in mlkg’min1 (p<0.O5), whencompared to the water immersion running (WI) VO2max (Figure 8.0 A and B,respectively). The lower WIvo2max was accompanied by significantlylower maximal heart-rate (p<O.O5) (Figure 8.1 A) and RER (p<0.05)(Figure 8.2 A) responses. However there were similar minuteventilation (ye) responses (p>O.O5) (Figure 8.1 B), ratings of perceivedexertion (RPE) (p>O.OS) (Figure 8.2 B) and post-test blood lactateconcentrations ((BLa]) (both for 30 sec. (p>0.O5) and 5 mm. post-test(p>O.O5) values) (Figure 8.3 A) for both protocols. The duration of theWIvo2max and Tryo2max tests were similar (p>0.OS) (Figure 8.3 B). SeeTable 2 mean values (±std) for maximal responses of V02, HR, Ve, RER,RPE, (BLa], and test duration.67Table 2.0. VO2m Results : Maximal Responses.CONDITION TREADMILL WI (T-TEST)VARIABLE Mean (std) Mean (std) p-valueV02 (I/mm) 3 92 (0 89) 3 60 (0 78) 0 001V02 (mI/kg/mm) 59.7 (6.4) 54.6 (5.2) 0.001HR (bpm) 190 (11) 175 (12) 0.001Ve (1/mm) 109.0 (22.7) 105.8 (19.1) 0.73RER 1.20 (0.08) 1.10 (0.06) 0.003[BLa]-30 sec.-post 10.4 (1.9) 9.8 (2.3) 0.24[BLa] 5 mm post 9 7 (2 0) 9 2 (2 5) 0 57Test Duration (mm) 14 30 (2 00) 15 00 (2 40) 0 37RPE 20 (0) 20 (0) 1.00684.2.2 Ventilatory Threshold (Tvent) ResponsesThe treadmill ventilatory threshold (TrTveflt) (ie. V02 at Tvent) wassignificantly higher, expressed in lmin (p<O.O5) and in mlkg”min(p=O.03), when compared to the water immersion ventilatory threshold(WlTvent) (Figure 8.0 A and B). When Tvent was expressed as apercentage of the respective VO2max results the TrTveflt and the WITvefltoccurred at approximately 78 percent (p>O.O5) (Figure 8.4). Asignificantly lower WlTveflt versus TrTveflt heart—rateresponse wasexhibited (p<O.05) (Figure 8.1 A) and the WlTvent occurred approximately2 minutes earlier in the TrTyeflt (p<0.05) (Figure 8.3 B). There were nosignificant differences in Ve (p>O.O5) (Figure 8.1 B), RER (p>0.O5)(Figure 8.2 A) and RPE (p>O.O5) (Figure 8.2 B) responses at TrTveflt andWlTvent. See Table 3 for mean values (±std) for Tvent responses of V02,HR, Ve, RER, RPE, [BLa), test duration, and % VO2max.69Table 3.0. VO2m Results : Results at Tvent.‘:CONDITION TREADMILL WI (T-TEST)VARIABLE Mean (std) Mean (std) p-value? V02 (1/mm) 3.03 (0.74) 2.81 (0.69) 0.04V02 (mI/kg/mm) 46 3 (6 4) 42 8 (5 1) 0 03HR (bpm) 165 (10 8) 152 (12) 0 002‘ Ve (I/mm) 66.4 (16.4) 65.7 (16.0) 0.73RER 0 99 (0 04) 0 98 (0 04) 0 45% V02n,ax 77 7 (6 8) 78 3 (4 7) 0 76Tvent Time (mm) 8 10 (2 00) 6 20 (2 00) 0 004£ RPE 13(2) 12(2) 0.13‘70V02 (I/mm) V02 (mI/kg/mm)*Figure 8.0. Mean oxygen consumption (+1 std) at maximal effort and Tvent level fromthe treadmill (Tr) and water immersion (WI) VO2m tests. A. Absolute oxygenconsumption (lmin1) at VO2m and Tvent. B. Relative oxygen consumption (mlkg’1in)at VO2m and Tvent. * Significant differences at a=0.05.I *ITMaximal Tvent Maximal Tvent71HR (bpm) Ve (I/mm)Figure 8.1. Mean heart-rate (HR) and minute ventilation (Ve) (+1 std) at maximaleffort and Tvent level from the treadmill (Tr) and the water immersion (WI) VO2mtests. A. Mean HR (bpm) response at VO2m and Tvent, significant differences foundat a=O.05 (*). B. Mean Ve (Imint) response at maximal and Tvent, no differencesfound for Ve on the Tr and WI conditions at a=O.05.Maximal Tvent Maximal Tvent72Maximal MaximalFigure 8.2. Mean RER and ratings of perceived exertion (RPE) (+1 std) at maximaland Tvent level from the treadmill (Tr) and the water immersion (WI) VOm tests. A.Mean RER responses at VO2max and Tvent, significant differences (*) were found atVO2m level only (a=O.05). B. Mean RPE responses at VO2m and Tvent, nodifferences were found for RPE on the Tr and WI at VO2m and Tvent at a=O.05.R ER RPETvent Tvent73[BLaJ (mmol/l) Duration (mm)Figure 8.3. Mean post-test blood lactate concentrations ([BLa]} and VO2ma,, testduration at maximal effort and at Tvent level from the treadmill (Tr) and the waterimmersion (WI) VO2ma,, tests. A. Mean [BLa] at 30 sec. and 5 mm. post-test on theTr and WI following maximal effort, no significant differences were found on theTr and in the WI conditions at a=0.05. B. Mean VO2m test duration time andmean time at which Tvent occurred in the Tr and WI VO2m tests, significant (*)differences found only for Tvent time occurance (a=0.05).30 sec.-post 5 min.-post Maximal Tvent746055Figure 8.4. Comparison of the treadmill and WI VO2m,, and Tvent responses andthe %age of respective VO2max that each Tvent represents, compared to theirrespective VO2m responses. Significantly lower VO2max and Tvent responseswere exhibited with WI running. No differences were found when WI and TrTvent were expressed as a percentage of the respective VO2max.V02 (mlkg1m1n’)65%age80—I705045403560503040 ETreacimillIwiVO2maxTvent % of VO2max753.3.0 Tvent Steady State Performance Tests Results4.3.1 Heart-rateHeart—rate responses during the steady state performance tests wereexamined in relation to HR response during the performance tests in the2 Conditions (treadmill versus WI) and to Tvent (the TrTveflt versus theWlTvent intensity) over Time and averaged over the Time factor.There was a significant Condition main effect exhibited for HRaveraged over the Tvent and the Time factors (F1,9=19.35, p<O.O5). WhenHR responses were averaged across all the time intervals and over thetwo Tvent’s (TrTveflt and WITveflt) mean HR was significantly different inthe two conditions. Mean HR averaged over condition and across time was9 bpm higher on the treadmill vs WI (TrHR=162 bpm vs WIHR1SB bpm), andthe lower mean WIHR is directly attributable to the WI environment(Figure 9.0 B).There was a significant Tvent main effect for HR, when HR wasaveraged over Condition and across the Time factor (F1,9=6.48, p<0.05).Averaged over the 2 conditions and across the time intervals mean HRresponse was significantly lower with the WlTvent (HRwITventl53 bpm)versus the TrTveflt (HRTrTventl62 bpm) tests (Figure 9.0 A and B).There was a significant Condition by Tvent interaction (F19=6.88,p<O.O5) Averaged across all time intervals mean HR response was 12 and7 bpm respectively higher when the performance test was performed on the76treadmill (HRTrTveflt=l6S bpm and HRWITvent=i56 bpm) versus WI(HRTrTvent=l5G bpm and HRWITVent=l49 bpm) (repeated measures (RM’s)analysis of mean HR averaged over time for TrTrTVent VS WlTrTvent andfor TrWITvent VS WIWITvent identified that mean HRes were significantlylower when TrTveflt and WlTvent was completed in the WI condition).Averaged across all, time intervals mean HR response was 12 and 7 bpmhigher when TrTvent (TrHRTrTvent=l6B bpm vs WIHRTrTvent=i56 bpm,p<O.0002) versus WlTvent (TRwITventl5G bpm vs WIHRWITVent=149 bprn,p<0.05) intensity was performed in the same condition (Figure 9.0 A andC). See Table 5.0 for HR RN’s results and Tables 5.1 and 5.2 for HRRN’s results for TrTrTVent VS WITrTvent and TrWITveflt VS WIWITventrespectively.There was a significant Time main effect, and conclude that therewas a significant difference in mean HR response over Time(F654=40.34, p<O.05). Ninety nine percent of the variability in Timewas accounted for by a significant linear trend (F19=62.82, p<O.O5) asevidenced by the steady linear increase in mean HR from 153 bpm at Ti to162 bpm at T7 (see Figure 9.1 A and B for mean HR responses over Timefor individual tests).There was a significant Condition by Time interaction (F654=i0.96,p<O.O5) and conclude that the nature of the overall change in mean HRresponses over the 7 collection times was different between the twoconditions. Mean HR responses over Time were consistantly lower in theWI versus the treadmill condition. Ninety five percent of thevariability is accounted for by a significant linear trend (F194.23,77p<O.O5), as evidenced by the steady linear increase in mean HR in bothconditions (with WIHR at T1=151 bpm to T7155 bpm and TrHR at T1=].55 bpmto T7=168 bpm) (Figure 9.2 A and B).RM’s analysis of mean HR over time for TrTrTVent VS WlTrTvent andTrwipvent VS WIWITvent found significant Time main effects and Conditionby Time interactions, in both comparisons. Lower mean HR responses overtime were exhibited in the WI compared to the treadmill condition atboth TrTveflt and WlTvent (p<O.O5 in both analyses) with significantincreasing linear trend exhibited over time (Figure 9.2 A and B).There was no significant Tvent by Time interaction (F554=2.60,p>O.O5) (Figure 9.2 A and C) and Condition by Tvent by Time interaction(F654=O.26, p>O.O5).7811111Tvent Tr WI TotalsTr 168 156 162CONDITIONWI 156 149 153Totals 162 153_______________________Figure 9.0. Mean HR response for Condition and Tvent main effects, andCondition X Tvent interaction. A. Table of the mean HR response byCondition and by Tvent. B. Comparison of mean HR response over Condition(Tr vs WI) and over Tvent (TrTvent vs WlTvent) averaged over Time (Conditionand Tvent main effects). C. Comparison of mean HR response averaged overthe steady state tests performed on the treadmill (ie. at Tr and WI Tvent) versusthe steady state tests performed in WI (ie. at Tr and WI Tvent) (Condition XTvent interaction).HR (bpm) HR (Iprn)Condition Tvent Tr—I—IR WI—HR79Time Ti T2 T3 T4 T5 T6 T7• TrTvent 160 164 166 168 172 174 175TRWlTvent 149 152 154 156 159 160 161TrTvent 154 155 155 156 157 158 159:wiWlTvent 148 149 148 148 148 150 151: Mean Test 153 155 156 157 159 161 162Figure 9.1. Mean HR response over the steady state performance tests over time.A. Table of mean HR response over time for the 4 steady state tests and mean Tventtest. 8. Comparison of mean HR response over time for each test condition andTve nt.HR (bprn)1 80B155150 -1451 40Ti T2 T3 T4 T5 T6 T7TimTrTrTvent TrWITvent *WlTrTvent *-WIWITvent80TIME Ti T2 T3 T4 T5 T6 T7Tr 155 158 160 162 166 167 168CONDITIONWI 151 152 152 152 153 154 155Tr 157 160 161 162 165 166 167‘ TventWI 149 151 151 152 154 155 1561 80Tr WI170160150HFigure 9.2. Mean HR response for Condition X Time and Tvent X Timeinteractions. A. Table of mean HR responses for Condition X Time and Tvent XTime interactions. B. Comparison of mean HR response over time for the meansteady state tests completed on the treadmill vs in WI (ie. mean HR at each timeinterval for Tr and WI Tvent combined) (Condition X Time). C. Comparison ofmean HR response over time for mean steady state tests completed at Tr vs WITvent (ie. mean HR at each time interval for Tr and WI conditions combined)(Tvent X Time).HR (bprn)1 40HR (bpm)180Tr WI170160- -150- -140Ti T2 T3 T4 T5 T6 T7TimeTi T2 T3 T4 T5 T6 T7Time814.3.2 Oxygen ConsumptionOxygen consumption (V02) was the variable used to set the Tventintensity of each 42 minute performance test. After the workloadproducing the specific V02 was established and a steady V02 at thespecific Tvent (either the TrTveflt or the WITvent) intensity wasobtained, V02 was no longer controlled. V02 responses during the steadystate tests were examined in relation to V02 response during theduration of the performance tests in the 2 Conditions (treadmill and WI)and to the 2 Tvent (the TrTvent and the WlTvent) intensities over theperformance tests’s time intervals and averaged over the Time factor.There was no significant Condition main effect averaged over the Tventand Time factors (F1,9=1.14, p>0.05) (Figure 10.0 A and B).There was a significant Tvent main effect when averaged overCondition and across the Time factor (F1,g=7.27, p<O.O5). Averagedacross all time intervals the mean V02 on TrTveflt (47.1 mlkg4in)was significantly greater than the mean V02 on WITveflt (42.9 mlkg1min’) averaged over the two conditions, as hypothesized (Figure 10.0 Aand B).There was no significant Condition by Tvent interaction (F1,90.68,p>O.O5) (see Table 5.0 for oxygen consumption RM’s results). RN’sanalysis of mean V02 for TrTrTvent VS WlTrTvent and for TrwlTveflt VSWIWITvent found no significant differences in mean Va2 averaged overtime for TrTveflt (and no difference for WlTvent) intensity test82completed in WI versus completed on the treadmill (see Table 9.1 and 9.2for RM’s analysis results for TrTrTVent V5 WlTrTvent and TrWITVent VSWIWITvent).There was a significant Time main effect (F654=4.70, p<O.O5), withseventy two percent of the variability accounted for by asignificantlinear trend in mean V02 over time from T1=44.4 mlkgmin to T7=45..3mlkgmin (see Figure 10.1 A and B for mean V02 responses over timeand individual test V02 responses over Time).There was no significant Condition by Time interaction (F654=O.25,p>O.05) (Figure 10.2 A and B). RMs analysis of mean V02 over time forTrTrTVent vs WlTrTvent and TrwlTveflt vs WIWITventfound no significantTime main effects and Condition by Time interactions, in bothcomparisons (p>O.OS). There was a small increase in mean V02 over timeexhibited in the WITrTvent and TrTrTVent (see Table 6.0 for RM’sanalysis results and Tables 6.1 and 6.2 for RMs analysis of TrTrTventvs WlTrTvent and TrwlTveflt VS WIWITvent respectively and Figure 10.2 Aand B).There was no significant Tvent by Time interaction (F654=0.47,p>O.O5) (Figure 10.2 A and C), and Condition by Tvent by Timeinteraction (F654=O.82, p>O.O5).83Tvent Tr WI Totals.Tr 471 432 452CONDITIONWI 47.0 42.5 44.8Totals 471 429V02 (mlkg1in)Figure 10.0. Mean V02 (in mIkg1in)response for Condition and Tvent maineffects , and Condition X Tvent interaction. A. Table of mean V02 response bycondition and by Tvent. B. Comparison of mean V02 response over condition(Tr vs WI) and over Tvent (TrTvent vs WlTvent) averaged over Time (Conditionand Tvent main effects).84Time Ti T2 T3 T4 T5 T6 T7TrTvent 46 5 47 0 47 0 46 7 47 0 47 4 47 8TRWlTvent 42.5 43.0 43.0 43.1 43.3 43.8 43.6; TrTvent 46.1 47.2 47.2 47.0 46.9 47.7 47.2WIWlTverit 42 5 42 5 42 5 42 2 42 4 42 8 42 7Mean Test 44 4 44 9 44 9 44 8 44 9 45 4 45 3V02 (mIkg1in)40Ti T2 T3 T4 T5 T6 T7TIMETrTrTvent TrWITvent WITrTvent WIWITventFigure 10.1. Mean V02 (in mIkg1in)response over the steady stateperformance tests over time. A. Table of mean V02 response over time for the 4steady state tests and mean test. B. Comparison of mean V02 response over timefor each test condition and Tvent.85TIME Ti T2 T3 T4 T5 T6 T7Tr 44 5 45 0 45 0 44 9 45 2 45 6 45 7CONDITION-WI 44 3 44 9 44 9 44 6 44 7 45 3 45 0Tr 46 4 47 1 47 1 46 9 47 0 47 6 47 5TventWI 42 5 42 8 42 8 42 7 42 9 43 3 43 2;V02 (m[kg’1in) V02 (m[kg1inj::44 - 4442 42-40Ti T2 T3 T4 T5 To T7 Ti T2 T3 T4 T5 To T7Time TimeFigure 10.2. Mean V02(mI’kg1in-)response for Condition X Time and Tvent XTime interactions. A. Table of mean V02 response for Condition X Time andTvent X Time interactions. B. Comparison of mean V02 response over time forthe mean steady state tests completed on the treadmill vs WI (ie. mean V02 at eachtime interval for Tr and WI Tvent combined) (Condition X Time). C. Comparisonof mean V02 response over time for mean steady state tests completed at Tr vs WI(ie. mean V02 at each time interval for Tr and WI conditions combined) (Tvent XTime).864.3.3 VentilationMinute Ventilation (Ve) responses during the steady state tests wereexamined in relation to Ve response during the duration of theperformance tests in the 2 Conditions (treadmill and WI) and to the 2Tvent (the TrTveflt and the WlTvent) intensities over the performancetests’s time intervals and averaged over the Time factor.There was no significant Condition main effect averaged over theTvent and Time factors (F1,g=3.87, p>O.O5). Averaged over the twoTvent’s and across all time intervals, the mean ventilation response onthe Treadmill (Ve=68.0 l’mirz1) was similar to the mean response in WI(Ve=73.5 lmin) (Figure 11.0 A and B).There was a significant Tvent main effect when Ve was averaged overCondition and across the Time factor (F1,9=9.26, p<O.05). Averaged overthe two conditions and across all time intervals mean ventilationresponse at TrTveflt (Ve=76.2 lmin) was significantly higher than atWlTvent (Ve=65.3 lmin) (Figure 11.0 A and B).There was a significant Condition by Tvent interaction averagedover the Time factor (F19=5.33, p=O.O5). Averaged across all timeintervals mean ventilation response was 8.8 and 2.2 lmin respectivelylower when Tvent intensity was performed on the treadmill(VeTrTveflt=7l.B lmin1 and VewlTvent=64.2 1min) versus WI(VeTrTveflt=BO.6 lmin’ and vewlTvent=66.4lmin1). RM’s analysis ofmean ye for TrTrTvent vs WlTrTvent and for TrwlTveflt vs WIWITvent found87significantly higher mean ye averaged over time for TrTveflt (and nodifference for WITveflt) intensity test completed in WI versus completedon the treadmill (see Table 7.1 and 7.2 for RM’s analysis results forTrTrTvent VS WlTrTvent and TrWITVent VS WIWITvent). Averaged across alltime intervals mean ventilation response was 7.6 and 14.2 imin’significantly higher when TrTveflt intensity (TrVeTrTveflt=l.B lmin1and WIVSTrTVSnt=BO.6lmin1) versus WlTvent intensity (TrVewITvent=642lmin and WIVeWITVent=66.41min) was performed. RM’s analysis ofTrTrTVent VS WlTrTvent and TrWITveflt VS WIWITvent respectively foundmean Ve averaged over time to be higher in the WI compared to thetreadmill condition (Figure 11.0 A and C).There was a significant Time main effect (F654=7.09, p<0.O5) with97 percent of the variability accounted for by a significant Time lineartrend as evidenced by the steady linear increase in mean ventilationfrom 68.5 lmin at Ti to 72.7 lmin at T7. RN’s analysis of mean Vefor TrTrTVent VS WlTrTvent and for TrwITVent VS WIWITvent foundsignificantly higher mean Ve over time for TrTveflt completed in the WIversus treadmill condition (p<0.O5), with a significant linear trendexhibited over time (p<O.O5) (Figure 11.1 A and B).There was a significant Tvent by Time interaction (F654=4.09,p<0.O5) with mean ventilation response consistantly lower over Time withWlTvent (ie. TrwITVent and WIWITvent combined) versus TrTvent (ie.TrTrTVent and WlTrTvent combined) tests. Ninety seven percent of thevariability was accounted for by a significant linear trend (F195.59,p<0.O5) as evidenced by the steady linear increase in mean ventilation88response in both the WlTvent and TrTveflt tests (with mean veTrTvent atTl=72.8 lmin to T7=79.7 1min and mean veWITvent at Tl=64.2 1minto T7=65.8 lmin1) (Figure 11.2 A and C).There was no significant Condition by Time interaction (F654=O.64,p>O.O5) (Figure 11.2 A and B) and Condition by Tvent by Time interaction(F654=O.79, p>O.O5). See Table 7.0 for ventilation RM’s analysisresults.89A:Tvent Tr WI TotalsTr 71.8 64.2 68.0CONDITIONWI 80.6 66.4 73.5Totals 76 2 65 3e*tB CVe (Imin1)Tr—VeFigure 11 .0. Mean Ve response for Condition and Tvent main effects, andCondition X Tvent interaction. A. Table of the mean Ve response by Conditionand by Tvent. Comparison of the mean Ve response over Condition (Tr vs WI)and over Tvent (TrTvent vs WlTvent) averaged over Time (Condition and Tventmain effects). C. Comparison of mean Ve response averaged over the steadystate tests performed on the treadmill (ie. at Tr and WI Tvent) versus the steadystate tests performed in WI (le. at Tr and WI Tvent) (Condition X Tventinteraction).8075QTrTvent•WlTventWI-ye706560Condition Tvent90TRWIVe (Imin’)80 - -75 - -70 - -65 - -Ti T2 T3 T4 T5 T6 T7TIMETrTrTvent TrWlTvent * WITrTvnt WIWITventFigure 11 .1. Mean Ve response over the steady state performance tests overtime. A. Table of mean Ve over time for the 4 steady state tests and meantest. B. Comparison of the mean Ve response over time for each testcondition and Tvent.TrTventWlTvent68.3 68.6 70.6 70.9 73.1 74.7 76.3TrTvent61.4 63.7 64.0 64.2 65.1 65.5 65.5Time Ti T2 T3 T4 T5 T6 T7.. Mean Test 68.5 69.6 70.4 70.4 71.4 72.3 72.7-WlTvent77.3 79.3 79.9 80.3 81.3 82.9 83.167.0 66.6 67.2 66.0 66.2 66.0 66.091:: t:TIME Ti T2 T3 T4 T5 T6 T7 LTr 64.9 66.2 67.3 67.6 69.1 70.1 70.9CONDITION:gWI 72.2 73.0 73.6 73.2 73.8 74.5 74.6Tr 72 8 74 0 75 3 75 6 77 2 78 9 79 7Tvent::. WI 64.2 65.2 65.6 65.1 65.7 65.8 65.8-$4 4:4:1CVe (Imin1)85Tr WITi T2 T3 T4 T5 Te T7Ti meFigure 11 .2. Mean Ve response for Condition X Time and Tvent X timeinteractions. A. Table of mean Ve response for Condition X Time and TventX Time interactions. 5. Comparison of mean Ve response over time formean steady state tests completed on the treadmill (Tr) vs in WI (ie. meanVe at each time interval for Tr and WI Tvent combined) (Condition X Time).C. Comparison of mean Ve response over time for mean steady state testscompleted at Tr vs WI Tvent (le. mean Ve at each time interval for Tr and WIconditions combined) (Tvent X Time).Ve (Imin’)8tTr WI8075: z*rTi T2 Ta T4 T5 T6 T7Time924.3.4 Blood Lactate ConcentrationBlood lactate concentration ([BLa]) responses during the steady stateperformance tests were examined in relation to [BLa] response during theduration of the performance tests in the 2 Conditions (treadmill and WI)and to the 2 Tvent (the TrTvent and the WITVent) intensities over theperformance tests’s time intervals (T2 to T7) and averaged over the Timefactor.There was a significant Condition main effect averaged over the Tventand Time factors exhibited (F19=5.57, p<O.05). Averaged over the 2Tvent’s and across all time intervals the mean [Bla] response on thetreadmill (4.86 mmol11) was significantly higher than in WI (4.13mmoll) (Figure 12.0 A and B).There was a significant Tvent main effect averaged over Conditionand the Time factors exhibited (F19=12.29, p<0.05). Averaged over thetwo conditions and across all time intervals the mean [BLa] response onTrTveflt (5.31 mmoll) was significantly higher than Ofl WITvent (3.68mmoll1) (Figure 12.1 A and B). There was no significant Condition byTvent interaction averaged over the Time factor (F19=0.40, p>O.OS)(Figure 12.0 A and C). See Table 8.0 for [BLa] RN’s results.There was no significant Time main effect (F5451.60, p>O.O5) (seeFigure 12.1 A and B for individual test mean [BLa] responses over Time).There was a significant Condition by Time interaction (F545=6.17,p<O.O5) with mean [BLa] response consistantly higher over time on the93treadmill versus the WI condition. Ninety eight percent of thevariability is accounted for by a significant linear trend (F19=9.83,p<O.O5) as evidenced by the steady linear increase in mean blood lactateresponse on the treadmill tests and the steady (small) linear declineexhibited on the WI tests (Figure 12.2 A and and B). RM’s analysis ofmean [BLa) for TrTrTvent vs WlTrTvent and for TrwlTvent VS WIWITventfound significant Condition by Time interactions (p<O.O5).Significantly lower mean [BLa) responses over time were exhibited forTrTvent and WlTvent intensity tests completed in the WI versus treadmillcondition (p<O.O5), with a significant decreasing linear trend over timeexhibited for TrTveflt in WI and increasing linear trendover timeexhibited in the treadmill condition (p<O.05) (see Table 8.1 and 8.2 forRN’s analysis of TrTrTVent VS WlTrTvent and TrWlTveflt vs WIWITventandFigure 12.2 A and B).There was no significant Tvent by Time interaction (F545=2.l3,p>O.O5) (Figure 12.2 A and C). There was no significant Condition byTvent by Time interaction (F545=2.12, p>O.O5).94LATvent Tr WI TotalsTr 55 42 49CONDITIONWI 51 32 41Totals 5.3 3.7[BLa] (mmolI-1)Figure 12.0. Mean [BLa] response for Condition and Tvent main effects, andCondition X Tvent interaction. A. Table of the mean [BLa] response byCondition and by Tvent. B. Comparison of mean [BLa] response overCondition (Tr vs WI) and over Tvent (TrTvent vs WlTvent) averaged over Time(Condition and Tvent main effects). c. Comparison of mean [BLa] responseaveraged over the steady state tests performed on the treadmill (ie. Tr and WITvent) vs the steady state tests performed in WI (ie. at Tr and WI Tvent)(Condition X Tvent interaction).Condition Tvent Tr-[BLa] Wl-[BLa]95ATime T2 T3 T4 T5 T6 T7TrTvent 4.7 4.9 5.4 5.3 6.2 6.8TRWlTvent 3.8 3.8 3.9 4.4 4.8 4.4TrTvent 5.5 5.3 5.1 5.0 4.8 4.8WIWlTvent 3.7 3.4 3.2 3.1 3.0 2.8Mean Test 4.4 4.3 4.4 4.4 4.7 4.7[B] (mmolr1)TimeTrTrTvent TrWITvent+WlTrTvent -WWITventFigure 12.1. Mean [BLa] response over the steady state performance tests overtime. A. Table of mean [BLa] response over time for the 4 steady state tests andmean Test. B. Comparison of mean [BLa] response over time for each testcondition and Tvent.96iei, TIME T2 T3 T4 T5 T6 T7Tr 4.2 4.3 4.6 4.8 5.5 5.6CONDITIONWI 4.6 4.4 4.1 4.0 3.9 3.8Tr 5.1 5.1 5.2 5.1 5.5 5.8Tvent, WI 3.7 3.6 3.6 3.7 3.9 3.6aNI r-[BLa) (mmolM)Tr WITi T2 T3 T4 T5 T6Ti meHFigure 12.2. Mean [BLa] response for Condition X Time and Tvent X Timeinteractions. A. Table of mean [BLa] responses for Condition X Time andTvent X Time interactions. B. Comparison of mean [BLa] over time for themean steady state tests completed on the treadmill vs in WI (ie. mean [8Lal ateach time interval for Tr and WI Tvent combined) (Condition X Time). C.Comparison of mean [BLa] response over time for mean steady state testscompleted at Tr and WI Tvent (ie. mean [BLa] at each time interval for Tr andWI conditions combined) (Tvent X Time).[BLa] (mmoIt1)Tr WI:-4_:_—-j3Ti T2 T3 T4 T5 T6Time974.4 HYPOTHESIS VERIFICATION4.4.1 Test of Hypothesis 1The significant T—Test for VO2max response on the treadmill versusWI running does not support Hypothesis 1, which predicted similarTrvO2m and WIvo2max responses among elite distance runners trained inWI running (the level of significance as a one—tailed hypothesis was0.0005, with T-value=4.ll) (Figure 8.0).4.4.2 Test of Hypothesis 2The significant T—Test for V02 at TrTveflt versus WlTvent supportsHypothesis 2, which predicted a higher TrTveflt versus WlTvent V02. As aone—tailed hypothesis the tests has a level of significance equal to0.02 (and T—value=2.46).The hypothesis postulated equal treadmill and WI VO2max responses(Hypothesis 1), which was however rejected. Expression of the TventV02s as a percentage of their respective VO2m responses, indicatesthat both the TrTvent and WlTvent occurred at approximately 78 % oftheir respective treadmill and WI VO2max responses (see Table 3 forvalues and Figure 8.4). Therefore we conclude that although theabsolute mean V02 at TrTveflt was greater than at WlTvent, expression ofV02 at Tvent as a percentage of their respective treadmill and WI VO2maxreveals that Tvent occurred at the same mean relative intensity for thegroup.98The analysis of the Tvent tests for HR, V02, ye [BLa] over time willfollow for the hypotheses set for TrTveflt>WlTveflt.4.4.3 Test of Hypothesis 3Significant Condition X Tvent interaction, Condition X Time andTvent X Time interactions, a significant Condition main effects andCondition X Time interaction for TrTrTVent VS WlTrTvent and TrwlTveflt VSWIWITvent comparisons, give support to hypothesis 3, which predictedhigher HR responses at both TrTveflt and WlTveflt intensity when the Tventtest was performed on the treadmill versus WI. Higher HR responses werealso predicted at each collection interval and overall, when the TrTvefltand WlTvent intensity were performed on the treadmill versus WI (evenfor the TrTrTVent test over WlTrTvent test) (Figures 9.0 to 9.2).4.4.4 Test of Hypothesis 4A significant Tvent main effect suggests that V02 at TrTveflt washigher than at WITveflt, however the nonsignificant Condition X Tvent,Condition X Time and Tvent X Time interactions, and Condition maineffects and Condition X Time interactions for TrTrTVent vs WlTrTveflt andTrwlTvent VS WIWITvent comparisons do not support Hypothesis 4 (Figures10.0 to 10.2). Hypothesis 4 predicted that V02 would increase over timein WI tests due to a greater energy expenditure over time in WI versustreadmill work, related to the viscocity friction and turbulance of theWI environment and the larger muscle mass recruited for WI work.994.4.5 Test of Hypothesis 5A significant Condition X Tvent and Tvent X Time interaction, Timemain effect, and Condition X Time interactions for TrTrTvent VSWlTrTvent and TrwlTveflt VS WIWITvent comparisons support hypothesis 5,which predicted higher Ve responses at WlTvent and TrTveflt when theTvent test (that is the same absolute intensity) was performed in WIversus on the treadmill. The significant Time main effect, with asignificant Time linear trend, suggests that over time Ve increased in alinear fashion as the intensity remained constant (Figure 11.1).The significant Tvent X Time interaction, with a significant Tvent XTime linear trend suggests that the lower ye responses which wereexhibited over time , when the WlTvent (ie. in the TrwlTventandWIWITvent tests) versus when the TrTvent intensity was applied, were dueto the absolute intensity of the test and the body’s ability to copewith the demands placed on it (Figure 11.2 C).The non—significant Condition X Time interaction supports Hypothesis4, which presupposed that the WI condition would not be responsible forVe behaviour, but that differences exhibited would be due to the Tventapplied in the test (Figure 11.2 B).4.4.6 Test of Hypothesis 6A significant Condition main effect suggests a higher mean [BLa) onthe treadmill versus WI. This is in conflict with the expected trend.100Hypothesis 6 predicted that mean [BLaJ would be higher in WI (ieWIWITvent and WlTrTvent) versus treadmill (ie. TrWITveflt and TrTrTvent)tests and that mean [BLa] response would increase over time in WI testsdue to the higher relative intensity performed during these Tvent testswhen completed in WI.The nonsignificant Condition X Tvent interaction suggests that mean[BLa] at TrTvent and WITVent intensities respectively, performed on thetreadmill and the WI conditions did not differ. The nonsignificantTimemain effect suggests that there were no differences in mean [BLa)response over time. The significant Condition X Time interactionandCondition X Time linear trend suggest a significant linear response of[BLa) over Time. The trend is, however contrary to our hypothesis,significantly higher in the treadmill tests with an increasing trendover time and significantly lower in the WI tests with a decreasingtrend over time Figures 12.1 B and 12.2 B).The nonsignificant Tvent X Time interaction and suggests that mean[BLa] was similar over time whether the test intensity completed was theWlTvent or the TrTvent (Figure 12.2 C). The higher mean [Bla]over timeon treadmill performance tests is contrary to Hypothesis 6 andis mostlikely due to the laboratory conditions with respect to air temperatureand humidity.1014.5 SUMMARY OF HYPOTHESIS RESULTSHypothesis 1 : TrVO2max = WIvo2max REJECTHypothesis 2 : TrTveflt > WlTvent ACCEPTHypothesis 3 TrHRwirvent > WIHRWITVent ACCEPTTrHRTrTVent > WIHRTrTVent ACCEPTHypothesis 4 WIVO2WITVeflt > TrVO2WITveflt REJECTWIVO2TrTvent > TrVO2TrTVent REJECTHypothesis 5 : wIvewITvent > TrVewITveflt ACCEPTWIVeTrTvent > TrVeTrTveflt ACCEPTHypothesis 6: WI[BLa]wITveflt > Tr[BLaJwITveflt REJECTWI[BLaJTrTveflt > Tr(BLa)TrTvent REJECT102CHAPTER 55.0 DISCUSSIONThe primary purpose of this study was to compare the treadmill andWI running VO2max values and Tvent responses in elite endurance runnersfamiliar with WI running. A secondary purpose was to monitor thecardiorespiratory and metabolic responses to prolonged performance atexercise intensities reflecting the treadmill and WI Tvent on thetreadmill and during WI running. It was postulated that VO2max would besimilar for runners accustomed to WI running when tested in bothconditions (treadmill and WI). However, it was postulated that theTvent (V02 at Tvent) would be lower in WI testing. The data do notfully support these hypotheses. The simulation of treadmill running inthe water, the quality (intensity of exercise in WI running) andfrequency of WI running training sessions, possibly explain thedisagreement. Some of the limitations associated with WI running arethe viscosity friction of water and the subsequent reduced stridefrequency and increased upper body work. Also the non—weight bearingnature of WI running and subsequent reliance on concentric work ofrecruited musculature are implicated.Prolonged performance (42 minutes) at treadmill and WI Tvent wereexplored to compare cardiorespiratory (HR, ye, V02) and metabolic([BLa]) responses during steady state exercise. The hypothesis testedfor HR stated that WI would produce a central shift in blood volume.103This would result in facilitated venous return, preload and strokevolume which would be responsible for the lower HR exhibited (forsimilar V02) over time at both exercise intensities for the WI runningtests. Higher Ve and [BLa] (for similar V02) were postulated for the WIcondition for both the WI and treadmill Tvent. Data did not support allof the study’s hypotheses.5.1 Maximal and Tvent Responses from VO2max Test ResultsIt was hypothesized that distance runners who regularly perform WIrunning workouts and simulate land—based running mechanics in WI runningwould exhibit similar treadmill and WI VO2max values, conforming toprevious studies comparing land vs WI ergometer cycling (Christie et al,1991; Connelly et al, 1991; Sheldahl et al, 1987; Sheldahi et al, 1984;Dressendorfer et al, 1976). The similar post—test [BLa) (obtained at 30seconds and 5 minutes post-test) and VO2max RPE (RPEmax) for thetreadmill and the WI condition lend support that maximal effort wasachieved in the WI condition. However, lower VO2max values were notedfor WI versus treadmill running. This finding is in agreement withother WI running studies (Svedenhag and Seger, 1992; Town and Bradley,1991; Butts et al, 1991; Welsh, 1988).The premise, for equal WI and treadmill VO2max values was thatdifferences found between the two modalities in previous studies wereprimarily due to the following: a) classification and definition of anathlete ‘trained in WI running’, b) appropriate WI running style, c) WIVO2max protocol and d) upper body musculature recruitment. The present104study attempted to control these variables. Also, similar valueson land and WI stationary ergometer cycling demonstrate that controllingbody position and musculature utilized for the activity results in nodifferences being exhibited due to the differing environmental condition(land vs WI) (Christie et al, 1991; Connelly et al, 1991; Sheldahi etal, 1987; Dressendorfer et al, 1976). Consequently, differences inVO2max exhibited with WI versus treadmill running seems to be related todifferences in WI and treadmill running style and training.However, adherence to these criteria in controlling for the otherstudies’ limitations still produced a lower WI versus treadmill VO2max.To ensure that the runners achieved maximal effort, Borg’s ratings ofperceived exertion (RPE) and post-test blood lactate concentration([BLa]) were compared. RPEmax of 20 at treadmill and WI VO2max suggeststhat the subjects perceived that they had achieved maximal effort. Mean[BLa] exhibited immediately post—test and 5 minutes post-test aresimilar with peak [BLa] values observed at maximal effort by otherstudies (Luhtanen et al, 1990; Withers et al, 1981; Farrell et al, 1979;Costill et al, 1973). It would therefore seem that maximal effort wasattained in both protocols. Svedenhag and Seger (1992) noted higher[BLa), whereas Town and Bradley (1991) noted lower [Bla] in the WIcompared to the treadmill VO2max condition. The discrepancy betweenstudies may be related to the lower WI capabilities of the runnersresulting in the recruitment of additional musculature and consequentlyhigher [BLa]. Another implication may be the unfamiliarity of therunners with WI running in combination with limitations of the WI (4105mm) VO2max protocol to elicit maximal effort (Svedenhag and Seger,1992).A minimum RERmax of 1.10 also demonstrates that maximal effort wasachieved in the WI and the treadmill protocols. The lower WI RERmax(1.10) compared to the treadmill ‘1max (1.20) suggests dissimilaritiesin the two conditions. Similar values or relationships were reported bySvedenhag and Seger (1992), and Dressendorfer et al (1976) and Butts etal (1991) respectively. Town and Bradely (1991) reported a WI RERmaxbelow 1.10 (ie. 1.07), which is below the criterion RERmaX normally setfor achieving VO2max, and further suggests that this sample may not haveachieved maximal effort in the WI condition.It is unclear why lower RERrnax values in WI versus treadmill runningwere exhibited in this study. The treadmill and WI VO2max testprotocols in this study were matched for progressive incremental loadincreases per minute, and the WI and treadmill mean test durations werenot statistically different (15 versus 14.5 minutes respectively). Thiswas not the case with the protocols in Svedenhag and Seger (1992) andTown and Bradley (1991) where the test duration for the WI VO2maxprotocols were 4 minutes and the subjects were asked to subjectivelyincrease their effort to maximal for the remaining 1—2 minutes of thetest. The treadmill protocol which they utilized, more objectivelycontrolled the maximum determination.V02 at Tvent was lower in the WI compared to the treadmill conditionfor similar RPE and RER responses. Welsh (1988) also reported lower106WlTvent vs TrTveflt. When V02 at Tvent was expressed as a percentage ofthe respective WI and treadmill VO2max, no differences were exhibited.The similar RPE (13 and 12) and RER (0.99 and 0.98) values at WI andtreadmill Tvent support that Tvent was identified. This would seem tosuggest that differences in V02 (and RERX) exhibited were possiblyrelated to factors which limited VO2max in WI. The main implicationwould be that in WI there is an inability to simulate treadmill (land-based) running style due to the viscocity of the water medium producinga lower stride frequency and thus turn—over rate and increased work inthe forward and backward motion of the arms.The lower stride frequency with a similar pattern of increase overtime with increasing load in the WI condition suggests the following: a)the runners were predominately utilizing their lower trunk musculaturefor the activity, b) the high viscocity friction of the water condition,does influence running style by interfering with ‘how fast the runnercan run in WI’ and by increasing the work performed by the arms duringthe forward and backward pumping action, and c) the non—weight bearingcharacteristics of WI running lends to no push-off phase in the WIrunning cycle and therefore no eccentric contraction of the lower trunkmusculature. These factors would not affect WI cycling and VO2max(Welsh, 1988). The cyclist is stabilized on the cycle and holds thehandle bars (thereby stabilizing and controlling upper body muscle massinvolvement) whereas in WI running the arms are utilized in a forwardand backward motion. The incremental increase in intensity of exerciseto maximal effort on both the WI and land—based cycle ergometer wereaccomplished by increasing the force generation through increased107resistance (Sheldahl et al, 1987; Dressendorfer et al, 1976). Thus,there is more similarity in the work required for cycling in bothconditions than for WI and treadmill running. Welsh (1988) suggests,however, that WI running shows similarities to cycling whichpredominately involves concentric contraction which elicits restrictedblood flow (Eiken et al, 1987).Welsh (1988) suggests that lower WI VO2max values may be due totask specificity, which he translates to: a) the total muscle massrecruited, b) the type of muscle mass recruited, c) the familiarity withthe recruitment pattern, d) the type of muscular contractions and e) thestate of muscular adaption. This study attempted to control the musclemass recruited by selecting subjects who simulated in the WI conditiontreadmill running style. To reduce upper body muscular recruitment,subjects were provided with a boyuancy device to wear for WI running.Analysis of stride frequency in WI and treadmill running showed asimilar increase in stride frequency over time with increasing load.This would indirectly indicate that the leg musculature was primarilyinvolved in the activity. Use of the upper body musculature in WIrunning would result in the utilization of musculature with a higherfast twitch fiber composition. The resistance offered by the WIcondition would increase upper body muscular involvement for similar armrunning movements without a neccessary increase in recruitment due to adifferent pattern of movement in the WI condition (Welsh, 1988).Another possible explanation for the differences in WI and treadmillVO2max values in this study may lie in WI running training. This study108attempted to control WI running style and familiarity with WI running(regular training). Although this study accounted for the quantity ofWI running training completed over time (ie. minimum sessions per month,duration of each workout and minimum period involved in WI running), itdid not account for the runners’ quality (intensity) of their personalworkouts (see Appendix E). There appears to be a greater magnitudedifference in WI versus treadmill VO2max on runners (N=2) whoexclusively limit their WI running work-outs to low intensity (belowTvent) exercise. Subjects who performed WI running workouts similar totheir land—based training (ie. in intensity and program type) exhibitedsmaller deviations in WI and treadmill VO2max.The lower HR’s exhibited at Tvent (by 13 bpm) and at maximal effort(by 15 bpm) in the WI condition are attributed to the central shift inblood volume (approx. 700 ml). This results from the hydrostaticpressure gradient in WI, causing a facilitated central venous return andgreater preload and stroke volume (Christie et al, 1990; Connelly et al,1991; Arborelius et al, 1972). Lower maximal HR responses have beenreported by WI running studies (Svedenhag and Seger, 1992; Town andBradley, 1991; Butts et al, 1991; and Welsh, 1988) and WI ergometerstudies (Christie et al, 1991; Connelly et al, 1991; Sheldahl et al,1987; Dressendorfer et al, 1976). Welsh (1988) reported lower HRresponses at WI Tvent (12 bpm) similar to the present study. Lowersubmaximal HR responses have also been reported by Svedenhag and Seger(1992), Richie and Hopkins (1991), Bishop et al (1991), and Yamaji et al(1991) during short and longer duration WI versus treadmill runningtests at specified submaximal intensities (<80 %VO2max).109Minute ventilation at maximal effort (Vemax) and at Tvent (eTvent)did not differ in the WI condition compared to treadmill running. Thisis in agreement with the studies by Svedenhag and Seger (1992) andSheldahl et al (1987) for Vemax and Welsh (1988) for Vemax and VeTvent.It is in contrast to Butts et al (1991) and Dressendorfer et al (1976)who reported a 9 and 11 % lower WI Vemax when comparing land—basedVem.Similar Ve at maximal effort and Tvent suggest that the WI conditionand related increase in intrathoracic blood volume and hydrostatic chestcompression do not restrict Ve. Resting respiratory mechanics areaffected (reduced) by the WI condition (Agostoni et al, 1966; Hong etal, 1969; Dressendorfer et al, 1976). Ve during exercise, however, isnot limited by the WI condition. Expression of ye relative to V02(ventilatory equivalent for V02, Ve/V02), however, suggests a higher Vefor similar V02. A trend for higher Ve/V02 at Tvent in the WI comparedto the treadmill condition was noted in this study (23.4 vs 21.9,p>O.O5). A significantly higher Ve/V02 was noted for maximal effort inthe WI compared to the treadmill condition (29.4 vs 27.8, p<O.05).These findings concur with Welsh (1988). This seems to suggest thatthere is a tendency to ventilate more air, for similar V02 in the WIcondition at maximal effort. Higher ye is normally exhibited in linewith higher V02, indicating a higher muscle mass recruitment, or isexhibited with a greater [BLa) and RERmax, however in this study VO2maxand RERmax were lower in the WI condition.110Christie et al (1991) reported higher cardiac index (cardiac outputper square meter of body surface area) in WI without an elevation inVO2max. Higher cardiac output in WI has been noted by Sheldahi et al(1984), Nielson et al (1984), Lin (1984), Fahri and Linnarson (1977) andArborelius et al (1972). Christie et al (1991) concluded that theadditional oxygen consumption supplied by the heart to the exercisingmuscle is not utilized. This would seem to suggest that oxygenextraction in the muscle is lower or limited in the WI condition. Thereis some evidence that muscle blood flow is increased in WI (Connelly etal, 1991). It is also believed that other vascular beds accomodate thisincreased blood flow, but there is still no clear evidence on whichcompartments do so (Christie et al, 1991). Alterations in the bloodflow—metabolic relationship are implicated (Christie et al, 1991).In summary it appears that differences in WI and treadmill VO2maxand Tvent may be attributed to less familiarity of runners to WIrunning, with respect to WI training regimens (ie. mileage of steadystate exercise per week, incorporation of high intensity interval workouts) and dissimilar (less intense) WI compared to land—based training.The WI condition also accounts for the differences exhibited in V02, HR,ye, RER in WI versus treadmill running at and Tvent. Therunners perceived effort at VO2max and Tvent is exercise intensitydependent. RPE and peak [BLa] appear not to be affected by the WIcondition.1115.2 Comparison of the treadmill and WI steady state Tvent performancetestsThere is paucity of research literature available on steady stateexercise at Tvent on treadmill and WI running. Exercise at Tvent forone hour duration has been reported to maintain steady state V02, HR,Ve, and [BLa] over time (Loat, 1991). Literature comparing treadmilland WI running during submaximal exercise of a prolonged nature haveproduced conflicting results. These studies failed to utilize runnerswho regularly incorporate WI running into their training regimen. Thesubjects subjectively selected a preferred exercise intensity forcompleting 30 (Richie and Hopkins, 1991) or 45 minute (Bishop et al,1989) WI running tests. The results from these WI running tests werethen compared to the subjects’ selected treadmill running pace forcompleting a similar duration test. The only conclusions, which can bedrawn, are that subjects were possibly unable to exercise at the similarhigher treadmill intensity in the WI condition because of theirunfamiliarity with WI running. Consequently, the WI running pace was ata lower V02, or possibly the subjects were able to maintain a similarpace in WI for the specified time period, but due to their unfamiliaritywith WI running did so at a higher V02 in WI.This study is the first to compare WI and treadmill running duringprolonged exercise at similar relative and absolute intensities ofexercise. The WI and treadmill Tvent’s were expressed as V02, and theV02 at Tvent was used to determine the WI and treadmill Tventintensities for the 42 minute performance tests. The WI condition was112not expected and did not influence V02 during the perfomance tests. Asmall increase in V02 was noted for the WlTrTvent test. This increase,however, was overshadowed by a similar increase during the TrTrTventtest. Increases of greater magnitude in HR, Ve, and [BLa] wereexhibited during the treadmill tests (at WI and treadmill Tvent).This upward drift in HR, Ve, and (BLa], with very little change inV02, in the treadmill condition over the 42 minute tests (at both thetreadmill and WI Tvent intensities) can possibly be attributed to theenvironmental conditions in the laboratory. The present study wasconducted over a seven month period (over three seasons; summer(June/July), fall (September/October), and winter (December). Duringthe summer and fall testing the mean temperature in the laboratory was26.9 and 23.5 degrees celcius (0C) respectively. During winter testingthe mean temperature in the laboratory was lower,18.40 C. Thebarometric pressure ranged between 764—759 mm Hg during the 3 testperiods (see Appendix F). Subjects participating in the summer testperiod were most affected by the hot humid conditions in the laboratory.Similar patterns of cardiorespiratory drifts exhibited in this studyduring prolonged exercise in heat, have been reported in the literature.Martin et al (1981) noted an upward drift in Ve as core temperaturerose, during exercise at Tvent. Ve and HR (by 23 bpm) increased fromminute 12 to 60 without changes exhibited in [BLa] and pH. Foley et al(1993) compared 60 minutes of submaximal exercise at 20° and 32.2° Croom temperature. An increase in CO and HR (by 20 bpm) with no changein a—v02 difference were noted during exercise at room temperature of11332.2° C. Heaney et al (1993) similarily reported an increasing ye withincreasing core temperature, with no change in V02 exhibited duringprolonged exercise in a hot environment. The authors concluded thatcore temperature contributed to ye drift.Attempts were made to provide adequate cooling (electric fan) andunlimited cool water was provided to prevent dehydration during thesteady state treadmill performance tests. The measures taken wereunfortunately, unsuccessful in alleviating the heat problem for thesesubjects, resulting in inflated HR, ye, and [BLa) values. There wasincreased sweating during the treadmill condition tests. Subject 1 lost2.5 kg following performance of the treadmill TrTvent test at a roomtemperature of 27.8° C.Perfuse sweating during the treadmill tests likely caused a decreasein plasma volume, resulting in increases in HR in an attempt to maintainCO. The increase in core temperature may have resulted in the increasein lactate production and / or the reduction in the lactate consumed(re—oxidized). The loss in blood volume as a consequence of perfusesweating may also have resulted in increases in [BLa] due to haemo—concentration. Ve most likely increased due to the decrease in pH andincrease in (BLa).HR, Ve, and (BLa] responses were least affected during the first 15minutes of the treadmill tests (similar to the patterns exhibited inMartin et al (1981)) and comparisons are made with the WI tests withthis treadmill time period.1145.2.1 Heart-rateHR response was similar at WI Tvent intensity performed in the twoconditions over time, whereas HR response was lower at treadmill Tventin the WI compared to the treadmill condition. Sheldahi et al (1987)observed similar cycle ergometer HR responses below workloadscorresponding to 75 %VO2max and lower HR responses above this intensity.Similar HR responses have also been reported by Connelly et al (1990),Christie et a]. (1990) and Svedenhag and Seger (1992) during 5 minuteexercise bouts below 60%, 80% and 65% VO2max respectively. The presentstudy noted similar HR response at WI Tvent intensity corresponding to78% of WI VO2max, but lower HR response at treadmill Tvent correspondingto 84.8% of WI VO2max in the WI condition. Differences in sympatheticneural outflow, baroreceptor activity and cardiac output have beensuggested as possible explanations (Connelly et al, 1990; Christie etal, 1990; Sheldahl et al, 1987). Connelly et al (1991) suggest apossible relationship between cardiopulmonary baroreceptor activity andthe increase in central blood volume. The present study does suggest anexercise intensity dependent HR response, which may be related to anincrease in muscle glycogenolysis. HR response in the present study didshow an increasing trend over the 42 minute test at the treadmill Tventintensity performed in the WI condition. This would be expected forexercise above ones Tvent (toat and Rhodes, 1992; Loat, 1991; Rusko etal, 1986; Hearst, 1982) in that (ie. WI) condition.Determination of HR at Tvent from the WI VO2max test produced asignificantly lower HR compared to the HR at Tvent from the treadmill115VO2max test. The results from the steady state performance testsdemonstrate that differences in HR exhibited at Tvent during the VO2maxtests were simply related to the lower V02 at WI Tvent compared to theV02 at treadmill Tvent. Consequently, the lower WI HR response at Tventreported by the present study and by Welsh (1988) from the progressiveincremental load VO2max tests, were the product of the lower absolute WITvent and not the result of the WI condition.5.2.2 VentilationAlthough resting lung volumes are reduced in upright WI (Withers andHanidorf, 1989; Hong et al, 1969; Agostoni et al, 1966), exercise ye isnot affected. Similar ye responses (when averaged over time) were notedfor exercise at WI Tvent in both the WI and the treadmill condition.The WI condition Ve responses during WI Tvent seemed to be higher if theupward drift in ye during the treadmill performance was considered to berelated to heat stress. This is not in agreement with Svedenhag andSeger (1992) and Sheldahi et al (1984) who reported similar ye in bothconditions during 5 minute exercise intervals at workloads correspondingto 62% and 87%, and 37% and 47% respectively of WI VO2max. The exerciseintensities in the above studies represent absolute workloads, however,which likely represent higher relative intensities of exercise in the WIcondition.The present study also noted higher Ve, with an increasing trendover the 42 minutes during the treadmill Tvent intensity test performedin WI. This is an expected finding since the runners were exercisingabove their Tvent (Loat, 1991; Rusko et al, 1986; Hearst, 1982). This116is in conflict with Svedenhag and Seger (1992), who found no differencein Ve during WI running at 87% of WI VO2max. This is most likelyrelated to the small duration (5 minutes) of the exercise bout andconfounded by the comparison of absolute workloads.The upward drift in ye during the treadmill performance tests (due tothe heat stress) may be masking (statistically) significantly higher yeresponses in the WI condition performed at treadmill and possibly WITvent. It may be that the reduced vital capacity, total lung capacityand lung compliance exhibited during resting WI (Fahri and Linnarsson,1977; Hong et al, 1969; Agostoni et al, 1966) and greater increase inbreathing frequency to tidal volume during WI exercise versus tidalvolume to breathing frequency exhibited during land exercise (Welsh,1988; Sheldahl et al, 1987) may also be responsible for the higher yeresponses in WI.5.2.3 Blood Lactate ConcentrationA progressive increase in HR, ye and V02, during exercise aboveone’s Tvent, is related to the inability of the body to meet exercisedemands aerobically and therefore must rely more on its anaerobic systemfor fuel. This results in the production of lactate at a greater ratethan can be removed (Loat, 1991; Loat and Rhodes, 1991; Rusko et al,1986; Hearst, 1982). A greater increase in V02 would have been expectedduring the 42 minute test at TrTveflt in the WI condition. Christie etal (1990) noted a higher cardiac output at a given V02 during WI versusland ergometer cycling exercise at 41%, 60%, 83%, and 100% VO2max. Theysuggested that the additional oxygen supplied is not utilized by the117exercising muscle. This would seem to indicate then that there wasgreater reliance on the anaerobic system for fuel, and as a result anincrease in lactate production.The higher WI [BLa] values noted by Svedenhag and Seger (1992),however, are most likely related to the higher relative intensity of theexercise workload in the WI versus treadmill condition. The similar(BLa] values noted in Connelly et al (1991) folllowing 5 minute exercisebouts concur with this study’s finding during exercise at WI Tvent inthe WI condition for the first 8-10 minutes of the test.The present study noted initially higher [BLa) in the WI conditionin the TrTvent test, with [BLa] progressively declining during the test.Similar trend in [BLaJ behavior was noted during the WlTvent test in theWI condition. Similar [BLa) values were noted in the WITVent testsperformed on the treadmill and the WI condition. [BLa] decreasedprogressively over the duration of the test in the WI condition. Thisis contrary to [BLa] behavior on land during steady state exercise atTvent (Loat, 1991; Rusko et al, 1986). Stegmann and Kinderman (1982)and Schnabel et al (1982) report [BLa) to initially increase duringexercise (up to the first 10—20 mm of exercise), and thereafter tolevel off or decrease.The initial rise in [BLa) is related to the oxygen debt incurredduring the onset of exercise. This is later corrected by oxidation ofthe lactate produced within the muscle and by removal of the lactateinto the bloodstream, where it will be eliminated (reoxidized) by non118exercising muscles and other tissues (ie cardiac muscle, liver, kidneyetc.) (Favier et al, 1986; Karisson and Jacobs, 1982). In the presentstudy, the subjects performed a self selected warm—up (5—15 minutes)followed by a 5 minute test warm—up and 5 minutes of exercise to set theTvent intensity. Since (BLa] is progressively reduced during WIexercise at treadmill and WI Tvent it would seem to suggest that thereis either less pooling of lactate in the blood as a result of lowerefflux of lactate from the muscle, or more re—oxidization of lactate inthe muscle primarily by slow oxidative muscle fibers (Goilnick et al,1986). It is also possible that less lactate is produced in the muscle,or lactate which initially appears in the blood is later removed byorgan tissues and slow oxidative muscle and therefore less appears inthe blood. The progressive increase in Ve (and decrease in RER, seeAppendix D) seen with declining [BLa] over time supports the view oflactate re—oxidization during exercise. The process may also behormonally mediated (lower epinephrine concentration during WI exercise)reducing the rate of muscle glycogenolysis or related to increase inmuscle blood flow in WI. This would result in reduced [BLa] over timeand enhanced aerobic metabolism (Connelly et al, 1990).5.2.4 Respiratory Exchange RatioRER followed a similar pattern to [BLa]. A progressive decline inRER over the 42 minutes was exhibited in the WI condition for thetreadmill and WI Tvent (see Appendix D for RER results). The decline inRER in both WI tests at treadmill and WI Tvent from 0.99 to 0.96 doessuggest that the higher initial [BLa]’s exhibited in WI were the resultof greater reliance on anaerobic processes during the first 15 minutes119of exercise, resulting in an incurred oxygen debt. The RER pattern ofdecline also suggests the reliance on aerobic processes for fuel supplyand the re—oxidation of accumulated lactate in the latter part of the WItests (at WI and treadmill Tvent).An increasing trend in RER over time was expected for the WI test attreadmill Tvent intensity. This would have supported a greater relianceon anaerobic processes with increasing lactate over time for exerciseabove one’s Tvent. Svedenhag and Seger (1992) noted higher RER during 5minutes of exercise at 87 percent of WI VO2max with higher [BLa] and RPEcompared to treadmill performance at a similar absolute V02 (81 percentof treadmill VO2max). The authors concluded that the higher anaerobicmetabolism during WI exercise was partly related to a lower perfusionpressure in the legs during WI running, with a decline ormaldistribution in total muscle blood flow. However, the higher [BLa]and RER exhibited in the WI compared to treadmill condition, in thestudy by Svedenhag and Seger (1992) may be solely related to therelative intensity of the exercise in the latter condition. Thesubjects were most likely exercising above their Tvent in the WIcondition, and so a higher [BLa) and RER as well as RPE responses wouldbe expected.5.2.5 Ratings of Perceived ExertionRPE responses increased over the 42 minutes for the WI testcompleted at the treadmill Tvent. This confirms the fact that thesubjects perceived this intensity as more difficult in WI than on thetreadmill. This is an expected finding, since the subjects were working120above their Tvent for the WI condition. (BLa] and RER do not supportthe subject’s perceived effort, although an increasing trend over timewas noted for HR and Ve.Svedenhag and Seger (1992) reported higher RPE for WI running(RPE=14.6) at a V02 of 3.5 lmin’ (corresponding to 87 % of WI VO2max)compared to treadmill running (RPE=12.6) at the same absolute intensity(corresponding to 81 % of treadmill VO2max). Similar higher RPE valueswere noted in the present study for WI exercise at treadmill Tventintensity. This may suggest that the sample in Svedenhag and Seger(1992) were exercising above their Tvent in the WI condition, and as aresult higher RPE ([BLa] and RER) are anticipated and can be attributedto the intensity of exercise and not to differences in physiologicalresponse to the WI condition.In the present study mean RPE response at WITVent performed in theWI condition was equal to the RPE response determined at WITveflt(RPETventl2) from the WI VO2max test. Perceived effort at WITveflt wassimilar for the 42 minute test on the treadmill and WI condition. Thisfinding further substantiates that higher RPE values reported for WIrunning by Svedenhag and Seger (1992) and Richie and Hopkins (1991) arerelated to the relative intensity of exercise and also familiarity withWI running and are not related to the WI condition.In summary it appears that HR, Ve, RER and [BLa] responses toexercise at WI and treadmill Tvent are affected by the WI condition. HRis lower in WI at exercise intensities above WI Tvent. The declining121trend over time exhibited in RER and [BLa] may be partially accountedfor by the WI condition. Ve appears to be slightly higher in the WIcondition. It is, however, unclear whether this is related to the WIcondition or the relative exercise intensity. The runners’ perceivedeffort of the activity is intensity dependent.122CHAPTER 66.0 CONCLUSIONS1) WI V02 at Tvent and maximal effort were lower than treadmillresponses in elite distance runners who regularly incorporate WI runningin their training regimens, for similar peak [BLaI and RPE.2) Although land-based running style was simulated by the runnersduring WI running the viscosity friction of the water medium reducedstride frequency to 60-65% of the treadmill values.3) Heart—rate at Tvent and maximal effort were lower in the WI versusthe treadmill condition. The lower HR at Tvent determined from the WIVO2max test, however, was related to the lower V02 at WI Tvent and notto the WI condition. There is an intensity dependent response forsubmaximal HR in water immersion to the neck. HR response in WI issimilar to treadmill values for V02 at and below WI Tvent and lower inWI during exercise above WI Tvent even though an upward drift associatedwith increased reliance on anaerobic metabolism is noted.4) Ventilation at Tvent and maximal effort were not affected by the WIcondition; responses were similar in WI and treadmill running. Veduring steady state exercise at and above WI Tvent in the WI conditionwas not affected by the WI condition, but differences exhibited wererelated to the exercise intensity.1235) [BLa] response during steady state exercise may be affected by theWI condition; a decreasing trend over the 42 minute tests in [BLa] wasexhibited in the WI condition at and above WI Tvent.6) Differences in RPE on the treadmill and WI condition are related tothe relative intensity of exercise and the subjects’ familiarity with WIrunning and not the WI condition.6.1 RECOMMENDATIONS FOR FUTURE RESEARCH1) To study VO2max levels during water immersion to the neck (WI) andtreadmill running among runners who incorporate WI running in theirtraining regimens and meet all other criteria for WI running set by thisresearcher’s study. In the proposed study the runners will bedistinguished into groups according to the intensity of trainingutilized in their WI running workouts. Runners should be distinguishedinto at least two groups, that is: a) Runners who’s WI running workoutsare limited to exercising at and below ventilatory threshold (Tvent) andb) Runners who’s WI running workouts incorporate exercising at and aboveTvent level.In this manner the relationship between the intensity of exercisefor WI running workouts and the magnitude of the difference in WI versustreadmill running VO2max and Tvent can be explored.2) To study the cardiorespiratory and metabolic adapations to WI runningtraining and the implications to land—based running performance.124a) To study cardiorespiratory and metabolic adapations to WIrunning following a long term WI running training regimen in individualspreviously untrained in WI running. This groups improvements would becompared to a control group who will have been prescribed a similarintensity training program for land-based running. A treadmill andcycle ergometer would both be used for pre— and post—testing at Tventand VO2m level.b) To compare cardiorespiratory and metabolic adapations to WIrunning, shallow water (weight—bearing) running and treadmill runningfollowing long term training. A treadmill and cycle ergometer wouldboth be used for pre— and post-testing at Tvent and level.3) To compare WI and treadmill running style via biomechanical(kinematic) analysis combined with cardiorespiratory and metabolicanalysis.4) To replicate the Tvent steady state performance test portion of thisresearchers study. WI running, or a cycle ergometer immersed in thewater could be used as the mode of exercise for the WI conditioncompared to treadmill and stationary ergometer exercise on land,respectively. Also to ensure that land—based laboratory environmentalconditions do not produce heat stress in the subjects. V02, HR, Ve,[BLa), RER, RPE responses would be monitored to determine whether WIresponse patterns exhibited in this study are reproduceable. Additionalvariables that should be considered for collection include thefollowing:125a) Blood glucose and plasma catecholamine levels to provide someindication of the energy sources utilized for exercise and therebyprovide additional information regarding [BLa] behavior.b) Body weight before and after WI testing to determine themagnitude of fluid loss due to diuresis in WI versus sweating duringtreadmill testing.4) To study HR response to various intensities of exercise in WIcompared to land exercise to elucidate HR response in the WI condition.That is, to study HR responses in WI at rest, during exercise below WITvent, at WI Tvent and above WI Tvent to maximal effort intensitiescompared to similar absolute intensity exercise (matched for V02) onland.6.2 TRAINING I1PLICATIONS1) WI running style and the ability to simulate land-based runningmotion in deep water. WI running can be used to complement a runner’straining regimen. It is, however, important that land—based runningstyle be simulated in the WI condition to ensure peripheral trainingadaptations in the musculature utilized for land running. Turn—overrate (stride frequency) will be 30—40% lower in the WI condition relatedto the water resistance. The upper body energy expenditure for similararm motion to land—based running will be higher in the WI condition andthis is related to the increased resistance encountered in the waterversus encountered by the air during land—based running. Upper bodywork can further be increased in the WI condition by utilizing the arms126and hands to propel the body forward, by reaching forward and cuppingthe water. This action will be visually and kinesthetically evident,because it results in an extreme forward lean of the body to an almosthorizontal orientation. It is, therefore, important to maintain properrunning form in the water. Unlike land running where improper runningstyle (eg. extreme forward lean, improper arm motion, etc.) can resultin a fall, this is unlikely with WI running. The ability to pushthrough water is reduced with running in the water versus swimming andthis may lead to the use of the upper body, as discussed above, tomaintain the head above the water level. Utilizing a limited boyancydevice can enhance simulating land—based running style in WI. Theboyancy device will provide enough boyancy to keep the head above thewater level and therefore the runner can concentrate on simulating land—based running motion during WI running sessions.2) Training intensity of WI running sessions. The purpose ofincorporating WI running in a runner’s training regimen should be thefollowing: a) to reduce stress on the joints by running some her weeklytraining mileage in the water and b) during injury as a method ofmaintaining physical conditioning and possibly continuing one’s trainingimmediately following injury and during the rehabilitation process. WIrunning training must incorporate similar work—outs as completed duringland—based training with respect to exercise duration and intensity tobe effective.3) The use of HR to monitor the training intensity of WI running workouts. In using HR to set the training intensity of a WI running work—127out session it is important to account for the following: a) HR valuesat low submaximal intensities, below WI Tvent level are not affected bythe WI condition, b) HR values above WI Tvent are likely lower in the WIcondition versus the land response for similar intensity of exercise(ie. matched for V02). A 10-13 bpm lower HR response should be expectedand accounted for when setting the training HR values for one’s workout. For example if you know that Runner A has a HR of 165 bpm at hisland-based Tvent, or HRmax of 186 bpm and would like him to complete aninterval workout, or a run in the WI condition at 10% above his Tvent,or at 90% of his HRmax you would then want the runner to have thefollowing target HR values:a) for 10% above the runner’s land—based Tvent (ie. 165 bpm), the targetHR would be the following: 165 bpm - 11 bpm (adjusting for the lower WIHR response) = 154 bpm154 bpm X 10% = 15.4 bpm , therefore the target HR for the exercisesession would be: 154 bpm + 15.4 bpm = 169 bpm.b) for 90% of the runner’s land—based the target HR would be thefollowing: 186 bpm - 11 bpm (adjusting for the lower WI HR response) =175 bpm175 bpm X 90% = 158 bpm.4) Training implications of the declining (BLa] and RER responsesduring prolonged WI running exercise. 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Appl.Physiol., 63:55—59.134APPENDICES135Appendix A Subject’s Raw Data.136IJBJECT 1Male subject, 28 yrs old. Competes in 10 km and half marathon runs, duathlons(5 km run-30 km cycle-5 km run), sprint distance triathlon (1 .5 km swim-40 kmcycle-b km run). Has been WI running for 10 yrs. For the 6 months prior toparticipating in the study he had been WI running at least 4-10 times per month,30-45 minute duration per session. WI running training consisted of intervaltraining above his HR at WI Tvent to full exhaustion and also completed steadystate runs at his WI Tvent HR (45 mm). This subject used a HR monitor duringhis WI training to control his workout intensity. Used no floatation device.Comparison of subject’s race pace from event completed close to the time whenparticipating in the study found him to have completed the final 10 km from asprint distance triathlon at 10.8 mph. The subject’s calculated TrTvent pace was10.0 mph.Variable Treadmill WIHeight (cm) 180 180Weight (kg) 67 7 67 7VO2max (I/mm) 4 24 4 15VO2max (mI/kg/mm) 62 6 61 6HRmax (bpm) 200 180Vemax (I/mm) 131 1 1234RERmax 118 116RPEmax 20 2030 sec post-test [BLa] 11 2 11 25 mm post-test [BLa] 11 5 111Max duration (mm) 16 00 17 00V02 at Tvent (I/mm) 3 65 3 26V02 at Tvent (mI/kg/mm) 54 0 48 2HR at Tvent (bpm) 176 161Ve at Tvent (1/mm) 87 0 73 2RER at Tvent 0.96 0.99RPE at Tvent 16 13Time of Tvent 9 30 5 00137Stride frequency from Tr and WI VO2max tests.Time point in test Minute 1 Tvent Minute VO(in strides/mm)Treadmill VO2max test 82 88inute1WI VO2max test 48 50 66Prolonged performance tests.TIMETi T2 T3 T4 T5 T6 T7TrTrTvent 171 174 175 180 182 187 187• HR TrWlTvent 153 162 163 165 169 172 173WlTrTvent 157 161 160 159 165 166 163. WIWITvent 146 146 144 146 144 150 147TrTrTvent 53.4 54.5 54.1 54.8 54.8 55.5 55.2V02 TrWlTvent 47.7 49.7 49.5 49.5 49.8 50.4 51.2WlTrTvent 52.4 54.2 54.6 54.3 55.4 55.6 56.1WIWITvent 48.2 48.3 48.6 48.4 47.9 49.9 48.9TrTrTvent 90.0 91.5 92.4 93.8 98.0 102.4 104.7Ve TrWlTvent 77,0 83.1 85.5 85.9 87.4 88.5 88.0WlTrTvent 90.2 92.2 96.9 98.37 100.7 101.8 103.5WIWITvent 79.9 79.8 82.1 82.0 78.3 82.5 80.1TrTrTvent 7.2 8.4 8.3 8.4 8.8 9.4(BLa] TrWTvent 3.2 4.2 3.8 3.7 3.4 3.1WlTrTvent 3.6 3.4 5.7 5.3 5.5 2.9WIWTvent 5.9 6.1 3.4 3.3 3.1 5•5138:::: Ti T2 T3 T4 T5 T6 17TrTrTvent 0.97 0.95 0.95 0.95 0.96 0.97 0.97RER TrWlTvent 0.97 0.97 0.96 0.96 0.96 0.95 0.95WlTrTvent 1 03 1 00 0 99 0 99 0 98 0 99 0 99WIWITvent 0.97 0.96 0.96 0.96 0.94 0.96 0.95TrTrTvent 13 14 15 16 16 17 18:• RPE TrWlTvent 12 13 13 13 14 14 14WlTrTvent 13 15 15 16 17 17 17WIWITvent 13 13 13 14 14 14 14139UBJECT2 :1Male subject, 29 yrs old. Competes in 10 km and marathon runs. Has been waterrunning for 10 yrs. For the 6 months prior to participating in the study he hadbeen WI running at least 12 times per month, 45-60 minute duration per session.WI running sessions consisted of steady state runs at his WlTvent HR. Thissubject used a HR monitor during his WI training to control his workoutintensity. Used no floatation device.Comparison of the subject’s race pace from an event completed close to the timeparticipating in the study found him to have completed a marathon at 10.2 mphpace. The subject’s calculated TrTvent pace was 10.4 mph.Variable Treadmill WIHeight (cm) 182 0 182 0Weight (kg) 78 0 78 0VO2max (1/mm) 4.85 4.40VO2max (mI/kg/mm) 60 0 56 0HRmax (bpm) 190 178Vemax (1/mm) 126 9 109 4RERmax 1 20 1 14RPEmax 20 2030 sec post-test [BLa] 9 6 9 85 mm post test [BLa] 10 9 10 5Max. duration (mm) 15:30 20:00V02 at Tvent (1/mm) 3.87 3.74V02 at Tvent (mI/kg/mm) 48 9 47 6HR at Tvent (bpm) 163 149Ve at Tvent (1/mm) 97 9 93 5RER at Tvent 1 01 1 00:: RPE at Tvent 15 12:.. Time of Tvent 10:00 10:00140Stride frequency for Tr and WI VO2max tests.p oint in test Minute 1 Tvent Minute VO(in strides/mijI2rntestnute180 92test 50 50Prolonged performance tests.TIMETi T2 T3 T4 T5 T6 17TrTrTvent 158 169 169 174 183 183 184HR TrWlTvent 154 161 168 171 174 176 178WlTrTvent 155 157 161 159 155 158 157WIWITvent 153 152 152 144 146 146 149TrTrTvent 50.4 50.3 52.4 52.2 53.2 55.7 57.6V02 TrWlTvent 47.2 48.0 49.6 49.4 49.5 50.6 51.0WlTrTvent 49.0 53.8 54.3 53.2 52.5 53.3 51.8WIWITvent 47.5 48.0 46.8 44.5 44.9 44.9 45.5TrTrTvent 90.4 94.9 95.9 105.0 109.1 115.4 63.3Ve TrWlTvent 80.2 88.1 92.1 90.9 97.4 96.5 101.4WlTrTvent 105.0 108.3 111.6 106.4 105.4 104.9 98.3WIWITvent 99.7 101.2 98.0 85.9 86.5 83.5 83.2TrTrTvent 4.8 6.4 8.8 6.9 9.7 8.8[BLa] TrWlTvent 6.5 5.1 6.4 6.1 7.3 8.3WiTrTvent 6.8 7.2 6.7 6.2 5.3 4.4WIWITvent 5.3 4.8 3.9 3.4 3.1 3.1141TIMETi T2 T3 T4 T5 T6 T7TrTrTvent 1.00 1.00 1.02 1.01 101 0.99 0.99ER TrWlTvent 0.98 0.99 1.00 1.01 1.02 1.00 0.99WlTrTvent 1.05 1.03 1.04 1.01 1.00 1.00 0.98WIWITvent 1.02 0.99 0.99 0.94 0.93 0.91 0.92TrTrTvent 14 14 14 15 16 19 19RPE TrWlTvent 13 13 13 13 14 15 17WlTrTvent 14 14 14 14 14 14 14WIWITvent 13 13 13 13 13 13 13142UBJECT 3Female subject, 22 yrs old. Competes in 3, 5, 10 km and cross country runs.Has been water running for 1 .5 yrs. For the previous 6 months prior toparticipating in the study she has been WI running at least 12 times permonth, 30-60 minute duration per session. WI running consistedpredominately of progressive runs resulting in exhaustion by the end of thesession. Also did some interval type training (15 mm) when she missed ahard land training session and finished her session with steady state WIrunning (15-20 mm). Used no floatation device.No comparison with race pace from an event completed close to the time sheparticipated in the study was possible for she was not competing at that time(during the summer months).Variable Treadmill WIHeight (cm) 168.2 168.2Weight (kg) 61 .1 61 .1VO2max (I/mm) 3.17 3.03VO2max (mI/kg/mm) 51 .8 49.6HRmax (bpm) 194 186Vemax (1/mm) 88.5 91.7RERmax 1.03 1.08RPEmax 20 2030 sec. post-test [BLa] 10.2 11.05 mm. post-test [BLa] 8.2 11.0Max. duration (mm) 11:00 11:00V02 at Tvent (I/mm) 2.77 2.57V02 at Tvent (mI/kg/mm) 45.3 42.0HR at Tvent (bpm) 181 168Ve at Tvent (1/mm) 65.4 72.9RER at Tvent 0.98 0.97RPEatTvent 16 12Time of Tvent 7:00 5:30Time point in test Minute 1 Tvent Minute VO2max Minute(in strides/mm)Treadmill VO2max test 84 88 92WI VO2max test 52 54 58143SUBJECT4 IMale subject, 25 yrs old. Competes in 10 km and marathon runs. Has been waterrunning for 8 months. For the 6 months prior to participating in the study he hadbeen WI running at least 16 times per month, 40-50 minute duration per session. WIrunning training consisted of interval training above his HR at WlTvent (15-20 mmduration) and steady state runs at his WlTvent HR and above (20-50 mm duration).This subject used a HR monitor during his WI training to control his work intensity.Uses a floatation device (‘aquajogger).Comparison of the subject’s race pace from an event completed close to the timeparticipating in the study found him to have completed a marathon at 9.3 mph pace.The subjects calculated TrTvent pace was 9.0 mph.Variable Treadmill WIHeight (cm) 183.3 183.3Weight (kg) 71 .6 71 .6VO2max (I/mm) 4.71 4.47VO2max (mI/kg/mm) 65.7 62.4HRmax (bpm) 183 175Vemax (1/mm) 123.1 126.7RERmax 1.20 1.10RPEmax 20 2030 sec. post-test [BLa] 10.4 12.85 mm. post-test [BLa] 8.1 11.2Max. duration (mm) 13:30 16:00V02 at Tvent (1/mm) 3.83 3.32V02 at Tvent (mI/kg/mm) 53.4 46.4HR at Tvent (bpm) 160 140Ve at Tvent (1/mm) 76.7 78.6RER at Tvent 0.99 0.99RPE at Tvent 15 13Time of Tvent 8:30 6:00144tJBJECT5Female subject, 20 yrs old. Competes in 3, 5, and 10 km runs, and crosscountry. Has been water running for 3 yrs. For the previous 6 months prior toparticipating in the study she had been WI running at least 7 times per month,30-60 minute duration of each session. WI running training consisted of 15minute interval training sessions and 30-60 minute steady state runningsessions.Variable Treadmill WITime point in test.Minute 1 Tvent Minute VO2max Minute(in strides/mm)Treadmill VO2max test 78 84 94WI VO2max test 44 54 64Height (cm) 163.2 163.2Weight (kg) 51 .7 51 .7VO2max (J/mi,) 3.15 2.76VO2max (mIlkg/miri) 61.0 53.3HRmax (bpm) 191 180Vemax (1/mm) 88.5 75.4RERmax 1.19 1.14RPEmax 20 2030 sec. post-test [BLa] 8.0 7.75 mm. post-test [BLa] 8.0 7.2Max. duration (mm) 14:00 15:30V02 at Tvent (1/mm) 2.32 2.25V02 at Tvent (mI/kg/mm) 45.0 43.5HR at Tvent (bpm) 164 148Ve at Tvent (l/mmn) 51 .7 49.6RER at Tvent 1 .03 1 .00RPE at Tvent 14 12Time of Tvent 8:00 8:00145Prolonged performance tests.TIMETi T2 13 T4 T5 16 17TrTrTvent 155 161 164 170 173 174 175HR TrWlTvent 151 153 157 161 163 164 167WlTrTvent 151 161 154 162 164 166 166WIWITvent 150 156 158 154 153 160 155TrTrTvent 45 5 44 3 45 2 44 8 44 7 45 0 44 7V02 TrWlTvent 43 5 44 0 43 4 44 0 44 9 44 3 44 5WlTrTvent 454 50 3 504 49 1 51 1 52 2 48 2V WIWITvent 43.0 44.5 43.1 43.2 42.7 42.6 41.0 HTrTrTvent 56.4 55.0 59.4 61.0 60.2 61.7 63.3Ve TrWlTvent 50.8 53.3 53.8 56.6 56.0 55.7 57•5WlTrTvent 53.2 65.2 63.9 63.9 64.5 65.7 60.2WIWITvent 54.6 58.2 57.3 56.9 56.0 55.8 53.6TrTrTvent 4.1 4.5 3.4 4.9 7.7 11.3[BLa] TrWlTvent 2.2 2.7 1.9 2.7 4.6 5.3WlTrTvent 3 6 3 1 4 1 3 6 3 1 3 2.. WIWITvent 2.5 2.0 2.0 2.0 1.8 1.6:. TIME,• Ti T2 T3 T4 T5 T6 T7TrTrTvent 1.00 1.00 0.99 1.00 0.99 0.98 1.00RER TrWlTvent 0.92 0.92 0.94 0.93 0.91 0.91 0.91VWlTrTvent 1.02 1.05 1.01 1.02 1.00 1.00 1.00WIWITvent 1.06 1.08 1.07 1.07 1.05 1.05 1.02H TrTrTvent 14 15 17 17 17 17 17 LRPE TrWlTvent 13 13 13 13 13 13 13WlTrTvent 13 15 15 15 15 15 15WIWITvent 13 13 13 13 13 13 13146UBJECT 6Female subject, 26 yrs old. Competes in 5 and 10 km runs and cross country runs.Has been water running for 2 yrs. For the previous 6 months prior to participating inthe study she has been WI running at least 12 times per month, 45-60 minute durationof each session. Used no floatation devise. WI running training consisted of intervaltraining above her WI Tvent HR and also completed steady state runs around her WITvent HR (60 mm).Comparison of the subject’s race pace from event completed close to the time whenparticipating in the study found her to have completed a 10 Km race at 8 mph pace.The subject’s calculated TrTvent was 7.7 mph.Variable Treadmill WIHeight (cm) 166.0 166.0Weight (kg) 51.5 51.5VO2max (I/mm) 2.60 2.43VO2max (mI/kg/mm) 50.5 49.2HRmax (bpm) 190 178Vemax (1/mm) 80.5 89.4RERmax 1.19 1.20RPEmax 20 2030 sec. post-test [BLa] 12.4 12.95 mm. post-test [BLa] 10.7 13.3Max. duration (mm) 10:15 13:00V02 at Tvent (1/mm) 2.09 1 .72V02 at Tvent (mI/kg/mm) 40.5 33.4HR at Tvent (bpm) 172 149Ve at Tvent (1/mm) 50.8 39.2RERatTvent 1.01 1.00RPE at Tvent 11 7Time of Tvent 5:00 4:30r— —Time point in test Minute 1 Tvent Minute VO2max Minute: (in strides/mm)Treadmill VO2max test 84 88 92WI VO2max test 56 60 70147Prolonged performance tests.11 ‘IETi T2 T3 T4 T5 T6 T7 HTrTrTvent 170 176 175 175 179 181 184HR TrWlTvent 147 150 153 154 156 158 159.WlTrTvent 161 161 159 162 163 164 160H WIWITvent 145 143 140 150 151 151 153TrTrTvent 40.0 42.6 43.2 40.0 40.8 41.6 41.4V02 TrWlTvent 33.1 33.5 33.0 33.1 33.8 34.1 32.7WTrTvent 40.8 40.4 40.3 40.4 41.0 40.8 40.3H WIWITvent 33.3 29.7 31.9 33.3 35.1 35.9 35.5; TrTrTvent 48.7 53.9 55.9 47.8 52.9 57.1 57.9Ve TrWlTvent 37.5 40.4 36,3 37.1 39.3 38.9 40.4WlTrTvent 59.2 55.8 58.0 60.9 63.3 66.4 66.6.WIWITvent 43.7 35.6 40.6 44.7 46.8 51.3 49.3H TrTrTvent 8.2 6.3 7.3 5.6 6.6 8.6[BLa] TrWlTvent 4.7 2.8 2.3 2.8 2.2 3.2WlTrTvent 5.9 5.8 5.6 4.9 5.3 5.7WIWITvent 2.4 2.3 3.1 3.2 3.3 2.7TIMETi T2 T3 T4 T5 T6 T7TrTrTvent 0.98 0.97 0.97 0.92 0.95 0.96 0.96RER TrWlTvent 0.92 0.94 0.91 0.91 0.92 0.91 0.94WlTrTvent 1.03 0.96 0.98 0.97 0.97 0.97 0.95WIWITvent 1.03 0.95 0.98 0.99 0.98 1.00 0.98TrTrTvent 12 13 13 14 16 17 18RPE TrWlTvent 7 9 11 11 13 12 12WlTrTvent 6 9 10 12 13 15 17WIWITvent 8 9 9 10 10 11 11148LJBJECT 7Male subject, 29 yrs old. Competes in marathons. Has been water running for 9 months.For the previous 6 months prior to participating in the study he has been WI running atleast 16 times per month, 30-60 minute duration of each session. WI running trainingconsisted solely of low intensity training below his WI Tvent HR (30-60 mm). Used aflotation devise (water ski belt).Comparison of the subject’s race pace from an event completed close to the time ofparticipating in the study found him to have completed a marathon at 10.7 mph pace. Thesubject’s calculated TrTvent pace was 10.8 mph.Variable Treadmill WIHeight (cm) 182.0 182.0Weight (kg) 67.9 67.9VO2max (I/mm) 4 94 3 82VO2max (mI/kg/mm) 72.7 55.9HRmax (bpm) 183 148Vemax (1/mm) 115.1 108.8RERmax 1.14 1.09RPEmax 20 2030 sec. post-test [BLa] 1 1 .2 6.75 mm. post-test [BLa] 8.7 6.8Max. duration (mm) 16:45 16:00V02 at Tvent (1/mm) 3.98 2.00V02 at Tvent (mI/kg/mm) 58.8 44.0HR at Tvent (bpm) 1 67 130Ve at Tvent (1/mm) 71.3 71 .8RER at Tvent 0.90 0.93RPEatTvent 12 14Time of Tvent 1 1 :45 8:30Time point in test.Minute 1 Tvent Minute VO2max Minute(in strides/mm)Treadmill VO2max test 88 94 98WI VO2max test 60 58 68149Prolonged performance tests.TI ME: Ti T2 T3 T4 T5 T6 T7TrTrTvent 163 167 168 168 172 174 177HR TrWlTvent 133 132 131 134 134 133 150WlTrTverit 151 149 148 148 148 148 152WIWITverit 126 131 128 130 129 129 128TrTrTvent 58,2 60.5 59.4 58.2 59.6 59.0 60.5V02 TrWlTvent 44.3 44.4 44.0 44.2 43.9 45.4 44.9WlTrTvent 57.9 56.9 56.7 56.4 53.9 54.7 42.0WIW?Tvent 43.7 44.8 44.6 44.2 45.8 45.1 43.1TrTrTvent 75 6 81 3 81 8 81 9 81 4 83 6 85 6Ve TrWlTvent 57.6 57.1 57.1 54.7 56.1 56.3 55.6WlTrTvent 109.4 106.2 106.2 108.7 105.6 95.71 101.1WIWITvent 71.8 77.2 77.3 78.5 77.7 73.4 69.2TrTrTvent 3.5 3.9 3.3 4.1 4.0 4.6[BLa] TrWlTvent 4.6 5.2 4.5 5.9 6.4 3.9WlTrTvent 6.9 6.1 5.5 5.8 4.6 4.9WIWITvent 2.4 2.2 1.9 1.8 1.9 1.8TIMETi T2 T3 T4 T5 T6 T7TrTrTvent 0.97 0.99 0.96 0.96 0.94 0.97 0.97RER TrWlTvent 0.83 0.84 0.81 0.81 0.84 0.81 0.82WlTrTvent 0.94 0.93 0.90 0.90 0.89 0.88 0.90WIWTvent 0.92 0.94 0.95 0.95 0.91 0.91 0.92TrTrTvent 13 13 13 13 14 14 14RPE TrWlTvent 9 9 9 9 9 g 9WlTrTvent 16 18 18 18 19 19 20WIWITvent 12 13 13 13 13 13 13150UBJECT8Male subject, 22 yrs old. Competes in 10 km, half marathon and cross country runs, istraining for marathon distances. Has been water running for 4.5 yrs. For the previous6 months prior to participating in the study he has been WI running at least 6 timesper month, 30-60 minute duration of each session. Uses no floatation devise most ofthe time, sometimes uses a ‘water ski belt’. WI running training consisted of intervaltraining and ‘hard’ steady state runs.Variable Treadmill WIHeight (cm) 1 87.7 1 87.7Weight (kg) 69.8 69.8VO2max (1/mm) 4.27 3.86VO2max (mI/kg/mm) 61.1 55.2HRmax (bpm) 197 172Vemax (1/mm) 1121 1096RERmax 1.16 1.11RPEmax 20 2030 sec. post-test [BLaI 8.2 7.25 mm. post-test [BLa] 7.0 6.2Max. duration (mm) 16:30 14:00V02 at Tvent (1/mm) 2.75 3.00V02 at Tvent (mI/kg/mm) 39.4 43.0HR at Tvent (bpm) 164 153Ve at Tvent (1/mm) 58.6 72.2RER at Tvent 0.98 0.99RPEatTvent 9 10Time of Tvent 7:30 6:30R______________ -II Time point in testMinute I Tvent Minute VO2max MinuteI (in strides/mm)jTreadmill VO2max test 80 84 90j WI VO2max test 36 36 40151UBJECT 9Male subject, 34 yrs old. Competes in marathon and ultramarathon runs, and triathloris(2.4 mile swim-114.0 mile cycle-26.4 mile run). Has been water running for 4 yrs. Forthe previous 6 months prior to participating in the study he has been WI running atleast 10 times per month, 30-60 minute duration of each session. Uses a floatationdevise sometimes (‘aquajogger’), but not always. WI running training consisted solelyof low intensity exercise below WI Tvent HR.Comparison of the subject’s race pace from event completed close to the time whenparticipating in the study found him to have completed a 50 mile run at 9.4 mph pace.The subject’s calculated TrTvent pace was 9.0 mph.Variable Treadmill WIHeight (cm) 174.7 174.7Weight (kg) 69.3 69.3VO2max (1/mm) 4.18 3.40VO2max (mI/kg/mm) 60.3 49.1HRmax (bpm) 176 168Vemax (1/mm) 124.3 117.5RERmax 1.37 1.11RPEmax 20 2030 sec. post-test [BLa] 14.1 13.8 L5 mm. post-test [BLa] 13.5 13.3 HMax. duration (mm) 14:00 14:00V02 at Tvent (1/mm) 2.90 2.49V02 at Tvent (mI/kg/mm) 42.0 35.9HR at Tvent (bpm) 156 146Ve at Tvent (I/mm) 60.1 59.2RER at Tvent 1 .02 1 .01RPE at Tvent 13 11 1Time of Tvent 8:30 5:30-Time point in test(in strides/mm) Minute 1 Tvent Minute VO2max MinuteTreadmill VO2max test 82 84 96WI VO2max test 52 62 701 52Prolonged performance tests.TIMETi T2 T3 T4 T5 T6 T7: TrTrTvent 148 149 151 154 156 158 159 :• HR TrWlTvent 131 132 133 133 133 133 134:. WlTrTvent 151 149 149 149 153 155 158: WIWITvent 137 135 138 136 135 138 140.TrTrTvent 42.3 42.1 41.7 42.2 43.7 43.5 43.4V02 TrWlTvent 36.4 36.0 36.9 36.4 36.4 36.9 35.8WlTrTvent 41.4 41.3 41.6 40.6 40.8 43.1 44.2 :WIWTvent 36,2 36.0 36.2 35.8 36.1 36.3 36.5TrTrTvent 65.1 63.5 63.5 68.1 72.2 73.5 72.4Ve TrWlTvent 51.7 52.5 52.6 52.1 50.7 54.2 49.8. WlTrTvent 76.3 77.0 79.8 78.9 84.4 98.6 105.3: WIWITvent 60.6 56.4 58.9 55.4 54.8 54.0 56.7. TrTrTvent 6.0 6.6 6.6 7.5 8.2 9.4:: [BLa] TrWlTvent 5.4 5.4 8.3 6.3 9.0 7.8: WlTrTvent 9.6 9.6 8.9 9.1 8.9 9.6.:: WIWITvent 5.0 4.6 3.9 3.5 3.2 2.9TIMETI T2 T3 T4 T5 T6 T7TrTrTvent 0.98 0.95 0.94 0.99 0.99 0.99 0.99RER TrWlTverit 0.98 0.96 0.95 0.92 0.91 0.94 0.91WlTrTvent 1.02 1.02 1.01 0.97 1.01 1.00 1.03WIWITvent 0.97 0.94 0.95 0.92 0.91 0.92 0.93TrTrTvent 13 12 13 15 15 15 15RPE TrWlTvent 11 9 8 9 9 9 9WlTrTvent 15 15 15 15 15 15 17WIWITvent 10 10 10 10 10 10 101 53UBJECT 10Male subject, 22 yrs old. Competes in 800, 1500 m, 5 and 10 km runs. Has been waterrunning for 2 yrs. For the previous 6 months prior to participating in the study he hasbeen WI running at least 10-12 times per month, 50-60 minte duration of each session.Used no floatation devise. WI running training consisted of interval training and steadystate runs about his WI Tvent HR.Variable Treadmill WIHeight (cm) 191.0 191.0Weight (kg) 79.4 79.4VO2max (I/mm) 5 03 4 63VO2max (mI/kg/mm) 63.3 59.1HRmax (bpm) 194 184Vemax (1/mm) 131.2 123.6RERmax 1.24 1.16RPEmax 20 2030 sec. post-test [BLa] 1 1 .3 8.95 mm. post-test [BLa] 12.4 7.5Max. duration (mm) 15:30 12:00V02 at Tvent (1/mm) 3 57 3 96V02 at Tvent (ml/kg/mmn) 45.0 50.5HR at Tvent (bpm) 148 1 64Ve at Tvent (1/mm) 69.7 77.0RER at Tvent 0.95 1 .02.: RPE at Tvent 10 13Time of Tvent 7:30 4:30154Prolonged performance tests.TI ME::: Ti T2 T3 T4 T5 T6 T7* TrTrTvent 147 150 152 157 158 159 160HR TrWlTvent 161 164 166 171 174 176 178WlTrTvent 146 145 145 146 152 152 150WIWITvent 162 163 164 165 168 170 173TrTrTvent 45 0 45 9 45 0 45 8 44 8 45 3 45 7V02 TrWlTvent 50 6 51 8 50 1 51 8 51 5 51 7 52 2WlTrTvent 45 2 45 2 45 1 45 6 44 7 46 7 45 2: WIWITvent 50.6 50.1 50.5 50.7 50.4 52.7 54.0TrTrTvent 77.6 78.1 78.8 81.0 80.0 78.0 80.2Ve TrWlTvent 88.8 93.8 90.7 94.6 93.2 92.3 92.3WlTrTvent 72.9 71.8 70.8 69.6 70.7 74.1 68.8WIWITvent 79.5 79.3 80.4 81.7 79.5 84.7 87.8 HTrTrTvent 3.9 4,2 2.7 2.0 3.6 3.3[BLa] TrWlTvent 4.2 3.8 3.2 5.1 5.0 2.8WlTrTvent 3.6 3.4 3.2 3.4 3.6 3.1WIWITvent 4.7 4.4 4.3 4.5 4.5 3.7TIMETi T2 T3 T4 T5 T6 T7TrTrTvent 1.00 0.99 1.00 0.99 0.98 0.98 0.99RER TrWlTvent 1.01 1.01 1.00 1.01 1.01 1.01 1.00WlTrTvent 0.95 0.95 0.94 0.92 0.94 0.95 0.91WIWITvent 0.96 0.96 0.95 0.95 0.94 0.94 0.95TrTrTverit 11 12 12 13 13 13 13RPE TrWlTvent 12 12 13 14 14 14 14WlTrTvent 10 11 12 12 12 12 12WIWITvent 11 12 12 12 13 15 13155ubject :111Female subject, 35 yrs old. Competes in 10 km and marathon runs. Has been waterrunning for 3 yrs. For the previous 6 months prior to participating in the study shehad been WI running at least 6 times per month, 45 minute duration of each session.Used no floatation devise. WI running training consisted of steady state runsaroung WI Tvent HR.Comparison of subject’s race pace from event completed close to the time ofparticipating in the study found her to have completed a marathon at 8.7 mph. Thesubject’s calculated TrTvent pace was 8.5 mph.Variable Treadmill WIHeight(cm) 1709 1709Weight (kg) 57 6 57 6VO2max (1/mm) 3 02 2 89VO2max (mI/kg/mm) 52 4 49 1HRmax (bpm) 180 166Vemax (I/mm) 87.13 87.7RERmax 1.28 1.10RPEmax 20 2030 sec post-test [BLa] 8 7 8 05 mm post-test [BLa] 8 0 7 2Max duration (mm) 13 00 14 00V02 at Tvent (1/mm) 2 35 2 24V02 at Tvent (mI/kg/mm) 40.8 38.0HR at Tvent (bpm) 159 152Ve at Tvent (I/mm) 48 4 47 0RER at Tvent 0 99 1 01RPEatTvent 14 12Time of Tvent 7 00 6 00156Prolonged performance tests.TIME:: Ti T2 T3 T4 T5 T6 T7TrTrTvent 162 159 158 159 162 163 164HR TrWlTvent 147 146 147 146 149 151 150H WlTrTvent 154 155 155 155 157 155 160:. WIWITvent 149 149 148 149 148 148 151TrTrTvent 40.8 40.9 39.8 40.0 40.5 40.1 40.3V02 TrWlTvent 38.0 38.2 38.3 38.2 38.6 37.9 38.9WlTrTvent 40 9 40 2 40 5 40 6 41 3 42 4 42 0WIWITvent 38 4 38 2 38 5 38 7 38 1 37 8 38 2TrTrTvent 58 1 57 6 55 6 57 8 57 5 57 2 56 2Ve TrWlTvent 48 2 49 0 48 6 48 6 48 6 47 6 47 4WlTrTvent 61 0 58 5 57 2 58 2 62 1 64 0 65 3WIWITvent 53.0 52.9 52.5 53.5 52.5 51.8 54.3TrTrTvent 2 7 1 7 2 9 2 3 1 9 2 4[BLa] TrWlTvent 1 5 1 8 2 2 2 3 2 4 1 5WlTrTvent 3 2 3 1 3 0 3 0 3 3 3 5:• WIWITvent 2.6 2.7 2.5 2.6 2.4 2.5TIMETi T2 T3 T4 T5 T6 T7TrTrTvent 1 .05 1 .02 1 .02 1 .04 1 .03 1 .03 1 .02RER TrWlTvent 0.97 0.98 0.97 0.97 0.96 0.95 0.94WlTrTvent 0.97 0.91 0.90 0.90 0.90 0.91 0.91WIWITvent 0.93 0.93 0.92 0.92 0.92 0.91 0.92TrTrTvent 12 12 12 12 12 12 12RPE TrWlTvent 12 12 12 12 12 12 12WlTrTvent 13 13 13 13 13 13 13WIWITvent 12 12 12 12 12 12 12157UBJECT 12Female subject, 20 yrs old. Competes in 3-10 km track runs and cross country runs.Has been water running for 1 yr. For the previous 6 months prior to participating inthe study she has been WI running at least 6 times per month, 40 minute duration persession. Used no floatation device. WI running training consisted of interval andsteady state runs at and above WI Tvent HR.Comparison of the subject’s race pace from event completed close to the time whenparticipating in the study found her to have completed a 10 km race at 9.4 mph pace.The subject’s calculated TrTvent pace was 7.5 mph.Variable Treadmill WIHeight (cm) 159.7 159.7Weight (kg) 49.2 49.2VO2max (1/mm) 2.60 2.47VO2max (mI/kg/mm) 52.9 50.9HRmax (bpm) 211 199Vemax (1/mm) 71 .0 80.0RERmax 1.18 1.10RPEmax 20 0.9930 sec. post-test [BLa] 11.9 9.15 mm. post-test [BLa] 8.7 7.8Max. duration (mm) 12:30 16:00V02 at Tvent (1/mm) 1 .87 1 .87V02 at Tvent (mI/kg/mm) 38.5 38.6HRatTvent(bpm) 177 174Ve at Tvent (I/mm) 43.4 45.7RER at Tvent 1 .00 0.99RPEatTvent 12 12Time of Tvent 5:30 6:30158Prolonged performance tests.HR Tr(Tr/WI)TventWI(Tr/WI)TventV02 Tr(Tr/WI)TventWI (Tr/WI)TventVe Trfrr/WI)TventWI (Tr/WI)Tvent[BLa] Tr(Tr/WI)TrTventWI(Tr/WI)TventTr(Tr/WI) TventRER WI(Tr/WI)TventTr(Tr/WI)TventRPE WI(Tr/WI)Tverit38.9 38.5 38.438.1 39.2 39.051.7 49.7 52.050.4 52.1 52.7TI0.991 .0112IiT20.991 .031213T31.011 .04131319416938.538.350.447.43.93.1TI METi T2 T3 T4 T5 T6 T7175169180 184169 16918717019016819216738.338.551.153.05.13.238,8 38.538.7 38.151.6 51.552.5 51.54,3 5.43.2 3.22.53.93.33.5TIMET4 T5 T61.001.021.011 .02T71.001.0113131 .001 .00131313131313159UB]ECT IMale subject, 29 yrs old. Competes in marathons. Has been water running for 3 yrs.For the previous 6 months prior to participating in the study he had been WI runningat least 6-8 times per month, 60 minute duration of each session. Uses floatationdevice (‘aquajogger’). WI running training consisted of interval training above WITvent HR and steady state runs at WI Tvent HR.Comparison of the subject’s race pace from an event completed close to the time whenparticipating in the study found him to have completed a marathon at 10.2 mph pace.The subject’s calculated TrTvent pace was 10.0 mph.Variable Treadmill WlHeight (cm) 179 6 179 6Weight (kg) 68 4 68 4VO2max (I/mm) 4 22 4 04VO2max (mI/kg/mm) 61 7 60 2HRmax (bpm) 177 163Vemax (I/mm) 1376 1329RERmax 1 26 1 12RPEmax 20 2030 sec post-test [BLa] 8 22 8 55 mm post-test [BLa] 8 8 7 9Max. duration (mm) 17:00 16:00V02 at Tvent (1/mm) 3 48 3 05V02 at Tvent (mI/kg/mm) 50.8 45.4HR at Tvent (bpm) 152 140Ve at Tvent (1/mm) 82 2 73 2RER at Tvent 1 .02 0.91RPEatTvent 13 13Time of Tvent 1 1 30 5 30Time point in test Minute 1 Tvent Minute VO2max Minute(in strides/mm)Treadmill VO2max test 76 86 94WI VO2max test 50 50 56160Pro’onged performance tests.TIMETI T2 T3 T4 T5 T6 T7TrTrTvent 153 156 160 162 162 166 167HR TrWlTvent 140 142 142 142 144 146 145WlTrTvent 140 146 147 147 148 147 151WIWITvent 142 141 141 139 141 141 142TrTrTvent 50.6 50.1 51.3 50.4 49.5 50.4 50.9V02 TrWlTvent 45.9 46.0 46.7 45.5 45.8 49.9 45.9WlTrTvent 49.5 50.3 49.7 50.9 50.3 51.0 51.6WIWITvent 45.7 46.1 45.5 44.8 45.1 45.0 46.0: TrTrTvent 70.6 67.4 70.4 69.7 72.3 73.8 77.1Ve TrWlTvent 71.0 70.3 71.7 69.9 70.6 73.7 72.3WlTrTvent 95.4 102.7 102.4 105.2 104.7 104.8 108.5WIWITvent 77.2 74.2 72.0 69.4 78.3 69.9 72.3TrTrTvent 4.1 3.5 5.9 5.9 6.2 5.8[BLa] TrWlTvent 3.0 3.2 2.2 3.4 2.4 2.3WlTrTvent 5.1 5.2 5.0 5.2 5.2 5.2H WIWITvent 4.1 4.0 3.7 3.4 3.5 3.4TI METi T2 T3 T4 T5 T6 T7TrTrTvent 0.95 0.92 0.93 0.92 0.94 0.95 0.96RER TrWlTvent 0.98 0.98 0.98 0.98 0.98 0.99 0.99WlTrTvent 0.95 0.97 0.96 0.94 0.95 0.94 0.95WIWITvent 1.05 1.00 0.98 0.95 0.98 0.96 0.96TrTrTvent 12 12 13 13 13 14 14RPE TrWlTvent 10 ii ii ii ii 11 iiWlTrTvent 14 14 15 15 16 16 17WIWITvent 13 13 14 14 15 15 151 61Appendix B : Repeated measures analysis for HR, V02, ye and [BLa).162Table 4.0. 2 X 2 X 7 Repeated Measures Analysis Results for Heart-rate.SOURCE SS DF MS F-RATIO P-VALUEMEAN 6934099.89 1 6934099.89 2428.95 0.0001El 25692.93 9 2854.77CONDITION 6634.89 1 6634.89 19.35 0.03E2 3085.36 9 342.82TVENT 6791.58 1 6791.58 6.48 0.03E3 9434.39 9 1048.27CON X TVENT 450.09 1 450.09 6.88 0.03E4 588.45 9 65.38TIME 2358.29 6 393.05 40.34 0.001E5 526.14 54 9.74TIME (1) 23337.43 1 2337.43 62.82 0.001E(l) 334.85 9 37.21CON XTIME 786.19 6 131.03 10.96 0.001E6 645.81 54 11.96CON X TIME (1) 745.89 1 745.89 14.23 0.004E(1) 471.90 9 52.43TVENT X TIME 69.80 6 11.63 2.60 0.03E7 241.49 54 4.47CON X TVENT X TIME 5.59 6 0.93 0.26 0.95E8 192.13 54 3.56163Table 4.1. 2 X 7 Repeated Measures Analysis Results TrTrTVent V5 WlTrTvent for Heart-rate.SOURCE SS DF MS F-RATIO P-VALUEMEAN 3687456.01 1 3687456.01 3553.31 0.0001El 9339.78 9 1037.75CONDITION 5270.58 1 5270.58 34.91 0.0002E2 1358.64 9 150.96TIME 1594.64 6 265.77 38.78 0.0001E3 370.07 54 6.85TIME (1) 1567.80 1 1567.80 75.41 0.0001E(1) 187.11 9 20.79CON XTIME 396.07 6 66.01 10.27 0.0004E4 347.21 54 6.43CONXTIME(1) 382.80 1 382.80 16.97 0.003E (1) 202.97 9 22.55Table 4.2. 2 X 7 Repeated Measures Analysis Results for TrWlTveflt VS WIWITvent forHeart-rate.SOURCE SS DF MS F-RATIO P-VALUEMEAN 3253435.46 1 3253435.46 1 1 35.47 0.0001El 25787.54 9 2865.28CONDITION 1814.40 1 1814.40 7.05 0.03E2 2315.17 9 257.24TIME 833.44 6 138.91 18.87 0.0001E3 397.56 54 7.36TIME (1) 828.14 1 828.14 26.19 0.0006E(1) 284.59 9 31.62CON X TIME 395.70 6 65.95 7.26 0.004E4 490.73 54 9.09CON XTIME (1) 363.22 1 363.22 10.04 0.01E (1) 325.59 9 36.18164Table 5.0. 2 X 2 X 7 Repeated Measures Analysis Results of Oxygen Consumption.SOURCE SS DF MS F-RATIO P-VALUEMEAN 565630.85 1 565630.85 610.84 0.0001El 25692.93 9 925.99CONDITION 8.53 1 8.53 1.14 0.31E2 67.50 9 7.50TVENT 1243.30 1 1243.30 7.27 0.03E3 1538.38 9 170.93CON X TVENT 7.34 1 7.34 0.68 0.43E4 97.44 9 10.83TIME 27.34 6 4.56 4.70 0.003E5 52.31 54 0.97TIME (1) 19.76 1 19.76 6.96 0.03E5 (1) 25.56 9 2.84CON X TIME 2.28 6 0.38 0.25 0.84E6 81.68 54 1.51TVENTXTIME 2.77 6 0.46 0.47 0.71E7 53.09 54 0.98CON X TVENT X TIME 4.34 6 0.72 0.82 0.50E8 47.62 54 0.88165Table 5.1. 2 X 7 Repeated Measures Analysis Results for TrTrTVent VS WlTrTvent forOxygen consumption.SOURCE SS DF MS F-RATIO P-VALUEMEAN 309955.89 1 309955.89 515.85 0.0001El 5407.82 9 600.87CONDITION 0.02263 1 0.02263 0.00 0.97E2 130.20 9 14.47TIME 21.51 6 3.59 2.92 0.05E3 66.41 54 1 .23CON X TIME 3.53 6 0.59 0.42 0.78E4 75.42 54 1.40Table 5.2. 2 X 7 Repeated Measures Analysis Results for TrWlTveflt VS WIWITvent forOxygen consumption.SOURCE SS DF MS F-RATIO P-VALUEMEAN 256918.25 1 256918.25 517.92 0.0001El 4464.49 9 496.05CONDITION 15.84 1 15.85 4.10 0.07E2 34.74 9 3.86TIME 8.59 6 1.43 1.98 0.12E3 38.99 54 0.72CON X TIME 3.09 6 0.51 0.52 0.66E4 53.88 54 0.99166Table 6.0. 2 X 2 X 7 Repeated Measures Analysis Results for Ventilation.SOURCE SS DF MS F-RATIO P-VALUEMEAN 1401356.29 1 1401356.29 174.21 0.001El 72398.29 9 8044.25CONDITION 2130.06 1 2130.06 3.87 0.08E2 4953.24 9 550.36TVENT 8250.78 1 8250.78 9.26 0.01E3 8023.30 9 891.48CON X TVENT 759.79 1 759.79 5.33 0.05E4 1282.18 9 142.46TIME 537.99 6 89.66 7.09 0.003E5 682.55 54 13.64TIME (1) 522.91 1 522.91 11.83 0.007E5(1) 397.87 9 44.21CON XTIME 110.43 6 18.40 0.64 0.70E6 1553.26 54 28.76TVENT X TIME 265.89 6 44.31 4.09 0.03E7 584.52 54 10.82TVENT X TIME (1) 257.49 1 257.49 5.59 0.04E7 (1) 414.74 9 46.08CONXTVENTXTIME 36.84 6 6.14 0.79 0.51E8 421.00 54 7.80167Table 6.1. 2 X 7 Repeated Measures Analysis Results TrTrTVent VS WlTrTvent forVentilation.SOURCE SS DF MS F-RATIO P-VALUEMEAN 812331.57 1 812331.57 172.32 0.0001El 42425.69 9 4713.97CONDITION 2717.09 1 2717.09 5.50 0.04E2 4443.11 9 493.68TIME 768.71 6 128.12 7.63 0.007E3 906.39 54 16.79TIME (1) 757.14 1 757.14 10.34 0.01E (1) 685.89 9 73.21CON X TIME 48.32 6 8.05 0.38 0.69E4 1130.63 54 20.94Table 6.2. 2 X 7 Repeated Measures Analysis Results for TrWlTvent VS WlwlTvent forVentilation.SOURCE SS DF MS F-RATIO P-VALUEMEAN 597275.51 1 597275.51 141.48 0.0001El 37995.90 9 4221.77CONDITION 172.76 1 172.76 0.87 0.38E2 1792.30 9 199.14TIME 35.16 6 5.86 0.88 0.49E3 360.67 54 6.68CON X TIME 98.95 6 16.49 1.06 0.37E4 843.64 54 15.62168Table 7.0. 2 X 2 X 6 Repeated Measures Analysis Results for Blood Lactate Concentration.SOURCE SS DF MS F-RATIO P-VALUEMEAN 4850.64 1 4850.64 125.26 0.0001El 348.51 9 38.72CONDITION 31.62 1 31.62 5.89 0.04E2 48.29 9 5.37TVENT 158.89 1 158.89 12.29 0.007E3 116.35 9 12.93CON X TVENT 3.95 1 3.95 0.40 0.55E4 89.92 9 9.99TIME 5.76 5 1.15 1.60 0.20E5 32.45 45 0.72CON XTIME 37.30 5 7.46 6.17 0.004ES 54.42 45 1.21CON X TIME (1) 36.59 1 36.59 9.83 0.01E (1) 33.48 9 3.72TVENTXTIME 4.55 5 0.91 2.13 0.08E7 19.22 45 0.43CON X TVENT X TIME 3.04 5 0.61 2.08 0.10E8 13.17 45 0.29169Table 7.1. 2 X 7 Repeated Measures Analysis Results TrTrTVent VS WlTrTvent for BloodLactate concentration.SOURCE SS DF MS F-RATIO P-VALUEMEAN 3382.68 1 3382.68 87.96 0.0001El 346.11 9 38.46CONDITION 6.61 1 6.61 0.82 0.39E2 72.68 9 8.08TIME 8.75 5 1.75 2.24 0.08E3 35.09 45 0.78CON X TIME 28.46 5 5.69 6.67 0.002E4 38.41 45 0.85CON X TIME (1) 27.30 1 27.30 11.54 0.008E(l) 21.30 9 2.37Table 7.2. 2 X 7 Repeated Measures Analysis Results for TrWITveflt VS WIWITvent forBlood Lactate concentration.SOURCE SS DF MS F-RATIO P-VALUEMEAN 1626.85 1 1626.85 123.29 0.0001El 118.76 9 13.20CONDITION 28.97 1 28.97 3.98 0.08E2 65.52 9 7.28TIME 1.56 5 0.31 0.85 0.52E3 16.58 45 0.37CON X TIME 11.88 5 2.38 3.66 0.03E4 29.19 45 0.65CONXTIME(1) 11.08 1 11.08 5.77 0.04E(1) 17.29 9 1.92170Appendix C : Stride Frequency171Comparison of Stride Frequency during the Treadmill and WI VO2max testStride frequency was measured during the treadmill and the WI VO2mtests. Stride frequency was measured each minute in both tests, andcommenced 15 seconds following loading for 30 second measurement periodsfor each minute (values were then multiplied by 2 for minute cadencevalues) of the tests. Three time points during the tests were used forcomparison of treadmill and WI stride frequency, minute 1, minute atwhich Tvent occurred and the last minute of the tests at maximal effort(VO2m). A 2 X 3 within subject repeated measures analysis of variancewith trend analysis was used to analyze the data, with the level ofsignificance set at 0.05. The analysis represents data collected fromonly 12 of the 13 subjects due to technical problems during WI test datacollection for one subject.A significant Condition main effect was exhibited for stridefrequency (p<O.O5) Averaged across the three time intervals meanstride frequency was significantly lower in the WI (54 strides/mm)compared to the treadmill (88 strides/mm) condition (Figure Cl.0 B).A significant increase in mean stride frequency over time wasexhibited (Time main effect, p<O.O5) with 98 percent of the variabilityin time accounted for by a significant time linear trend (p<O.O5). Asimilar steady linear increase in mean cadence was exhibited for boththe treadmill and the WI VO2max tests (Figure Cl.0 A, lines).172There was no significant Condition by Time interaction (p>O.O5) andtherefore conclude that a similar pattern of increase was exbibited inboth conditions (see Figure Cl.O A and B and see Table C1.O for RWsanalysis results). Increases over time per interval were similar forthe 2 conditions with a 4.5 (4.3) and 6.8 (8.2) percent increase fromminute 1 to Tvent and from Tvent to VO2max for the treadmill and WI (WIvalues are in parentheses) conditions. A total percent increase instride frequency (from minute 1 to VO2max) of 2.3 and 3.9 was exhibitedin the treadmill and WI conditions repectively. The WI stride frequencyat minute 1 to VO2max represented 59, 61, and 65 % of the treadmillstride frequency.173Stride Frequency (strides/mm)Figure C1.O. Comparison of stride frequency (strides/mm) during the treadmill vsthe WI VO2ytests. Comparisons were made ror stride frequency during the firstminute of each test, at Tvent time and at maximal effort (V02m8jtime. A. Plot ofmean stride frequency (+1 std) at each of the 3 intervals on the treadmill (Tr) andwater immersion (WI), including plot of the change over time (lines). B. Table ofmean stride frequency over time (at minute 1, Tvent and VO2m) and totals for thetreadmill and the WI VO2m test conditions.Minute 1 Tvent VO2mTime Point in VO2max testsTreadmillMinute 1CONDITIONWITv ent83VO2max87 94Mean total498853 61 541 74Appendix D : Repeated measures analysis for RER and RPE.175Dl.O Respiratory Exchange RatioRESULTSRespiratory exchange ratio (RER) responses during the steady statetests were examined in relation to RER response during the performancetests in the 2 conditions (treadmill and WI) and to the 2 Tvent (theTrTveflt and WlTvent) intensities over the performance test’s timeintervals and averaged over the Time factor. A 2 X 2 X 7 within subjectrepeated measures analysis of variance with trend analysis, with a=O.05was used to analyze the data.Averaged over the two Tvent’s and across all time intervals, themean RER response on the treadmill (RER=O.96) was similar to the meanresponse in WI (RER=O.97) (Condition main effect; F1,9=O.27, p>O.O5)(Figure Dl.l A). Averaged over the two conditions and across all timeintervals mean RER response at TrTveflt (RER=O.97) was similar to theWlTvent response (RER=O.96) (Tvent main effect; F1,9=l.93, p>O.O5)(Figure Dl.l A).Averaged across all time intervals mean RER response was similarwhen Tvent intensity was performed on the treadmill (RERTrTventO.98 andRERWITventO.95) versus WI (RERTrTVent=O.97 and RERWITventO.97)(Condition by Tvent interaction; F19=O.65, p>O.OS) (see Figure Dl.l B).There was a significant Time main effect (F654=8.82, p<O.O5) with89 percent of the variability accounted for by a significant Time linear176trend as evidenced by the steady linear response in mean RER over time.Mean RER remained relatively constant over time for TrTvent and WITVentintensity tests performed on the treadmill. Mean RER exhibited adecline over time in the two WI tests (performed at TrTveflt andWlTvent). The pattern of decline is in line with [BLa] response in WIand supports the arguement of an oxygen debt incurred during the onsetof WI exercise, which was most likely re-oxidized during the latter partof these tests (see discussion).A mean change in RER values of 0.01 during treadmill performance attreadmill and WI Tvent does not represent a physiological change ordifference in fuel utilization. During the WI tests at treadmill and WITvent, a significant declining trend for RER was exhibited. A change inRER from 0.99 during the initial 15 minutes of both tests to an RER of0.96 in the latter part of both tests was noted. This pattern ofdecline does not represent a major physiological change in fuelutilization, although does suggest glycogenolysis as the major processof fuel utilization during the initial 15 minutes of WI exercise.The significant Time (F654=3.86, p<O.05), Time linear trend(F1,9=8.01, p<O.05) and Condition by Time interaction (F6543. ,p<O.O5) for RN’s analysis of TrTrtveflt versus WlTrTvent confirm that adifferent response over time was exhibited at TrTveflt in the twoconditions. The non-significant Condition by Time interaction(F6,542.14, p>O.O5), with a significant Time (F654=7.59, p<O.O5) andTime linear trend (F19=19.92, p<O.O5) for the RN’s analysis for177TrwlTveflt versus WIWITvent denotes the change over time in mean RER, butno difference in BER response related to the WI condition (Figure Dl.2).See Table Dl.O for RER RN’s results and tables D1.1 and Dl.2 for RERRN’s results for TrTrtveflt versus WlTrTveflt and TrwlTvent versusWIWITvent respectively.178RER (VCO2NO)Figure Dl .1. Mean RER response for Condition and Tvent main effectsand Condition X Tvent interaction. A. Comparison of mean RER responseover Condition (Tr vs WI) and over Tvent (TrTvent vs WlTvent) averagedover time. B. Comparison of mean RER response averaged over thesteady state tests performed on the treadmill (ie. at Tr and WI Tvent)versus the steady state tests performed in WI (ie. at Tr and WI Tvent).RER (VCO2/ 0)O.9!J TrTvent•WlTvent0.94Condition Tvent Tr-RER WI-RER179;:Time Ti T2 T3 T4 T5 T6 T7TrTvent 0.98 0.97 0.97 0.97 0.97 0.98 0.98:TRWlTvent 0.96 0.96 0.95 0.95 0.95 0.95 0.95:TrTvent 0.99 0.99 0.98 0.96 0.96 0.96 0.96WIWlTverit 0 99 0 98 0 98 0 97 0 96 0 96 0 96Figure Dl .2. Mean RER response over the steady state performance testsover time. A. Table of mean RER over time for the 4 steady state tests. B.Comparison of mean RER response over time for each test condition andTvent.RER (VCO2NO)10.990.980.970.960.950.94zz:Ti T2 T3 T4 T5 T6 T7TimeTrTrTvent TrWlTvent *WlTrTvent WIWlTvent180Table Dl .0. 2 X 2 X 7 Repeated Measures Analysis Results for Respiratory Exchange Ratio.SOURCE SS DF MS F-RATIO P-VALUEMEAN 262.08 1 262.08 11145.68 0.001El 0.21 9 0.02CONDITION 0.004 1 0.004 0.27 0.61E2 0.15 9 0.02TVENT 0.01 1 0.01 1.93 0.20E3 0.06 9 0.01CON X TVENT 0.01 1 0.01 0.65 0.43E4 0.11 9 0.01TIME 0.01 6 0.002 8.82 0.001E5 0.02 54 0.0003CON X TIME 0.01 6 0.00 1 3.63 0.006E6 0.02 54 0.0003TVENT X TIME 0.00 1 6 0.0002 0.88 0.45E7 0.001 54 0.0002CON X TVENT X TIME 0.00 1 6 0.000 1 0.85 0.50E8 0.01 54 0.0002181Table Dl .1. 2 X 7 Repeated Measures Analysis Results TrTrTVent V5 WlTrTvent forRespiratory Exchange Ratio.SOURCE SS DF MS F-RATIO P-VALUEMEAN 132.89 1 132.89 12361.27 0.0001El 0.09 9 0.01CONDITION 0.0002 1 0.0002 0.02 0.90E2 0.12 9 0.01TIME 0.005 6 0.0009 3.86 0.004E3 0.01 54 0.0002TIME (1) 0.004 1 0.004 8.01 0.02E (1) 0.004 9 0.0005CON X TIME 0.003 6 0.0006 3.54 0.009E4 0.009 54 0.0002Table Dl .2. 2 X 7 Repeated Measures Analysis Results for TrWITveflt VS WlWITvent forRespiratory Exchange Ratio.SOURCE SS DF MS F-RATIO P-VALUEMEAN 129.19 1 129.19 6617.18 0.0001El 0.18 9 0.02CONDITION 0.01 1 0.01 0.79 0.40E2 0.14 9 0.02TIME 0.009 6 0.002 7.59 0.0001E3 0.01 54 0.0002TIME (1) 0.009 1 0.009 19.92 0.002E (1) 0.004 9 0.0005CON X TIME 0.004 6 0.0006 2.14 0.10E4 0.02 54 0.0003182D2.O Ratings of Perceived ExertionRESULTSRatings of perceived exertion (RPE) responses during the steadystate tests were examined in relation to RPE response during theperformance tests in the 2 conditions (treadmill and WI) and to the 2Tvent (the TrTvent and WlTvent) intensities over the performance teststime intervals and averaged over the Time factor. A 2 X 2 X 7 withinsubject repeated measures analysis of variance with trend analysis, witha=O.05 was used to analyze the data.Averaged over the two Tvents and across all time intervals, themean RPE response on the treadmill (RPE=l2.5) was similar to the meanresponse in WI (RPEl3) (Condition main effect; F19=l.38, p>O.O5)(Figure D2.l A).Averaged over the two conditions and across all time intervals meanRPE response at TrTveflt (RPE=13.5) was similar to the WITveflt (RPE12)(Tvent main effect; F1,g=]..97, p>O.OS) (Figure D2.l A).Averaged across all time intervals mean RPE response was similarwhen Tvent intensity was performed on the treadmill (RPETrTventl3 andRPEwITventl2)versus WI (RPETrTventl4 and RPEWITVeflt=l2)(Condition byTvent interaction; F19=O.53, p>O.O5). RM’s analysis of mean RPE for183TrTrTVent VS WlTrTvent and for TrwlTveflt VS WIWITvent found nosignificant differences in RPE response (Figure D2.1 B).There was a significant Time main effect (F654=11.O1, p<O.05) with98 percent of the variability accounted for by a significant Time lineartrend as evidenced by the steady linear increase in mean RPE over time(Figure D2.2).There was no significant Condition by Time interaction (F654=O.65,p>O.O5). There was a significant Tvent by Time interaction (F654=4.7 ,p>O.O5) with mean RPE response lower over time with WlTvent (ie.WlTrTvent and TrwITveflt) versus TrTvent (ie. TrTrTvent and WlTrTvent).Ninety eight percent of the variability was accounted for by asignificant linear trend (F19=7.31, p<O.05) as evidenced by the steadylinear increase in mean RPE response over time, averaged over the twoconditions, in both the WITvent and TrTVeflt tests.RMs analysis of TrTvent intensity performed on the treadmillcompared to in WI reported a mean RPE increase over time for both thetreadmill and WI tests at treadmill Tvent. Mean RPE at TrTvefltincreased from 11.4 at Ti to 13.6 at T7 and from 12.5 at Ti to 15.5 atT7 performed on the treadmill and WI condition respectively. Thissuggests that the TrTVent intensity in the WI condition was perceivedby the subjects to be more difficult. Progressively over time perceivedexertion ratings increased for the subjects. The [BLa] and RER,however, do not conform with the subjects perceived effort. The RPE atTrTvent intensity performed on the treadmill showed a small increase in184RPE over time, but this increase is most likely attributed to thelaboratory conditions (ie. heat and humidity) and is in line with the(increased) [BLa], Ve and HR responses exhibited. The similar mean RPEat WlTvent in both the WI and treadmill conditions suggest that theexercise was perceived as_moderate.See Table D2.O for RRE RM’s results and tables D2.l and D2.2 for RPERM’s results for TrTrtvent versus WlTrTvent and TrwlTveflt versusWIWITvent respectively.185RPE RPEFigure D2.1. Mean RPE response for Condition and Tvent main effects andCondition X Tvent interaction. A. Comparison of mean RPE response overCondition (Tr vs WI) and over Tvent (TrTveflt V5 WlTvent) averaged over time. B.Comparison of mean RPE response averaged over the steady state testsperformed on the treadmill (ie. at Tr and Wi Tvent) versus the steady state testsperformed in WI (ie. at Tr and WI Tvent).Condition Tvent Tr-RPE Wl-RPE1 86LATime Ti T2 T3 T4 T5 T6 T7: TrTvent 11.4 11.6 12.1 12.6 13.2 13.5 13.6TR, WlTvent 11.1 11.3 11.6 11.8 12.2 12.2 12.4TrTvent 12.5 13.7 14.0 14.3 14.7 14.9 15.5wIWlTvent 11.6 11.6 12.2 12.4 12.6 12.9 12.7RPE161311T2T3T4T5T6T7Time°-TrTrTvent TrWITvent *WlTrTvent WIWlTventFigure D2.2. Mean RPE responses over the steady state performance testsover time. A. Table of mean RPE over time for the 4 steady state tests. B.Comparison of mean RPE responses over time for each test condition andTvent.1 87Table D2.O. 2 X 2 X 7 Repeated Measures Analysis Results for Ratings of PerceivedExertion.SOURCE SS DF MS F-RATIO P-VAUJEMEAN 45441.03 1 45441.03 1375.99 0.0001El 297.22 9 33.02CONDITION 85.80 1 85.80 1.38 0.27E2 558.88 9 62.10TVENT 122.23 1 122.23 1.97 0.19E3 558.59 9 62.07CON XTVENT 21.18 1 21.18 0.53 0.49E4 362.36 9 40.26liME 113.09 6 18.85 11.08 0.001E5 92.41 54 1.71TIME (1) 110.63 1 110.63 12.99 0.006E (1) 76.62 9 8.51CON X TIME 2.62 6 0.44 0.65 0.55E6 36.45 54 0.68TVENTXTIME 13.09 6 2.18 4.74 0.01E7 24.84 54 0.46TVENT X TIME (1) 12.86 6 12.86 7.31 0.02E(1) 15.82 54 1.76CON X TVENT X TIME 1.85 6 0.31 0.71 0.48E8 23.36 54 0.43188Table D2. 1. 2 X 7 Repeated Measures Analysis Results TrTrTVent V5 WlTrTvent for Ratingsof Perceived Exertion.SOURCE SS DF MS F-RATIO P-VALUEMEAN 25138.40 1 25138.40 366.92 0.0001El 616.60 9 68.51CONDITION 96.11 1 96.11 1.04 0.33E2 830.60 9 92.29TIME 101.10 6 16.85 11.39 0.002E3 79.90 54 1.47TIME (1) 99.46 1 99.46 13.50 0.005E (U 66.29 9 7.37CON X TIME 3.59 6 0.59 0.81 0.44E4 39.70 54 0.74Table D2.2. 2 X 7 Repeated Measures Analysis Results for TrWlTvent VS WlWlTvent forRatings of Perceived Exertion.SOURCE SS DF MS F-RATIO P-VALUEMEAN 20424.86 1 20424.86 768.47 0.0001El 239.21 9 26.58CONDITION 10.86 1 10.86 1.08 0.32E2 90.64 9 10.07TIME 25.09 6 4.18 6.05 0.01E3 37.34 54 0.69TIME (1) 24.03 1 24.03 8.27 0.01E(1) 26.15 9 2.91CON XTIME 0.89 6 0.15 0.40 0.84E4 20.11 54 0.37189Appendix E : Quality of Workouts.190(Tr-WI)VO2max(ml1kgmin)Interval/steady(...HR at WIvent)HARDSteady state(<HR at WlTvent)LIGHTQuaIty of WI WorkoutsFigure E1.O. Comparison of the quality of the subjects’ WI running workoutscompared to the magnitude of difference in WI and treadmill VO2max (in mV1kgin).Although all the subjects met the present study’s criteria for accetable WI runningstyle and quantity of WI running (le. # of sessions per month and duration of eachworkout for the previous 6 months prior to participation in the study), the type of WIworkouts performed (hard vs light) distinguished the subjects. Subjects whoperformed exclusively low intensity workouts (HR at WlTveflt) during their WIworkouts exhibited much lower Wlvo2max compared to their TrvQ2max response(difference ranging btwn 11.2-16.8 mI1kg’’min). The differences were smaller for thesubjects performing hard WI workouts (ie. at .HR at Wltvenj, differences of 1-5.9 and3.3-7.7 ml1kgin for interval/steady and steady state respectively.Steady state(.HR at WlTvent)HARD191Appendix F : Laboratory Temperature and Barometric Pressure over TestSessions.192Temperature (°C) Barometric Pressure(mm Hg)Figure Fl .0. Graph of the mean laboratory room temperature (bars) andbarometric pressure (*) during steady state Tvent performance tests. Thetemperature in the lab ranged between 23.2-30° C during June/July testing andmean HR for the TrTrTveflt tests increased from Ti to T7 by 19 bpm (N=4). Thetemperature in the lab during September testing ranged between 22-25° C andmean HR for the TrTrtveflj tests increased from Ti to T7 by 13 bpm (N=2). Thetemperature in the lab during December testing ranged between 13-19.8° C andmean HR for the TrTrTveflt increased from Ti to T7 by 12 bpm (N=4). The hot labenvironment affected the subjects’ 42 minute treadmill performance tests. HR, Veand [BLa] exhibited an upward drift over the 42 minute treadmill tests at Tr and WITvent intensity. The subjects were performing at and below their Tvent level.The exercise intensity of the 2 tests should have taxed predominately their aerobicsystem. Evaluation of the subjects’ field race performances during the period oftheir participation in this study did substantiate their treadmill Tvent levels whichwere determined from the treadmill VO2m tests.20272523211017754782700756758754752750..J un/J uly Septern ber Decm ber193Appendix G Determination of Tvent from Ventilatory Parameters.1943328Ve/V022.11.91.71.51.3Time (mm)HR (bpm)Figure Gi .0. Determination of Tvent from ventilatory parameters (ExCO2andVeNO2). Tvent is defined as the point of non-linear increase in ExCO2. TheVe/V02 curve over time was also used to confirm the Tvent level.Nonmetabolic (excess) C02 results from the buffering of lactate and will begenerated for as long as the rate of lactic acid production is increasing.This generates additional hydrogen ions to buffer and because thehydrogen ion and CO2 can readily diffuse from within the muscle cellintothe bloodstream, increases in excess 002 will be detected sooner than therise in blood lactate concentration. Consequently excess CO2 willmoreaccurately reflect muscle lactate production and accumulation (Rhodes andAnderson, 1989; Wasserman et al, 1973).The minute V02 (in mlkg1in)(and HR, Ve) at the point of Tvent was thencalculated and used to determine the workload of the prolongedperformance tests at treadmill and WI Tvent. V02 over the VO2m test isshown on the top figure with the excess CO2 curve and HR is plotted withthe Ve/V02 curve.2318131 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16.Time (mm)1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16.195Appendix H Subject Informed Consent Form196THE UNIVERSITY OF BRITISH COLUMBIASchool of Human Kinetics210, War Memorial Gym________6081 University Boulevard_______Vancouver, B.C. Canada V6T 1ZJTel: (604) 822-3838 Fax: (604) 822-6842CARDIORESPIRATORY AND METABOLIC RESPONSES OF TREADMILLVERSUS WATER RUNNING IN ELITE DISTANCE RUNNERSINFORMED CONSENT FORMInvestigators:1. Dr. Edward C. Rhodes (office tel # 822-4585), Principal Investigator and Faculty Advisor2. D. Daisy Frangolias, Co-Investigator3. Dr. Angelo Belcastro4. Dr. Kenneth Coutts5. Dr. Jack C. Taunton6. Dr. Igor MekjavicPurpose:The purpose of this study is to investigate differences in response to treadmill vswater immersion to the neck (WI) exercise (running) in elite endurance male and femalerunners, familiar with water running. Specific questions to be addressed are: a) Can runnersfamiliar with WI running perform to a similar maximal level (ie. VO2max) in the WI as on thetreadmill condition?, b) Are there differences in the ventilatory threshold (Tvent) levels in WIversus treadmill running?, c) Is the WI condition responsible for physiological differencesexhibited during WI compared to treadmill running? Differences in VO2max and ventilationthreshold (Tvent), and responses to 42 minutes of running on the treadmill and WI Tvent’Swill be examined in this study.Tvent is the intensity of exercise above which fatigue begins to set in, whenworking at Tvent intensity you are able to continue exercising aerobically for a long duration(ie. complete a marathon). VO2max is the maximum amount of oxygen your muscles canconsume and show no further increase in oxygen uptake workload. VO2max provides agood indication of your aerobic fitness. The higher your aerobic fitness, the greater theworkload you can achieve before exhaustion sets in during a VO2max test.Methodology:You will perform a total of 6 tests, 3 on the treadmill and 3 in the deep end of thepool attached to a ‘WI Ergometer’ and wearing a ‘Water Ski Belt’ around your waist. The197THE UNIVERSITY OF BRITISH COLUMBIASchool of Human Kinetics________210, War Memorial Gym6081 University Boulevard_______Vancouver, B.C. Canada V6T 1Z1Tel: (604) 822-3838 Fax: (604) 822-6842WI Ergometer Consists of a series of pulley systems with a bucket,which is loaded withweights (400-750 grams on specified intervals) on one end and a belt which attaches toyour waist on the other end. Specifically you will perform the following tests within a onemonth period:1. You will perform a 5-10 mm warm-up followed by a Treadmill VO2max test(protocol: initial velocity 5 mph, increased by 0.5 mph/mm until volitional fatigue; ifvolitional fatigue is not experienced within 15 minutes of treadmill running the velocity willremain at 12 mph and the grade will be increased by 2% per mm until volitional fatigue).Blood lactate samples will be drawn from your finger (by finger pricking) at 30 sec and 5mm post-test. Complications during such a test are few and usually clear quickly with littleor no treatment. You may stop the test when you wish to because of personal feelings offatigue or discomfort. There will be a spotter by your side for the duration of the test tosupport and catch you if you loose your balance while running on the treadmill. Every effortwill be made to conduct the test in such a way to minimize discomfort and risk.2. You will perform a 5-10 mm warm-up followed by a WI VO2max test (protocolfor female and (male) subjects: 500 (750) grams initial bucket weight, increased by 400grams/mm until volitional fatique; if volitional fatigue is not experienced, within 1 5 minutesthe weight will be increased from minute 16 by 500 (750) grams/mm until volitionalfatigue). Blood lactate samples will be drawn at 30 sec and 5 mm post-test, as stated in 1.Underwater running motion (from the neck down only) will be videotaped, for analysis ofwater running style. Please refer to 1 above for symptoms and possible risks. There is norisk of ingesting water during the test, because you will be wearing a mouth piece and noseclip for the duration of the test.3. You will be asked to run at Tvent intensity (determined from the treadmillVO2max protocol) for 42-50 mm continously and expired gases and blood lactate samplesobtained at 7 minute intervals on the treadmill and WI (a total of 6 blood samples/test), onseparate days.4. You will be asked to run at Tvent intensity (determined from the WI VO2maxprotocol) for 42-50 mm continously and expired gases and blood lactate samples obtained at7 minute intervals on the treadmill and WI (a total of 6 blood samples/test), on separatedays.198THE UNIVERSITY OF BRITISH COLUMBIASchool of Human Kinetics________210, War Memorial Gym6081 University BoulevardVancouver, B.C. Canada V6T 1Z1Tel: (604) 822-3838 Fax: (604) 822-6842For all tests you will wear a nose clip and breath into a mouth piece attached viahoses to a Beckman Metabolic cart (which will measure your expired breaths for expiredoxygen, carbon dioxide and amount of air you ventilate per minute) and wear a heart ratemonitor around your chest. Slight discomfort may be experienced from finger pricking tocollect the (20 microliter) blood samples. A total of 6 hours (1 hour/test) will be required toperform all tests within a 2.5 to 4 week period, on separate days. All information/datacollected will be confidential and a copy of your results and report of your performance inthe study will be provided for you. All data collected and videotape of your water runningperformance will be coded by a number from 01 to 15 and no reference to your identity willever be made in order to maintain confidentiality. Data collected will be used for myMasters thesis in Human Kinetics and for possible publication in a scientific journal. There isno monetary compensation available for your participation in this study, except for mygratitude.Consent:At any time before or during testing you may withdraw from the study. Every effortwill be made to ensure that you do not experience any unnecessary discomfort. If you haveany questions concerning the procedures, or anything else regarding this study, please feelfree to ask me. Daisy Frangolias (my home phone number is 734-1912 and the J.M.Buchanan Lab phone # is 8224356), or my Advisor Dr. E.C. Rhodes (office phone 822-4585).In signing this consent form you will have stated that you have read the consentform (and received a copy for your own records) and understood the description of the testsand that you have entered willingly and may withdraw at any time. I have read the abovecomments and understand the explanation and wish to proceed with all the tests in. thisstudy.Date:_______________________Subject’s signature:________________________Witness’s signature:_________________________199

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