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Critical time in the PWC 170 test: the influences of work load duration, work load intensity, and state… Carr, Robin Victor 1980

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CRITICAL TIME IN THE PWC 1?0 TEST: THE INFLUENCES OF WORK LOAD DURATION, WORK LOAD INTENSITY, AND STATE OF TRAINING by ;OBIN VICTOR CARR B.P.E., U n i v e r s i t y of B r i t i s h Columbia, 1968 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF PHYSICAL EDUCATION i n THE FACULTY OF GRADUATE STUDIES (School of P h y s i c a l Education and Recreation) We accept t h i s t h e s i s as conforming to- the r e q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA December 1979 ^ R o b i n V i c t o r Carr, 1979 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. School of Physical Education and Recreation The University of British Columbia 2075 Wesbrook P l a c e Vancouver, Canada V6T 1W5 Date December 20, 1979 i ABSTRACT The purpose of t h i s study was to examine the concept of " c r i t i c a l time" ( i . e . the time r e q u i r e d to achieve steady-state heart r a t e s ) i n the admi-n i s t r a t i o n of the PWG 170 three-stage submaximal b i c y c l e ergometer t e s t . S p e c i f i c a l l y , the problem i n v o l v e d determining the e f f e c t s of f o u r d i f f e r e n t work l o a d d u r a t i o n p r o t o c o l s on 'D' scores (which r e f l e c t e d the r e l a t i v e attainment of steady-state heart r a t e s ) and on PWG 170 scores. The combined e f f e c t of the order and r e l a t i v e i n t e n s i t y of the work loads on the 'D' scores was a l s o s t u d i e d , as was the e f f e c t of s t a t e of t r a i n i n g on both 'D* scores and PWG 170 scores. E i g h t endurance-trained and e i g h t untrained c o l l e g e males, aged 18 t o 30 , took a p r e l i m i n a r y t e s t t o v e r i f y placement i n t o t h e i r groups and to determine work loads f o r the experimental study. Each s u b j e c t then underwent fo u r experimental PWG 170 t e s t s . Each t e s t c o n s i s t e d of three periods of b i c y c l e ergometer work of i n c r e a s i n g i n t e n s i t y w i t h the d u r a t i o n of the work p e r i o d s e t at 3 i >^ 5> o r 6 minutes f o r the f o u r t e s t v a r i a t i o n s . There was an i n t e r v a l of at l e a s t two days between t e s t s , which were administered i n a counterbalanced Latin-square design. The p e d a l l i n g cadence on the Monark b i c y c l e ergometer was 50 r.p.m., and the warm-up c o n s i s t e d of work loa d f o r two minutes. Continuous monitoring of the subject's E.K.G. permitted c a l c u l a t i o n s o f f a v e r a g e heart r a t e f o r every 15-second i n t e r v a l . These heart r a t e s , and the a s s o c i a t e d work loads, provided the raw data f o r t h i s study. L i n e a r r e g r e s s i o n was used t o determine the PWG 170 scores, while an i i asymptotic r e g r e s s i o n program was chosen t o p r e d i c t steady-state heart r a t e f o r each s u b j e c t a t each work loa d i n a l l f o u r t e s t s . These p r e d i c t e d s t e a d y - s t a t e heart r a t e s were then subtracted from the l a s t 15-second average heart r a t e s f o r a l l work periods t o y i e l d a 'D' score. This 'D* score then gave an i n d i c a t i o n of the extent t o which steady-state heart r a t e s were achieved. The hypotheses were t e s t e d through the use of two-way and three-way ANOVA's and preplanned orthogonal comparisons. The o r i g i n a l a n a l y s i s showed a tr e n d toward i n c r e a s i n g PWG 170 scores w i t h s h o r t e r d u r a t i o n work p e r i o d s , but the e f f e c t was not s i g n i f i c a n t a t the .05 l e v e l . However, a f t e r a c a r e f u l a n a l y s i s of the r e s u l t s , one of the t r a i n e d s u b j e c t s was c l a s s i f i e d as an " o u t l i e r " (one whose data c o n t r i b u t e s too much variance t o be considered r e p r e s e n t a t i v e ) and another ANOVA was run w i t h t h i s s u b j ect's aberrant data d e l e t e d . The s t a t i s t i c a l r e s u l t s were now very d i f f e r e n t , w i t h the p r o t o c o l s e f f e c t h i g h l y s i g n i f i c a n t (p<.001), and expl a i n e d w e l l by a l i n e a r f u n c t i o n ( p < . 0 0 l ) . On the b a s i s of these ambiguous f i n d i n g s , confident conclusions r e g a r d i n g the p r o t o c o l s e f f e c t must await f u r t h e r study. The f i r s t ANOVA showed no evidence of an i n t e r a c t i o n e f f e c t between s t a t e of t r a i n i n g and the p r o t o c o l s e f f e c t , however the second, 'post hoc ANOVA' ( w i t h s u b j e c t " o u t l i e r " deleted) found a s i g n i f i c a n t d i f f e r e n c e which suggested t h a t t r a i n e d a t h l e t e s may have t h e i r PWG 170 scores overestimated more than untrained subjects as a r e s u l t of s h o r t e r d u r a t i o n p r o t o c o l s . There was a h i g h l y s i g n i f i c a n t p r o t o c o l s e f f e c t i n the 'D' scores ( p < . 0 0 l ) which was expla i n e d almost e n t i r e l y by a l i n e a r f u n c t i o n ( p < . 0 0 l ) . This data t h e r e f o r e tends t o support the 'post hoc ANOVA' f o r the PWG 170 i i i s c ores, s i n c e these scores are o b v i o u s l y dependent on the extent to which steady-state has been achieved. Although the 'D' scores suggested t h a t the h~minute p r o t o c o l might be optimal f o r a c h i e v i n g s t e a d y - s t a t e v a l u e s , t h i s assumes t h a t an asymptotic f i r s t - o r d e r model a c c u r a t e l y p r e d i c t s steady-state heart r a t e s . I n t h i s l i g h t , the l a c k of a s i g n i f i c a n t e f f e c t of s t a t e of t r a i n i n g or work l o a d number/intensity on c r i t i c a l time, shown by t h i s study, must be i n t e r p r e t e d w i t h c a u t i o n . F u r t h e r study w i t h 'D' scores based on second-order models may uncover s i g n i f i c a n t main and i n t e r a c t i o n e f f e c t s . i v TABLE OF CONTENTS Chapter Page I STATEMENT OF THE PROBLEM 1 I n t r o d u c t i o n 1 Purpose 3 D e l i m i t a t i o n s 3 Assumptions and L i m i t a t i o n s . . . 4 Hypotheses it-D e f i n i t i o n s 5 S i g n i f i c a n c e of the Study 5 I I REVIEW OF THE LITERATURE 7 L i m i t a t i o n s of R e s t i n g and Recovery Heart Rates and Maximal E x e r c i s e Tests f o r Measuring C i r c u l a t o r y F u n c t i o n a l Capacity 7 A Summary of the P r i n c i p l e s Underlying Submaximal C i r c u l a t o r y F u n c t i o n a l Capacity and P h y s i c a l Work Capacity Tests Based on Steady-State Heart Rates 9 - Mechanical Work versus P h y s i o l o g i c a l Work . . 14 - P h y s i o l o g i c a l Work versus Oxygen Uptake . . . 15 - Oxygen Uptake versus Cardiac Output . 16 - Cardiac Output versus Heart Rate 16 The PWC 170 Test . . . 17 E f f e c t s of Work Load Duration 20 E f f e c t s of Work Load I n t e n s i t y 24 E f f e c t s of Sta t e of T r a i n i n g . 25 I I I METHODS AND PROCEDURES 28 Subjects 28 Procedures 28 V TABLE OF CONTENTS Chapter Page Experimental Conditions 29 C o l l e c t i o n of the data 30 Treatment of the Data 30 Experimental Design and S t a t i s t i c a l A n a l y s i s . . . . 31 - Hypotheses 1 and 2 31 - Hypotheses 3> ^ and 5 32 IV RESULTS AND DISCUSSION 33 R e s u l t s - • 33 - pwc 170 34 - 'D' Scores 38 D i s c u s s i o n . 44 - PWC 170 44 - 'D' Scores 49 V SUMMARY AND CONCLUSIONS 53 S ummary 53 Conclusions 55 - PWC 170 Scores - 5 5 - 'D' Scores 56 REFERENCES 58 APPENDICES 71 Appendix A - Raw Data 72 Appendix B - 'D' Scores ( C a l c u l a t i o n s ) . . . • 81 v i LIST OF TABLES Table Page I I - 1 Chain of Assumptions 13 ( C o r r e l a t i o n Between Work Loads and Heart Rates) I I - 2 Mean Tran s i e n t Heart Rate Responses . 2 3 (Percentage of 6th Minute " S t a b l e - S t a t e " Values) I I I - 1 Schedule of Test P r o t o c o l s 29 (Counterbalanced Latin-square Design) I I I - 2 C a l c u l a t i o n of 'D' Scores 31 I I I - 3 Experimental Design - Hypotheses 1 and 2 J2 I I I - 4 Experimental Design - Hypotheses 3. 4 and 5 32 IV - 1 I n d i v i d u a l PWC 170 Scores . . 34 IV - 2 PWC Scores 34 (Group Means and Standard Deviations) IV - 3 PWG Scores 35 (Summary of ANOVA) IV - 4 I n d i v i d u a l *D* Scores 39 IV - 5 'D' Scores 39 (Group Means and Standard Deviations).. „ IV - 6 'D' Scores 40 (Summary of ANOVA) IV - 7 'D' Scores 41 P r o t o c o l s E f f e c t on Group Means (Averaged Over A l l 3 Work Loads) IV - 8 PWG 170 Scores, 46 (Summary of ANOVA - Post Hoc - Subject ' 0 5 ' Deleted) v i i LIST OF FIGURES Figure Page IV - 1 PWG 1?0 Scores (Means) 37 IV - 2 'D' Scores h2 (Group Means Averaged Over the Three Work Loads Under A l l Four P r o t o c o l s ) IV - 3 PWG 170 Scores (Means) 48 (Subject ' 0 5 ' Deleted) v i i i ACKNOWLEDGEMENTS The author wishes t o express h i s g r a t i t u d e t o the members of h i s t h e s i s committee: Dr. Kenneth Coutts (Committee Chairman), Dr. Robert Schutz, Dr. S t a n l e y Brown, and Dr. Hugh Venables. T h e i r patience and e f f o r t s were appreciated. S p e c i a l thanks go t o Drs. Coutts and Schutz f o r t h e i r valuable help and suggestions throughout the d u r a t i o n of t h i s study. I a l s o wish to thank my w i f e , Wendy, f o r t y p i n g even i n good weather. CHAPTER 1 STATEMENT "OF THE PROBLEM I n t r o d u c t i o n The s i m p l e s t , s a f e s t , and most e x t e n s i v e l y a p p l i e d method of t e s t i n g the c i r c u l a t o r y f u n c t i o n a l c a p a c i t y i s achieved through the determination of heart r a t e response t o submaximal e x e r c i s e ( American College of Sports Medicine, 1975; Andersen e t a l . , 1971; Astrand and Rodahl, 1970). Tests of t h i s type u s u a l l y i n v o l v e measurement of the steady-state heart r a t e s produced by given work loads, and y i e l d a p r e d i c t i o n of c i r c u l a t o r y f u n c t i o n a l c a p a c i t y as d e f i n e d by maximal oxygen uptake or p h y s i c a l work ca p a c i t y . The r a t e at which e x t e r n a l mechanical work can be performed a t a heart r a t e of 170 beats per minute (PWC 170) has been w i d e l y used as a measure of p h y s i c a l working c a p a c i t y and, t o a l e s s e r extent, as an i n d i r e c t measure or p r e d i c t o r ,<3f c i r c u l a t o r y f u n c t i o n a l c a p a c i t y . The t e s t was o r i g i n a l l y devised by S j o s t r a n d (19^7) and Wahlund (19^8), and has been reporte d i n the l i t e r a t u r e as having been used i n at l e a s t 36 s t u d i e s i n many d i f f e r e n t c o u n t r i e s (Watson and O'Donovan, 1976). I n i t s o r i g i n a l form i t c o n s i s t e d of three 6-minute periods of submaximal e x e r c i s e (Wahlund, 19^8). Since then a number of i n v e s t i g a t o r s have modified t h i s p r o t o c o l . Some have used a p r o t o c o l which i n c l u d e d two 6-minute work loads (Adams, I 9 6 I ; Cumming and Danzinger, 1963; Be V r i e s , I 9 6 5 ).while i n one Canadian study, Alderman (1969) used three 4-minute work loads. Watson and O'Donovan i n I r e l a n d (1976) r e p o r t t h a t reducing the work perio d s from s i x t o f i v e minutes d u r a t i o n had no s i g n i f i c a n t e f f e c t on PWC 170 scores, but t h a t a r e d u c t i o n t o f o u r minutes r e s u l t e d i n a 4 per 1 2 cent e l e v a t i o n of scores. According t o the p r i n c i p l e s u n d e r l y i n g t h i s t e s t , t h i s e l e v a t i o n of scores i n d i c a t e s decreased heart r a t e s f o r a t l e a s t one of the workloads, and t h i s suggests t h a t the f o u r t h minute measurements may have been premature f o r the attainment of steady-state values, at l e a s t f o r some of the subgects i n v o l v e d . Weiner and Lourie (1969) s t a t e t h a t i n submaximal t e s t s three 4-minute work loads may be p r e f e r a b l e t o f o u r 3-rcinute l o a d i n g s , suggesting i m p l i c i t l y that' there i s a minimum c r i t i c a l time r e q u i r e d f o r working a t each l o a d , t h a t ttime being dependent upon the r a t e of c a r d i o a c c e l e r a t i o n t o s t e a d y - s t a t e . Withers e t a l . (1977) compared PWG 170 scores u s i n g 3 d i f f e r e n t formats: two 6-minute work loads, three 4—minute work loads, and f o u r 3-minute work loads. Although they d i d not ; f i n d any s t a t i s t i c a l l y s i g n i f i -cant d i f f e r e n c e s ( a t the .05 l e v e l ) , the group mean scores of the d i f f e r e n t formats (expressed i n KGM./KG./Miri.) suggested a trend toward higher scores f o r the s h o r t e r work pe r i o d s . The group means were, r e s p e c t i v e l y , 17.295i 17.992, and 18 .179. According t o Andersen e t a l . (1971) the o b j e c t i v e of t h i s type of submaximal e x e r c i s e t e s t should be t o produce "...4 evenly spaced,pulse readings over the range 40 - 80% of aerobic power..." (p. 55) and the work loads should each be of ". . . a t l e a s t 4 minutes..." d u r a t i o n (p. 5^)• No mention was made, however, of the nature of the j u s t i f i c a t i o n f o r choosing 4 minutes as the minimum c r i t i c a l time f o r each w o r k l l o a d . There may be mediating f a c t o r s which have been overlooked as f a r as t h e i r e f f e c t s on t h i s c r i t i c a l time i s concerned. I t may w e l l be, f o r in s t a n c e , t h a t the c r i t i c a l time decreases f o r the heavier work loads, s i n c e Astrand and Rodahl s t a t e t h a t "the heavier the work load, the steeper 3 i s the increase i n ... heart r a t e " (Astrand and Rodahl, 1970, •:2:&5-'6)z-This g r e a t e r c a r d i o a c c e l e r a t i o n may l e a d to the q u i c k e r attainment of ste a d y - s t a t e . Also, the i n d i v i d u a l ' s s t a t e of t r a i n i n g may modify t h i s c r i t i c a l time. Although there i s l i t t l e e x i s t i n g evidence i n t h i s area, i t i s a t l e a s t t h e o r e t i c a l l y p o s s i b l e t h a t a h i g h l y t r a i n e d c i r c u l a t o r y system may be able to achieve steady-state f a s t e r i n order t o minimize the amount of anaerobic work t h a t must be done d u r i n g the f i r s t few minutes. Purpose The purpose of t h i s study i s t o examine the concept of " c r i t i c a l time" i n the a d m i n i s t r a t i o n of the PWG 170 t e s t , by a n a l y z i n g the heart r a t e responses and t e s t r e s u l t s of subjects undergoing f o u r d i f f e r e n t p r o t o c o l s of t h i s t e s t ; ( i . e . three 3-minute loads, three 4-minute loads, three 5-minute loads, three 6-minute l o a d s ) . S p e c i f i c a l l y , the problems are as f o l l o w s : 1. t o determine the e f f e c t s of these f o u r d i f f e r e n t d u r a t i o n p r o t o c o l s on c r i t i c a l times and PWG 170 scores; 2. t o determine the e f f e c t s of r e l a t i v e i n t e n s i t y of the work loads on c r i t i c a l times; 3. t o determine the e f f e c t s of the su b j e c t ' s s t a t e of t r a i n i n g on c r i t i c a l times and PWG 170 scores. D e l i m i t a t i o n s 1. T h i s study i s d e l i m i t e d t o c o l l e g e males between the ages of 18 and 30. Assumptions and l i m i t a t i o n s 1. The subjects of t h i s study do not represent a random sampling of t h e i r r e s p e c t i v e p o p u l a t i o n s , since they were a l l v o l u n t e e r s . I t i s assumed, however, t h a t t h i s b i a s w i l l not a f f e c t the p h y s i o l o g i c a l v a r i a b l e measured. 2. I t i s assumed t h a t *D' scores, obtained by p r e d i c t i n g the asymptotic heart r a t e and s u b t r a c t i n g i t from the a c t u a l heart r a t e recorded d u r i n g the l a s t minute of a given work load, give a reasonably v a l i d measure of the extent to which st e a d y - s t a t e s , and t h e r e f o r e c r i t i c a l times, have been achieved. Hypotheses 1. The PWG 170 scores f o r untrained s u b j e c t s d e r i v e d from 3 - and 4-minute C-£pl*work l o a d d u r a t i o n p r o t o c o l s are higher than those r e s u l t i n g from 5 -and 6-minute p r o t o c o l s . 2. The PW!G 170 scores f o r t r a i n e d subjects d e r i v e d from the 3 _ m i n u " t e work lo a d d u r a t i o n p r o t o c o l are higher than those r e s u l t i n g from 4 - , 5-» K-:> and 6-minute p r o t o c o l s . 3. There i s a s i g n i f i c a n t d i f f e r e n c e i n 'D1 scores among the d i f f e r e n t p r o t o c o l s , w i t h the 3~ and 4-minute p r o t o c o l s producing g r e a t e r nega-t i v e values than the 5- and 6-minute p r o t o c o l s . These gre a t e r negative values thereby i n d i c a t e a decreased extent t o which s t e a d y - s t a t e , and t h e r e f o r e c r i t i c a l times, have been achieved. 4. There i s a s i g n i f i c a n t d i f f e r e n c e i n *D' scores between t r a i n e d and u n t r a i n e d s u b j e c t s , w i t h the t r a i n e d subjects e x h i b i t i n g s i g n i f i c a n t l y •_ ':• fewer negative values, i n d i c a t i n g a g r e a t e r achievement of s t e a d y - s t a t e . 5. There i s a s i g n i f i c a n t d i f f e r e n c e i n 'D' scores between the 1st and 3rd 5 work loads of the PWG 170 t e s t s , w i t h the Jxd (most intense) work l o a d producing s i g n i f i c a n t l y l e s s negative values, i n d i c a t i n g a g r e a t e r achievement of s t e a d y - s t a t e . D e f i n i t i o n s ? C r i t i c a l time. The minimum time r e q u i r e d f o r e x e r c i s i n g at a submaximal work loa d i n order to achieve a steady-state heart r a t e . Work l o a d i n t e n s i t y ( i n PWG 170 t e s t ) . Work loa d i n t e n s i t y r e f e r s t o the amount of mechanical work being performed per u n i t of time. I n the case of 2. the PWG 170 t e s t , t h i s i s measured i n k i l o p o n d meters per minute, (KPM/Min.). Increases i n r e l a t i v e i n t e n s i t y are s e q u e n t i a l l y ordered i n a l l PWG 170 t e s t p r o t o c o l s ( i . e . the f i r s t work loa d i s the l i g h t e s t , the t h i r d i s the h e a v i e s t ) , so t h a t i n t e n s i t y of e f f o r t i n the PWG 170 t e s t r e f l e c t s a compounded v a r i a b l e i n v o l v i n g not only r e l a t i v e i n t e n s i t y but a l s o the amount of elapsed t e s t time and the heart r a t e responses t o previous l o a d s . S i g n i f i c a n c e of the study The present study may add t o the body of knowledge concerning submaximal p h y s i c a l work c a p a c i t y t e s t s based on steady-state heart r a t e s , s p e c i f i c a l l y the PWG 170. I t i s hoped t h a t i t w i l l add t o the i n f o r m a t i o n r e q u i r e d to e s t a b l i s h more v a l i d p r o t o c o l s f o r t h i s and s i m i l a r t e s t s , and perhaps as w e l l shed some l i g h t on c a r d i o a c c e l e r a t i o n t o s t e a d y - s t a t e , the c r i t i c a l times r e q u i r e d f o r a c h i e v i n g s t e a d y - s t a t e , and the extent to 6 which c r i t i c a l times are a f f e c t e d by work loa d i n t e n s i t y and the su b j e c t ' s s t a t e of t r a i n i n g . CHAPTER I I REVIEW OF-THE LITERATURE L i m i t a t i o n s of r e s t i n g and recovery heart rates'and maximal e x e r c i s e  t e s t s f o r measuring c i r c u l a t o r y f u n c t i o n a l c a p a c i t y "No o b j e c t i v e measurements made on the r e s t i n g i n d i v i d u a l w i l l r e v e a l h i s c a p a c i t y f o r p h y s i c a l work or h i s maximal aerob i c power." (Astrand and Rodahl, 1970, 3^ +9) An examplexwhi'ch supports t h i s statement i s the use of the s o - c a l l e d " r e s t i n g heart r a t e " i n the p r e d i c t i o n of an i n d i v i d u a l ' s c i r c u l a t o r y f i t n e s s or f u n c t i o n a l c a p a c i t y . Even i f a true r e s t i n g heart r a t e i s measured, f r e e from the confounding e f f e c t s of i n c r e a s e d a r o u s a l l e v e l s , temperature r e g u l a t i o n f u n c t i o n s , f a t i g u e , e t c . , accurate p r e d i c t i o n s s t i l l cannot s a f e l y be made. A low r e s t i n g heart r a t e may be an i n d i c a t i o n of a l a r g e stroke volume which has r e s u l t e d from a prolonged p e r i o d of an aerobic form of t r a i n i n g , but i t may a l s o be a symptom of c a r d i o v a s c u l a r disease. For example, the l e f t v e n t r i c u l a r hypertrophy which may r e s u l t from chronic hypertension i s o f t e n a s s o c i a t e d w i t h a bradycardia which could be mistaken f o r a b e n e f i c i a l e f f e c t of a e r o b i c t r a i n i n g . A l s o , w h i l e an i n d i v i d u a l w i l l g e n e r a l l y e x h i b i t decreases i n the r e s t i n g heart r a t e a f t e r adapting to i n c r e a s e d l e v e l s of p h y s i c a l a c t i v i t y , such c o r r e l a t i o n s d i m i n i s h s i g n i f i c a n t l y when comparisons are made between i n d i v i d u a l s (Astrand and Rodahl, 1970, 3^9; Gureton, 19^7, 1951, 1957). On the other hand, maximal t e s t s f o r c i r c u l a t o r y f u n c t i o n a l c a p a c i t y have t h e i r own attendant problems. While the e r r o r of estimate from p r e d i c t i o n equations i s avoided by d i r e c t l y measuring the maximal values of oxygen uptake or work c a p a c i t y during work done t o exhaustion, other p o t e n t i a l sources of e r r o r appear. M o t i v a t i o n i s a d i f f i c u l t f a c t o r t o c o n t r o l , and l a c k of motivation i n the s u b j e c t may prevent true maximal 7 8 values from being a t t a i n e d . Even i n a h i g h l y motivated sub j e c t , the a c t u a l maximal work performed i s a compounded v a r i a b l e which r e f l e c t s much more than j u s t c i r c u l a t o r y f u n c t i o n a l c a p a c i t y . This work c a p a c i t y measure would be a f f e c t e d by f a c t o r s l i k e the mechanical e f f i c i e n c y of the s u b j e c t at the s p e c i f i c p h y s i c a l t a sk i n v o l v e d , the anaerobic energy resources a v a i l a b l e to the s u b j e c t , the l a c t i c a c i d t o l e r a n c e of the s u b j e c t , e t c . , t h e r e f o r e any p r e d i c t i o n of c i r c u l a t o r y f u n c t i o n a l c a p a c i t y based on maximal work c a p a c i t y would have these f a c t o r s as sources of e r r o r . Only the d i r e c t measurement of maximal oxygen uptake from a work t e s t c a r r i e d to or near exhaustion i s f r e e from other than measurement e r r o r , and t h i s procedure's requirements of s o p h i s t i c a t e d equipment, t r a i n e d personnel, g e n e r a l l y large time committment, and the assumption of a c e r t a i n amount of discomfort and even r i s k on the p a r t of the s u b j e c t who must be h i g h l y motivated, make the use of t h i s type of t e s t p r a c t i c a l under only the best of circumstances (see Astrand and Rodahl, 1970, 344-9). Another p o s s i b l e approach i n v o l v e s the measurement of heart r a t e s immediately a f t e r the c e s s a t i o n of e i t h e r maximal or submaximal work (see Astrand and Rodahl, 1970, 350-1, and Guretorn, 194-7, 1951, 1957). Tests i n v o l v i n g recovery heart r a t e s have been i n use f o r some time, but they have some s p e c i f i c d e l i m i t a t i o n s as f a r as t h e i r usefulness i n p r e d i c t i n g c i r c u l a t o r y f u n c t i o n a l c a p a c i t y i s concerned (Astrand and Rodahl, 1970, 350-1; Guretonn, 194-7, 1951, 1957; Johnson et a l . , 194-2; Rhyming, 1953)• Although the c o r r e l a t i o n between the heart r a t e d u r i n g submaximal work and 1 t o i f - minutes a f t e r the work has been r e p o r t e d as h i g h as r=0.96 f o r the same i n d i v i d u a l s (Rhyming, 1953)» i t decreases s u b s t a n t i a l l y when based on a group of subjects (r=0.77, Rhyming, 1953). F a c t o r s such as the amount of anaerobic work performed, the degree of oxygen debt and the amount of blood l a c t a t e accumulated may a f f e c t the recovery heart r a t e and weaken i t s c o r r e l a t i o n w i t h c i r c u l a t o r y f u n c t i o n a l c a p a c i t y . While recovery heart r a t e g e n e r a l l y decreases a f t e r a p e r i o d of aerobic t r a i n i n g , i t gives o n l y a rough i d e a of the c i r c u l a t o r y func-t i o n a l c a p a c i t y when measured at a s i n g l e p o i n t i n time, e s p e c i a l l y i n - • terms of comparing one i n d i v i d u a l t o another. A summary of the p r i n c i p l e s u n d e r l y i n g submaximal c i r c u l a t o r y f u n c t i o n a l  c a p a c i t y and p h y s i c a l work c a p a c i t y t e s t s based on steady-state heart r a t e s P.O. Astrand (1952) s t u d i e d the r e l a t i o n s h i p between steady-state heart r a t e s and oxygen uptakes i n 86 p h y s i c a l education students, and found t h a t i n submaximal and maximal work, heart r a t e s i n c r e a s e d i n two, b a s i c a l l y l i n e a r p a t t e r n s (one f o r males and one f o r females) w i t h i n c r e a s e s i n oxygen uptakes. There was, however, considerable s c a t t e r of the data around these l i n e a r p a t t e r n s , i n d i c a t i n g a l e s s than p e r f e c t c o r r e l a t i o n . This l e d P.O. Astrand and I . Rhyming (195^) "to c o n s t r u c t a nomogram f o r the p r e d i c t i o n of maximal oxygen uptake from submaximal steady-state pulse r a t e s ranging from 120 t o 170 beats per minute. Rates above 170 and below 120 were found t o no longer adequately abide by a l i n e a r r e l a t i o n s h i p . This nomogram was subsequently modified by I . Astrand ( i 9 6 0 ), who found t h a t persons over 25 years of age c o n s i s t e n t l y had t h e i r maximal oxygen uptakes overestimated. She e x p l a i n e d t h i s on the b a s i s of the observed r e d u c t i o n i n maximal pulse r a t e s w i t h age, and a c c o r d i n g l y i n t r o -duced an age c o r r e c t i o n f a c t o r i n t o the nomogram, which allowed more accurate p r e d i c t i o n s f o r people i n v a r i o u s age groups or w i t h , i f known, various maximal heart r a t e s . The standard e r r o r of t h i s method of 10 p r e d i c t i n g maximal oxygen uptake from submaximal steady-state heart r a t e s i s r e p o r t e d t o be 10% i n r e l a t i v e l y w e l l - t r a i n e d i n d i v i d u a l s of the same age group. I t r i s e s t o 15% i n moderately t r a i n e d i n d i v i d u a l s of d i f f e r e n t age groups, however, even when the age f a c t o r f o r the c o r r e c -t i o n of maximal heart r a t e s i s used ( I . Astrand, i 9 6 0 ). Astrand and Rodahl (1970, 355) suggest t h a t s e v e r a l t e s t s should be performed at d i f f e r e n t t e s t loads, and the mean f i g u r e s c a l c u l a t e d according t o the nomogram. The v a l i d i t y of t h i s nomogram has been t e s t e d i n a number of s t u d i e s , w i t h the p r e d i c t i o n s from the nomogram sometimes c o r r e l a t i n g w e l l w i t h measured maximal oxygen uptakes ( G l a s s f o r d et a l . , 19^5; T e r a s l i n n a et a l . , I966), and at other times underestimating the a c t u a l maximal oxygen uptakes ((iGhase et a l , , I966; Rowell et a l . , 1964; von Dobeln et a l . , 1967) . I t should be noted t h a t while t h i s nomogram was p r i m a r i l y used i n b i c y c l e ergometer s t u d i e s , i t has a l s o been adapted f o r use w i t h step t e s t s and t r e a d m i l l running t e s t s (E??jAsjtrand951960; M a r i t z et a l . , I96I; Rhyming, 1953; Wyndham e t a l . , 1966). With some other submaximal t e s t s , the steady-state heart r a t e s are used t o p r e d i c t c i r c u l a t o r y f u n c t i o n a l c a p a c i t y as d e f i n e d i n d i r e c t l y ; l i e . as i n d i c a t e d by p h y s i c a l work c a p a c i t y (PWC). Although Brown (1974) has pointed out the t e r m i n o l o g i c a l i n c o n s i s -t e n c i e s t h a t have p r e v a i l e d i n the past w i t h i n d i s c r i m i n a t e use of the term " p h y s i c a l work c a p a c i t y " , the c o n s t r u c t so l a b e l l e d u s u a l l y i n v o l v e s ( w i t h submaximal t e s t s ) e i t h e r the p r e d i c t i o n of the maximal amount of work ( i . e . power output) t h a t can be s u s t a i n e d over a given p e r i o d of time, or,more o f t e n , the p r e d i c t i o n of the power output t h a t can be 11 maintained w i t h a s p e c i f i c p h y s i o l o g i c a l response (e.g. the p r e d i c t e d p h y s i c a l work c a p a c i t y a t a heart r a t e of 170 beats per minute - the PWG 170) ( S j o s t r a n d , 19^7; Wahlund, 1948). The c a l c u l a t e d PWG 170 ( o r 150, 180, etc.) i s r e l a t e d t o the maximal stroke volume of the heart (Astrand and Rodahl, 1970, 358). Adequate t r a i n i n g programs u s u a l l y r e s u l t i n an inc r e a s e d PWG 170 score, ( i . e . an increased amount of work t h a t can be performed at a heart r a t e of 170 beats per minute). This i s p r i m a r i l y a r e f l e c t i o n of an increased s t r o k e volume a l l o w i n g more work t o be accomplished at a given heart r a t e . I t cannot be s a i d , however, to be by i t s e l f a p r e c i s e p r e d i c t o r of c i r c u l a t o r y f u n c t i o n a l c a p a c i t y unless, once again, a c o r r e c t i o n f a c t o r i s introduced t o account f o r d i f f e r e n c e s i n age. For example, a 20 y e a r - o l d male may have a p r e d i c t e d PWG 170 score of 1000 KPM/Min.. His maximal heart r a t e i s l i k e l y t o be above 200 beats per minute, however, suggesting t h a t h i s maximal p h y s i c a l work c a p a c i t y i s l i k e l y t o be w e l l above 1000 KPM/Min.. On the other hand, a 70 y e a r - o l d male w i t h an i d e n t i c a l PWG 170 score ( p r e d i c t e d as usual from submaximal steady-state heart r a t e s ) may not have a r e a l maximal p h y s i c a l work c a p a c i t y even as high as 1000 KPM/Min., sin c e h i s maximal heart r a t e may be as low as 150 beats or l e s s per minute (see Astrand and Rodahl, 1970, 358; and I . Astrand, i960) . Further, some studies have i n d i c a t e d a low c o r r e l a t i o n between the oxygen uptake or work loa d achieved at a s e t heart r a t e (e.g. 170) and the measured maximal oxygen uptake ( S t r a n d e l l , 1964). This may p a r t l y be due, however, t o the p o s s i b i l i t y t h a t maximal oxygen uptake i s i t s e l f an imprecise d e s c r i p t o r of c i r c u l a t o r y f u n c t i o n a l c a p a c i t y , i f t h i s c a p a c i t y i s d e f i n e d as the a b i l i t y to c i r c u l a t e (and t h e r e f o r e t r a n s p o r t ) oxygen, 12 r a t h e r than i n c l u d i n g the a b i l i t y of the c e l l s t o e x t r a c t and use the a v a i l a b l e oxygen. (For a d e t a i l e d a n a l y s i s of t h i s problem see Rowe11, 1974, 82)) I n f a c t , a l l o o f the submaximal approaches t o t e s t i n g based on steady-state heart r a t e s can at best be s a i d t o give only an approximation of c i r c u l a t o r y f u n c t i o n a l c a p a c i t y , since they are dependant on the o v e r a l l assumption t h a t a l i n e a r r e l a t i o n s h i p e x i s t s between steady-state heart r a t e s and mechanical work loads, thus a l l o w i n g p r e d i c t i o n s t o maximal values. Although t h i s l i n e a r r e l a t i o n s h i p ( i . e . a h i g h c o r r e l a t i o n ) does i n f a c t e x i s t (see Astrand and Rodahl, 1970, 352), non-random e r r o r s of estimate ( i . e . meaningful d e v i a t i o n s from t h i s l i n e a r i t y ) may be due t o the f a c t t h a t t h i s o v e r a l l c o r r e l a t i v e assumption i s s t a t i s t i c a l l y & dependent upon a chain of p h y s i o l o g i c a l assumptions, any or a l l of which may be subjected i n c e r t a i n circumstances t o f a c t o r s which w i l l i ncrease the variance around the l i n e a r r e l a t i o n s h i p . This chain of p h y s i o l o g i c a l assumptions and the f a c t o r s which can modify them are presented i n TABLE I I - l , and are discussed below. 13 TABLE -II -1 CHAIN OF ASSUMPTIONS (CORRELATION BETWEEN WORK LOADS AND HEART RATES) ASSUMPTIONS OF LINEARITY FACTORS POTENTIALLY CAUSING VARIANCE Mechanical work ( i . e . KPM/Min.) versus > Mechanical E f f i c i e n c y P h y s i o l o g i c a l work (i.e.KCAL. demand) P h y s i o l o g i c a l work (i.e.KCAL. demand) versus ^ Aerobic vs. anaerobic work Oxygen uptake ( i . e . VO2) Oxygen uptake ( i . e . VO2) versus ^ A-V d i f f e r e n c e Cardiac output ( i . e . H.R. xS.V.) Cardiac output ( i . e . H . R . x S . V . ) versus ^ Stroke volume L-^Heart r a t e ( i . e . B.P.M.) 14. Mechanical work versus p h y s i o l o g i c a l work I t i s o f t e n assumed i n submaximal c i r c u l a t o r y f u n c t i o n t e s t s t h a t e x e r c i s i n g a t a given mechanical work loa d w i l l allow a p r e c i s e p r e d i c t i o n of the p h y s i o l o g i c a l work ( i . e . KGAL. demand) r e q u i r e d t o perform i t , due t o the l i n e a r r e l a t i o n s h i p between mechanical work loads and energy outputs (see Astrand and Rodahl, 1970, 364). However, d e v i a t i o n s from t h i s l i n e a r r e l a t i o n s h i p may be present due t o d i f f e r e n c e s i n mechanical e f f i c i e n c i e s (MS1E.) between subjects or t e s t a d m i n i s t r a t i o n s . Mechanical e f f i c i e n c y ranges from 0% i n i s o m e t r i c s t o about 20-25% i n b i c y c l e ergometer e x e r c i s i n g (Astrand and Rodahl, 1970, 7-1), and even w i t h i n any one a c t i v i t y v a r i a t i o n s i n mechanical e f f i c i e n c y can occur. For example, b i c y c l e ergometer s t u d i e s have shown t h a t higher mechanical e f f i c i e n c i e s have been found a t p e d a l l i n g frequencies of 40-50 RPM as opposed t o 60-70 RPM a t the same power output ( B a n n i s t e r and Jackson, 1967; Astrand and Rodahl, 1970, 363} M i c h i e l l i and S t r i c e v i c , 1977; Pandolf and IS^le, 1973). Astrand and Rodahl (1970, 353) r e p o r t t h a t the mechanical e f f i c i e n c y on a b i c y c l e ergometer may vary by + 6%. I . Astrand (i960) has shown t h a t there i s no age d i f f e r e n c e i n mechanical e f f i c i e n c y i n subjects working a t submaximal work loads on the b i c y c l e ergometer. She s t a t e s , however, t h a t women e x h i b i t a somewhat higher mechanical e f f i c i e n c y (lower oxygen uptake) at a given work l o a d compared t o men. Also , any given e x e r c i s e w i l l produce both i n t r a - and i n t e r - i n d i v i d u a l d i f f e r e n c e s i n mechanical e f f i e n c y . I n general, increased muscle temperature w i l l i n c r e a s e M.E., as w i l l i ncreases i n s k i l l l e v e l s (see Passmore and Durri e n , 1955), while increases i n body weight w i l l reduce M.E. i n non-weight-supported a c t i v i t i e s . ( B i c y c l i n g i s weight-supported, and the r e f o r e 15 weight does not appear t o provide much variance i n M.E. (Astrand and Rodahl, 1970, 362.) M.E. may a l s o be a f f e c t e d by genetic and morphologic f a c t o r s such as the l e n g t h and the r e l a t i v e weights of body segments, the leverage provided by muscle lengths and tendon i n s e r t i o n p o i n t s , e t c . . . . T r a i n a b l e f a c t o r s i n c r e a s i n g M.E. might i n c l u d e not only improvements i n s k i l l but a l s o increases i n s t r e n g t h , as i n c r e a s e d muscle f i b r e c o n t r a c -t i l i t y may reduce the number of f i b r e s r e q u i r e d (and t h e r e f o r e the oxygen required) to perform a given work load. An i n d i v i d u a l w i t h a. h i g h M.E. f o r a given work task w i l l e x h i b i t a r e l a t i v e l y l a r g e d e v i a t i o n from the l i n e a r r e l a t i o n s h i p between mechanical work and oxygen demand, w i t h the oxygen demand being l e s s than t h a t p r e d i c t e d f o r a given work l o a d . Of course the opposite w i l l be true f o r an i n d i v i d u a l w i t h a low M.E. f o r a given work task. P h y s i o l o g i c a l work versus oxygen uptake "With a work load ( l e g work) t h a t demands an oxygen uptake higher than 50 percent of the i n d i v i d u a l ' s maximal c a p a c i t y and which i s performed f o r some minutes, l a c t i c a c i d ( l a c t a t e ) appears i n the blood i n a concentration t h a t can be measured even i n the a r t e r i a l blood. The heavier the work l o a d , the more important i s the anaerobic energy c o n t r i b u t i o n . " /. , , , n N , , O D ^ N (Astrand and Rodahl, 1970, 283) Since the l i t e r a t u r e i n d i c a t e s t h a t t r a i n i n g r e s u l t s i n decreases i n blood l a c t a t e s a t given w o r k l o a d s ( C r e s c i t e l l i and T a y l o r , 1944; D i l l e t a l . , 1930; Robinson and Harmon, 1941; Withers, 1977), one might expect t h a t higher oxygen uptakes might be found among t r a i n e d a t h l e t e s at given submaximal work loads as compared w i t h the untrained. However, provided there are no d i f f e r e n c e s i n mechanical e f f i c i e n c y , the oxygen consumption i n the t r a i n e d and untrained s t a t e s at given sub-16 maximal work loads i s i d e n t i c a l (Clausen e t a l . , 1969; C r e s c i t e l l i and Tay l o r , 1 9 4 4 ;'Saltin e t a l . , 1968; S a l t i n e t a l . , I969). I t has been shown q u i t e c o n s i s t e n t l y t h a t increased submaximal p h y s i o l o g i c a l work (expressed i n .KCAL. demand) w i l l r e s u l t i n q u i t e p r e d i c t a b l e increases i n oxygen uptake (Astrand and Rodahl, 1970, 280 - 6 ) . The assumption of l i n e a r i t y between these two v a r i a b l e s seems t o be the st r o n g e s t l i n k i n the chain of assumptions u n d e r l y i n g the l i n e a r r e l a t i o n s h i p between mechanical work and asso c i a t e d heart r a t e s . Oxygen uptake versus c a r d i a c output Oxygen uptake i s the product of car d i a c output and the mean a r t e r i o -venous 0 2 d i f f e r e n c e (Rowell, 1974). V 0 2 ^ X i . / m i n ^ = CO Cl./minC) X A-V 0 2 DIFF. ( pi./}1 ;•) Therefore, increases i n VO2 could be accounted f o r by incre a s e s i n e i t h e r or both c a r d i a c output and arterio-venous 0 2 d i f f e r e n c e . I n f a c t , i t has been demonstrated t h a t t r a i n i n g i s accompanied by a decreased blood flow t o the a c t i v e muscles d u r i n g submaximal work,bbut t h a t t h i s i s compensated f o r by an augmented A-V Og d i f f e r e n c e (Clausen and Trap-Jensen, I968; Varnauskas e t a l . , 1970). Thus the assumption of a p e r f e c t c o r r e l a t i o n between oxygen uptake and ca r d i a c output cannot be supported (Clausen, I969, 305), e s p e c i a l l y i f a range from r e s t i n g values to maximal ones i s considered (Astrand and Rodahl, 1970, 157-60). This r e l a t i o n s h i p provides another p o t e n t i a l source of variance accounting f o r any e r r o r s of estimate i n p r e d i c t i n g mechanical work loads from heart r a t e s , and v i c e - v e r s a . Cardiac output versus heart r a t e The f i n a l l i n k i n t h i s chain i s the one between c a r d i a c output and heart r a t e . Cardiac output i s the product of heart r a t e and stroke volume. 17 C0('l./min.) =.-• HR (b../mih.)X SV ,(l,/beat> Any increase i n c a r d i a c output may "be caused by an inc r e a s e i n e i t h e r heart r a t e or stroke volume, or both. Rowell (1974), however, r e p o r t s t h a t , i n general, c a r d i a c output and heart r a t e s r i s e w i t h i n c r e a s i n g oxygen consump-t i o n , whereas stroke volume reaches a near-maximal value a t r e l a t i v e l y low l e v e l s of oxygen uptake and remains e s s e n t i a l l y constant up to maximum VCv,. Therefore the r e l a t i o n s h i p between c a r d i a c output and heart r a t e remains q u i t e l i n e a r above low l e v e l s , and c o n s t i t u t e s a reasonably s t r o n g l i n k i n the chain of assumptions un d e r l y i n g the r e l a t i o n s h i p between heart r a t e and mechanical work. I n summary, the l i n e a r r e l a t i o n s h i p g e n e r a l l y observed between heart r a t e and mechanical work forms the b a s i s f o r the design of submaximal c i r c u l a t o r y f u n c t i o n and p h y s i c a l work c a p a c i t y t e s t s . I t must be remembered, however, t h a t t h i s s t a t i s t i c a l l y v a l i d and p h y s i o l o g i c a l l y sound g e n e r a l i t y i s s u b j e c t t o the assumptions l i s t e d above, and t h a t d e v i a t i o n s w i t h i n these assumptions provide a p o t e n t i a l source of variance from t h i s l i n e a r i t y , causing e r r o r s of estimate i n p r e d i c t i n g c i r c u l a t o r y f u n c t i o n and/or p h y s i c a l work c a p a c i t y . The PWG 170 t e s t Since being introduced by S j o s t r a n d (1947) and Wahlund (1948), the PWC 170 t e s t has been w i d e l y used as a method of p r e d i c t i n g c i r c u l a t o r y f u n c t i o n a l c a p a c i t y . At l e a s t 36 s t u d i e s have been reporte d i n the l i t e r a -ture as having used t h i s t e s t (Watson and 0'Donovan, 1976), and a la r g e number of these have had c h i l d r e n as s u b j e c t s . Many i n t e r n a t i o n a l comparisons have a l s o been made (see Shephard, 1971 and Larson, 1974 f o r r e v i e w s ) . 18 There are two p h y s i o l o g i c a l p r i n c i p l e s u n d e r l y i n g the PWC 170 t e s t . F i r s t , t h a t there i s a p o s i t i v e l i n e a r r e l a t i o n s h i p between heart r a t e and submaximal work loads ( s u b j e c t t o the assumptions described i n the second s e c t i o n of t h i s chapter). This l i n e a r r e l a t i o n s h i p allows a p r e d i c t i o n of the work load r e q u i r e d t o produce a heart r a t e of 170 beats per minute, based on heart r a t e s recorded a t lower, submaximal work loads. The t e s t thus minimizes the problems re g a r d i n g motivation and r i s k , mentioned p r e v i o u s l y , by not r e q u i r i n g the su b j e c t t o work a t an i n t e n s i t y t h a t would produce a maximal heart r a t e , nor one even as high as 170. The second p r i n c i p l e i s t h a t an increase i n c i r c u l a t o r y f u n c t i o n a l c a p a c i t y (through aerobic t r a i n i n g ) w i l l r e s u l t i n a decreased heart r a t e a t any given work load, due p r i m a r i l y t o an Increase i n stroke volume (Astrand, 1970, 358; Withers, 1977). This w i l l r e s u l t i n grea t e r work loads being r e q u i r e d t o produce the same heart r a t e (e.g. 170 beats per minute). The slope of the r e g r e s s i o n l i n e between heart r a t e and work loa d i s thus d i s p l a c e d , and/or has i t s angle decreased, without the l i n e a r r e l a t i o n s h i p being destroyed. A number of researchers have made s t u d i e s on the f a c t o r s which i n f l u e n c e the PWC 170 score. I t i s now w e l l e s t a b l i s h e d t h a t p h y s i c a l working c a p a c i t y (PWC I70) g e n e r a l l y increases w i t h agecduring adolescence (Bengtsson, 1956; Watson and O'Donovan, 19?6) and appears t o reach i t s peak at about 25 years of age ( S e l i g e r , 1978). However, the changes i n PWC w i t h age g e n e r a l l y p a r a l l e l those i n body s i z e (Bengtsson, 1956; Knutten, I967; Matsui e t a l . , 1972). The e f f e c t of leanness versus fatness on PWC has a l s o been researched. These s t u d i e s i n d i c a t e t h a t PWC i s more h i g h l y r e l a t e d t o f a t f r e e body weight than t o t o t a l body weight, but i t i s not s i g n i f i c a n t l y r e l a t e d t o • 1 9 percentage of body f a t ( ( B u s k i r k and T a y l o r , 1 9 5 7 ; Davies e t a l . , 1 9 7 2 ) . Considerable c a u t i o n i s necessary when i n t e r p r e t i n g the r e s u l t s of t e s t s of p h y s i c a l working c a p a c i t y on people of d i f f e r i n g ages. Although the PWC 170 t e s t appears t o be a r e l i a b l e measure of aerobic c a p a c i t y , i f administered by experienced personnel (Howell, I 9 6 8 ; Wahlund, 1 9 4 8 ; Watson and 0 'Donovan, 1 9 7 6 ), the i n t e r p r e t a t i o n of t h a t measure must take i n t o account the f a c t t h a t maximal heart r a t e d e c l i n e s w i t h i n c r e a s i n g age. A PWC 170 score may represent a work lo a d t h a t would only be m i l d l y strenuous t o a 2 0 year o l d male whose maximal heart r a t e may be w e l l over 2 0 0 , whereas the same t e s t score might represent an unattainable work load f o r a 70 year o l d male whose maximal heart r a t e may be l e s s than 1 5 0 . There are some s t u d i e s which have suggested t h a t there i s only a low c o r r e l a t i o n between the PWC 170 and the measured maximal oxygen uptake, ca r d i a c output, heart s i z e , and blood volume i n i n d i v i d u a l s from twenty t o seventy years of age (Astrand and Rodahl, 1 9 7 0 , 3 5 8 ; S t r a n d e l l , 1 9 6 4 ) . On the other hand, a number of researchers have continued t o f i n d reasonably high c o r r e l a t i o n s between PWC 170 scores and maximal oxygen uptake. DeV;ries and K l a f s ( 1 9 6 5 ) r e p o r t e d a v a l i d i t y c o e f f i c i e n t of 0 . 8 7 7 . Knutten ( 1 9 6 7 ) 0 . 7 5 , Holmgren ( 1 9 6 7 ) 0 . 9 3 , and Burke ( 1 9 7 6 ) O . 5 8 . Withers ( 1 9 7 7 ) r e p o r t e d very low c o r r e l a t i o n s f o r scores d e r i v e d from s e v e r a l d i f f e r e n t p r o t o c o l s of the t e s t i n r e l a t i o n to max. V0 2 ( - 0 . 0 8 4 , 0.040, - 0.142), but he admitted t h a t these low c o r r e l a t i o n s were l i k e l y due t o the homogeneity of h i s data. Two c o r r e l a t i o n s seem t o have been g e n e r a l l y drawn w i t h r e s p e c t t o the v a l i d i t y of t h i s t e s t . F i r s t , t h a t comparisons among people of w i d e l y d i f f e r e n t ages must be c o r r e c t e d f o r age before t e s t v a l i d i t y can be claimed, and before meaningful i n t e r p r e t a t i o n s can be made. Second, t h a t the grea t e s t use the PWC 170 apparently has i s i n monitoring©. 20 the changes i n an i n d i v i d u a l over a p e r i o d of time. I n such cases, the i n d i v i d u a l acts as h i s own c o n t r o l . E f f e c t s of work loa d d u r a t i o n S j o s t r a n d (194-7) and Wahlund (194-8) f i r s t i n t r o d u c e d the PWG 170 using three p r o g r e s s i v e l y i n c r e a s i n g work loads designed t o produce steady-s t a t e heart r a t e s f a l l i n g w i t h i n the i n t e r v a l s 115-130, 14-0-150, and 160-170. Each work loa d was maintained f o r 6 minutes, and provided the d i f f e r e n c e between the 5th and 6th minute heart r a t e s was l e s s than 5 beats per minute, steady-state was assumed t o have been achieved and the average of these two heart r a t e s was recorded f o r that p a r t i c u l a r work load . I f the d i f f e r e n c e was greater than 5» more time was given a t t h a t work loa d u n t i l s teady-state was achieved (see Wahlund, 194-8). Subsequent i n v e s t i g a t o r s have often d e v i a t e d from the above p r o t o c o l . Adams et a l . (1961), Gumming and Danzinger (1963), and Dearies (1965), used a p r o t o c o l which i n c l u d e d only two 6-minute work loads . I n one Canadian study Alderman (1969) used three 4-minute work loads. I n a l l the s t u d i e s encountered by t h i s author the p r o t o c o l s i n v o l v e d between 2 and 4 work loads, w i t h e i t h e r 3~> 5- ° r 6-minute d u r a t i o n s . I t i s obvious t h a t marked changes i n the p r o t o c o l used f o r a d m i n i s t e r i n g t h i s t e s t have the p o t e n t i a l f o r d e s t r o y i n g i t s v a l i d i t y , s i n c e a funda-mental assumption un d e r l y i n g the t e s t i s t h a t the heart rates,which are t o be p l o t t e d against the work loads, must represent r e l a t i v e steady-state (Andersen, 1971, 77} Doroschuk, 1966; Franz and Me l l e r o w i c z , 1977). I f a short d u r a t i o n p r o t o c o l (e.g. 3 minutes a t each work load) does not allow enough time f o r t h i s r e l a t i v e s teady-state t o be achieved, the heart r a t e s recorded f o r each work l o a d may be l e s s than what would be recorded i n 21 s t e a d y - s t a t e . T h i s could r e s u l t i n an overestimate of the PWC 170 score. I f there were a d i f f e r e n t i a l e f f e c t among the loads there could he e i t h e r an overestimation or an underestimation of the tru e value. For example, i f s teady-state was not achieved i n the f i r s t work load, but was i n the t h i r d , the slope of the r e g r e s s i o n l i n e of the PWG on heart r a t e would be l e s s steep, even though i t would s t i l l go through the same f i n a l p o i n t on the 3^ cL work l o a d . This would underestimate the tr u e value. Watson and O'Donovan i n I r e l a n d (1976) r e p o r t t h a t reducing the work periods from 6 t o 5 minutes d u r a t i o n had no s i g n i f i c a n t e f f e c t , but th a t a r e d u c t i o n t o 4 minutes r e s u l t e d i n a 4 percent e l e v a t i o n ^ o f scores. This suggests t h a t the f o u r t h minute measurements may have been^premature f o r the attainment of steady-state values, at l e a s t f o r some of the subjects i n v o l v e d . Franz and Mellerowicz (1977), i n an attempt t o reduce the time-consuming p r o t o c o l of three 6-minute work loads, compared PWG 170 scores between a p r o t o c o l i n v o l v i n g 50 watt increases every 6 minutes and one using 25 watt increases every 2 minutes. The d i f f e r e n c e between these two forms was not s i g n i f i c a n t . Withers e t a l . (1977) compared scores u s i n g three d i f f e r e n t formats: two 6-minute work loads, three 4-minute work loads, and f o u r J-minute work loads (the t o t a l t e s t time remaining the same). Although they d i d not f i n d any s i g n i f i c a n t d i f f e r e n c e s a t the .05 l e v e l , the group mean scores of the d i f f e r e n t p r o t o c o l s suggested a trend toward higher scores f o r the s h o r t e r work p e r i o d s . (They a l s o recommended against having only two work loads, s i n c e having only two heart r a t e p o i n t s to p l o t leaves the r e g r e s s i o n l i n e more open to d i s t o r t i o n from even s m a l l e r r o r v a r i a n c e s . Watson and O'Donovan (1976 (2)) r e p o r t a decreased t e s t - r e t e s t r e l i a b i l i t y from 22 u s i n g only two work loads.) M o c e l l i n et a l . (1971) and Withers e t a l . (1977) r e p o r t t h a t l o c a l muscle f a t i g u e i n the legs may be a problem w i t h a 6-minute p r o t o c o l , e s p e c i a l l y i f the subjects are c h i l d r e n or u n f i t a d u l t s . Weiner and L a u r i e (1969) s t a t e t h a t i n submaximal t e s t s three 4-minute work loads may be p r e f e r a b l e t o f o u r 3-minute loadings, suggesting i m p l i c i t l y t h a t there i s a minimum c r i t i c a l time r e q u i r e d f o r working at each load, t h a t time being dependent upon the r a t e of c a r d i o a c c e l e r a t i o n t o steady-s t a t e . I t i s worthwhile mentioning that none of the above authors e x p l i c i t l y s t a t e s the concept of a minimum c r i t i c a l time; they appear concerned only w i t h whether or not i n c r e a s i n g scores tending t o r e s u l t from s h o r t e r , more convenient work loa d durations have any s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s fromtthe accepted 6-minute p r o t o c o l . Although t h i s undoubtedly r e f l e c t s the major concern t h a t researchers have w i t h group means, i t overlooks the problems t h a t may occur when an i n d i v i d u a l undergoes s e r i a l t e s t i n g over a p e r i o d of time, under d i f f e r e n t p r o t o c o l s . Variance r e s u l t i n g from changes i n t e s t p r o t o c o l may d i s g u i s e the changes expected from a t r a i n i n g program, f o r example. According t o Andersen e t a l . (1971) the o b j e c t i v e of t h i s type of submaximal e x e r c i s e t e s t should be to produce "4- evenly spaced pulse readirigs,gover the range kO-80% of aerobic power" (p. 55) and- the work loads should each be of "at l e a s t 4 minutes" d u r a t i o n (p. 54). No mention was made, however, of the nature of the j u s t i f i c a t i o n f o r choosing 4 minutes as the minimum c r i t i c a l time f o r each work l o a d . Another area of research, d e l v i n g i n t o the t r a n s i e n t responses of heart r a t e t o work loa d changes, a l s o f a i l s to provide any d e f i n i t e answers. Broman and Wigertz (1971) analyzed the t r a n s i e n t dynamics of 23 heart r a t e i n response t o 650 KPM/Min. step changes i n submaximal work loads i n s i x male a t h l e t e s i n t t h e supine p o s i t i o n . By applying mathematical parameter i d e n t i f i c a t i o n , they observed t h a t the heart r a t e responses r e q u i r e d second-order models, w i t h the two time constants ranging from 9.0 to 11.7 seconds and from 1.8 to 3*7 minutes, and with'the share of the "slower component" i n c r e a s i n g w i t h the i n t e n s i t y of the i n i t i a l work l e v e l . The f o l l o w i n g t a b l e summarizes the percentage of the 6th minute " s t a b l e - s t a t e " heart r a t e means a t t a i n e d at 0.5» 1.0, and 2.0 minutes a f t e r the onset of step changes i n work loads from d i f f e r e n t work l e v e l s . TABLE I I - 2 MEAN TRANSIENT HEART RATE RESPONSES (PERCENTAGE OF 6TH MINUTE "STABLE-STATE" VALUES) STEP CHANGE IN WORK LOAD ( i n KPM/Min.) 0-0$650 300-950 65O-I3OO PERCENTAGE OF "STABLE-STATE" HEART RATE 0.5 MIN. 797° 59% 1.0 MIN. 85% 80% 72% 2.0 MIN. 89% m% (modified from Broman and Wigerts, 1971) I t i s c l e a r t h a t , at l e a s t w i t h the s i x male a t h l e t e s used i n t h i s study, over &(J% of the heart r a t e increases occurred w i t h i n the f i r s t two minutes a f t e r the work l o a d i n c r e a s e . However, the "slow component" increase c a r r i e d on g r a d u a l l y over the next 4 minutes, making i t d i f f i c u l t t o e s t a b l i s h when " s t a b l e - s t a t e " , on the average, occurred. A l s o , the responses of nonathletes may be q u i t e d i s s i m i l a r t o those r e p o r t e d here. 24-F u j i h a r a e t a l . (1973) found some sub j e c t s whose heart r a t e c o n t r o l systems were slower t o respond than those of others. They s t a t e t h a t i n three of t h e i r s u bjects they could not det e c t a c o n t i n u i n g l a t e r i s e i n heart r a t e a f t e r about 2 minutes, w h i l e i n the other two subjects suchaa component may have been present. No attempt was made by them to elaborate on a p o t e n t i a l cause of t h i s , or to attempt t o i d e n t i f y the subjects according to p o t e n t i a l mediating f a c t o r s . This does suggest;?,however, the analyses f o r s i g n i f i c a n t d i f f e r e n c e s i n PWG 170 scores d e r i v e d from different© d u r a t i o n p r o t o c o l s should perhaps attempt to take i n t o account d i f f e r e n c e s i n the types of sub j e c t s being t e s t e d , ( i . e . q u i c k responders versus slow responders). E f f e c t s of work l o a d i n t e n s i t y I t may w e l l be t h a t the c r i t i c a l time r e q u i r e d t o achieve steady-s t a t e decreases f o r the heavier work loads, s i n c e Astrand and Rodahl (1970) s t a t e t h a t "the heavier the work load, the steeper i s the increase i n ... heart r a t e " (p. 285-6). This g r e a t e r c a r d i o a c c e l e r a t i o n may be an advantage, " f o r the sooner the aerobic processes can come i n t o f u l l swing, the l e s s would be the demand on the anaerobic processes, and l e s s l a c t i c a c i d would accumulate" (p. 286). However, there i s disagreement i n -"the":- l i t e r a t u r e as t o t h i s e f f e c t . G e r e t e l l i e t a l . (1966) found the time constants f o r the changes i n c a r d i a c output to be independent of the e x e r c i s e i n t e n s i t y . Jones e t a l . (1970) and Broman and Wigertz (1971) found t h a t the r a t e of increase i n heart r a t e became slower when heavier work loads were i n v o l v e d . ' I t remains t o be seen what e f f e c t the. step i n c r e a s e s i n work l o a d during the PWG 170 have on c r i t i c a l time. I n t h i s regard, the problem i s 25 compounded i n t h a t increases i n r e l a t i v e i n t e n s i t y are s e q u e n t i a l l y ordered i n a l l t e s t p r o t o c o l s ( i . e . the f i r s t i s the l i g h t e s t , the t h i r d i s the h e a v i e s t ) , so t h a t the heart r a t e response may r e f l e c t not only the increased work loa d i n t e n s i t y , but a l s o the i n c r e a s e d amount of elapsed t e s t time, and the heart r a t e responses t o previous loads. E f f e c t s of s t a t e of t r a i n i n g Although there i s l i t t l e e x i s t i n g evidence i n t h i s area, i t i s at l e a s t t h e o r e t i c a l l y p o s s i b l e t h a t a h i g h l y t r a i n e d c i r c u l a t o r y system may attempt to achieve steady-state and i t s a s s o c i a t e d c a r d i a c output as q u i c k l y as p o s s i b l e , i n order t o minimize the amount of anaerobic work that must be done du r i n g the f i r s t few minutes. The heart has i t s own pace-maker, l o c a t e d i n the s i n o - a r t e r i a l (S-A) node, and from here i t i n i t i a t e s a r a t e of about 70 impulses per minute i f i t i s l e f t undisturbed by e x t e r n a l i n f l u e n c e s (Astrand and Rodahl, 1970, IkO). This i s termed the i n t r i n s i c heart r a t e (IHR). Both sympathetic and parasympathetic nerve impulses, through t h e i r r e s p e c t i v e neurotransmitter substances, can modify t h i s i n t r i n s i c r a t e . Many parasympathetic nerve f i b e r s from the vagus nerve t e r m i n a t e s i n the r e g i o n of the pace-maker i n the S-A node, and when s t i m u l a t e d they d e l i v e r a c e t y l c h o l i n e , which causes an i n h i b i t i o n and r e d u c t i o n of the heart r a t e ( b r a d y c a r d i a ) . The sympa-t h e t i c e f f e r e n t f i b e r s from the p a r a v e r t e b r a l g a n g l i a j o i n the c a r d i a c sympathetic nerves, which end i n a densely packed network w i t h i n the myocardium. These sympathetic nerves have two simultaneous e f f e c t s upon the heart. F i r s t , they cause an increase i n the heart r a t e ( t a c h y c a r d i a ) . Second, they cause an increase i n the c o n t r a c t i l e f o r c e of the c a r d i a c muscle f i b e r s , r e s u l t i n g i n an i n c r e a s e d . v e n t r i c u l a r d e l i v e r y . (The vagus 26 does not seem t o have an e f f e c t on heart muscle c o n t r a c t i l i t y ; ) . , * (Astrand and Rodahl, 1970, 121). I n a d d i t i o n t o these n e u r a l c o n t r o l s ( c a l l e d " f a s t component" c o n t r o l s by Broman and Wigertz (1971)) are humoral c o n t r o l s ("slow component") which l i k e l y account f o r the b i - p h a s i c c a r d i o a c c e l e r a t i o n s i n e x e r c i s e , r e p o r t e d above. The changes i n heart f u n c t i o n and c i r c u l a t i o n are i n i t i a t e d from higher b r a i n centers (probably the c e r e b r a l c o r t e x and diencephalon) perhaps even before e x e r c i s e begins (see Rushmer, 1965). Through a r e c i p -r o c a l i n n e r v a t i o n there i s a simultaneous increase i n the sympathetic a c t i v i t y and a decrease i n the parasympathetic impulses t o the heart. The combination of reduced vagal i n f l u e n c e and incr e a s e d sympathetic s t i m u l a t i o n r e s u l t s i n an immediate increase i n the heart r a t e (Scher e t a l . , 1972). A decrease i n the r e s t i n g heart r a t e i s one of the c h a r a c t e r i s t i c changes a s s o c i a t e d w i t h aerobic t r a i n i n g (Bevegard e t a l , 1963; Hanson and Tabakin, I965)• Although the p r e c i s e mechanisms i n v o l v e d are s t i l l n n o t understood, s e v e r a l p o s s i b i l i t i e s have been proposed. I t has g e n e r a l l y been suggested t h a t an inc r e a s e i n t o n i c c a r d i a c vagal a c t i v i t y i n the t r a i n e d s u b j e c t may be the prime f a c t o r (Raab e t a l , , i960; Steinhaus, 1933)-S e v e r a l i n t r a c a r d i a c mechanisms have a l s o been suggested, i n c l u d i n g the p o s s i b i l i t y of a great e r r e l e a s e of nonneural a c e t y l c h o l i n e i n the t r a i n e d s u b j e c t ' s heart ( T i p t o n and Tay l o r , 1965). Winder e t a l . (1978) have demonstrated a t r a i n i n g - i n d u c e d decrease i n the sympathoadrenal catecholamine response. A l s o hypothesized are. changes i n a t r i a l s t r e t c h r e s u l t i n g from a t r i a l d i s t e n s i o n and hypertrophy, which might modify the normal s i n o a t r i a l rhythm by s t i m u l a t i n g mechanoreceptors i n the w a l l s of the a t r i a ( H a l l , I963)• B o l t e r e t a l . (1973) concluded t h a t the brady c a r d i a of t r a i n i n g probably i n v o l v e s a t l e a s t two mechanisms; a decrease i n the i n t r i n s i c r a t e of the 2? s i n o a t r i a l node, and an increase i n t o n i c c a r d i a c parasympathetic a c t i v i t y . Warner and Cox (1962) i n d i c a t e d t h a t there i s a d i f f e r e n c e i n the speed of the motor response when the two branches of the autonomic nervous system a l t e r the heart r a t e . Vagal responses were found t o be extremely f a s t , w h i l e sympathetic responses were shown t o be as much as e i g h t times slower. Scher e t a l . (1972) found the same phenomenon, and a c t u a l l y used these d i f f e r e n c e s i n speed M response t o d i f f e r e n t i a t e parasympathetic from sympathetic c o n t r o l f u n c t i o n s . I t could be hypothesized t h e r e f o r e , t h a t , s i n c e the t r a i n e d a t h l e t e i s l i k e l y t o have h i s i n t r i n s i c h e art r a t e i n f l u e n c e d more predominantly by a parasympathetic "vagal tone", and s i n c e t h i s v a g a l c o n t r o l appears to be capable of responding much more q u i c k l y than sympathetic c o n t r o l s , the t r a i n e d subject may respond t o the onset of submaximal e x e r c i s e w i t h a quicker withdrawal of parasympathetic s t i m u l a t i o n , a r e s u l t a n t q u i c k e r i n -crease i n heart r a t e , and, p o s s i b l y , a decreased c r i t i c a l time r e q u i r e d f o r a c h i e v i n g s t e a d y - s t a t e . Thus d i f f e r e n c e s i n the s u b j e c t s ' s t a t e of t r a i n i n g may p a r t l y account f o r the f a s t and slow responders described by F u j i h a r a e t a l . (1973) and. discussed above. This would a l s o i n d i c a t e the need f o r PWG 170 t e s t p r o t o c o l s which take i n t o account s u b j e c t s ' s t a t e of t r a i n i n g and the d i f f e r e n t c r i t i c a l times which may thus be i n v o l v e d . CHAPTER I I I METHODS. AND PROCEDURES Subjects The s u b j e c t s of t h i s study were 8 endurance-trained and 8 untrained c o l l e g e males, aged 18 t o 30. The t r a i n e d s ubjects were a l l a c t i v e l y competing i n the middle-distance or long-distance running events i n t r a c k and f i e l d , or i n road r a c i n g , and were r e q u i r e d t o have PWG-170/Kg. scores exceeding 15.69 KPM/Kg./Min. ( i . e . above the 70th p e r c e n t i l e on the C.A.H.P.E.R. norms). The untrained subjects were a l l l e a d i n g r e l a t i v e l y sedentary l i v e s , as re p o r t e d s u b j e c t i v e l y by themselves, without any r e g u l a r strenuous aerobic a c t i v i t y . They were r e q u i r e d t o have PWG-170/Kg. scores of l e s s than 12.93 KPM/Kg./Min. ( i . e . below the kOth p e r c e n t i l e on the C.A.H.P.E.R. norms). A l l s u b j e c t s werevolunteers. Procedures A l l volunteers underwent a " p r e l i m i n a r y " PWG 170 t e s t , i n v o l v i n g three work l o a d s , each of 6 minutes d u r a t i o n . T h i s served the f o l l o w i n g purposes: i t confirmed the s e l e c t i o n of subjects f o r the t r a i n e d and untrained groups as def i n e d above, . i t ' a f f o r d e d an opportunity f o r the subj e c t s t o overcome the problems of l e a r n i n g and h a b i t u a t i o n , and i t allowed f o r the establishment of i n d i v i d u a l s u b j e c t work loads which would l a t e r . : * f l i c i t the optimal heart r a t e s r e q u i r e d f o r the experimental t e s t s o f t h i s study. Each s u b j e c t then underwent f o u r more PWG 170 t e s t s , one of each of the experimental p r o t o c o l s . There was an i n t e r v a l of at l e a s t two days between the t e s t s i n order t o minimize problems of f a t i g u e . The experimental t e s t s were administered i n a counterbalanced Latin-square design t o avoid problems r e s u l t i n g from the order of the treatments ( i . e . t e s t p r o t o c o l s ) , 28 29 as o u t l i n e d i n Table I I I - l below: TABLE I I I - l SCHEDULE OF TEST PROTOCOLS (COUNTERBALANCED LATIN-SQUARE DESIGN) SUBJECTS TEST #1 TEST #2 TEST #3 TEST #4 l , 5, 9, 13 3 Min. 4 Min. 5 Min. 6 Min. 2, 6, 10, 14 4 Min. 6 Min. 3 Min. 5 Min. 3, 7, 11, 15 5 Min. 3 Min. 6 Min. 4 Min. 4, 8, 12, 16 6 Min. 5 Min. 4 Min. 3 Min. (Subjects 1 through 8 comprised the t r a i n e d group, w h i l e s u b j e c t s 9 through 16 were the untrained group.) Experimental c o n d i t i o n s . The environmental and subje c t c o n t r o l s were those recommended by Andersen e t a l . ( l 9 7 l ) . Every attempt was made t o assure t h a t a l l f o u r t e s t s f o r a given s u b j e c t were administered a t the same time of day. The l a r g e s t d e v i a t i o n from t h i s goal was a two-hour d i f f e r e n c e f o r one t r a i n e d and one untrained s u b j e c t . The l a b o r a t o r y temperature was kept w i t h i n the range of 18-22°G. E a t i n g , d r i n k i n g , and smoking were p r o h i b i t e d w i t h i n two hours of each t e s t . The subjects were asked not to e x e r c i s e on the day of each t e s t , although three members of the t r a i n e d group admitted t o having had moderate runs e a r l i e r the same day of a t e s t . F i n a l l y , a n x i e t y was probably minimized due t o the p r e l i m i -nary t e s t which a l l subjects underwent. The Monark b i c y c l e ergometer was c a l i b r a t e d a t the beginning of the t e s t i n g p e r i o d , but was not r e - c a l i b r a t e d at any other time. However, the 30 same b i c y c l e was used f o r each t e s t , and the pendulum was always s e t p r e c i s e l y a t ' 0 ' before each t e s t began. A l s o , any i n a c c u r a c i e s r e s u l t i n g from i n a c c u r a t e c a l i b r a t i o n would have been averaged out by the counter-balanced design of the study, and would t h e r e f o r e have c o n t r i b u t e d only t o an increase i n the o v e r a l l e r r o r term. A l s o , there was no reason t o b e l i e v e that the c a l i b r a t i o n would change over the d u r a t i o n of the t e s t p e r i o d . The p e d a l l i n g cadence was s e t to 50 r.p.m. (see M i c h i e l l i and S t r i c e v i c , 1977), and the warm-up c o n s i s t e d of a '0* work load free-wheeling f o r two minutes (Watson, 1976; Watson, 1977)• The r e s t p e r i o d between work loads was two minutes (see S e l i g e r , 1978; Withers e t a l , , 1977). The appropriate work loads were determined from the r e s u l t s of the p r e l i m i n a r y t e s t . C o l l e c t i o n of the data An A v i o n i c s Cardioguard 4000 e l e c t r o c a r d i o g r a p h , w i t h d i g i t a l d i s p l a y s of heart r a t e and elapsed time, was used to measure the heart r a t e . The voltage changes from the EKG were f e d i n t o a Hewlett Packard 3052A Data A c q u i s i t i o n System, which then provided a continuous p r i n t - o u t of heart r a t e s averaged over each 15-second i n t e r v a l throughout the t e s t p e r i o d . These heart r a t e s , and the a s s o c i a t e d work loads determined from the Monark b i c y c l e ergometer, provided the raw data f o r t h i s study. Treatment of the data The PWC 170 scores were determined from the three work loads i n each t e s t , and from the l a s t 15-second average heart r a t e recorded a t each of these work loads. The r e g r e s s i o n between the heart r a t e s and the work loads was p l o t t e d by a least-squares method, through use of the l i n e a r r e g r e s s i o n f u n c t i o n of a polynomial r e g r e s s i o n Computer program, UBC BMD 05R. The equations t h a t r e s u l t e d from t h i s l i n e a r r e g r e s s i o n were used t o c a l c u l a t e the work l o a d t h a t could be s u s t a i n e d w i t h a heart r a t e of 170 beats per minute ( i . e . the PWG 170 s c o r e s ) . The d i f f e r e n c e ('D') scores were determined by f i r s t f i t t i n g an asymptotic r e g r e s s i o n between each 15-second time i n t e r v a l and i t s c o r r e s -ponding average heart r a t e , according t o a least-squares method, through a p a r t i c u l a r f u n c t i o n of UBG BMD P3R'. The p r e d i c t e d asymptotic heart r a t e was then su b t r a c t e d from the a c t u a l f i n a l "15-second average" heart r a t e recorded, f o r each s u b j e c t , at a l l three work loads, under each of the f o u r p r o t o c o l s . The 'D' scores thus are an i n d i c a t i o n of the extent t o which steady-state heart r a t e s have been achieved. Negative 'D' scores suggest th a t steady-state heart r a t e s have not been achieved. P o s i t i v e 'D' scores i n d i c a t e t h a t the f i n a l heart r a t e has exceeded the p r e d i c t e d steady-state value. (See Table I I I - 2 . ) TABLE I I I - 2 CALCULATION OF 'D' SCORES A. Y = A + B p x where Y = ordinate = p r e d i c t e d heart r a t e A+B = Y i n t e r c e p t s p r e l i m i n a r y heart r a t e p = r a t e of curvature s. heart r a t e dynamics X = a b s c i s s a g time B. F i n a l HR - P r e d i c t e d Asymptotic HR = 'D' score Experimental design and s t a t i s t i c a l a n a l y s i s Hypotheses 1 and 2. Hypotheses 1 and 2 were t e s t e d w i t h a two-way a n a l y s i s of variance (ANOVA), through the computer program UBC BMD P2V, w i t h the two independent v a r i a b l e s being 'state of t r a i n i n g ' and 'PWC 170 p r o t o c o l 1 , w i t h repeated measures on the l a t t e r f a c t o r . The dependent v a r i a b l e was 'PWC 170 score', expressed i n KPM/Min. ( k i l o p o n d metres per minute). 32 TABLE I I I - 3 EXPERIMENTAL DESIGN - HYPOTHESES 1 AND 2 St a t e of t r a i n i n g PWG 170 p r o t o c o l s 3 Min. 4 Min. 5 Min. 6 Min. Trained X X X X Untrained X X X X PWG 170 scores Preplanned orthogonal comparisons were used t o t e s t the s p e c i f i c statements i n hypotheses laand 2. S i g n i f i c a n c e was accepted a t the .05 l e v e l . Hypotheses 3i 4 and 5» Hypotheses 3i 4 and 5 were t e s t e d w i t h a three-way a n a l y s i s of variance (ANOVA), a l s o through UBG BMD P2V, w i t h 'state of t r a i n i n g ' , 'PWG 170 p r o t o c o l ' , and 'work loa d number' ( i n d i c a t i n g a l s o ' r e l a t i v e i n t e n s i t y ' ) being the three independent v a r i a b l e s , and w i t h the l a t t e r two f a c t o r s being repeated measures. The dependent v a r i a b l e was the 'D' score. S i g n i f i c a n c e was again accepted a t the .05 l e v e l . TABLE I I I - 4 EXPERIMENTAL DESIGN - HYPOTHESES §, 4 AND 5 S t a t e of t r a i n i n g PWG 170 p r o t o c o l s • 3 Min. 4 Min. 5 Min. 6 Min. Work load number A B C A B C A B C A B C Trained X X X X X X X X X X X X Untrained X X X X X X X X X X X X 'D' scores Preplanned orthogonal comparisons were used t o t e s t the s p e c i f i c s t a t e -ments i n hypotheses 3 and 5, w h i l e 4 was t e s t e d by a main e f f e c t i n the ANOVA. CHAPTER IV RESULTS AND DISCUSSION R e s u l t s The raw data c o l l e c t e d In t h i s study are i n c l u d e d i n appendix A. Each work loa d amount i s described f o r every s u b j e c t under a l l f o u r p r o t o c o l c o n d i t i o n s , and i n c l u d e d w i t h t h i s i s a complete l i s t i n g of each heart r a t e averaged and recorded every f i f t e e n seconds. Also included, i n appendix B, i s a l i s t i n g of the f i n a l recorded heart r a t e s f o r each sub j e c t a t each work loa d under a l l f o u r p r o t o c o l c o n d i t i o n s . Beside these f i n a l recorded heart r a t e s , and sub t r a c t e d from them, are the p r e d i c t e d asymptotic h e a r t r a t e s f o r the same work loads. The d i f f e r e n c e i n each case, the 'D" score, i s l i s t e d beside each f i n a l and p r e d i c t e d asymptotic heart r a t e . I t should be noted t h a t two subjects withdrew from the study before i t was completed, and t h e i r r e s u l t s had t o be discarded s i n c e incomplete r e s u l t s were not amenable t o the design of t h i s research. These su b j e c t s were r e p l a c e d by two others who met the q u a l i f i c a t i o n s f o r assignment t o the groups, and they completed a l l the t e s t s r e q u i r e d . This s e c t i o n of the chapter provides the p e r t i n e n t r e s u l t s of the study and t h e i r a s s o c i a t e d s t a t i s t i c a l analyses. A statement i s made whenever an a n a l y s i s supports, or f a i l s to support, a hypothesis. The second s e c t i o n o f t h i s chapter, the d i s c u s s i o n , attempts t o e x p l a i n these r e s u l t s and analyses both i n the context of t h i s study and i n l i g h t of the cur r e n t r e l a t e d r e search. I n t h i s case, an a l t e r n a t e a n a l y s i s r e l a t e d t o the PWC 170 scores i s provided, on a post hoc i n v e s t i g a t o r y b a s i s . 33 34 PWC 170 The PWG 170 scores f o r hoth t r a i n e d and untrained i n d i v i d u a l s , under a l l f o u r p r o t o c o l c o n d i t i o n s , are l i s t e d i n Table IV- 1 . The group means and standard d e v i a t i o n s are presented i n Table I V - 2 . TABLE IV - 1 INDIVIDUAL PWG 170 SCORES Group Subject P r o t o c o l s T 3 Min. 4 Min. 5 Min. 6 Min. Trained 01 1296 1318 1256 1263 02 1416 1414 1340 1289 03 1632 1594 1404 1514 04 1335 1285 1245 1226 05 1704 1702 1800 2050 06 1317 1333 1320 1298 07 1414 1399 1378 1331 08 1286 1282 1242 1236 Untrained 09 996 965 953 944 10 960 952 947 936 11 629 616 602 596 12 1031 938 961 947 13 703 679 659 650 14 859 851 854 859 15 760 752 75^ 742 16 809 744 775 746 TABLE IV - 2 PWC 170 SCORES GROUP MEANS AND STANDARD DEVIATIONS Group D e s c r i p t i v e P r o t o c o l s Groups S t a t i s t i c s 3 Min. 4 Min. 5 Min. 6 Min. Trained Means 1425 1416 1373 1401 1404 S t . Dev.'s 159 154 183 277 Untrained Means 843 812 813 803 818 S t . Dev.'s 144 133 139 139 P r o t o c o l s (P) 1134 1114 1093 1102 11111 35 The r e s u l t s of the ANOVA f o r these scores are summarized i n Table I V - 3 . I n s e r t i o n of an a s t e r i s k (*) w i t h i n the ANOVA t a b l e s i g n i f i e s s t a t i s t i c a l s i g n i f i c a n c e a t p< . 0 5 f o r t h a t p a r t i c u l a r source. TABLE IV - 3 PWG 170 SCORES SUMMARY OF ANOVA Source df Mean square F P Groups ( G ) * 1 5493164.06 50.46 < .001 SwG 14 108861.14 P r o t o c o l s (P) 3 5080.79 I . 6 3 .20 GP 3 1551.10 0.50 .69 SwGP 42 3122.67 The r e s u l t s contained i n Table IV - 3 i n d i c a t e t h a t the only s i g n i f i -cant d i f f e r e n c e (p< . 0 5 ) i n PWC 170 scores l i e s i n the o v e r a l l d i f f e r e n c e between the t r a i n e d and unt r a i n e d groups (p^.OOl) . T h i s merely demon-s t r a t e s the e f f e c t i v e n e s s of the s e l e c t i o n c r i t e r i a used f o r a c c e p t i n g subjects i n t o each group. Hypothesis 1 s t a t e s t h a t "the PWC 170 scores f o r untrained subjects d e r i v e d from 3- and 4-minute work l o a d d u r a t i o n p r o t o c o l s are higher than those r e s u l t i n g from 5- and 6-minute p r o t o c o l s . " Pre-planned orthogonal comparisons y i e l d e d a n o n - s i g n i f i c a n t e f f e c t (F=.97» p> .05) and f a i l e d t o support hypothesis 1. Hypothesis 2 s t a t e s t h a t "the PWC 170 scores f o r t r a i n e d s u b j e c t s d e r i v e d fromtthe J-jnlnvbe work l o a d d u r a t i o n p r o t o c o l are higher than those r e s u l t i n g from 4- , 5 _ and 6-minute p r o t o c o l s " . Once again, 36 pre-planned orthogonal comparisons demonstrated a n o n - s i g n i f i c a n t e f f e c t (F=1.54, p> . 0 5 ) , and hypothesis 2 was not s u b s t a n t i a t e d . Figure IV - 1 describes the p r o t o c o l s e f f e c t (P) and the groups by p r o t o c o l s e f f e c t (GP), as w e l l as showing the groups e f f e c t (G) mentioned above. This f i g u r e suggests a downward t r e n d ( i . e . decreases i n group mean PWG 170 scores) as the p r o t o c o l durations increase from 3 minutes at each work l o a d to 6 minutes a t each work load. Two p o i n t s d e t r a c t f r o m t t h i s downward tren d - the 5-m.nute p r o t o c o l f o r the untrained group ( i n which the mean stays v i r t u a l l y the same as f o r the 4-minute p r o t o c o l ) , and the 6-minute p r o t o c o l f o r the t r a i n e d group ( i n which the mean r i s e s from a 4—minute p r o t o c o l mean of 1373 t o IkOl). The r e l a t i v e l y l a r ge i n c r ease i n the 6-minute p r o t o c o l mean f o r the t r a i n e d group outweighs the 6-minute p r o t o c o l decrease found i n the untrained group mean,.resulting i n a s m a l l o v e r a l l mean score increase f o r the 6-minute p r o t o c o l . Although the pr o t o c o l s e f f e c t was n o n - s i g n i f i c a n t , a c l o s e r a n a l y s i s of t h i s phenomenon w i l l be found i n the "D i s c u s s i o n " s e c t i o n of t h i s chapter. I n summary, these r e s u l t s show s i g n i f i c a n t l y higher PWG 170 scores among the t r a i n e d group as opposed t o the untrained group, as was expected because of the c r i t e r i a e s t a b l i s h e d f o r a s s i g n i n g the subjects i n t o t h e i r r e s p e c t i v e groups. There was, however, no other s i g n i f i c a n t d i f f e r e n c e i n PWG 170 scores, e i t h e r on the b a s i s of a p r o t o c o l s e f f e c t , or a groups by p r o t o c o l s i n t e r a c t i o n . e f f e c t . Hypotheses 1 and 2 were not supported by the r e s u l t s of t h i s study. 1500 + Trained — • — Untrained — ® -O v e r a l l mean — X -1400 1300 + ,1200 4 (GP) (G) Trained group mean over a l l p r o t o c o l s = 1404 (P) 1100 + T o t a l group mean over aIT~pr£t ocols = 1111 1000 4 900 (G) (GP) Untrained group mean over a l l p r o t o c o l s = 818 800 4 1 3 Min. -+- -f-4 Min. 5 Min. P r o t o c o l s 6 Min. FIGURE IV-1 PWG 170 SCORES (MEANS) 38 'D' Scores As was described i n chapter I I I , the 'D' scores were determined by-s u b t r a c t i n g the p r e d i c t e d asymptotic heart r a t e from the a c t u a l f i n a l "15-second average" heart r a t e recorded, f o r each su b j e c t , at a l l three work loads, under each of the f o u r p r o t o c o l s . The raw data used to c a l c u l a t e the 'D' scores i s i n c l u d e d i n appendix A. The 'D' scores are, then, an i n d i c a t i o n of the extent t o which the heart r a t e reached i t s p r e d i c t e d asymptotic 'steady-state' value. A negative 'D' score s i g n i f i e s a f i n a l heart r a t e t h a t i s lower than i t s p r e d i c t e d asymptotic value, and i n d i c a t e s t h a t steady-state may not have been reached due t o a t o o - e a r l y c e s s a t i o n of the work p e r i o d . A p o s i t i v e 'D' score s i g n i f i e s a f i n a l heart r a t e t h a t i s higher than i t s p r e d i c t e d asymptotic value, suggesting t h a t e i t h e r the work load may have been too severe f o r steady-state t o be achieved, or t h a t other f a c t o r s such as i n c r e a s i n g core temperature have added an a d d i t i o n a l s t r e s s on the c a r d i o v a s c u l a r system, r e s u l t i n g i n an e l e v a t i o n of the heart r a t e above t h a t normally demanded by the given work loa d . The 'D' scores f o r i n d i v i d u a l s i n both t r a i n e d and untrained groups, f o r each of the three work loads under a l l f o u r p r o t o c o l c o n d i t i o n s , are given i n Table IV - 4 , w i t h the group means and standard d e v i a t i o n s being presented i n Table I V - 5 . TABLE IV - 4 INDIVIDUAL 'D' SCORES Pr o t o c o l s Subjects Trained 3 Min. Loads 4 Min. Loads 5 Min, Loads Untrained 6 Min. Loads A B c A B c A B C A B C 01 -2 3 - l 2 -1 0 -1 3 2 4 1 1 02 0 0 3 0 2 -1 2 .3 3 3 3 3 03 -2 -2 - l -1 0 0 0 2 2 . 3 3 3 04 0 0 -2 0 0 -1 0 1 -1 2 2 2 05 -3 -1 1 -3 -1 0 1 0 -1 2 1 3 06 l 1 0 0 1 1 1 1 1 1 0 0 07 3 -3 -3 0 1 -1 . 1 0 -1 -2 0 l 08 - l -2 -4 -1 -2 2 0 -3 1 0 -1 0 09 2 1 1 0 -1 1 1 3 1 4 7 2 10 -4 -2 -6 0 -2 -2 0 -2 -4 -1 2 0 11 -3 -2 -2 -5 0 0 0 4 1 -5 -2 0 12 -3 -2 -3 l 3 -2 1 2 -2 1 2 0 13 . -14 -1 -4 . 4 -1 1 2 0 1 -1 -2 1 14 3 -1 3 1 0 2 3 2 3 1 0 1 15 1 -3--11 1 -1 -2 l 1 0 1 3 0 16 0 3 4 -1 3 3 2 1 3 3 2 4 TABLE IV - 5 •D' SCORES GROUP MEANS AND STANDARD DEVIATIONS Pr o t o c o l s r - n - x - 3 Min. Group D e s c r i p t i v e -S t a t i s t i c s Loads Trained Means •St.Dev .sl Untrained Means S t . Dev. sj A B C_ -.50 -.50 - .88 1.93 1-93 2.23 -2.25 - .88-2.25 5-39 1-96 4.95 4 Min. Loads A B C - .38 0.00 0.00 1.41 1.31 1.07 0.13 0.13 0.13 2.53 1-89 1.96 5.Min. Loads A B C 0.50 0 .88 0.75 0.93 1.96 1.58 1.25 I . 3 8 0.38 1.04 1.85 2.39 6 Min.. Loads A B C 1.63 1.13 1.63 1.92 1.46 1.30 0.38 1.50 1.00 2.77 2.93 1.41 39 40 The r e s u l t s of the ANOVA f o r these scores are summarized i n Table IV-6 . I n s e r t i o n of an a s t e r i s k (*) w i t h i n the ANOVA t a b l e s i g n i f i e s s t a t i s t i c a l s i g n i f i c a n c e a t p< . 0 5 f o r t h a t p a r t i c u l a r source. Note t h a t Table IV - 6 i s only a summary of the ANOVA f o r the *B.' scores. As such, i t was deemed appropriate t o i n c l u d e c a t e g o r i e s of variance by l i n e a r , q u a d r a t i c , and cubic f u n c t i o n s only when the source i n v o l v e d showed s i g n i f i c a n c e a t p< . 0 5 - Thus, only the variance a t t r i b u t e d t o the p r o t o c o l s e f f e c t (p< 0 . 0 0 l ) was l i s t e d i n terms of i t s l i n e a r , q u a d r a t i c and cubic f u n c t i o n s . TABLE IV - 6 'D.' SCORES SUMMARY OF ANOVA Source df Means square F P Groups (G) 1 3-79 0.20 .66 SwG 14 18.60 P r o t o c o l s ( P ) * P l i n e a r * 3 55.47 10.68 <.001 1 157.62 28.24 <.00l P q u a d r a t i c 1 8.75 1.27 .28 P cubic l .05 .02 • 89 GP 3 5.77 1.11 • 36 SwGP 42 5-19 Load (L) 2 2.76 0.54 • 59 GL 2 2.36 0.46 .63 SwGL 28 5.09 PL 6 0.87 0.24 • 96 GPL 6 1.31 0.37 • 89 SwGPL 84 3.57 The r e s u l t s contained i n Table IV - 6 i n d i c a t e t h a t there i s a s i g n i f i -cant d i f f e r e n c e (p< . 0 0 l ) i n 'D' scores obtained from among the f o u r d i f f e r e n t p r o t o c o l s . The group means f o r these scores had negative values f o r a l l three loads under the three minute p r o t o c o l ( f o r both the trained.and untrained groups), while they had p o s i t i v e values f o r a l l three loads under 41 the s i x minute p r o t o c o l ( a l s o f o r both groups). The f o u r and f i v e minutes p r o t o c o l s seemed t o f i t i n w i t h t h i s t r a n s i t i o n from negative t o p o s i t i v e values, as the variance from the p r o t o c o l s e f f e c t could almost t o t a l l y be explained by a l i n e a r f u n c t i o n ( p < . 0 0 l ) . No i n t e r a c t i o n e f f e c t s approached s i g n i f i c a n c e , nor was there any s i g n i f i c a n t d i f f e r e n c e i n the 'D' scores between the t r a i n e d and untrained group o v e r a l l , nor among the loads o v e r a l l . Table IV-7 gives the group means of the 'D' scores, averaged over the three work loads, under a l l f o u r p r o t o c o l s . Figure IV - 2 shows t h a t the e f f e c t of the p r o t o c o l s on the 'D' scores i s c l e a r l y demonstrated by a variance which suggests a l i n e a r f u n c t i o n . The l a c k of a s i g n i f i c a n t d i f f e r e n c e between the t r a i n e d and untrained groups i s a l s o suggested by Figure I V - 2 . TABLE IV - 7 'D' SCORES PROTOCOLS EFFECT ON GROUP MEANS tAVERAGED OVER ALL $ WORK LOADS) P r o t o c o l s Groups (G) Group 3 Min. 4 Min. 5 Min. 6 Min. Trained - .63 -.13 171 1.46 •35 Untrained -1.79 .13 1.00 .96 .08 P r o t o c o l s (P) -1.21 .00 .86 1.21 .22 42 FIGURE IV-2 'DV SCORES (GROUP MEANS AVERAGED OVER THE THREE WORK LOADS UNDER ALL FOUR PROTOCOLS) k3 Hypothesis 3 s t a t e s t h a t "there i s a d i f f e r e n c e i n 'D1 scores among the d i f f e r e n t p r o t o c o l s , w i t h the 3- and 4-minute p r o t o c o l s producing g r e a t e r negative values ( i n d i c a t i n g a decreased extent t o which steady s t a t e , and theref o r e c r i t i c a l times, have been achieved) than the 5~ and 6-minute p r o t o c o l s . " The ANOVA summarized i n Table IV - 6 supports t h i s hypothesis on a p r o t o c o l s (P) e f f e c t (p<T . 0 0 l ) , and f u r t h e r i n d i c a t e s t h a t the e f f e c t can be best described by a l i n e a r f u n c t i o n ( p < . 0 0 l ) . F i g u r e IV - 2 shows t h a t the s h o r t e r d u r a t i o n p r o t o c o l s tend t o e x h i b i t g r e a t e r negative values. Preplanned orthogonal comparisons showed a s i g n i f i c a n t d i f f e r e n c e between the 3 - and 4—minute p r o t o c o l 'D' scores versus the 5 _ and 6-minute p r o t o c o l scores (F=8 .23, p < . 0 l ) . Hypothesis 4 s t a t e s " t h a t there i s a s i g n i f i c a n t d i f f e r e n c e i n 'D' scores between t r a i n e d and untrained s u b j e c t s , w i t h the t r a i n e d subjects e x h i b i t i n g s i g n i f i c a n t l y l e s s negative values, i n d i c a t i n g a greater achieve-ment of steady-s t a t e . " The mean 'D' score under a l l f o u r p r o t o c o l s was .35 f o r the t r a i n e d group, and .07 f o r the untrained group. Table IV - 6 shows, however, t h a t the d i f f e r e n c e (.28) i n t h i s groups e f f e c t (G) was n o n - s i g n i f i c a n t (F=.20, pj> .05)• There were a l s o no s i g n i f i c a n t i n t e r a c t i o n e f f e c t s between groups and p r o t o c o l s (GP), (F -1 . 11 , p> . 0 5 ) . F i n a l l y , hypothesis 5 p r e d i c t s "a s i g n i f i c a n t d i f f e r e n c e i n 'D' scores between the 1st and 3 r ( i work loads of the PWG 170 t e s t s , w i t h the 3rd (most intense) work load producing s i g n i f i c a n t l y l e s s negative values, i n d i c a t i n g ^ g r e a t e r achievement of steady-s t a t e . " This d i f f e r e n c e was t o be t e s t e d by the use of preplanned orthogonal comparisons. However, the o v e r a l l mean 'D' score f o r the 1st work load was .375, and i t was a l s o .375 f o r the 3rd work load . This l a c k of any d i f f e r e n c e f a i l s t o support hypothesis 5. There were a l s o no s i g n i f i c a n t i n t e r a c t i o n e f f e c t s i n v o l v i n g the work loads; i . e . 44 groups by loads (GL), p r o t o c o l s by loads ( P L ) , and groups by p r o t o c o l s by loads ( GPL) . Di s c u s s i o n PWG 170. The ANOVA r e s u l t s shown i n Table IV - 3 i n d i c a t e t h a t the only s i g n i f i c a n t d i f f e r e n c e i n PWG 170 scores r e s i d e s i n the o v e r a l l d i f f e r e n c e between the means of the t r a i n e d versus the untrained group. This d i f f e r e n c e i s not s u r p r i s i n g , and indeed was expected as a r e s u l t of the s e l e c t i o n c r i t e r i a f o r a s s i g n i n g the s u b j e c t s i n t o each group; i . e . p i l o t PWG 170 t e s t r e s u l t s exceeding 15.69 KPM/Kg./Min. allowed assignment to the t r a i n e d group, whereas those scores l e s s than 12.93 KPM/Kg./Min. provided f o r i n c l u s i o n i n the untrained group. Hypothesis 1, which p r e d i c t s s i g n i f i c a n t l y higher scores f o r untrained subjects d e r i v e d from the 3- and 4-minute p r o t o c o l s as opposed t o the 5~ and 6-minute p r o t o c o l s , was not supported i n t h i s study. S i m i l a r l y , hypothesis 2, which p r e d i c t s s i g n i f i c a n t l y higher scores f o r t r a i n e d subjects d e r i v e d from the 3-roi n u"te p r o t o c o l as opposed t o the 4- , 5- and 6-minute p r o t o c o l s , was a l s o not s u b s t a n t i a t e d . I n f a c t , there was no s i g n i f i c a n t p r o t o c o l s e f f e c t , nor were there any s i g n i f i c a n t i n t e r a c t i o n e f f e c t s . According to these r e s u l t s , i t appears t h a t any of these f o u r p r o t o c o l s may be used t o administer the PWG 170 t e s t , and even the s h o r t e s t 3-minute p r o t o c o l i s of s u f f i c i e n t d u r a t i o n t o obta i n approximately steady-state heart r a t e s . This f i n d i n g d i f f e r s from t h a t of Watson and O'Donovan (1976) who r e p o r t e d t h a t a 4-minute p r o t o c o l r e s u l t e d i n scores 4 percent higher than those d e r i v e d from 5~ and 6-minute p r o t o c o l s . The f i n d i n g s i s s i m i l a r , however, t o that of Withers e t a l . (1977) who found no s i g n i f i c a n t d i f f e r e n c e among 6-, 4- and 3-minute p r o t o c o l s , even though the group means suggested 45 a trend toward higher scores f o r the s h o r t e r work pe r i o d s . However, an i n t e r e s t i n g observation leads t o a f u r t h e r a n a l y s i s , suggesting t h a t a tren d e x i s t s i n t h i s data which warrants f u r t h e r study. I n Table I V - 2 , the standard d e v i a t i o n s of the PWG 1?0 scores f o r both groups under a l l f o u r p r o t o c o l s vary from 133 "to 183, a range of 50, w i t h one exception. The standard d e v i a t i o n of the t r a i n e d group f o r the 6-minute p r o t o c o l i s l i s t e d as 277. This i s 94 u n i t s above the highest value f o r the seven other standard d e v i a t i o n s t h a t have a range of only 50. I t was a l s o noted above (see Figure l ) t h a t a downward tren d i n the PWG 170 group mean scores, as the p r o t o c o l s i n c r e a s e d i n d u r a t i o n , was only i n t e r r u p t e d twice — once by an increase i n the mean score of 1 f o r the untrained group from the 4-minute p r o t o c o l to the 5~rcinute p r o t o c o l , and once by a r a t h e r l a r g e increase i n the mean score from 1373 "to 1401 f o r the t r a i n e d group from the 5-minute p r o t o c o l to the 6-minute p r o t o c o l . This l a r g e i n c r e a s e i n the 6-minute p r o t o c o l mean score i s a s s o c i a t e d w i t h the large increase i n the standard d e v i a t i o n f o r t h a t group mean, as can be shown by r e f e r r i n g to Table I V - l , i i n which i t can be observed t h a t s u b j e c t 05 increased by a score of 250 from the 5- "to 6-minute p r o t o c o l s . Subject 05 could r e a l l y be de f i n e d as an " o u t l i e r " , s i n c e a l l of h i s scores were extreme — under each p r o t o c o l they were the highest recorded — and they r e s u l t i n an inc r e a s e d variance and an exaggerated e r r o r term of 3122.67 i n the ANOVA (Table IV - 3 ). Since an o v e r a l l s i g n i f i c a n c e f o r the p r o t o c o l s e f f e c t was not achieved, a Scheffee post hoc a n a l y s i s could not be a p p l i e d . ( A l s o , the Scheffee uses the o v e r a l l e r r o r term, which was h i g h l y i n f l a t e d by the 6-minutes p r o t o c o l variance.) I t was there f o r e decided i n s t e a d to run a "post hoc ANOVA" w i t h the scores of the " o u t l i e r " , s ubject 05, d e l e t e d . The r e s u l t s of t h i s post hoc ANOVA, summarized i n 46 Table TV-8, d i f f e r g r e a t l y from the o r i g i n a l r e s u l t s r e p o r t e d i n Table I V - 3 . TABLE IV-8 PWG 1?0 SCORES SUMMARY OF ANOVA (POST HOC ANOVA - SUBJECT '05 ' DELETED) SOURCE d f df MEAN SQUARE F P Groups ( G ) * 11 4152550.79 71.54 <0.001 SwG 13 58041.86 P r o t o c o l s ( P ) * 3 11249.21 15.49 <0.001 GP* 3 3414.52 4.70 <0.01 SwGP 39 726.36 P ( l ) L i n e a r * 1 32223.41 39-20 <0.00l GP (1) L i n e a r * 1 5537.26 6.74 <0.02 ERROR L i n e a r 13 822.10 P(2) Quadratic 1 668.75 1.06 0.32 GP (2) Quadratic 1 195.75 0.31 0.59 ERROR Quadratic 13 630.48 P(3) Cubic 1 855.46 1.18 0.29 GP (3) Cubic* 1 4510.54 6.21 <0.03 ERROR Cubic 13 . 726.50 I t can be seen t h a t by simply d e l e t i n g the scores of su b j e c t '05 ' from a l l f o u r p r o t o c o l s the e r r o r term drops from 3122.67 ( T a b l e I I I - 3 ) to 726.50 (Table IV-8). The B e f f e c t then changes fromaa n o n - s i g n i f i c a n t p=*.200to a h i g h l y s i g n i f i c a n t p<^.001. Table IV - 8 shows t h a t the p r o t o c o l s e f f e c t can 4 7 best be described by a l i n e a r f u n c t i o n ( p C . O O l ) . According t o the r e s u l t s of t h i s new ANOVA, preplanned orthogonal comparisons now support hypothesis 2 , showing a s i g n i f i c a n t d i f f e r e n c e i n PWG 1 7 0 scores between the 3-rainute p r o t o c o l versus the 4 - , 5 - and 6-minute p r o t o c o l s f o r the t r a i n e d group ( F = 2 0 . 5 6 , p < C . 0 l ) . Hypothesis 1 , which p r e d i c t s a s i g n i f i c a n t d i f f e r e n c e between the scores from the 3 - and 4-minute p r o t o c o l s versus the 5 ~ a^id 6-minute p r o t o c o l s f o r the untrained group ( F - 4 . 1 9 ) , i s supported at the s i g n i f i c a n c e l e v e l p < . 0 5 ( F = 4 . 0 9 ) but not at the l e v e l p < . 0 1 (F= 7 3 3 ) . There a l s o a r i s e s a s i g n i f i c a n t groups by p r o t o c o l s (GP) i n t e r a c t i o n e f f e c t (p < . 0 1 ) which can most s u c c e s s f u l l y be explained by a l i n e a r model (p "C .05) but which can a l s o be i n t e r p r e t e d by a cubic f u n c t i o n ( p < " . 0 5 ) . Figure I V - 3 demonstrates the o v e r a l l P and G e f f e c t s , and shows the GP i n t e r a c t i o n . Both t r a i n e d and untrained groups decrease t h e i r mean PWG 1 7 0 scores w i t h longer d u r a t i o n p r o t o c o l s , but there i s a s i g n i f i c a n t d i f f e r e n c e between the groups i n the way or extent to which t h i s decrease occurs, ( i . e . the GP e f f e c t ) . I t appears t o be a f a s t e r decrease among the t r a i n e d subjects w i t h i n c r e a s i n g p r o t o c o l d u r a t i o n s , suggesting t h a t , i f t h i s a n a l y s i s were indeed v a l i d , i t may be even more important f o r t r a i n e d a t h l e t e s t o undergo longer d u r a t i o n p r o t o c o l s of t h i s t e s t s i n c e the s h o r t e r p r o t o c o l s may overestimate t h e i r scores even more than those of untrained s u b j e c t s . This would be c o n t r a r y to the i n t e n t of hypothesis f o u r . 1500r 14001 1300 I 1200 1100 1000 800 ^ Trained — Untrained — © -O v e r a l l Mean — J f -Previous means wit h ' 0 5 ' i n c l u d e d -,-Bv-( Q i P l ) ( G P ) without '05V (G^) Trained group mean'over a l l p r o t o c o l s = I4b5 ( G ) Trained group mean over a l l p r o t o c o l s = 1345 (Pi) (P) ---a w i t h '05 ' _« -a without '05 ' ( G) Untrained group mean over a l l p r o t o c o l s = 818 ( G P ) 3 Min. 4 Mini; ;v-3:-Min. P r o t o c o l s 6 Min. F I G U R E I V - 3 PWC 170 SCORES (MEANS) ( S U B J E C T ' 0 5 ' DELETED) 4 9 No f u r t h e r a n a l y s i s of t h i s post hoc ANOVA i s undertaken here, s i n c e i t i s a f t e r a l l somewhat i l l e g i t i m a t e . I n summary, i t was in c l u d e d because su b j e c t 0 5 had h i g h l y d i s c r e p a n t scores throughout, c o n t r i b u t i n g to a great increase i n the variance and th e r e f o r e the e r r o r term, and he can j u s t i f i a b l y be c l a s s i f i e d as an " o u t l i e r " . While acknowledging the p o s s i b l e v a l i d i t y of the data d e r i v e d from s u b j e c t 0 5 , and not t o t a l l y d i s c a r d i n g the o r i g i n a l a n a l y s i s , i t was deemed appropriate to re-analyze the data w i t h t h i s s u b j e c t deleted, s i n c e the l a r g e v a r i a b i l i t y introduced by h i s data ( e s p e c i a l l y r e g arding the SwGP e r r o r term) could e a s i l y r e s u l t i n a type I I s t a t i s t i c a l e r r o r . The post hoc ANOVA i s th e r e f o r e i n c l u d e d as a "data-snooping" technique. I t should a l s o be noted t h a t t h i s a l t e r n a t e a n a l y s i s i s somewhat j u s t i f i e d by the s t r e n g t h of the s i g n i f i c a n t e f f e c t s i t uncovers, (P e f f e c t s i g n i f i c a n t a t p O O O l , and GP i n t e r a c t i o n e f f e c t s i g n i f i c a n t a t p < ^ . 0 l ) , and by the f a c t t h a t i t agrees much more r e a d i l y w i t h the a n a l y s i s of the 'D' scores, w i t h which the PWG 1?0 scores are l i k e l y t o have an a s s o c i a t i o n . There i s l i t t l e evidence t o e x p l a i n the seemingly aberrant r e s u l t s of subject 0 5 , except the f a c t t h a t he admitted t o having a s l i g h t c o l d at the time of undergoing the s h o r t e r d u r a t i o n p r o t o c o l t e s t s . This could have reduced these scores somewhat (by e l e v a t i n g h i s submaximal heart r a t e s ) , making i t appear t h a t h i s " t r u e " scores would increase w i t h greater durations p r o t o c o l s . 'D' Scores I t should f i r s t be noted t h a t there appeared t o be no need t o delete the 'D1 scores of subject 0 5 , s i n c e they d i d not seem to take on the c h a r a c t e r i s t i c s of an " o u t l i e r " (see Table I V - 4 ) , and sin c e they d i d not seem t o c o n t r i b u t e any s u b s t a n t i a l increase i n the variance of the scores 5 0 f o r the t r a i n e d group (see Table IV -5) standard d e v i a t i o n s ) . I t a l s o seems reasonable t o i n c l u d e themimithe a n a l y s i s because of the vary nature of these scores, i n t h a t they are not d i r e c t l y comparable between subjects because they are based on the d i f f e r e n c e between p r e d i c t e d and achieved scores f o r an i n d i v i d u a l . A variance i n an i n d i v i d u a l ' s heart r a t e s i n comparison t o others' i s r e a l l y independent of changes i n t h a t i n d i v i d u a l ' s 'D' scores, and the subject, i n a sense, acts as h i s own c o n t r o l . Table I V - 6 , which summarized the ANOVA f o r the *D' scores, i n d i c a t e d a s i g n i f i c a n t p r o t o c o l s (P) e f f e c t (p^.OOl) which could be explained almost e n t i r e l y by a l i n e a r model ( p < f . 0 0 l ) . Hypothesis 3 i s a l s o supported, i n d i c a t i n g s i g n i f i c a n t l y more negative 'D' scores a r i s i n g from the 3 - and 4-minute p r o t o c o l s as opposed t o the 5~ and 6-minute p r o t o c o l s ( F = 8 . 2 3 , p O o i ) . The 'D' scores r i s e from negative values d u r i n g the 3-rcinute p r o t o c o l t o approximately 0 i n the 4—minute p r o t o c o l , and t o p o s i t i v e values i n the 5~ and 6-minute p r o t o c o l s (see Figure I V - 2 ) . Since a negative 'D' score i n d i c a t e s a f i n a l recorded heart r a t e which i s l e s s than the p r e d i c t e d asymptotic r a t e , i t i s q u i t e reasonable t o assume t h a t the negative 'D' scores r e s u l t e d from a t o o - e a r l y c e s s a t i o n of the work load . I n other words, the 3-minute p r o t o c o l which produced the negative values may not be of optimal d u r a t i o n f o r a t t a i n i n g s t e a d y - s t a t e . I t may be too sh o r t a time p e r i o d f o r t h e c a r d i o v a s c u l a r system t o complete i t s " f i n e - t u n i n g " i n terms of meeting the metabolic demands of e x e r c i s e . This f i n d i n g concurs reasonably w e l l w i t h t h a t of Watson and O'Donovan ( . 1 9 7 6 ) , who found t h a t even a 4-minute du r a t i o n p r o t o c o l produced a 4 percent e l e v a t i o n of scores. However, i n co n t r a s t , the 'D' scores from t h i s study i n d i c a t e t h a t the 4-minute d u r a t i o n p r o t o c o l i s optimal w i t h regard t o a c h i e v i n g steady-state (the 'D' scores approximating 0 ) , while the 5- and 6-minute p r o t o c o l s r e s u l t i n p o s i t i v e 5 1 'D' scores which a r i s e from f i n a l heart r a t e readings exceeding the p r e d i c t e d asymptotic value, perhaps i n d i c a t i n g d u r a t i o n p r o t o c o l s which are o v e r l y long. This suggests s e v e r a l p o s s i b i l i t i e s . F i r s t , i t may i n d i c a t e t h a t the workloads were too heavy t o maintain a s t e a d y - s t a t e . I f metabolic demands exceed the anaerobic t h r e s h o l d they may cause a c o n t i n u i n g r i s e i n the heart r a t e . However, i f t h i s were the explanation i t would t h e r e f o r e be expected t h a t the 3rd. (and heaviest) loads under a l l p r o t o c o l s would e x h i b i t s i g n i f i -c a n t l y higher p o s i t i v e 'D* scores than the r e s p e c t i v e 1 s t loads. This was not the case, however, s i n c e there was no o v e r a l l s i g n i f i c a n c e i n the loads e f f e c t (Table I V - 6 ) . A second p o s s i b l e e x p l a n a t i o n i s t h a t d u r i n g the longer d u r a t i o n p r o t o c o l s - t h e r e i s the onset of an a d d i t i o n a l s t r e s s o r such as an increase i n ambient temperature. Since these t e s t s were conducted i n a e c o n t r o l l e d l a b o r a t o r y s e t t i n g i n v o l v i n g n e g l i g i b l e changes i n ambient temperature (and presumably minimal changes i n core temperature) t h i s p o s s i b i l i t y i s not considered l i k e l y . A t h i r d , and more l i k e l y , e x p l a n a t i o n r e s i d e s i n the d i s t i n c t p o s s i -b i l i t y t h a t sunasymptotic r e g r e s s i o n f u n c t i o n i s inadequate f o r p r e c i s e l y d e s c r i b i n g the heart r a t e response t o submaximal e x e r c i s e . The "slow component" of heart r a t e a c c e l e r a t i o n s , observed by Broman and Wigertz ( 1 9 7 1 ) , and suggested as being caused by humoural agents such as sympathoadrenal hormones (epinephrine and norepinephrine), r e s u l t e d i n a b i p h a s i c second-order model being r e q u i r e d t o provide a best f i t f o r the heart r a t e response to submaximal e x e r c i s e . Even though the t r a n s i e n t heart r a t e responses were not considered important t o t h i s study, the e f f e c t of t r y i n g t o f i t . a f i r s t -order asymptotic r e g r e s s i o n model to data which might be of a second-order 5 2 nature may w e l l l e a d t o unavoidable d i f f e r e n c e s between p r e d i c t e d asymptotic and f i n a l recorded heart r a t e s . I n t h i s l i g h t , the 'D' scores of t h i s study seem to provide an e x c e l l e n t way of d i s c r i m i n a t i n g among the heart r a t e responses t o d i f f e r e n t d u r a t i o n p r o t o c o l s , yet f a l l s h o r t of p r o v i d i n g a s a t i s f a c t o r y method of e v a l u a t i n g which p r o t o c o l best lends i t s e l f t o the achievement of steady-state heart r a t e s . The f a i l u r e of the 'D' scores t o support hypothesis 4 i n d i c a t e s t h a t there i s no s i g n i f i c a n t d i f f e r e n c e between t r a i n e d and untrained subjects i n the extent t o which they achieve steady-state under d i f f e r e n t d u r a t i o n p r o t o c o l s . At l e a s t according t o the parameters of t h i s study, i t cannot be s t a t e d that a t r a i n e d subject's heart r a t e w i l l respond more q u i c k l y to the demands of submaximal e x e r c i s e . However, the decreased p r e c i s i o n t h a t comes from f i t t i n g data to models by least-squares methods e l i m i n a t e s e f f e c t i v e measurement of the t r a n s i e n t dynamics of heart r a t e response, which may s t i l l show d i f f e r e n c e s between t r a i n e d and untrained responses i f a more p r e c i s e measurement technique were i n v o l v e d . F i n a l l y , a n o n - s i g n i f i c a n t loads e f f e c t , and the l a c k of any d i f f e r e n c e i n 'D' scores between the 1 s t and 3 r d loads o v e r a l l (which f a i l e d to support hypothesis 5 ) , i n d i c a t e d t h a t the combined e f f e c t s of increased work l o a d i n t e n s i t y and greater elapsed t e s t time do not r e s u l t i n s i g n i f i -cant changes i n the extent t o which steady-state heart r a t e s are achieved. Once again, however, i t cannot be s t a t e d t h a t there i s no d i f f e r e n c e i n the speed of heart r a t e response under d i f f e r e n t work load i n t e n s i t i e s , s i n c e the t r a n s i e n t responses may be averaged out by the m o d e l - f i t t i n g least-squares procedure. CHAPTER V SUMMARY AND CONCLUSIONS Summary a The purpose of t h i s study was to examine the concept of " c r i t i c a l time" i n the a d m i n i s t r a t i o n of the PWC 170 t e s t , by a n a l y z i n g the heart r a t e responses and t e s t r e s u l t s of sub j e c t s undergoing f o u r d i f f e r e n t p r o t o c o l s of t h i s t e s t . S p e c i f i c a l l y , the problem i n v o l v e d determining the e f f e c t s of f o u r d i f f e r e n t work loa d d u r a t i o n p r o t o c o l s on the " c r i t i c a l times" r e q u i r e d to achieve s t e a d y - s t a t e , and on the PWC 170 scores. The combined e f f e c t of the order and r e l a t i v e i n t e n s i t y of the work loads on c r i t i c a l times was a l s o s t u d i e d , as was the e f f e c t of s t a t e of t r a i n i n g on both c r i t i c a l times and PWC 1 7 0 scores. The subjects o f t h i s study were 8 endurance-trained and 8 untrained c o l l e g e males, aged 18 tx>iJQ. A l l were vo l u n t e e r s . The t r a i n e d s u b j e c t s were a l l a c t i v e l y competing inmmiddle- or long-distance running, and achieved PWC 1 7 0 scores ( i n KPM/Kg./Min.) exceeding the 7 0 t h p e r c e n t i l e on the C.A.H.P.E.R. norms i n the p r e l i m i n a r y t e s t . The unt r a i n e d s u b j e c t s were a l l l e a d i n g r e l a t i v e l y sedentary l i v e s w i t h o u t any r e g u l a r strenuous aerobic a c t i v i t y , and i n t h e i r p r e l i m i n a r y t e s t they a l l scored lower than the 40th p e r c e n t i l e on the C.A.H.P.E.R. norms. A l l s u b jects took the p r e l i m i n a r y t e s t . As w e l l as confirming t h e i r s e l e c t i o n i n t o t h e i r r e s p e c t i v e groups, and a f f o r d i n g them an opportunity t o overcome the problems of learningaand h a b i t u a t i o n , the p r e l i m i n a r y t e s t a l s o allowed the experimenter t o d i s c o v e r the appropriate work loads f o r use i n the experimental t e s t s . Each s u b j e c t then underwent the experimental PWC 170 t e s t s — one of each of the f o l l o w i n g f o u r p r o t o c o l s ; three 3-minute work loads, three 53 5 4 4-minute work loads, three 5-minute work loads, and three 6-minute work loads. There was an i n t e r v a l of at l e a s t two days between the t e s t s i n order t o minimize problems of fatigue.. The experimental t e s t s were administered i n a counterbalanced Latin-square design t o avoid problems r e s u l t i n g from the order o f the treatments. The p e d a l l i n g cadence ontthe Monark b i c y c l e ergometer was s e t a t 5 0 r.p.m., and the warm-up c o n s i s t e d of ' 0 ' work l o a d free-wheeling f o r two minutes. Continuous h e a r t r a t e monitoring was f e d i n t o a computer which p r i n t e d out average heart r a t e s based on 1 5-second i n t e r v a l s throughout the e n t i r e t e s t time. These heart r a t e s , and the a s s o c i a t e d work loads, provided the raw data f o r t h i s study. A computer program was used t o f i t a l i n e a r r e g r e s s i o n between each work l o a d i n a t e s t , and the corresponding l a s t 15-second average heart r a t e p r i n t e d out f o r t h a t l o a d . The c o e f f i c i e n t s of t h i s l i n e a r r e g r e s s i o n were used t o determine the PWC 1 7 0 scores. Another computer program was used t o f i t an asymptotic r e g r e s s i o n between each 15-second time i n t e r v a l d u r i n g a given work load, and i t s r e s p e c t i v e 15-second average heart r a t e . The c o e f f i c i e n t s of t h i s asymp-t o t i c r e g r e s s i o n were used to determine the asymptotic steady-state heart r a t e . This p r e d i c t e d steady-state heart r a t e f o r each work loa d was then subtracted from the a c t u a l f i n a l 15-second average heart r a t e recorded, f o r each s u b j e c t , a t a l l three work loads, under each of the f o u r p r o t o c o l s . These 'D' scores thus gave an i n d i c a t i o n of the extent to which steady-state h e a r t r a t e s were achieved — negative 'D' scores suggesting t h a t steady-estate had not yet been achieved, w h i l e p o s i t i v e *D' scores i n d i c a t e d t h a t the f i n a l heart r a t e had exceeded the p r e d i c t e d s t e a d y - s t a t e value. 5 5 The experimental design allowed s t a t i s t i c a l analyses by two-way and three-way analyses of variance (ANOVA's). The independent v a r i a b l e s i n the f i r s t ANOVA were 'state of t r a i n i n g ' and 'PWC 1 7 0 p r o t o c o l ' , w h i l e the dependent v a r i a b l e was the PWC 1 7 0 score ( i n EPM/Min.). I n the second ANOVA the three independent v a r i a b l e s were 'state of t r a i n i n g ' , 'PWC 1 7 0 p r o t o c o l ' and 'work l o a d number' ( i n d i c a t i n g a l s o r e l a t i v e i n t e n s i t y ) . The dependent v a r i a b l e i n t h i s case was the 'D' score. Preplanned orthogonal comparisons were used t o t e s t the s p e c i f i c statements of the hypotheses. Conclusi ons PWC 1 7 0 scores. The o r i g i n a l a n a l y s i s showed a tr e n d toward i n c r e a s i n g PWC 1 7 0 scores w i t h s h o r t e r d u r a t i o n p r o t o c o l s , f o r both the t r a i n e d and untrained groups, but t h i s p r o t o c o l s e f f e c t trend was not s i g n i f i c a n t ( p ^ . 0 However, a f t e r a c a r e f u l a n a l y s i s of the r e s u l t s , s u b j e c t ' 0 , 5 ' was def i n e d as an " o u t l i e r " and another ANOVA was run w i t h the data from sub j e c t ' 0 5 ' d e l e t e d . The r e s u l t s were d r a m a t i c a l l y d i f f e r e n t , w i t h the p r o t o c o l s e f f e c t now h i g h l y s i g n i f i c a n t ( p < . 0 0 l ) , and expla i n e d w e l l by a l i n e a r f u n c t i o n ( p < . 0 0 l ) . On the b a s i s of these two analyses i t must be l e f t up to the reader t o conclude whether or no.it decreased d u r a t i o n p r o t o c o l s i n the PWC 1 7 0 t e s t s i g n i f i c a n t l y i n c r e a s e the t e s t scores. Strong evidence i n c l u d e d h e r e i n suggests t h a t they do, and f u r t h e r study i s recommended. Although the t r a i n e d group achieved higher PWC 1 7 0 scores than the untrained group (aa was expected, and i n f a c t demanded by the c r i t e r i a f o r subject s e l e c t i o n ) , the f i r s t ANOVA showed no evidence of an i n t e r a c t i o n e f f e c t between s t a t e of t r a i n i n g and the p r o t o c o l s e f f e c t d e s c r i b e d above. The second 'post hoc ANOVA' d i d f i n d a s i g n i f i c a n t i n t e r a c t i o n ( p ^ . O l ) which could s u c c e s s f u l l y be de s c r i b e d by e i t h e r a l i n e a r f u n c t i o n ( p < . 0 5 ) 5 6 or a cubic f u n c t i o n ( p < . 0 5 ) . Both t r a i n e d and untrained groups had t h e i r mean scores increased w i t h the s h o r t e r d u r a t i o n p r o t o c o l s , but the t r a i n e d group seemed t o have t h e i r scores i n c r e a s e d more d r a m a t i c a l l y . This suggests t h a t , i f the second ANOVA were v a l i d , i t may be even more important f o r t r a i n e d a t h l e t e s t o undergo longer d u r a t i o n p r o t o c o l s of the t e s t since the s h o r t e r p r o t o c o l s may overestimate t h e i r scores even more than those of the untrained s u b j e c t s . 'D' Scores There was a h i g h l y s i g n i f i c a n t p r o t o c o l s e f f e c t i n the 'D' scores ( p < . 0 0 l ) which was e x p l a i n e d almost e n t i r e l y by a l i n e a r f u n c t i o n ( p < " . 0 0 l ) . This i n d i c a t e s t h a t , t o the extent t h a t the p r e d i c t e d asymptotic steady-state heart r a t e represents the r e a l steady-state values, d i f f e r e n t p r o t o c o l s have a l i n e a r r e l a t i o n s h i p w i t h the extent to which steady-state i s achieved. According t o the data h e r e i n , the 4 -minuted p r o t o c o l provided f i n a l heart r a t e s c l o s e s t to steady-state ( f o r both t r a i n e d and untrained groups). The 3 - m i n u ' t e p r o t o c o l was not l o n g enough t o achieve s t e a d y - s t a t e , and r e s u l t e d i n negative 'D' scores. On the other hand, the 5 - and 6-minute p r o t o c o l s r e s u l t e d i n p o s i t i v e 'D' scores, suggesting e i t h e r t h a t something had occurred t o i n c r e a s e the heart r a t e beyond ste a d y - s t a t e , or t h a t the asymptotic model f a i l e d to a c c u r a t e l y describe the heart r a t e ' s r i s e t o steady s t a t e , perhaps by,.not t a k i n g i n t o account the "slow component" of heart r a t e a c c e l e r a t i o n s caused by humoural agents. A b i - p h a s i c second order model may be best even f o r purposes such as these. I n t h i s l i g h t , i t was concluded t h a t the 'D' scores seemed t o provide an e x c e l l e n t way of d i s c r i m i n a t i n g among the heart r a t e responses to d i f f e r e n t d u r a t i o n p r o t o c o l s , yet f e l l s h o r t of p r o v i d i n g a s a t i s f a c t o r y 57 method of e v a l u a t i n g which p r o t o c o l "best lends i t s e l f t o the achievement of steady-state heart r a t e s . The l a c k of a s i g n i f i c a n t d i f f e r e n c e i n the 'D' scores between the t r a i n e d and untrained groups i n d i c a t e s t h a t s t a t e of t r a i n i n g does not appear t o a f f e c t the c r i t i c a l time r e q u i r e d t o achieve s t e a d y - s t a t e . However, more p r e c i s e measures of heart r a t e response ( t h a t do not average out the fefiK: t r a n s i e n t dynamics by r e g r e s s i o n f i t t i n g on a least-squares b a s i s ) must be undertaken before t h a t a s s e r t i o n can be considered c o n c l u s i v e . The l a c k of a s i g n i f i c a n t loads e f f e c t i n d i c a t e d t h a t the combined f a c t o r s of work load number ( i n c l u d i n g elapsed time and previous heart r a t e responses) and r e l a t i v e work i n t e n s i t y have no s u b s t a n t i a l e f f e c t on the c r i t i c a l time r e q u i r e d t o achieve s t e a d y - s t a t e . This does not say, however, t h a t they have no e f f e c t on the t r a n s i e n t dynamics of the heart r a t e as i t increases toward s t e a d y - s t a t e , f o r the same reason mentioned above. 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"A comparison of three W170 p r o t o c o l s , " Europ. J . Appl. P h y s i o l . , 3 7 : 123-128, 1977-1 7 1 . Wyndham, G.H. "Submaximal t e s t s f o r e s t i m a t i n g maximum oxygen i n t a k e , " Gan. Med. Assoc. J o u r n a l , 9 6 : 736-742, I 9 6 7 . 1 7 2 . Wyndham, G.H., Strydom, N.B., e t a l . "Studies of the maximum c a p a c i t y of men f o r p h y s i c a l e f f o r t , " I n t e r n . J . Angew. P h y s i o l . , 22: 2 8 5 , 1 9 6 6 . 1 7 3 ' Yuhasz, M. P h y s i c a l f i t n e s s and sports a p p r a i s a l : l a b o r a t o r y manual. London, Ontario: U n i v e r s i t y of Western Ontar i o , 1 9 6 8 . APPENDICES 71 APPENDIX A RAW DATA 72 HEART RATES (Averaged and Recorded every 15 seconds) S = Subject P = P r o t o c o l (3 = 3 minutes, 4=4 minutes, 5=5 minutes, 6=6 minutes) L = Load (A = 1st l o a d , B = 2nd l o a d , G = 3rd load) PO = Power Output ( i n KPM/min.) S P L T O 1 2 3_ 4 i 6 7 8 2 - ' l U ^ 1 2 ] A l 5 l 6 l 2 l 8 l 2 20 ^ 2 2 2 2 2 l t 01 3 A 0900 078 100 102 111 114 117 119 123 122 122 123 120 01 4 A 0900 078 098 110 112 115 116 117 119 118 115 121 119 118 119 118 120 01 5 A 0900 092 101 106 109 114 112 112 116 116 116 123 125 124 121 124 124 125 126 125 126 01 6 A 0900 0.89 108 107 110 114 116 119 118 118 120 121 121 117 118 121 122 120 119 121 125 124 123 124 126 01 3 B 0975 Q85 106 115 119 122 123 124 125 126 124 125 128 01 4 B 0975 075 075 104 113 115 122 126 124 129 132 126 129 130 129 129 128 128 01 5 B 0975 0.86 108 117 122 126 129 129 131 132 133 134 133 132 133 133 I36 135 135 136 137 01 6 B 0975 092 111 117 121 125 127 129 130 129 129 133 133 130 133 135 138 140 137 135 136 135 134 134 136 01 3 C 1050 096 114 122 124 129 134 141 141 139 138 138 139 01 4 G 1050 082 112 121 127 129 134 135 137 135 139 139 139 140 139 138 138 01 5 G 1050 087 110 123 132 140 139 141 144 143 140 138 139 143 142 139 142 144 143 142 144 01 6 C 1050 113 120 128 133 136 137 138 141 139 143 143 142 141 142 143 143 140 143 140 143 143 145 144 144 02 3 A 0825 075 101 110 114 116 11? 119 117 120 121 120 119 02 4 A 0825 081 099 108bll3 114 113 113 115 118 120 120< 120 118 118 118 118 02 5 A 0825 085 102 109 116 115 119 121 119 121 121 122 121 123 124 124 124 125 126 124 125 02 6 A 0825 0 89 106 113 116 116 115 119 116 118 117 119 119 121 119 124 123 121 123 124 126 124 125 123 125 02 3 B 0975 0;89 108 117 125 128 130 130 130 130. 131 131 131 02 4 B 0975 088 108 121 123 129 131 131 131 132 131 128 130 127 130 133 133 02 5 B 0975 101 118 121 125 130 132 132 133 134 134 134 135 135 133 137 138 138 136 139 139 02 6 B 0975 102 118 123 129 134 133 134 133 136 135 135 137 134 137 137 139 137 139 139 139 138 137 137 140 02 3 G 1125 096 113 126 132 135 136 138 138 139 142 144 145 02 4 G 1125 101 114 126 131 138 139 138 142 143 145 144 143 144 145 145 144 02 5 G 1125 107 120 125 133 137 140 141 142 144 142 144 145 146 144 147 148 148 149 150 151 02 6 G 1125 108 122 131 134 139 140 140 141 146 148 147 147 148 150 150 149 148 152 152 151 153 155 152 154 74 tt) H C o o (D to i n >5 M (D > H •g o o CD PH § H CD bD to-rt CD w (D -p • H e ve-il N O CO 0 - P i n O id cn to ii CD -p o o -a- H it to CO • H cn a-CM II pq •iH CO O C • H - P ^ cn H < - P O' o o CD O •i-5 - P -2 ° CO Ph Ph - P pi o CD O g Hi Ph 31 i n 9 N O cn H C N -H fN-H H i n o cn i n H H SI CM CM rH i n cn H N O •d-H J" H H O en i n H H 811 rH CM rH en en H N O H CO H H NB O N cn H H C M | CM CM i—1 .3-cn H CN-H O N H H •in O N en ^3-H H °l cn CM 9 9 is- en en en H H H N O i n .3-H H i n o -H H H H en i n co C M en en ^ - ^ H H H H SI O N ^3" r l 9 CN - en cn en H H H N O ^n -3 -H H N O O H CM H H N O I en O N O N en en ^ -3-H H H H H | rH m 9 9 O - i n en en H H O N O *n .4-H H i n i n H H H H ^3" CN- H O N cn en i n ^ j -H H H H 51 CM CM H m CM i—1 >ic\ i n en en H H $ 3 H H CM H H H H CM H H en en i n i n H H H H 31 C O CM H C M H rH CM C M H H -3-en en en H H H H H H i n . 3 -H H H H H H cn en J - i n o H en en en ^ i n i n H H H H H H 31 C^  rH rH CM H rH CM CM rH H -d" CM cn en en H H H CM H CM H d H ^ N O jj-H H H H H H cn C M o i n o N O en cn en ^ i n ^ -H H H H H H 31 0 3 . CM 3 9 O CM rH CM -3" CM en en en H H H H C3N Q H H H i n U N N O H H H H H H CM O N ON i n C O i n en C M C M -d- -d- -3-H H H H H H SI O N CM r 1 9 O CM H C M -d" en en cn en H H H Q N O , H -5 ^3" H H H i n C M co H H H H H H C M C M oo mNO i n cn en en J ^ - j^-H H H H H H 91 CM r—1 CM H H H rH CM rH CM CM -d" ^ Q cn cn cn c n i r H H r i H H CO N O i—1 cn-d- -3-H H H i n en J - -3-H H H H H H H H o C M i n O N en N O c-cnenencM^}-je-^--cJ-H H H H H H H H "HI H| O CM H ON i n O ^3" C O i n CM Q rH CM C M 0°\N C ^ n ^ H H H H H H H H O N N O H c n . * -d-H H H N O >n ^3" CM H H H H H H H H o C M C - ^ C M cnoNO-en e n e n c n e n ^ - ^ - ^ - ^ -r-\r-\r-\Hr-ir-]Hr-i s i CM' CM H ON cn i—1 rH CM CM rH rH rH i ^ o ^ o enco O N C ^ J J -r-^r-ir-tr-ir-{r-i<-\<-t O - N O N O -3" H H H H H H H H CM inONH^j- C ^ N O C M cnencM e n ^ - ^ t ^ - ^ H H H H H H H H ON CM rH CM r—1 r—1 rH ON vr\ c\| \T\ CM P Q CTN Cn rH n c A n n ^ - ^ ^ ^ -H H H H H H H H r i -3- ^ N O CM H H H H H H H H o ^ n o H J - i n c N - o e n e n c n e n ^ - ^ - ^ - en H H H H H H H H » | CM CN-NO H CM H H H^tCM>nHcnCjNCOCM C M cn cn cn cn-3- on .4- -3-H H H H H H H H H i n ^ - i n i n H ^ - e n c M C M ^ - H o HHHHenencncn^-3-^}-^-r-\<-\r-\r-\r-{r-\rHr-tr-ir-\r^<-i «H CM CM H CM N O CM CM rH rH cncM c n i n c M CM Cn cn cn m-d" rH H H rH rH H Q N O CM 3 ^" H H H ininNO c -^oo H H H H CM rH rH rH rH rH cn C N - C O C M ^ -en C M en^3- ^ J J - 3-H H H H H H H CM CM H en N O CM CM H rH cn cn O rH CM O N H N O rH C M c n c n c n c n c n . 3 - . d - ^ f r H H H H H H H H r l i n C N - co N O H H H H H H H H C N - O N ^ j - i n o c n i n c n CMCMCMCn^-^-^}-^ H H H H H H H H ^1 CM CM H CM CM CM CM CM H H rH cnoCMrHCN-ON -d-ON r-ir-\r-ir-\r-ir-\Hr-{ O - N O i n i n N O co C ^ N O . i n o O N N O HHHHcMCMCMcnen^-encn H H H H H H H H H H H H •=H O N H H N H H H O CM H o o- cn O - N O moNO cn C M cn C M cn cn-3- cn H H H H H H H H i n *n en H r-] r-i r-i r-\ r-{ r-\ <-i CM H C N - ^ j - C N - o i n H N O C M C M cn en en cn cn r-i r-\ r-\ r-\ <-i r-{ r-\ cn| cnMD >n.d-H O H H rH H rH rH cn cn CN - o co CM CM CM CM CM r-\ r-{ r-\ r-i r-t O N en N O C M en C M H H H HOO-ONCO^-ONCn^tONO!N-H H O O H C M H C M C M en CM CM rHr-\r-\r-\r-ir-\r^r-]r-]r-<rHr-\ II II II II tn Ph hI O C\CM| PhI i-hM P4l CQl 9 ^ H 4 - Cn- CM ^3" H H H H CM H H ^3" H ON 3^-O On O On H H H H eS H l ^ H 4 ONONNO H CN-O O o m i CN- CO CN- CO CO ON 0 0 ON ON ON 0 0 C O o o o o o o o o o o o o o o o o o o o o o o o o o o o o i n ^ n i - n i n o o o o OnOnOnOnOOOOCMCMCMCM OCOOrHr-\r-ir-{r-it-ir-\r-i < t J < c ; < c ; < ; p q p q p q p q o o o o cn^t " ^ N O en^}- >nNO cn^- i n N O c ^ t ^ r ^ e ^ e ^ n e ^ n n n n n o o o o o o o o o o o o C J N N O C O incN-Hoo H i n c o O N ^ -O O O O O H O H H H H H H H H H H H H H H H H H en N O O N i n c N - c M n ^ 3 - H O m e n 0 N 0 0 C 0 0 0 0 0 0 0 0 N 0 N O O O O O O O O O O O O H H H H O O O O O O O O O O O O i n i n i n i n o o o o v n ^ n i n i n O-CN-CN-O -ONONONONO O O O O O O O O O O O H H H H en^3- i n N O en^- i n N O en^3- WN.NO ^ • ^ 3 - ^ - ^ - ^ 3 - ^ - - d - ^ - ^ 3 - ^ 3 - ^ 3 - ^ -o o o o o o o o o o o o HEART RATES (Averaged and Recorded every 15 seconds) S = Subject P = P r o t o c o l (3 = 3 minutes, 4 = 4 minutes, 5 = 5 minutes, 6 = 6 minutes) L = Load (A = 1st l o a d , B = 2nd load, G = 3rd load) PO = Power Output ( i n KPM/min.) s P L PO 1 2 3 4 5 6 7 8 1 10 11 12 n 14 15 ' 16 iZ 18 19 20 21 22 23 24 05 3 A 0975 087 109 118 123 124 124 122 121 120 120 120 118 05 4 A 0975 088 114 123 130 130 130 129 129 126 127 124 123 125 124 124 124 05 5 A 0975 091 112 121 125 127 128 128 127 124 122 123 124 125 125 123 124 123 124 124 126 05 6 A 0975 100 110 120 125 127 127 125 125 124 123 124 123 124 124 124 124 125 124 124 124 124 125 129 127 05 3 B 1050 104 114 123 126 127 127 127 125 125 125 126 125 05 4 B 1050 096 116 129 132 135 134 135 133 132 130 130 131 130 131 130 131 05 5 B 1050 095 116 124 128 132 132 132 132 131 130 129 129 129 130 129 128 128 129 130 130 05 6 B 1050 101 125 125 129 131 131 130 128 129 127 128 129 128 128 128 130 128 127 133 127 127 129 130 130 05 3 G 1200 093 118 128 133 132 133 132 130 132 134 134 134 05 4 G 1200 098 118 133 136 139 139 139 137 135 136 139 137 136 136 137 138 05 5 G 1200 101 119 129 136 138 139 139 138 139 140 137 137 137 138 140 139 140 139 139 138 05 6 G 1200 111 123 127 131 132 134 134 134 134 134 132 133 132 132 134 132 133 133 133 131 133 135 136 136 06 3 A 1050 078 110 121 124 123 121 122 122 124 123 125 124 06 4 A 1050 076 105 120 120 123 122 120 124 125 124 126 127 125 126 126 125 06 5 A 1050 082 108 124 126 124 124 125 126 125 128 126 124 124 126 128: 128 128 125 127 127 06 6 A 1050 072 104 118 124 122 126 125 122 124 128 127 124 126 126 128 127 126 124 126 126 128 128 126 127 06 3 B 1125 101 118 129 135 137 135 134 133 135 134 136 136 06 4 B 1125 092 113 124 130 134 133 134 130 132 131 134 135 132 133 131 134 06 5 B 1125 098 118 127 134 139 139 140 138 137 136 138 137 136 135 134 136 136 138 139 138 06 6 B 1125 101 119 129 136 140 139 138 141 138 137 138 136 138 139 140 141 141 139 139 140 141 141 140 140 06 3 G 1200 097 117 125 134 139 140 144 145 148 148 149 150 06 4 G 1200 099 120 127 128 134 138 144 144 146 146 145 147 145 148 149 149 06 5 G 1200 103 122 125 134 139 145 144 147 146 418 148 147 146 148 149 150 149 151 152 151 06 6 G 1200 105 125 128 136 139 146 148 152 151 151 153 152 152 150 149 151 153 153 154 155 154 153 153 153 HEART RATES (Averaged and Recorded every 15 seconds) S = Subject P = P r o t o c o l ( 3 = 3 minutes, 4 = 4 minutes, 5 = 5 minutes, 6 = 6 minutes) L = Load (A = 1 s t load, B = 2nd l o a d , G = 3 r d load) PO = Power Output ( i n KPM/min.) S P L PO 1 2 3 4 5 6 7 8 ? 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 07 3 A 0900 075 100 109 115 117 115 114 119 120 118 120 122 07 4 A 0900 082 0981108 117 119 118 120 121 123 121 123 124 123 125 123 123 07 5 A 0900 076 101 108 118 119 120 119 118 121 124 123 124 123 125 124 123 123 123 124 124 07 6 A 0900 080 100 105 112 119 122 124 122 121 124 123 124 125 126 126 126 127 124 123 122 121 123 124 122 07 3 B 1050 082 106 112 118 128 135 136 136 138 138 137 136 07 4 B 1050 086 108 120 129 136 137 135 134 136 135 137 137 136 136 138 138 07 5 B 1050 090 105 118 130 134 137 135 136 138 136 135 136 138 139 138 138 137 136 138 138 07 6 B 1050 092 109 118 129 136 135 140 141 140 139 139 140 138 139 141 140 139 138 139 139 139 140 140 140 07 3 G 1200 100 115 125 130 136 145 148 150 151 149 150 150 07 4 G 1200 098 113 126 133 137 144 146 148 150 152 151 150 151 149 150 151 07 5 G 1200 103 116 128 132 141 146 148 150 151 153 153 151 153 154 154 154 154 153 152 153 07 6 G 1200 105 118 129 135 145 149 151 152 153 152 153 150 149 151 153 153 154 156 154 155 156 154 155 155 08 3 A 0900 082 094 108 115 126 128 125 126 126 127 126 127 08 4 A 0900 09'1 095 109 116 123 125 126 127 128 128 127 126 126 127 126 127 08 5 A 0900 090 096 107 117 125 128 127 128 128 126 127 128 129 128 126 125 126 127 126 128 08 6 A 0900 086 088 099 105 118 127 128 128 127 128 127 126 127 126 125 127 128 128 126 129 128 130 128 129 08 3 B 1050 091 098 118 138 140 143 144 145 144 145 145 145 08 4 B 1050 088 096 120 137 144 145 143 144 142 143 143 143 142 143 144 143 08 5 B 1050 093 105 115 138 143 146 146 147 148 150 150 148 149 147 147 148 147 148 147 146 08 6 B 1050 090 101 122 139 141 144 147 148 147 146 146 144 146 144 148 148 147 146 146 146 145 147 146 146 08 3 G 1200 101 115 124 137 143 143 148 153 155 158 159 160 08 4 G 1200 094 116 128 139 145 145 148 154 153 157 155 157 158 159 161 161 08 5 G 1200 098 119 129 140 146 146 151 153 159 163 162 163 160 161 161 163 164 164 164 I65 08 6 G 1200 103 124 128 140 145 147 154 155 158 160 164 163 162 164 163 163 165 164 166 167 164 165 166 166 HEART RATES s = Subject • (Averaged and Recorded every 15 seconds) p = P r o t o c o l (3 = 3 minutes, 4 = 4 minutes, 5 = = 5 minutes, 6 = 6 minutes) L = Load ( 1st l o a d , B = 2nd load, G = 3rd load) PO = Power Output ( i n KPM/ min.) s p L _P0 1 2 1 3. 6 7 8 1 10 11 12 12 14 16 17 18 12 20 21 22 09 3 A 0675 074 092 103 110 114 118 121 120 114 116 118 121 09 4 A 0675 076 089 108 112 116 120 121 120 118 121 123 122 122 121 121 122 09 5 A 0675 079 094 101 112 110 115 118 122 120 124 123 122 121 122 121 124 123 124 123 124 09 6 A 0675 079 086 109 115 115 118 124 122 123 121 124 124 122 120 118 120 122 124 124 125 125 124 09 3 B 0750 081 103 114 125 127 128 125 128 130 129 131 131 09 4 B 0750 085 110 116 123 128 129 131 133 135 134 133 133 132 131 132 132 09 5 B 0750 084 106 114 126 128 126 124 128 130 129 131 132 134 131 132 133 133 134 135 135 09 6 B 0750 091 110 119 123 125 124 125 127 128 130 130 131 129 131 129 131 130 133 132 134 135 136 09 3 G 0825 090 110 118 128 143 143 136 136 140 141 144 144 09 4 G 0825 085 114 119 129 139 142 143 144 145 144 143 145 146 148 147 147 09 5 G 0825 092 112 119 127 142 144 146 147 146 145 145 147 147 146 145 147 149 150 149 149 09 6 G 0825 095 114 120 131 141 143 142 144 145 146 144 146 148 149 149 148 147 149 150 150 151 150 10 3 A 0750 095 106 111 110 122 121 124 122 127 132 128 127 10 4 A 0750 087 105 110 112 118 120 123 122 125 127 126 128 126 125 126 127 10 5 A 0.750 091 102 107 108 117 117 120 121 124 125 126 126 127 128 127 126 128 126 127 128 10 6 A 0750 086 103 109 110 116 116 121 120 122 127 130 127 127 128 130 130 127 128 131 131 131 127 10 3 B 0825 099 110 118 124 135 136 138 138 141 142 141 10 B 0825 096 108 114 120 129 130 135 138 139 140 142 143 144 143 142 143 10 5 B 0825 102 112 114 121 130 132 133 136 139 139 142 144 142 144 142 142 143 145 144 146 144 10 6 B 0825 100 118 123 124 130 134 136 138 141 141 142 142 141 140 142 141 143 143 145 145 145 146 10 3 G 0900 108 120 126 134 140 145 150 151 156 155 158 158 10 G 0900 105 121 125 130 135 140 150 148 151 153 155 157 156 155 158 159 10 5 G 0900 109 121 124 128 129 137 145 149 150 150 154 155 157 154 158 159 160 159 160 160 10 6 G 0900 103 121 125 134 140 144 147 150 151 153 154 159 160 159 159 160 161 160 160 161 163 163 126 127 138 139 149 151 132 129 146 146 163 162 78 EH CO H o o CO w UN u CD > CO H CD -d o o CD PH H C n5 t j 0 hD co* CD co CD - P C •H e NO II N O co CD - P 2 SH •H U N % O UN. H u - CN CQ jS 11 .3- o -d i n . CM -d co c3 |s 31 ON CM rH O U N rH H O-H C N C N H ON H UN NO H SI o C N rH CN! " N rH CN! O-H U N C N H CO •d" H UN NO H SI rH C N H C N U N rH CN! O-H C N C N H CO •d" H -d" NO H SI CN! CN H NO UN H C N O -H •3" C N H NO -3" H C N NO H ON CN! CN! C N H H CO CN! ^ UN H rH O H O - O -H H CN! CNi C N C N H H NO CO H H NO 5 H H si ON CN! CN! CN rH H U N O -3- U N rH H H ON O-NO H H CNi CN! C N C N H H UN NO -3" -d" H H CN -3" NO NO H H co o CN! C N H rH NO CN--3- -3" H H O CO 'CNJ.NO H H CN^3-C N C N H H CN! UN, -3- -d" H H C N NO NO H H si CO CO s s NO CO -3" rH H CO CO NO NO H H H H C N C N H H C N C N •3- -3" H H H H si CO CN-NO CN! CN! CN! H H H ON CN! H ^3- U N H H H U N CN- ON NO NO NO H H H ON H ON CN! CNCM H H H U N I—1 NO .3- -d- -3-H H H NO C N U N NO NO NO H H H si CO NO NO CN! CN! CN! H H H CN— CN! ON -3- -d-H H H -3; u > * C O NO NO NO H H H ON ON ON H H H NO* NO" NS H H H si ON NO C N CN! CN! CN! H H H CO CN! ON -3- -3- ^3-H H H -3" C N CN-N O NO NO H H H CN- ON O CN! CN) C N H H H O ON CN! -d- CN^3-H H H C N - d ; NO NO NO NO H H H si O-NO J3" CN! CN! CN! H H H CN- i—1 NO ^3- -3" -3" H H H UN H CO NO NO NO H H H -3" CN-CO CN! CN! CN! H H H ON CN- Q C N C N .3" H H H •3" C N U N NO NO NO H H H CN) ONNO U ^ C N ) O N C O CN) CN-CN! CNCN) CN-H C N ! C N ! C N ! C N 1 J J - J 3 - ^ - ^ 3 - N O N O N O N O H H H H H H H H H H H H H I C 0 C 0 I T I R I C 0 \ 0 N 4 O H H 4 H | C N ! C N ! C N ! C N ! ^ 3 - ^ - ^ 3 - ^ 3 - N O N O N O N O CO II. •H CO S o c C N H <H II - p " ^ CO - P CN H 3 PH II - £ H 3 - P O < O O O • 0 O •O -p O 3 M O O CO PH r l PH II II II II I CO PH h i O S3 PH O H oN co I M NO | UN| •^1 CN| CM | O PH N O ^ - C N - C O O N C O O N C N - C N - O H C N CM CM CM CM C N C N C N ^ - U N NO NO NO H H H H H H H H H H H H C N - U ^ U - N U N C O N O C O Q U N C O 0 0 O N C M C M C M C M m C N C N - 3 - U N U N U - N U N NO NO ^3" C N C N - C N - H N O O C M O N H C M C M C M C M ^ - ^ - - 3 - ^ 3 - N O N O U N N O H H H H H H H H H H H H CO .3- CM U N 0 - N O NO Q C O H C N - O N C M C M C M C M ^ J - ^ - C N ^ - " N N O U N UN H H H H H H H H H H H H N O C M C M C M N O U N N O C O N O O N ^ - O CM CM CM C M ^ - ^ T C N C N UN U N UN.NO H H H H H H H H H H H H ^ 3 - C M C M C O U N C M ^ - O N U N C O U N C N -C M C M C M H ^ J D - O N C N U N U N U N U N H H H H H H H H H H H H H ON O U N CM ON C N N O CM U N CN -3" C M H C M H - 3 - C N C N C N U N U N U N U N r-\r-\r-ir-\r-t<-\r-{v-trHrHHr-< CO ^ - C N - U N U N N O C N O N H O N O - O H H H H C N C N C N C M U N ^ - ^ - U N H H H H H H H H H H H H -4" CN-^3" CN-CM O CN-CN-UNCN-ON^3 -rH O H O C N C N C M C M - 3 - - 3 - C N - 3 -rA<-ir-ir-\r-{r-\<-\r-\r-ir-\r-{r-\ C M C M H ^ - C N - C N H O N - 3 - U N O H H O H O C M C M C M H C N C N C N C N CN- CO _d* NO CM CM CM CM H H H H NO CN- O NO CM CM CM CM H H H H -d - NO UN U N CM CM CM CM H H H H O O O C N CM CM CM CN-OO U N C O O O C N - U N , O N CNCNCNCNUNUNiUNUN. H H H H H H H H -3" NOi CO NO C N U N H N O C N C N C N C N U N U N U N U N C M ^ t ^ - C M C N C N O U N CNCNCNCNUNUNUNUN s CO NO O H H H CM CM H H H H CO ON UNCO r-\ r-\ <-{ r-\ r-\ r-i r-{ r-i UNCO UNCO UN ON CO O -O O O O O N C M O N H O C N , C O < r N C M C N C M C N U N J H / ^ 3 - U N r-\r-]r-\r-\r-\r-\rHv-i NO CN-UNOO U N .3- NO ON C M C M C M C M . 3 - - 3 - - 3 - . 3 -H H H H H H H H CNCNOO UN O N O CM UN CM CM H CM CN i? -3" -d" O C N U N C O C N ^ 3 - N O CN-CM CM H H C N C N C N C N rHrHr-\rHr-\<-\r-\<-\ H -3" O N C M N O U N O N U N ' O N H CM CM H CM ~ r-[ <-] r-{ r-\ <-\ r-\ <-\ O r-i PHI C0| ON U N U N CO CO NO O O O O H H H H CM -3" NO C N O O O O O O r-i <-\ r-\ r-i r-i O O O O UN U N U N UN U N UN CM CM •3- -3- -3- J " U N UN O O O O O O <t| < < <t| pq pq CN -3 " UN N O C N - 3 -O H H H H H ON CN CM O CM CM CM CM H H H H O - C N ON^3" CM C N ON O H H H H O H H H H H UN UN CM CM UN UN O O PP PH UN NO O O O O O O O O NO NO NO NO O O O O o o o o C N ^ - i U N NO H H H H H H H H H H H H H H H H CM NO -3* NO O O O O H H H H O ^3" CO NO ON ON CO 0 0 O O O O O O O O O O O O NO NO NO NO O O O O CN -3" U N NO CN! CM CM CM ON NO O N ^ - CN- UN - rr ON ON CO ON H H H O O O O H H H O N C N - C M C S X C N - H CM O O O C O C O C S X O N O O O O O O O . O H H H o o o o o o o o U N U N U N U N O O O O C N - C N - C N - O - O N O N O N O N O O O O O O O O P H P H P H P H O O O O C N ^ - U N NO C N ^ " U N NO C M C M C M C M C M C M C M C M r-\rHr-\rHr-\r-fr-]rH 79 CO m EH W d fl o o CO w VO CO > CO <d co d H o o CO « d <d 0 M nJ in > CO CO - P II MD CO -p c ^ •rl nri vo O H VO rH co to CO •rl •d O -3- rH II <d -3- CM, CO II CO - P o o o CO o •o-p ^ o CO 31 CO •3-rH CMi MD H - 3 CN-H CM| CO •3" H -3-MD rH CM O-rH MD - 3 H •3~ MD H •3~ rH SI rH O MD rH CM H CM| CO vo 3 3 CM -3c MD MD rH H CM O rH rH 31 co co 3 - -3" H rH CO VO MD MD H H ON OS MD MD H H H | CO VO -3" - 3 H H rH CO MD MD rH H CM ON O-MD H H <M H I 3 3 H rH CO o VOMD H rH CM ON !>-MD rH H 31 -3- -3- .3-rH rH rH O- CM -3r VOMD MD H H H ON O -3c MD £>-MD i—1 rH rH H H H ON VO^ -VOMD MD H r i H ON CO ON MD MD MD H H H ON H CM CO-3- -3-H H H O VOMD MD H H H C*- CM MD MD MD H H H SI I S N Q co-3- -3-H H H CO H n 1A\D MD H rH H CM CO CO MD MD MD H H H CM V O H H V O C O V O O O N J S O C O O ^ } -H CO CO -3" CO -3" VOMD VOMD MD MD MD H I H .3- C O 0 0 V O J J - O V O 4 - -3c H ON H C O C O ^ t C O ^ - VOMD VOMD MD MD vo O l C^- VO CO MD -3" -3" MD {>- CO -3" CM ON H CM CO CO C O S " vo vo VOMD MD MD vo r-{r-\r-ir-\^r-\r-\r^r-iHr-ir-f ONCO V O C M O O M D M D C O C M ^ - M D CO CN CM CM CO CO^J - vo vo VOMD MD VOMD Hr-\<-\rH^-\r-\r-{r-\r-\r-{r-lr-{ CO - 3 C O c O O O - 3 ; C O O 0 0 C O C M H COI CM CM CO CO VO VO VO VO VOMD MD MD r-\r-\r-\<-\r-\r-\r-\r-\r-ir-\r-\r-\ CO - 3 CO O N O - C M O O C N - O O O - O N CH CM CO CO CM vo vo vo vo VOMD vo H H H H H H H H H H H H H M D C M V O C ^ O - C O M D ^ - H O C O MDI CM CM CO CM - 3 -3" -3" VO VOMD vo H H H H H H H H H H H H II S pq e! "SB 0 H C •H - P - — [Q H - P II PH u d co nJ £ O O •3 PH MD - 3 CO -3" CO -3" MD VO) H N N W 3 i 4 - 3 CM O ON V O V O V O . 3 -•3-1 C O - 3 C O O M D H ^3 O N H M D M D CO H c M C M C M C O ^ - ^ - C O ^ } - ^ - C O ^ -C O O 0 0 O N V O O N O N V O O N O - V O O CO| H CM H H CM CM CO CO CM CO CO - 5 H H 0 O vO-3" H CN-VOCM ONVOCO OJ| HHHHHCMCMCMCMCM CO CO O PH O N C O H V O C M O ^ - C M H M D C M O N O N O N O O N O H H H H H C O C M O O H O H H H H H H H H v o v o v o v o o o o o v o v o v o v o N N N N O O O O N N N N vo VO vo VOMD MD MD MD MD MD MD MD O O O O O O O O O O O O CO PH ^ O PH II p.fM| CO -3 " VOMD C O ^ t VOMD C O ^ t VOMD CO| CO CO CO CO CO CO CO CO CO CO CO CO vo CO vo CO CO CO VO CO MD co VO CO ^3 co ON vo CM CO ON MD CM CO H H MD MD CM CO MD .3-MD -3-o --3-H CO •3; C M ^ O N M D -3" CO, _3" MD CM CM CO H ON CO -3" -3" CO CM CM C O ^ -O O CM CM -3" CO CO CM CO -3" 3>3 H H O CO - 5 -3" VO 3 " O vo co^- .3--3" H H -3" CM H 3" ^3 vo H H H CO H CO 3 " .3- -3-VO VO VO VO CO VO C O V O VO VO CO C O V O V O C O V O V O V O VO >?\ H H CO H H VO VO VO 1—I 0 CO VO vo^3 H H H CM vo V 0 . 3 - 3 " MD H CO CO O O ^3 -3" - 3 vo vo^ H H H H H H MD O CM CO H -3" C^-^3 -3- -3- vovo3- ^3" H H r-\ <-t r-i r-\ <-\ - 3 ON H CM O CM CO CO CO -3" V O V O - 3 - - 3 vo CM H CO CO CM O v^>A3 V O O N C O O - O - O C O C M C M ^ - ^ 3 - C O ^ - ^ - ^ - ^ - ^ 3 H H H H H H H H H H H O N C O C O V O C O O O N 0 \ 0 C M C M C M ^ ^ - ^ J - ^ ^ " ^ ^ MD CO CM CM H H CN- CM CM CM C O H 9 9 VO O CM CM H H H CO o - c o ^ 3 -CM CO CM "CM MD CO H MD H ^3 c o ^ -H H H ON vo vo CO C O CO H H H CN- C O CM CO CO CO CO H H ( CO CO C O -MD vo ON^J--3- -3- co3-00 J - C O ON ^3 3; -3" co CO 1—l VO ON - 3 -3" - 3 CO H H H H 00 H H CO-3 -3" MD CO -3" CO ON CO CO CM H H H O \ o 4 - I N CO-3" CO CO CN-00 O O O ON O O O MD O CM O ON ON O O O O O O MD MD O O <:< :< ; co^j- vo 3 - .3- -3-ON o H VO ON O O O MD O < MD •3; MD 00 00 O CM CM CO H H H VOMD CN— CM H r-\ r-i r-\ CO VO CM - 3 CO CO CO CO H H H H CO J 3 C ^ M D CM CM C\j CM VO !>-MD O pq CO .3-C O H H O O O H H H V O V O V O O -MD MD MD O O O PQ PQ PQ ^3" VOMD 3 " ^3" CO VOMD ON O O O H O O O O vo vo vo VO £>- CN- (N- C~-O O O O o u o u CO^ 3 VOMD - 3 -3- J" -3" H H H H 80 CO H K En 5 to <d C o o CO tQ " N CO TH CO H fH O o CD « -d p cd fH CD > CQ CD N O II NO co CD -P UN Hi o II rH U N rrj r) - CN CQ CO It a ' i ! <d~ -3- o TH CM • to II >H O £ CN rH . H II - P ^ CO -P C N H 3 PH 9. < O II -P o o CO O rH •Q+> >d 0 P o 3 s 3 rH O O CO PM r-H PM 31 H C N rH o UN rH C N O -rH SI H CN rH ON •3" H C N O -H SI CM C N H ON s -3-O -H SI O C N rH O -•3" H C N CN-rH o | CM| O- o s s CO U N •3" -3" rH rH ON O NO O -rH rH S| 00 CO s s NO NO -3- -3" rH rH ON O NO O -rH H SI NO O CM C N H H O - CO -3- -3" rH rH CO ON NO NO H rH si £>- ON s s NO NO -3- - 3 H H NO CO NO NO-H H si co CM H O - V O s s O - 0 0 CN -3- -3" -3-H H H O CO NO CN- NO SO rH rH rH si O - M O oo CM CM CM rH rH rH NO UN O -.3- -3- -3" rH rH rH ON NO VN NO NO NO H H H si 00 CM rH UNCO s s U N NO U N ^3- -3- -3-r l H H co _3 co NO NO NO H H H si NO NO NO CM CM CM n H H NO J " NO -3-3-^3-H H H O - O NO NO NO NO H H H £1 CN- UN^- .3- CO NO CM CN £>-NO CN^i £3 CMCMCMCM^3--3-^t-d-NONONONO r _ | l H H H H H H H H H H H H -3" C N CN -3" O - . 3 - -3-CM CM CM CM -3" 3" 3" H H H H H H H UN-3; ON ON! NO NO UN NO O U N UN U N^t UN CN- C<NNO C N H NO ' O " I C M C M C M C M - 3 - ^ - ^ - ^ - N O N O U N N O rHrHrHrHrHrHrHrHrHrHrHrH _ . NO 00 NO UN NO NO -3" UN ON CO UN CM ° N C M C M C M C M ^ - ^ - ^ - ^ 3 - U N U N UN NO H H H H H H H H H H H H „ ! H / v o c o c N ^ i o r N o c N - c o c O i N i "-'I CM CM CM CM ^ -3" ^ - 3 UN UN U N UN CM NO I UN| ^3-1 C N CM I UN -3" CM CM H H C N H s s O CO CM H -3" ON CM H H H O O N s s o 00 CM H 3*" •3-UN MO •3" -3" , C N C N UN UNS©. • .3- UN U N UN UN CV Q ON 1—I -3" NO C N - 3 - ^3- U N U N U N 00 .3- CN- UN CN- ON H H H H CM CM H H H H H H U N O NO H H H H H NO U N CM UN CNNO ON C N C N C N O N C N . 3 - - H - . 3 - UN rHrHrHrHrHrHrHrH NO ON CN- CM UN .3 -CM CM CN -3" -3" 3" rH rH rH rH rH rH O C N ON .3 - CN-NO CM CM CM C N CN C N CO PH h-H" O PH O PH HHI PHI CO| 00 U N O O H H. •3- O ON ON O O O O O O NO NO o o < < C N - 3 -U N U N 00 UN O O H H CO U N ON ON O O O O O O NO NO O O < < UN NO U N UN ON H H CM H H C N U N H H H H CM NO O O H H UN U N CN- CN-NO NO o o pq PQ CN -3 -UNUN, UN NO CNCM H H CM CM H H H H .MTiCO H U N O O H H H H H H U N UN o O CN- CN- U N U N NO NO CN- CN-O O O O pq PQ o o U N NO CN-3-U N UNCUN UN NO ON s s UN 0 -s s o o U N U N CN- CN-o o C3 C3 UN NO U N U N C N C N O C N -3-CN CM C N H ON CN CM CM O C N C N CO CM CM CN H H O O CN CN 3 H 3 NO - 3 3 NO -3-UN -3-H NO •3" 00 UN 00 U N H CN-U N H CO UN UN UN UN -3" CM C N -3- -3" H H 3^ 3^  -3" C N UN UN C N N O U N UN CM UN UN UN UN -3 - UN •3- -3; -3" O O CO CN CN CM H H H H CO N -3- CM NO CN CM CM 3-^3-^3-CN- O CN-UN UN U N UN CM UN UN U N UN ON NO U N CM NO C N C N 1—I C N CMCMCM - 3 ^3" -3" U N U N U N H H H H H H H H H O 00 CN-C N CM CM CN UN -3" -3- -3- ^ 3 O O N O O NO .3- H H ON ON CM CM - 3 -3" H H H H H H ON CM O C N ON CM C N C N CM C N . NO H CM NO H •3- "=i\ U N J 3 UN » 1—I U N ON o ON 00, • -3- -3- -3-- UN^3- ^ 3 -1—t 1—1 1 1 1—1 1—1 1—t i—I i—I H 1—I i—I H H CN-CO NO U N NO- -3- N H CO C N O - C N -C M C M C M C M C N 3 C N ^ 3 - r 3 ; U N ^ 3 - ^ H H H H H H H H H H H H H U N NO 00 VO » A O C O O N 3 C 0 3 H C M C M C N ! C M C N ^ 3 - C N C N 3 - ^ - 3 - U N H H H H H H H H H H H H H NO ON .3- - 3 CO H CM CM CM CM C N ^ 3 . > NO O NO CO O • C N 3 ; -3" -3" UN CN-CN-CM^3- .3 - CN-CO CN-CM CNNO ON CM CM CM CM CN CN CN ONidJ -3- -3- -3" H H H H H H H H H H H H ^3" CNO ONNO-3-NO UNNO CNJ- O CM CM CM H CN ON ON CN -3-. ^3" 3" UN 00 ^3" NO CO H CM CM H UN ON 00 .3" H H H H rH rH rH rH ON H UN CN-O H H O H H H H ON CM C N U N ON O O ON O H H O 0 3 H I N ON ON ON CO O O O O U N U N UN U N CM CM CM CM U N UN U N U N O O O O < < < < C N - 3 - UNNO NO NO NO NO CNNO CNONCM H H N O C N C N C N C N - 3 1 ^ - ^ - ^ 3 -H H H H r H H H H H H C N U N C N - O N H O N ^ -C N C N C N C N C T \ ^ 3 - CN-3-rHrHrHrH^rHrHrH H 3 \ O C 0 0 N N N 3 0 N C M C M C M C M C N N C N C N C N rH rH rH rH rH, H H H H NOONHOUNCMNO O N HHCNiCMCNjiCMCMCM H H H H H H H H H NONOHCNOCOCMUN O N O N O O e l O H H Or^rHrHrHrHrHrH O O O O O O O O O O ' O O C N - C N - O - C N -N O N O N O N O N O N O N O N O O O O O O O O O p q p q p q p q o o o o CNJ- UNNO CNUN UN NO NONpNONONpNONONO APPENDIX B 'D' SCORES (CALCULATIONS) 81 82 'D' SCORES (CALCULATIONS) Q T> T F i n a l Pred. F i n a l Pred. •D' D r -Li H.R. H.R. Scores H.R. H.R. Scores 01 3 A 120 122 -2 02 3 A 119 119 • 0 01 4 A 120 118 +2 02 4-A 118 118 0 01 5 A 126 •• 127 02 5 A 125 123 +2 01 6 A 126 122 +4 02 6 A 125 122 +3 01 3 B 128 125 +3 02 3 B 131 131 ' 0 01 4 B 128 129 -1 02 4 B 133 131 +2 01 5 B 137 134 +3 02 5 B 139 136 +3 01 6 B 136 135 +1 02 6 B 140 137 +3 o i 3 c 139 140 - l 02 3 G 145 142 +3 01 4 c 138 138 0 02 4 C 144 145 - l 01 5 c 144 142 +2 02 5 G 151 148 +3 01 6 C 144 143 +1 02 6 c 154 151 +3 03 3 A 120 122 -2 04 3 A 115 115 0 03 4 A 118 119 -1 04 4 A 115 115 0 03 5 A 123 123 0 04 5 A 115 115 0 03 6 A 125 122 +3 04 6 A 117 115 +2 03 3 B 132 134 -2 04 3 B 130 130 0 03 4 B 131 131 0 04 4 B 133 133 0 03 5 B 137 135 +2 04 5 B 133 132 +1 03 6 B 136 133 +3 04 6 B 135 133 +2 03 3 G 140 141 -1 04 3 G 143 145 -2 03 4 c 140 140 0 04 4 C 145 146 -1 03 5 G 151 149 +2 04 5 G 148 149 -1 03 6 c 147 144 +3 04 6 C 150 148 +2 05 3 A 118 121 -3 06 3 A 124 123 +1 05 4 A 124 127t -3 06 4 A 125 125 0 05 5 A 126 125 +1 06 5 A 127 126 +1 05 6 A 127 125 +2 06 6 A 127 126 +1 05 3 B 125 126 -1 0.6 3 B 136 135 +1 05 4 B 131 132 -1 06 4 B 134 133 +1 05 5 B 130 130 0 06 5 B 138 137 +1 05 6 B 130 129 +1 06 6 B 140 140 0 05 3 G 134 133 +1 06 3 G 150 150 0 05 4 C 138 138 0 06 4 C 149 148 +1 05 5 G 138 139 -1 06 5 G 151 150 +1 05 6 c 136 133 +3 06 6 C 153 153 0 S-= p = L = Subject P r o t o c o l (3=3 minutes, 4=4 minutes, 5 = 5 minutes, 6=6 minutes) Load (A = 1st load, B = 2nd load, C = 3rd load) c 83 'D'. SCORES (CALCULATIONS)  • S- P L • Final Pred. 'D' Final Pred. " H.R. H.R. Scores ' ' H.R.' ' ' H.R. S cores 07 3 A 122 119 +3 08 3 A 1271 128 -1 07 4 A 123 123 0 08 4 A 127. 128 -.1 07 5 A 124 123 +1 08 5 A 128 128 0 07 6 A 122 124 -2 08 6 A 129 129 0 07 3 B 136 139 -3 08' -3-B 145 147 -2 07 4 B 138 137 +1 08 4 B 143 145 -2 07 5 B 138 138 0 08 5 B 146 149 -3 07 6 B 140 140 0 08 6 B 146 147 -1 07 3 G 150 153 -3 08 3 C 160 164 _4 07 4 c 151 152 -1 08 4 C 161 159 +2 07 5 G 153 154 -1 08 5 C 165 164 +1 07 6 c 155 154 +1 08 6 C 166 166 " b 09 3 A 121 119 +2 10 3 A 127 131 _ ^ 09 4 A 122 122 0 10 4 A 127 127 0 09 5 A 124 123 +1 10 5 A 128 128 0 09 6 A 127 123 +4 110 6 A 129 130 -1 09 3 B 131 130 +1 10 3 B 141 143 -2 09 4 B 132 133 -1 10 4 B 143 145 -2 09 5 B 135 132 +3 10 5 B 144 146 -2 09 6 B 139 132 +7 10 6 B 146 144 +2 09 3 C 144 143 +1 10 3 C 158 164 -6 09 4 C 147 146 +1 10 4 C 159 161 -2 09 5 G 149 148 +1 10 5 G 160 164 -4 09 6 c 151 149 +2 10 6 C 162 162 0 11 3 A 129 132 -3 12 3 A 126 129 -3 111: 4,4 A 128 133 -5 12 4 A 129 128 +1 11 5 A 129 129 0 12 5 A 132 131 +1 11 6 A 129 134 -5 12 6 A 133 132 +1 1113 B 149 151 -2 12 3 B 139 141 -2 11 4 B 149 149 0 12 4 B 145 142 +3 11 5 B 148 144 +4 12 5 B 146 144 +2 11 6 B 150 152 -2 12 6 B 149 147 +2 11 3 c 162 164 -2 12 3 C 157 160 -3 11 4 C 165 165 0 12 4 C 166 168 -2 11 5 C 170 169 +1 12 5 G 164 166 -2 11 6 c 171 171 0 12 6 C 165 165 0 s p L = Subject = Protocol .(3=3 minutes, 4=4 minutes, 5 = 5 minutes, 6=6 minutes) = Load (A = 1st load, B = 2nd load, C = 3rd load) 84 'D' SCORES (CALCULATIONS) S P L . F i n a l ' H.R. Pred. H.R. 'D! Scores F i n a l ' H.R. Pred. H.R. 'D' S cores 13 3 A 135 149 -14 14 3 A 131 128 +3 13 4 A 143 139 +4 14 4 A 129 128 +1 13 5 A 148 146 +2 14 5 A 129 126 +3 13 6--A 148 149 -1 14 6 A 135 134 . +1 13 3 B 148 149 -1 14 3 B 144 145 -1 13 4 B 157 158 -1 14 4 B 143 143 0 13 5 B 162 162 0 14 5 B 142 140 +2 13 6 B 162 164 -2 14 6 B 146 146 0 13 3 C 165 169 -4 14 3 G 153 150 +3 13 4 C . I69 168 +1 14 4 C 153 151 +2 13 5 G 172 171 +1 14 5 C 153 150 +3 13 6 C 174 173 +1 14 6 C 155 154 +1 15 3 A 127 126 +1 16 3 A 130 130 0 15 4 A 128 127 +1 16 4 A 130 131 -1 15 5 A 127 126 +1 16 5 A 131 129 +2 15 6 A 131 130 +1 16 6 A 133 130 +3 15 3 B 148 151 -3 16 3 B 141 138 +3 15 4 B 147 148 - l 16 4 B 145 142 +3 15 5 B 148 147 +1 16 5 B 144 143 +1 15 6 B 150 147 +3 16 6 B 146 144 +2 15 3 G I67 178 - i l l 16 3 c 151 147 +4 15 4 c 170 172 -2 16 4 C 157 154 +3 15 5 G 169 169 0 16 5 c 154 151 +3 15 6 C 173 173 0 16 6 C 158 154 +4 S = Subject P = P r o t o c o l (3=3 minutes, 4=4 minutes, 5=5 minutes, 6=6 minutes) L = Load (A = 1st load, B = 2nd load, C = 3rd load) 

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