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The relationship between excess CO2 and blood lactate in elite cyclists Anderson, Gregory Steven 1988-12-31

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THE RELATIONSHIP BETWEEN EXCESS C02 AND BLOOD LACTATE IN E L I T E CYCLISTS  by  GREGORY STEVEN B„P.E.,  University  ANDERSON  of British  Columbia,  1985  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF PHYSICAL EDUCATION in FACULTY OF GRADUATE School  of Physical  We a c c e p t t h i s to  THE  STUDIES  E d u c a t i o n and R e c r e a t i o n  thesis  the required  as conforming standards  UNIVERSITY OF BRITISH COLUMBIA July,  (cjGregory  1988.  Steven Anderson,  198Q  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 department  or  by  his  or  her  representatives.  may be granted by the head of my It  is  understood  that  copying or  publication of this thesis for financial gain shall not be allowed without my written permission.  Department of  PfH^fSfC^L  The University of British Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3  DE-6(3/81)  EbU.CfiTlfit<]  ABSTRACT.  T h i s study metabolic while and  COS  examined  (EXC02) and  e m p h a s i s was  lactate  (15 m a l e s ,  sampling  (PIT)  occured  on  values  (EXTT, WTT,  when e a c h was significant  3.35  blood  expressed  RM  ANOVA  mmol/1, 14.84  values  lactate  indices; (LATT).  absolute  <F=S.41, P<8. 881)  VE/VO-2)  cyclists  intensity  bicycle  p a r a m e t e r s were  and  Threshold  blood  values excess  The  lactate  were C02  (EXTT),  three threshold  s i g n i f i c a n t l y (P<8.881>  VQ2  (I/min).  and  post  hoc  A correlated  s i g n i f i c a n t d i f e r e n c e s between t h e EIXTT  at an  WTT  values  average blood  (EXTT and the  LATT),  11  lactate  concentration  C02  volume a t  minute range a c r o s s  w h i c h were used  e x p i r e d EXC02 volume  concentration  and  <P<8.8£5>.  t h e mean e x p i r e d e x c e s s  ml/kg/min. O v e r an  points of reference, blood  intervals,  non-  lactate,  Twenty-one e l i t e  a progressive  lactate  a s an  blood  (EXC02 and  which v e n t i l a t o r y  t h e EXTT and  while  of  ventilatory  each minute.  LATT o c c u r e d  threshold  performed  15 s e c o n d  demonstrated  EXTT was  the  LATT) a l l c o r r e l a t e d  (P<8.881) and The  of  and  between e x p i r e d  accumulation  f o r each o f the t h r e e  (WTT),  LATT  on  during  o n - l i n e at  VE/V02  t-tests  placed  6 females)  determined  the  threshold relationship.  ergometer t e s t monitored  the r e l a t i o n s h i p  (mmol/1) c o r r e l a t e d  as  the  the  relative  (ml/kg/min)  and  significantly  <r=8. 69, period  of  nature of track  P<8. 881). time  Higher  <r=8.8£ - ©.96,  this relationship.  blood  lactate  significant  between t h e  These r e s u l t s  EXCO£ precede changes  EXCO£ volume a p p e a r t o  influenced  blood  by  varies  track  gender.  the  minute period min. ) was  a strong  although  lactate  c h a n g e s and  i n blood  c o n c e n t r a t i o n can  individuals  into  relationship  concentration  the  when  taken  Although changes  changes  individual  11  EXCO£ volume as  between  the  same  to  <1.35  values,  over the  EXCO£ volume appeared  indicate  <VE/VQ£).  lactate  from e x p i r e d  relationship  Expired  i n blood  equivelant  concentration,  P <8.©81) s t r e s s  difference  three threshold  ventilatory  correlations  l e v e l s over t h i s  threshold  consideration.  predicted  individual  in  expired  and  the  expired  lactate not  be  nature of  accurately this  and. a p p e a r s t o  be  - iv TABLE  OF  CONTENTS  Abstract  . ... i i  L i s t of Figures List  vii  of Tables  Acknowledgment  CHAPTER  ONE  ;  .......  vii  . . .'.......  viii  I N T R O D U C T I O N TO T H E  Trit r e d u c t i o n ........ ...... ....  PROBLEM.  "... ....... . .... . ... 2.  Statement o f the Problem J u s t i f i c a t i o n ..... ......  4. .'......... .•............  5.  D e f i n i t i o n s ... ... .......... .......... ...... ........ ........ ...... 6. Hypothesis ... ......... ..... . . ... ..... . ........ ..... ....... .. 7. Rat i o n a l e . . . ...... . .... . ........................ ... ... 8.  CHAPTER  TWO  ;  SELECTIVE  LITERATURE  REVIEW.  I n t r o d u c t i o n ... ......... ... .......... ... . . .,.  12.  Models o f T r a n s i t i o n ..... .... . ...... . . ........ ... . . . . .... . . 13. S i n g l e Breakaway  13..  Double Breakaway  14.  Exponential  .....16.  Thresholds  17.  Lactate  Threshold  . 19. 21.  .1  Tissue  .2  Production  .3  Muscle F i b e r Recruitment  £3.  .4  Fatigue  £4.  Ventilatory  02 S u p p l y v s . Removal  £2.  Threshold  £4.  .1  Vent i l a t o r y  Control  £5.  .2  VC02, RQ,  and E x c e s s COS  .3  Comparing  Noninvasive  .4  E x c e s s C02 and P e r f o r m a n c e  £7.  M e a s u r e s ..38.  Protocols' for' E l u c i d a t ing T r a n s i t ion  32. ............34.  C o n c l u s i o n s : . ....... ... ................... ...... ...... ..... .37.  CHAPTER THREE. ; METHODS AND  PROCEDURES.  Subjects Test ing  .40. P r o c e d u r e s and P r o t o c o l  Experimental.  CHAPTER FOUR  Design  40.  and D a t a A n a l y s i s - .  .42.  ; RESULTS AND DISCUSSION.  Results  .  Discussion  CHAPTER FIVE: ; SUMMARY AND Summary Cone 1 us i o n s  ..•  44. 50.  CONCLUSIONS. .  .57. 59.  - vi -  BIBLIOGRAPHY  60.  APPENDIX  68.  A. O b s e r v e r  Threshold  Values  B. EXC02  74.  C. EXC02 and B l o o d D. T h r e s h o l d E.  Pre/Post  69.  Lactate  76.  Curve Samples  78.  Threshold  Graphs  88.  - vii -  L I S T OF  FIGURES  Chpt. 4. Figure  1.  LATT v s . EXTT  (r)  4®.  Figures.  LATT v s . W T T  (r)  40.  F i g u r e 3.  EXTT v s . W A T  (r)  41.  F i g u r e 4.  L a c t a t e v s . E x p i r e d EXC02  (r)  .......43.  L I S T OF TABLES  Chpt. 3. Table  1.  The P r o g r e s s i v e L o a d i n g  Scheme  . . . . . . . . . . . 36.  Chpt. 4. Table  1.  D e s c r i p t i v e Subject  T a b l e 2.  A Threshold  T a b l e 3.  ANOVA and P o s t  Data  Correlation  39. Matrix  39.  Hoc C o r n p a r i s i o n s .......... 42.  Chpt. 5. Table  1.  Summary o f H y p o t h e s e s  .....52.  - viii -  ACKNOWLEDGEMENT  I would direction  like  t o t h a n k Dr. E.C.Rhodes f o r h i s g u i d a n c e and  throughout  this  project;  h i ssuggestions  were w e l l  recieved. I would suggestions for  their  also  like  t o t h a n k Dr. G. Ma.theson  and e d i t t i n g  suggestions  of the i n i t i a l  and d i r e c t i o n ;  for his  p r o p o s a l ; my  and my f r i e n d s  committee for their  many o p i n i o n s . I would patience,  like  t o t h a n k my f i a n c e ,  computer  many t r y i n g  e x p e r t i s e , and c o n t i n u e d  moments; my b r o t h e r ,  h i m s e l f - t h e best love,, s u p p o r t ,  Sherri  Watts, support  C l a y t o n Anderson,  o f b i g b r o t h e r s ; and o u r p a r e n t s  and u n d e r s t a n d i n g .  f o r her through t h e f o r being for their  - ] -  CHAPTER  ONE  INTRODUCTION AND STATEMENT OF THE  PROBLEM  INTRODUCTION  As  early  critical  as  exercise  muscles  an  excretion  reasoned  that  of  the  excess  COS  of  buffered  the  that  which also  and  produced  being  suggest  bicarbonate  was  an  was  working that  increase  the  a  <1930)  result  during  in  of  anaerobic  much a s  3Qi% of  the  metabolism  is in  fact  as  anaerobic  the  Pilcher  produced that  there  observed  l a c t a t e was  being  during  by  Owles  Harrison  acids  studies  produced  above  blood  ventilation.  Recent  immediately  level  and  metabolism.  recognized  acid.  accumulation  buffering  ion  Qwles  lactic  bicarbonate  hydrogen  W. H.  intensity  produced  accompanying COS  1930  system  (Wasserman  et.al,  1986). In  1964  blood in  Wasserman  lactate  Whipp  accumulation  ventilation  respiratory  and  (VE),  exchange  recognized  correlated highly  carbon  dioxide  ratio  (R),  the  with  break  excretion  parameters  noninvasively.  of  l a c t a t e accumulation r e f l e c t e d  a shift  metabolism,  of  anaerobic that  this  through time  the  that  non-linear the  point  of  a shift  defined  increase  "anaerobic  i n the  transition  noninvasive they  suggested  could  measures that  i n VE,  threshold."  use  be  the  energy  VCOS, o r  immediately the  sudden  "threshold"  and  the  could  be  onset  aerobic  pathways,  accurately  to and  determined  I t was  at  this  preceding  increase point  of  points  initial  from  investigated.  point  This  that  onset  (VCOS), which  monitored blood  I t was  that  the  in R  as  appears  to  represent is  a critical  severely  represent  intensity  limited  a  above  (Rhodes  transition  which  endurance  performance  e t a l , 1981) and i s p o s t u l a t e d t o  point  i n energy metabolism: a  transition  threshold. Since has  i t s time o f conception  been  put  threshold'  has  tolerance (Davis  to  many  been  endurance  al,  et.  1981,  described  as  maintain  of does  endurance  with  supporting  the  the  to  an  theory  mechanisms  original  et.  be  this  assessing  al,  1981),  1980),  al,  which  prescription  and  to  a  defines  "critical  increase  limited,  in  blood  and R, t h e r e  the  ability to  e t . a l , 1981),  intensity" and t h i s  the  Although  above  which  intensity i s  i s no c o n c l u s i v e e v i d e n c e  increases,  that  yet the  l a c t a t e accumulation,  of the anaerobic threshold. o f such  predict  The AT h a s been  extremely c o n t r o v e r s i a l .  i s severely  assumptions  exercise  to characterize  1981).  (Whipp  (AT)  'transition  i n exercise  al,  et  still  VE, VE/V02,  the  et.  exercise  is  past in  1964),  parameter  performance  EXC02,  in  AT  appear  concomitant  is  key  the  al,  (Rhodes  high-intensity  concept  VC02,  a  the  clinically  (Rusko  performance  In  Tanaka  athletes  endurance  there  used  (Wasserman  et.  uses.  the "anaerobic threshold"  It appears i t  t h e n o m e n c l a t u r e , and  explanation  f o r t h e AT i s  failing. Many being  the  the  challenged.  threshold et  of  and  a l , 1964), tissues  original It  ideas  was  originally  ventilatory and b e l i e v e d produce  and a s s u m p t i o n s o f t h e AT a r e  threshold that  lactic  only  acid  surmised that were synonymous  under  the lactate (Wasserman  h y p o x i c c o n d i t i o n s do  (Margaria  e t a l , 1933). The  appearance the  of  l a c t a t e i n the  production  idea  is  being  lactate  to  tissue and  of  lactic  challenged  be  released  oxygenation  finding  uncoupled blood,  the  (Segal  lactate  et  production  that  considerable  muscle  may  be  1986),  and  that  molecule that  may  the  production The  or  or  earlier blood  running  between  lactate W.E.  Hearst  correlated  highly  with  speeds  (r=8.89).  It  volume  may  reflect  1986).  to  be  that  cellular finding  within  the  (Brooks,  the-  lactate  These f i n d i n g s may  be  on  anaerobic  suggest  delayed,  not  energy  concentration.  blood  lactate  CVC02  -  (RQ  and  accumulation  x V02)3,  research  by  Rodahl  threshold EXC02  be  detected  unpublished blood has  CIode,  and  and  not  yet  Clark  and high  EXC02.  The  permits changes with  at  been p o s t u l a t e d  in  reasonable  thesis)  lactate  intracellular  has  (1961) r e p o r t e d  that  to  (1982,  1958), can  are  l a c t a t e formed  lactate  suggest  adequate  the  Investigators  hinderance  lactate  concentration  represent  this  finding  al,  a c t i v e muscle t i s s u e  early  the  et  the  Issekutz  investigations  accuracy. EXC02  and  be  the  lactate  although  to  Jobsis  yet  investigators believe  reliance  COS  believe  reflect  are  of  blood  between  to  ventilatory thresholds  (Stainsby,  of  thought  muscle c e l l ,  a l , 1984,  translocation  cellular  (1961)  they  accurately  within  non-metabolic  correlations  not  increased  the  the  concentration.  present  determined,  Campbell  EXC02  a  an  et  portion  relationship  EXC02, been  or  appearance  representing  u n d e r what  do  was  many i n v e s t i g a t o r s who  a l , 1979). O t h e r  oxidized  be  within  l a c t a t e and  levels  lactate a  by  -  bloodstream  acid  (Connett  that  4  found  four  specific  that  production  that  of  expired lactic  acid.  Recent  lactic  studies  acid  buffering  produced  system  periods  as  a progressive  relationship during  their  examine  buffered  lactic  test.  and  This  intensity  the  EXC02,  which  the  may  concepts  threshold  equality,  production  by  blood  and  of  the  lactate  both  the  bicarbonate  will  produced such  examine  at  while  the  a l l points  examining  lactate,  This  of  i s increasing,  study  test  occur.  the  lactate  blood  - 94*  EXC02 i s t h e n  acid  blood  9$  by  e q u a l i t y o r d i f f e r e n c e , and  discrepancies  part,  r a t e of  EXC02  much a s  a l , 1986).  intensity  between  thresholds, any  when t h e  progressive  relationship  as  i s immediately  between  a  that  (Wasserman e t  during in  suggest  and  the  the  the  VE/V02  consistency  of  investigation will,  in  lactate  reflection  of  and v e n t i l a t o r y cellular  lactate  accumulation.  jysiiEiQaiiQN  The  use  exercise  of-  the  physiology  capacity.  This  intensity  limited.  Examination  to  extract  examine and at  capacity,  and  performance mechanisms  become w i d e s p r e a d  i s thought  of  the  TT  times. which  which  oxygen  i n the  i s thought has The  will  ability  been  is  m e a s u r e s at  the  to transport  working  field  severely TT  allows  oxygen  a person's  the  performance  to, work  endurance  c o r r e l a t e d h i g h l y with  aerobic  that  m u s c l e mass. The  underlying  of  work  represents  capacity  to represent  mechanisms limit  i n the  one's a e r o b i c  (TT)  work  noninvasive  person's  EXCD2  to r e f l e c t  threshold  above  the  utilize  intensity  as  has  transition  critical  one  AT  TT and  marathon are  also induce  fatigue.  Determining  the  limiting  factors  patient  in a  aerobic  capacity,  exercise  that  Most gas  will  (Powers many  et.al.  has  failed  accumulation variables  to  the  1974,  and  between  question  the  the  points.  The  study EXC02  a l , 1984,  and  those  discussion  intensity  relationship  of  discrepancies  or  which  the  al.  on  This  lactate  1976),  of  the  topic  lactate exchange  threshold been  performance  1983,  the  gas  or  restricted  (Volkov  et a l ,  unpublished t h e s i s ) .  i t examines the  lactate  difference, may  Research  of  indices  (Simon e t . a l .  EXC02 h a s  1982  i n that  test.  between  equality  Hearst,  blood  Davis et.  some  use  reliable  v e n t i l a t o r y and  than  is justified  1982,  be  the  r e l a t i o n s h i p between b l o o d  noninvasive other  Although  validated  1982).  prescribe  v e n t i l a t o r y and/or  practice  et.al.  determine  and  TT.  them t o  r e l a t i o n s h i p between EXC02 and  progressive  their  have found  Hagberd  points  Rhodes e t . This  still  the  have  study  systems.  noninvasive  to  to  population,  energy  detecting  i n v e s t i g a t e the  at  "breakaway"  use  one  adaptations,  Caiozzo e t . a l .  1982,  to  in  and  1984,  et.al.  to  claimed  measures  researchers  Hughes  desired  opt  allows  athletic  s t r e s s the  have  noninvasive  and  training  variables  researchers  accurately  monitor  researchers  exchange  TT  at  all  study and and  will  points  during  a l s o examine  ventilatory the  relationship a the  thresholds,  consistency  of  any  occur.  DEFINITIONS  Transition  Threshold  (TT)  -  that  point  where t h e  aerobic  - 7 energy level an  pathways and  the  increased  accumulation  at  lactate;  reliance  which that  the  can  consumed.  on  anaerobic  (LATT)  there  is  -  an  rate  metabolic  a r e met  through  with  lactate  metabolism,  that  work r a t e  abrupt  below  Threshold  there  C0£  buffering  EXCO£  tissues  demands o f t h e t i s s u e s  (VT)  i s a non  just  below  i n c r e a s e i n venous  the  breakaway  (EXC02) of  point  work r a t e  the  blood  on  the  below  the  (EXTT),  and  by  VE/V02  the  (VVTT). produced  through  bicarbonate buffering  system.  by c o m p a r i n g  I t i s commonly c a l c u l a t e d  EXC02 - VC02 -  just  i n c r e a s e i n EXC02  - the nonmetabolic  acids  be c a l c u l a t e d  - that  linear  increase i n the r a t i o  Excess  the  curve.  where  abrupt  maintain  i t s removal.  work  Ventilatory  an  longer  increasing  Threshold.  lactate/time  point  no  exceding  Lactate point  can  C0£  t h e C0£  by  the  (resting  RQ  produced  following  x  and  the  02  equation:  V02)  HYPOJHESIS  1.  there  will  be  a significant  correlation  between EXTT  and  difference  between EXTT  and  LATT. 2.  there  will  be  a significant  LATT. 3.  EXC02 all  levels  will  stages of the  parallel  blood  lactate  progressive intensity  levels  test.  through  SECONDARY HYPOTHESIS  1.  will  there  be  a significarit  correlation  between EXTT  and  d i f f e r e n c e between EXTT  and  WTT. 2.  will  there  be  a significant  WTT. 3.  will  there  be  a significant  correlation  between W T T  and  d i f f e r e n c e between W T T  and  LATT. 4.  will  there-  be  a significant  LATT.  RATIONALE  Approximately working  immediately  non-metabolic will  to  is  test  The move by  the  dissociation  of  the  bicarbonate  C02  and  water  as  t h e r e w i l l . , be  (Wasserman (PIT)  with  continue  a relative  the  i o n and  as  et.al.  rise,  of  lactic  1986).  rate of  In  the  be  producing 1986). acid  progressive lactic  first  and  duration of  acid then the  i n EXC02.  produced  carbonic  the  will  lactic  a  workloads  f a s h i o n throughout  COS  in  a d d i t i o n a l hydrogen  at  increase  acid  system  slowly  m u s c l e membrane i n t o  presence  the  increasing to  ion produced  (Wasserman e t . a l .  increasing  hydrogen  across  the by  a curvilinear  producing  hydrogen  long  will  in  of the  as  test  production  94%  generated  buffer  intensity  rapidly  (excess) be  production ion  -  m u s c l e mass f r o m  buffered  EXC02  90  w i t h i n the the  blood  anhydrase  in  muscle  readily  stream,  enhanced  the  capillary  eridothel i a l diffusable  cells. across  removed  by  (Brooks  1986).  blood the  the  stream blood  lactate  the  l a c t a t e molecule m u s c l e membrane  oxidaitve Because  EXC02  and  determination directly  of  the  transition  l i n k e d to the  active  muscle  in  ventilation  pH  of  the  driving  force  precede  an  mass. The  are  blood.  an  points  metabolism  and  in  most  a c t i v e muscle  bed  release of  Rodahl  often  used  VE  and  r e l e a s e o f C02  i n the  PCOS and  increases  ventilation  accumulation  the onset  within  the  1961). in  VE  the  H+  and  are from  increases  decrease H+  the  cellular  VE/VOS,  in  provide  in expired  with the  and  into  lactate in  and  threshold,  overestimating  lactate  be  p r e d i c t i o n of  r e l e a s e o f COS  ventilation,  increase  may  accumulation  (Issekutz  and  and  prime d r i v i n g f o r c e s f o r  increase  Because the  for  threshold  production  the  1386)  delayed  a more a c c u r a t e  parameters  however, r e a d i l y  (Stainsby  lactate's  accumulation  ventilatory  i s not,  within  precede the  offer  and  fibers  of  will  may  production  The  the  The  COS  and  of  the the will  VE/VOS  anaerobic  working  muscle  mass.  DELIMITATIONS  T h i s study a)  This  b)  The  c)  The  i s delimited subject  sample s i z e  sample type, sampling  lactate  by:  (1 min.  (N=21).  c o n s i s t i n g of e l i t e rate  o f COS  intervals).  (15  s  cyclists.  i n t e r v a l s ) and  blood  — US — LIMITATIONS  This study's r e s u l t s are limited a)  Data  c o l l e c t i o n c a p a b i l i t i e s o f t h e Beckmari M e t a b o l i c  Measurement Acquisition b>  by:  Cart  and  interfaced  The i n d i v i d u a l ' s  The visual,  Packard  Data  system. metabolic response t o the protocol.  c) T h e b l o o d l a c t a t e s a m p l i n g and d>  Hewlett  measurement t e c h n i q u e .  determination of the t r a n s i t i o n threshold inspection.  through  CHAPTER SELECTIVE  TWO  REVIEW  THE LITERATURE  -  12  -  A CRITICAL REVIEW OF BLOOD LACTATE AND VENTILATORY METHODS OF DETECTING THE TRANSITION THRESHOLD  INIBODUCTigN fls e a r l y critical  produced lactate  ventilation. excess of  1930  exercise  muscles blood  as  Owles  intensity lactic  Owles  acid.  and  recognized  level  observed  Harrison  C02. being  acids  W. H.  above  that t h e r e was a  which  t h e working  Accompanying an accumulation o f an i n c r e a s e i n C02 e x c r e t i o n and  Pilcher  (1930)  reasoned  produced: was a r e s u l t o f b i c a r b o n a t e  being  produced  during  buffering  metabolism.  Wasserman  and  intensity  above which endurance performance i s s e v e r e l y l i m i t e d ,  i s postulated  i n 1964,  to  Physical and:  consumption  coupling  of  limited to  exercise  these  response  exercise.  which  of  magnitude,  the aerobic  limited  (Knuttgen,  intensity energy  may  required  be  work  i n energy  depends  on  the i n d i v i d u a l ' s  t h e c a r d i o v a s c u l a r and r e s p i r a t o r y systems seems  through  t r a n s i t i o n point  a  w i t h i n t h e working musculature. The  elements  the cardiovascular  insufficient  represent  by  r e q u i r e s a balance between t h e p r o d u c t i o n  two  There  a  to  threshold'  threshold*.  energy  of  appears  represent  metabolism — a ' t r a n s i t i o n  'anaerobic  This  intensity, Whipp  the  the  critical  and  dubbed  anaerobic  that  to  be  and/or failing  pathways, 1962).  Work  a 'critical  i n t e n s i t y ' above  r e s p i r a t o r y response i s o f an to and  supply work  t h e energy demanded capacity i s severely  performed  performed  for indefinite  f o r muscular  contraction  below t h i s durations i s being  critical as t h e supplied  - 13 predominately  through  waste  products  above  this  reliance of  are  unlimited being  critical  subject object  sources while  adequately removed. Work i n t e n s i t i e s  intensity result  on l i m i t e d a n a e r o b i c energy  determination of of  findings  i n r a p i d f a t i g u e due t o a  s o u r c e s and an  accumulation  release, on  of  this  transition  this  review  pertaining of  will  to  blood  be  the  has been the  muscle  lactate,  transition,  and the  the  subsequent  carbon dioxide.. Emphasis w i l l  a sharp i n c r e a s e i n i n t r a c e l l u l a r  The  present p r e v i o u s r e s e a r c h  aerobic-anaerobic  and  o f non—metabolic  to  the d e t e r m i n a t i o n o f the c r i t i c a l  .Kg  point  many i n v e s t i g a t i o n s and has found mixed reviews.  accumulation  be p l a c e d  i n t e n s i t y at which t h e r e i s  l a c t i c acid  formation.  MQDELS_QF_TRflNSITION  The.  concept:  increase  in  recognized this  et al. (1914) and at  phenomena  changes  were  (1964)  i n t e n s i t y above which t h e r e i s an i n t r o d u c e d i n the e a r l y l a t e r by Owles (1938).  (Douglas,  level  1927). It was  transition controversy  It was  with  long b e l i e v e d that  also  ( H i l l et a l , 1924)  1985).  threshold around  In has  the  more been  concept  these  a r e l a t i v e shortage o f oxygen at which lead t o the concept  "anaerobic t h r e s h o l d " forwarded (Davis,  1900's by  t h i s time that changes i n v e n t i l a t i o n accompanied  associated  muscular the  of a c r i t i c a l  blood l a c t a t e was  Christiansen  of  energy  i n h i b i t o r y waste products. The;  th&  aerobic  recent under has  by Wasserman and M c l l r o y y e a r s the concept o f a close  scrutiny  and  the  lead t o the f o r m u l a t i o n o f  t h r e e s e p a r a t e models o f a e r o b i c - a n a e r o b i c t r a n s i t i o n .  — 14 l l  -  SINGLE_BRE9KaWBY_M0D^  t  The:  classical,  progressive stemming above and  model  intensity  from  testing  early  model  in  that  and  they  established  and  muscle  hypoxia:  at  oxygen  deficit.,  (fin  In  blood  single  threshold"  others)  lactate the  Wasserman and to  during  o f exercise, and  questioned  Mcllroy  introduced  was  times  of  during  times o f  local  refuted  the term  fell  below  demand  and  increase  in  plasma  suggested blood  through a n a e r o b i c  the  by  lactate  respiratory  exchange  that  further  ventilatory  metabolism. They f i r s t  levels  t h a t t h i s point c o u l d  bicarbonate  later  "anaerobic  "excess" energy needs  point as t h a t point: immediately preceding  et  l a c t i c acid  t o date, f i r s t  this  log—log  initial  denote t h a t work r a t e at which the t i s s u e s oxygen  first  recently  l a c t a t e . Margaria  idea that  accumulated  onset,  idea:  the  supported  in  breakaway model  g r e a t l y i n f l u e n c e d the  were  also  during  1973) 1964  supply  the  an accumulation o f blood  (1933  formed  Hubbard,  is  transition  work which i d e n t i f y a " c r i t i c a l i n t e n s i t y "  which t h e r e was colleagues  of aerobic-anaerobic  or  pH,  ratio  or  (R).  investigated  measures  of  the  a disproportional  above r e s t i n g lev«?ls. They be determined by  an  It was and  anaerobic  supported the. s i n g l e t h r e s h o l d transformation  defined  abrupt  decreases  increase?  Wasserman and r e f i n e d the threshold.  i n the  colleagues non-invasive They  more  phenomena by employing a.  of l a c t a t e concentration  and  V02  (Beaver  a l , 1985).  1.2  D0UBLE_BREaK9WQY_MgDEL  A  three  phase,  double  breakaway  model  was  forwarded  by  Kindermann,  Simon  threshold found  lactate  that  of  aerobic be 1  4  blood  aerobics-anaerobic  concentration threshold'  model  and  to  breakaway  model  <FFA)  following, which  high  load  d u r a t i o n s . These  authors  per  that t h i s  ' t h r e s h o l d ' should  2  period and  of  4-  4  occured mmol/l,»  mmol/1  between  and t h a t a blood  represented  a: v a l u e above which l a c t a t e  endurance e x e r c i s e i s s e v e r e l y proposed  by  each  the  of  the  true  production limited.  Kindermann  by S k i n n e r and  stage  blood  et al.  McLe11an i n  three  1981.  articles,  phase double  and the p h y s i o l o g i c a l mechanisms u n d e r l y i n g  the  occured. and M c L e l l a n  on type as  of  developed  explain  phase,  reliance  at  drawing i n f o r m a t i o n from past: r e s e a r c h  attempted  aerobic  suggested  terminology  further  authors,  Skinner  maintained  authors  r e f l e c t e d the upper l i m i t o f e x c l u s i v e  -  exceeds- i t s removal and  events; which  reported  i n the range o f 2 mmol o f l a c t a t e  transition'  lactate,  These-  to  * a e r o b i c threshold'., In t h e i r framework the.  concentrations  r  be  f o r prolonged  and  lactate;  was  response  a. s t e a d y - s t a t e l a c t a t e c o n c e n t r a t i o n o f  volume,  r e f e r e d t o as t h e  (1979)  could  occured  metabolism,  The:  in  the a n a e r o b i c t h r e s h o l d proposed by Wasserman et  which  * anaerobic  (1979)  of both 2 and 4 mrnol/1. These  mmol/1,  that  (1964),.  liter  values  producing  approximately suggested  Keul  exercise  intensities,  al  and  the leads  involves  as  (1981) d e s c r i b e d the i n i t i a l  being  predominantly  I (ST o r SO) metabolic into  the  aerobic  muscle f i b e r s and  substrate.  The  the r e c r u i t m e n t  of type  with  the  a heavy  free fatty  aerobic  aerobic-anaerobic  phase,  acids  threshold,  t r a n s i t i o n phase  I l a (FOG)  f i b e r s and  the  appearance  of  decreases excess  lactate  blood  C02,  and  in  VE/V02.,  There  of  expired  02  concentration  (Fe02)  and  expired  rise  C02  <FeC02).  The  ends  production-  equals  i t s removal  type,  l i b - (FG)  production.; increase  This  fibers  i n blood  in  capacity. phase  with  a  production  turn  i n the fractional aerobic-anaerobic where l a c t a t e  The a n a e r o b i c  involves rapid  exceeds  increase  concentration  at the anaerobic threshold  follows.  Lactate  i n the fractional continued  phase  phase,  acid  pH and c a u s e s a n i n c r e a s e i n  a  transition  third  Lactic  ( V E ) , R and a d i s p r o p o r t i o n a l  i s an i n c r e a s e  of  blood.  intracellular  ventilation  in  the  phase, t h e  the recruitment  rise  in  i t s removal  l a c t a t e and VE, and a d e c r e a s e  lactic with  of acid  a rapid  i n FeC02.  1^3___EXP0NENTIftL_M0DEL The Hagan  exponential and  Smith  literature Hughson  In  (1984)  since  et, a l  increased  model  as  it  was  (1987)  described has  had  first  found:  by  Yeh  breif  described  that,  blood  the  continuous  i n the  by J e r v e l l  i n 1929...  concentration  progressive  function  model  exercise.  and t h e s i n g l e  breakaway  model  described  by B e a v e r e t a l (1985) Hughson e t a l (1987) f o u n d  the  mean  (P,0.001) to The  the  square when  threshold  l o g - l o g model o f t h r e s h o l d  error  the  continuous  authors  prefered  (the  appearances  lactate  a continuous function during  contrasting  e t a l (1983) and  was  approximately  times  that  larger  s i n g l e breakaway model was used a s compared function  suggested  that  plus a  indicator of 'fitness' concept.  3.5  determination)  Their  constant  lactate  model t h e y  slope  employed.  i n d e x would  replacing the previously  model  suggests  that  there  be a  applied is  no  "breakaway" anaerobic in  at  which  metabolism,  the  production  pathways all  point  from  but of  the  in  exercise.  This  belief  anaerobic  that  proportion  of  incremental  exercise.  lactate,  and  VE,  the  anaerobic  exercise.  VCO£,. and  ventilatory  energy sources  total  :  the  abrupt  increase  and  energy  transition  energy  In t h i s model  R - are thought  thresholds, supply  to  incremental critical  upholding  a  an ever i n c r e a s i n g  expenditure  from the onset  the  literature  under  (Wasserman et  a  be observed, and  has a  wide has  et  critical  variety  been al,  (Jacobs,  combination  The  been widely  a l , 1979), and  et a l <1976>  represents  l a c t a t e concentration,  century.  occurs  threshold'  (Kindermann Mader  i n blood  last  transition  threshold'  from a e r o b i c t o a n a e r o b i c  v e n t i l a t i o n may  'transition  by  the  During  throughout  the  through  increase  of  THRESHOLDS  (VC02),  this  energy  i s an e x p o n e n t i a l  model c h a l l e n g e s the very e x s i s t e n c e of  lactate  an  that t h e r e  i n c r e a s e d r e l i a n c e on  a c u r v i l i n e a r f a s h i o n from the onset o f  intensities,  2^®_  i s an  onset of incremental  parameters - blood  increase  there  of  refered  COS  i n t e n s i t y at which appearing  nomenclature.  in This  t o as the  'anaerobic  'aerobic  threshold'  'aerobic—anaerobic  threshold'  1964) the  expired  have been r e p o r t e d  researched of  metabolism  r  the  1986). T h i s t r a n s i t i o n both  a l a c t a t e and  threshold  a ventilatory  "threshold." The. become  use  of  widespread  the in  transition, the  field  or  'anaerobic'  threshold  o f s p o r t s c i e n c e and  has  exercise  - 18 physiology.  The  intensity  transition  above  Examination  of  investigators  to  to,  extract  work  representative  times the  and  at  factors al,.  are  determine  et  threshold  mechanisms  limited.  has  enabled oxygen  i s thought t o  adaptations  which  The be  (Rusko et a l ,  Determining  underlying  limit the  capacity  aerobic  transition  i n v e s t i g a t o r s t o study  a t h l e t i c populations  aerobic  limiting  (Wasserman et  ( F a r r e l l et a l , 1979),  (Ready et al,, 198£),  and  prescribe  w i l l s t r e s s the d e s i r e d energy systems (Davis et et  threshold'  defines  threshold  proposed mechanisms  fatigue.  p a t i e n t and  Tanaka  'anaerobic  severely  endurance c a p a c i t y  a l , 1981). The  induce  both  which  1981;  (Whipp  person's  threshold  training  exercise  which  a  transition  a c c u r a t e l y would allow  1964),  al,  the  et  and  in  monitor  transition  is  critical  been c o r r e l a t e d h i g h l y with marathon performance  transition  threshold  capacity  that  u t i l i z e , oxygen i n the working muscle mass.  has  performance.  represents  examine a person's a b i l i t y t o t r a n s p o r t  of  (Rhodes  threshold  work  the  and  intensity  1980),  which  -  the al,  al,  1981;  has  been  ability 1981),  described  et as  a l , 1979). a key  The  parameter  to maintain h i g h - i n t e n s i t y exercise  yet  the  the  'anaerobic  thresholds,  remains extremely c o n t r o v e r s i a l . It appears i t i s i n of  such  o f the  of  or  mechanisms  combination  concept  threshold',  the  any  Kinderman  increases,  l a c t a t e and v e n t i l a t o r y  the  nomenclature, and  o r i g i n a l assumptions t h a t the t r a n s i t i o n t h r e s h o l d Many threshold' the  o f the o r i g i n a l are being  lactate  ideas and  challenged.  threshold  and  is failing.  assumptions o f the  It was  the  'anaerobic  o r i g i n a l l y surmised that  v e n t i l a t o r y threshold  were synonymous  (Wasserman  et  conditions  did  1933).  appearance o f  to  The  reflect  These  1968), can  are  and  be  finding  that  cellular  are  finding  the  that  et  1986),  delayed,  not  and be  the  representing  energy production  or the  a l , 1984;  who  are  J o b i s et a l ,  accurately  within  represent  Investigators l a c t a t e formed  the  a c t i v e muscle  a t r a n s l o c a t i o n hinderance  increased  be  i n v e s t i g a t o r s are  p o r t i o n of the  present  cellular  cell.  ventilatory thresholds  not  (Stainsby,  appearance  an  muscle  believe to  or concentration.  that  et a l , thought  investigators  et  hypoxic  (Margaria  s t r e a m was  a l , 1979). O t h e r  oxidized  may  that  by  l e v e l s do  be  under  u n d e r what t h e y  considerable may  acid  blood  l a c t a t e and  lactate  molecule  suggest  of  blood  1986).  These  l a c t a t e may  r e l i a n c e on  the  to  be  anaerobic  lactate concentration.  LACTATE_THJESHOLD Almost best  all  in  presence  of  (Jobis pyruvate  et  i s the  order  to  supplement  reliance  (Jones et a l , 1968; formation  body c a n  blood on  Wasserman e t its  aerobic  stream  Pyruvate  muscle. energy  pathways  i s the  a l , 1986). An  oxidation  lactic  i n the  key  acid,  but  Lactate supply.  i s believed to  glycolytic  a l , 1981).  and  produce  exercising skeletal  l a c t a t e i n the  increased  production  t i s s u e s of the  example  produced  an  (Segal  only  a c i d w i t h i n the  (Connett  the  a  (Brooks,  findings  the  released  that  muscle  lactate  2^1  lactic  lactate production  the  tissues  of  oxygenation  blood  lactic  challenged  be  finding  the  within  to  uncoupled  believed that  l a c t a t e i n the  being  tissue  and  -  t i s s u e s produce  production  lactate  adequate  1964),  the  the  ideas  finding  al,  19  is The  represent of  energy  intermediary  imbalance  between  Krebs c y c l e  will  cause  pyruvate  lactate.  The  oxidation 1986; the  conversion  of  oxygen  1980).  ions.  Lactic  The  and  - and  lactate  has  lactate  i t s subsequent  pyruvate t o l a c t i c  acid will  lactate taken  which  up  utilized  threshold, been  has  defined  concentration  by  as a source  is  in,  or  increase  of fuel  be  adequate  (Brooks,  1986;  been o b s e r v e d  s i n c e t h e e a r l y 1900 s  set  as  systematic  et  a l , 1982),  as that  as in  that blood  definitions  i t s i n t r o d u c t i o n . The  2rnM (Hughson e t a l , 1982) o r 4mM  (Sjodin  an a b s o l u t e  at the i n i t i a l  i s an abrupt  e t a l , 1984),  increase  i n blood  at that  a l , 1982). B r o o k s  (1985) d e f i n e d  the lactate  was a n a b r u p t  non-linear  increase  defined  workload  immediately  preceding  lactate  concentration.  apply  as  where  a s 51 o r 45  (1986)  best  Davis  point  such  at which t h e r e high,  increase i n  lactate concentration  o r at a s e t slope value  workload  increase i n  (Wasserman e t a l , 1973; D a v i s  where t h e r e  (flunola  a  et  11  lactate  point  concentration.  threshold  t i s s u e s with  then  blood  disproportionally  lactate  later  at that  (Jones  threshold  may  the aerobic-anaerobic  been  as  accumulation  degrees  dissociate in  two l a c t a t e and two  formed  i n many ways s i n c e  has  such  a l , 1976),  (Ciaozzo  (Stainsby,  representing  l a c t a t e above r e s t i n g l e v e l s  there  is other  a l , 1981; K i n d e r m a n e t a l , 1979),  lactate  acid allows the  immediately  <pKa=3.9) f o r m i n g  threshold,  threshold  blood  conversion t o  1986).  transition and  The  to,  supply  Stainsby,  et  of  p h y s i o l o g i c a l pH r a n g e  transported  and  NftDH and t h e c o n t i n u a t i o n o f g l y c o l y s i s  Jones,  hydrogen  et  accumulation  account  the a  increase i n blood lactate  oroqressive  It aooears that the f o r inter-subject  variability, of  although  may  inter-observer error fit  the  onset  of  a  initial  increase  should  not  mistaken  will  be  maintained,  workload  which  point  there  blood  lactate  intensity ever of  in  be  lactate  increase very between  a  little,  stage  the  blood  fit  i s reached  level  critical critical  increase i n the increases in  a t w h i c h t h e r e i s an  al,  the r e l e a s e  1983).  increase  in  blood  l a c t a t e which o c c u r s at a p o i n t r e p r e s e n t i n g  Wasserman,  et  al,  t o an  gradual  lactate  (Davis  prior  ft  blood  threshold  noted  and  in  lactate  be  which  increase  the  may  et  1986)  this  progressive  (Davis  there i s a  uo t o a  or abrupt  During  test  threshold. This  r e l i a n c e on a n a e r o b i c m e t a b o l i s m  into  a wide margin  (Brooks,  individuals.  a disproportional  exercise  increasing  blood  intensity  as the t r a n s i t i o n  concentration.  of  lactate  progressive  or  varies  will  as having  in threshold determination.  slight  be  be c r i t i c i z e d  abrupt  1983;  Brooks,  1985;  l a c t a t e was  produced  during  1986).  iiliA_IAssue_0£_Supj3^ It  was  initially  believed that  periods  of  insufficient  Margaria  et  a l , 1933).  the  level  respiratory met,  the  energy of  of  muscular  system deficit  Dill  lactic  acid  al  activity the energy  et  al,  1924;  i n a p p r o p r i a t e response  to  by e i t h e r t h e c a r d i o v a s c u l a r o r  demand Jones,  ending  (1932) warned, was  (Hill  oxygen s u p p l y o f t h e muscle i s not  1965;  glycogen  alone  supply  I f t h e r e i s an  (fllpert,  and/or et  and in  production  glucose  acid.  of  oxygen  is  met  1980)  with the  through  anaerobic  with the  breakdown  formation of  however, t h a t t h e  inconclusive  evidence  lactic  accumulation o f an  oxygen  deficit the  (Gollnick,  quest  oxygen  Jobis  and  answer  acid  Stainsby  that  formation  indicated  adequate  found  oxygen  levels.  (1976)  the  Holloszy  found  later  h y p o x i a was  looked  presence that  content  utilization not  lactic (1978),  NftD c o n c e n t r a t i o n and concluded  related  at  (1986)  that  t o t h e more  rapid  changes i n blood  at  subrnaximal  or  absence  after  training  change.  present  I t was  a correct  information  there  is  regarding  oxygen  was  a  but  order to hypoxia.  while the  that  muscle  blood oxygen  hypoxia  l a c t a t e c o u l d not  workloads did  supply  levels  lower  (1985) s u g g e s t e d  f o r subrnaximal  undisputed  in  tissue  workload  as changes i n blood  assumption  supply  local  concluded  t o i n c r e a s e s i n vTJ£. D a v i s  lactate  workloads  of  a t t h e same subrnaximal  d i d not be  attributed  oxygen  or  NftD/NftDH l e v e l s f o r  o x y g e n s u p p l y . Graham between  Stainsby  utilization  determine  could  in  of g l y c o l y s i s over o x i d a t i v e phosphorylation.  Holloszy  lactate  adequate  t h e h i g h NftD l e v e l s d u r i n g  relationship  p r o d u c t i o n without  activation  was  no  lactate  lactate  t a k e n many d i r e c t i o n s  (1968) l o o k e d t o w a r d  concluded  blood  has  supply.  and  however,  and  Research  f o r conclusive evidence supporting e i t h e r  inadequate  an  1986).  not  that  where  the  this  adequate  however  above  be  reveal  anaerobic  threshold. Much  controversy  hypoxic  conditions  produced  in  (1985) ,  Davis  (1986)  reitterate  the  still are  working  (1985),  exsists  present  the  when  tissues.  Gollnick  et a l  concern.  around  the hypothesis that  lactic  acid  Recent  articles  (1986),  and  Production  of  is  being  by  Brooks  Wasserman e t a l lactate  does  augment  the  cellular  Sollnick  et a l  presence  or  and  (1986) a r e  absence  colleagues  accumulation redox  state  supply firm  of  et  o n l y due  to  the  rate  lactate  early the  local  molecule 1900's.  lactate  tissue  that  hypoxia  p r o d u c t i o n and  has  been  Recent  a  produced  but  (Cori  and  (Belcastro in  the  by  1929)  the  e t a l , 1975).  removal  suggested  that  clearance  of  et  of  lactate,  lactate  hepatic  consequence  of  an  removal  an  i n c r e a s e i n both  1986),  et  both  al, having  imbalance  1981;  between  Brooks,  c o u l d be  found  removed  1970),  by  the via  importance  of the  liver  and  flow,  Brooks  and  role  (1983)  hence h e p a t i c i n the  lactate  m u s c l e and  major p h y s i o l o g i c a l  research  brain  lactate  1985;  m u s c l e mass  or the  important limit  of  1961),  Donovan  blood  p l a y an  mechanisms  the  the  s i n c e the  ( Y u d k i n e t a l , 1975)  (Car1sten,  Recognizing  may  stream  was  between  a s much a s 75%  that  (Jorfeldt,  or kidney  heart  blood  reduced  muscle  Whichever  (Skinner  i n the  fate of  investigation  suggests  threshold.  is  The  a l , 1976). E a r l i e r  skeletal  Cori,  gluconeogenesis,  lactate  imbalance  i s removed w i t h i n t h e w o r k i n g  Hermansen  oxygenated  t o an  of  l a c t a t e r e l e a s e d into the blood  liver  that  accumulation  i t s removal.  topic  research  lactate  that  well  Wasserman  Removal  1986;  by  and  i n the  r e q u i r e s a change  (Brooks, the  (1985)  t h i s occurs  believers  and  (1976) s u g g e s t e d  not  lactate  Brooks  cell.  al  of  firm  dependent  2s.la.2_L.act a t e_ P r o d u c t i g n _ y s . Cohen  but  believers that  are  oxygen  of the  ATP,  adequate oxygen s u p p l y w h i l e  (1986)  is  of  lactate  removal,  the  p r o d u c t i o n and i t s  blood  Davis,  lactate  1985:  implications.  levels  Wasserman,  -  Muscle  f i b e r t y p e and f i b e r type r e c r u i t m e n t p a t t e r n s may be  important  factors  (Skinner fibers  £4 -  et  which  contribute  a l , 1981).  Jorfeldt  to  the  lactate threshold  (1970) suggested  that type II  a r e net producers o f l a c t a t e w h i l e type I f i b e r s a r e net  consumers, fiber  t h e r e f o r e l a c t a t e accumulation would depend on muscle  type  abundance  and of  M-LDH  lactate  (Sjodin,  have  a  low  rate  of  fibers  favors  Type  II f i b e r s have an  t h e r e d u c t i o n o f pyruvate t o  d e n s i t y , m i t o c h o n d r i a l c o n c e n t r a t i o n and  phosphorylation  the oxidation  of  to  patterns.  1976) and a r e more l i k e l y t o become hypoxic as  oxidative  abundance  which  capillary  favor  fibers  recruitment  H-LDH  of  (Sjodin,  (Tesch e t a l , 1981). Type I  lactate  t o pyruvate having an  1976). Graham  (1978) found tyoe I  have t h r e e times t h e amount o f l a c t a t e as compared t o  type II f i b e r s . £iljL^_L3£ti2_Bel^_3nd_Fat2gue  Lactic  a c i d produced  dissociates molecules. is  producing  for  the energy  (Cori  buffered  lactate  acid will  •reduction decrease  hydrogen  ions  and  immediately two  l a c t i c acid  i s an important  lactate  formation  by t h e b i c a r b o n a t e b u f f e r i n g  molecule  system,  form o f s t o r e d f u e l  p r o d u c t i o n , and s u p p l i e s p r e c u r s o r s f o r blood glucose  e t a l , 19£9; Brooks,  lactic there  two  The hydrogen i o n l i b e r a t e d from  predominately  while  during anaerobic g l y c o l y s i s  1986). I f , however, t h e b i D r o d u c t s o f  a r e allowed t o accumulate be will  a  rapid  cause  onset increased  of  w i t h i n t h e working  fatigue.  H+  release  Increased  tissue lactate  and a subseauent  i n muscle and blood pH (Wenger et a l , 1976). ft decrease  in  muscle  through  and  blood  anaerobic  limiting  enzymes  pH  will  glycolysis PFK  limit  through  phosphorylase  may  a l s o c a u s e f a t i g u e by a l t e r i n g al,  1976)  the i n h i b i t i o n  (phospho-fructokinase)  and  et  the production  or  interfering  with  the  Ca++  binding s i t e s  (Wenger e t a l , 1976).  production  may  role  supply  inhibiting  by  limiting  the  a  in  1965),  c e l l u l a r DH  permeability  actomyosin  play  of the rate  (Danforth,  ( H u l t m a n e t a l , 1 9 8 © ) . ft d e c r e a s e d membrane  o f energy  impairing  (Wenger  binding  at the  Increased  lactate  the aerobic  energy  FFft m o b i l i z a t i o n f r o m t h e a d i p o s e  supply  of  fuel  for  aerobic  energy  tissue,  production  ( I s s e k u t z e t a l , 1962). _E_TI_aTgRY_THRESHOLpS Noninvasive  measures o f t h e onset  transition  threshold,  refinement  of  threshold Owles  has  C02  intensity Robinson the  been  which  acidosis, the  wide use o f t h e concept.  The  measures t o d e t e r m i n e t h e t r a n s i t i o n  ongoing  process  s i n c e t h e 1931a's when  t h a t e x p i r e d volume  (Ve) and volume o f  (VC02) i n c r e a s e d d i s p r o p o r t i o n a l l y plasma  (1942) b e l i e v e d t h a t t h e i n c r e a s e i n C02 p r o d u c t i o n  was  (ft.),  HLa  with  began t o r i s e .  critical and  of bicarbonate  lactate  above a  Turrell  carbonic acid  buffering of the metabolic  the rapid  dissociation  acids  o f t h e newly  being formed  (B. ) : +• NaHC03 = NaLa + H2C03  B. The  an  recognized  at  result  produced  ft.  noninvasive  (1932)  expired  have a l l o w e d  of metabolic  (carbonic acid)  H2C03 = H20 + C02 increased  bicarbonate,  C02 and  production, a  rise  an  associated  in arterial  D H a r e now  fall  in  blood  b e l i e v e d t o be  prime  stimulators  expired  of  ventilation,  volume o b s e r v e d  by  accounting  Owles i n  f o r the  rise  in  1932.  2 i . 2 i . l _ Vent 2 l at o r y _ C o n t roi_ Under with  normal  changes  c o n d i t i o n s c h a n g e s i n m e t a b o l i c demand a r e  in  minute  maintain  the  pressures  at  depth  breathing  of  aveolar  control Input  arterial  of  is to  humoral  oxygen  r e l a t i v e l y constant are  ventilation  correction  ventilation  made  to  v e n o u s P02  central  stimuli  through  order to  al,  the  allow and  partial  of  and  for  the  system.  neurogenic the  of  ventilatory  nervous  through  control  rate  allow  central  will  a matching  1979). T h i s  system  sensitive  dioxide  Changes i n the  perfusion,  nervous  allow  a magnitude which  carbon  values.  <Sutton e t  accomplished the  and  in  blood  of  met  and  ventilatory  response. fit full  the  respiratory  cerebral in  onset  limbs  initial  ensuring P02,  although  variables  1975).  due  (Powers  and  pH,  and  i n c r e a s e s on  stimuli  from  sensitive  a  gradual  v a l u e s do  not  involving  work a b o v e  resDiratory The  first  mechanoreceptors  1985). Humoral s t i m u l i  ventilation.  prevents  the  a n e u r o g e n i c component  allow  aveolar  exact  humoral  increase  in  control stimuli,  resoiration  increase s i g n i f i c a n t l y ;  wide f l u c t u a t i o n s  i n the  the  humoral  occuring.  appears any  al,  cause  response  from  to  reflexive et  increase  their  ventilatory  than  cycle  appropriate  PC02,  It  exercise ventilation  i r r a d i a t i o n and  the  this  of  other Arterial  ventilation variable PC02  i s more c l o s e l y (Sutton et  is  al,  regulated  linked  1979, by  to  C02  output  Wasserman e t ventilation,  al, with  ventilation 1977),  a  primary will  increasing fact  regulating  increase  and  of  threshold"  load lactic  i n C02  ventilation allow  acidosis blood  hydrogen  ventilation  ion  lower  than  blood,  and  content normal  pH  will  Increased  C02  researchers to  to  answer  observed point  drop  metabolism.  of  however,  the  toward  in  in  1961  and  and  "anaerobic  proportion  to  point  the  increases  f o r PaCD2 c o m p e n s a t i o n f o r the  hydrogen  an  pursuing  do  lactic  ion entering  al,  attempt  to  the  drive  PaC02 of  intensity exercise  to  exercise  bloodstream. i n VCQ2 and  V02.  the  the  1980).  r e s p i r a t o r y Quotient  i n the  et a l ,  lower  buffering capacity  high  regards  V02  Issekutz  upper and  lead  (VC02/V02)  capacity  Balke et  al  UP to a  They t o o k t h i s  i n d i c a t i n g the 1962  (Sutton  Hyperpnea w i l l  the  at  increases  as  t o the  above t h i s  in  blood.  the  VCD2 e x c e d e d 1.0,  Up  an  a d d i t i o n a l independent v e n t i l a t o r y  (Whipp e t  lactate  than In  increase  production  look  which  greater  bicarbonate.  constraining  comparible  at  by  increases  questions  accumulation  production  c e n t r a l chemoreceptors  of  fats  due  an  the  metabolism of  t o the  a  production  introduced  a l , 1975). The  have  C02  a f t e r which  complete compensation  will  PC02 i s not  threshold"  will  et  The  to aerobic  above t h o s e r e s p o n s i b l e  stimulating and  1983).  (Swanson,  "anaerobic  production,  f o r the  stream  1979),  acid  (Wasserman  stimulus  be  production  believe that  (Asmussen,  to the will  t o C02  some t o  e x e r c i s e due  ventilation  increases  not  lead  factor  during  C02  buffering  was  has  c a r b o h y d r a t e s up  additional  in  that  in proportion  and  (1954)  specific  point,  wnere R  l i m i t s of  aeroPic  Rodahl  investigated  changes  i n RQ and r e l a t e d  maxV02.  They  degree  to  concluded  which  production  of  expenditure.  They  of  which  was l a t e r  Mcllroy  changes  glycolysis  considered  effort  be in  participated  that  the without  cardiac  patients  when  increase  R.  was  The  soon  was  and  or  measured  r e p r e s e n t e d by  nomenclature, known  anaerobic  measures  R  test,  musculature,  of  invasive  an  metabolism,  energy  Wasserman and  threshold  during a progressive intensity  anaerobic  to the total  by N a i m a r k e t a l (1964).  observed  in  i n the total  supply t o t h e working  continuously abrupt  represented the  c h a n g e s i n RQ a b o v e 8.75 t o be an  oxygen  concluded  could  i n RQ b e s t  i t s contribution  supported  (1964)  maximal  -  inadequate  metabolism  that  anaerobic  energy  index  them back t o a e r o b i c work c a p a c i t y and  threshold  refered  of  t o as t h e  "anaerobic threshold." Wasserman in  R  oxygen  at  and c o l l e a g u e s (Naimark e t a l , 1964) f o u n d  different  supply  musculature. onset  of  and They  blood  bicarbonate  that  cell.  blood Using  (r  C02  lactate  the nonmetabolic  demand  at  that  R  =  8.98).  reflects due  the balance  the level rose  with  the f a l l  thp  and d i s p l a c e m e n t  to i t s rapid  diffusion  i n blood  production  of  (1961) had  of bicarbonate  metabolism  more c l o s e l y  from  t h e muscle  RQ between 8.78 and 8.88 t h e v  calculated  CQ2,  Excess  o f t h e working  I s s e k u t z and Rodahl  anaerobic  between  a p p r e c i a b l y at t h e  and t h a t  correlated  production  resting  reflect  accumulation,  highly  the  a  to  recognized  COS  (nonmetabolic) than  oxygen  lactate  was  non-metabolic suggested  workloads  chances  C02 = VC02 -  (RQrest  * V02)  which  hiphly  levels,  correlated  and i n c r e a s e d  ( r = 0.9S) w i t h  i n proportion  The  results  the  accumulation of metabolic acids  COS  indicated  (Issekutz Using  (1966)  et a l ,  healthy  could  increase  in  lactic  decrease  in  standard  increases  Rodahl  with  but  the  excess  by  of excess  males  Bouhuys e t a l  c o r r e l a t i o n s f o u n d by  i n 1961. T h e i r  i n v e s t i g a t i o n found  acid  a greater  R  lactic  was  of  and  acid  with  excess  COS  accumulation  provided  a  that the  magnitude than t h e  the differences  workload.  They were  being  concluded  that  associated  with  ( r = 0.6SS and r = 0.796)  was n o t a l w a y s t r u e .  only  influenced  They s u g g e s t e d  rough e s t i m a t i o n  a c i d o s i s while d i r e c t  R and  that  o f t h e degree o f  lactate determination  was  preferable.  It  had  variables those  been  presented  Wasserman  in  as  blood  al,  estimated into  the  accurately  ventlatory ( i e . VCOS  (ie. R  and  lactate levels  1964).  body  that  volumes  ratios  evidence in  balancing  to  et  supporting balance  suggested  measured  proportional  taken  untrained  bicarbonate,  both  induced  and  increasing  reverse  COS  exercise still  in  i nventilation.  and t h e p r o d u c t i o n  duplicate the excellent  and  in  t o increases  lactate  1961).  Issekutz  increases  i n blood  v e n t i l a t i o n was h i p h l y  trained  not  intensified  that  changes  for  Clode this  and by  h y p o t h e s i s when  VCOS  t e c h n i q u e changes  Ve/VOS) would  They  when  blood  be more  (1969)  provided  i n v e s t i g a t i n g COS l a c t a t e could  be  c h a n g e s i n t i s s u e PCOS a r e  concluded  i n blood  than  e t a l , 1364, and  Campbell  that  gas exchange  and Ve) r a t h e r  (Nairnark  and  found  consideration.  and  that  using  lactate concentration  a  COS could  be e s t i m a t e d  with  reasonable  30  -  accuracy.  2_2_3_Comj3ar_I'_^ In "the  1973  Wasserman  level  metabolic occur  <pg-  these  be  o r 02 and  236)." using  exercise could  work  acidosis  variables  a  that  investigators  decrease  found  the  be  C02  is  much g r e a t e r t h a n  J.ft.  lactate  the  fts  be t h e  coefficient limitation  rate  'anaerobic  point  when a l l g a s gas of  02  immediately  i n c r e a s e i n R,  increases Of  these  The  without  RQ  workloads  metabolic  production of excess  a  measures R  as t h e m e t a b o l i c  was  increases producing  production C02  of  i n normal  overshadowed. investigated  threshold* (1973) t h e s e  measure. U s i n g  in  three  Ve  and  i n the  modes  investigators  of  found  alone to predict  thresholds a  of  both  correlation  that the  t h r e s h o l d from  R  the  coefficient  in correlating  They s u g g e s t e d  i n detect inn the t r a n s i t i o n  validity  measures  a correlation  transition found.  the  laboratory  p a r a m e t e r s were usee  was  exchange  incremental  V02  o r VCG2, an  C02.  C02.  produced  analysis 0.95  or  increased  noninvasive  sensitive  threshold  and  <1976)  Wasserman e t a l  least  and  al  using  of  exercise.  0.88,  et  of  detection  the  changes i n R being  Davis  feasability  lactate  at  amounts o f m e t a b o l i c  s u b j e c t s with  to  in end-tidal  tests  which  that the t r a n s i t i o n threshold  work  sensitive  as  exchange  gas  analysis during  end-tidal  least  incremental  increasing  gas  found  that  where  below t h a t a t  noninvassive  n o n l i n e a r i n c r e a s e i n Ve  corresponding  during  comparing  as  threshold  a s s o c i a t e d changes i n gas  breath-to-breath  point  to  consumption j u s t  the  In  determined  preceding or  of  et a l d e f i n e d the anaerobic  major  chances i n  gas  exchange  threshold  variables  point  use  of  the  criterion  acid  production.  et  al  used  It  was  correlation  (r  -  sensitive provide  indirect  gas  index  of the  0; 93,  measure  <r  excellent r  —  <r  values,  the  the  lower  threshold  p o i n t a s an et  correlations threshold in  work  the  (1984)  not  all  while of  measures  points  were  increments  of  lactate  provided  the  highest  and  not  and  Using three  Ve  lactate  best  test  the  least  appeared  threshold  analysis  detection expressed  did  over as  a  -  to  (r = not  Ve/VO£ %v"Q£max  did expressing  the  (1/min).  accurately  subjects.  and  the  correlational threshold  VCO£,  measure,  c o e f f i c i e n t s than  earlier be  (Ve,  threshold point  VC02  the  Caiozzo  The  R was  <  in  threshold.  0.001).  0.39)  lactic  and  0.93,  a b s o l u t e V0£  found  can  ve/VO£  P  as  accurate  the  correlation  al  most  by  provided  threshold  produced  i n 198£  < 0.001) and  Multiple  improve  Powers  = =  criterion  predictions  0.88).  while  P  the  e x c h a n g e m e a s u r e s used  noninvasive  that  tne  values  of muscle  lactate transition  the  of  Questioned  l e v e l s above r e s t i n g  and  found  significantly  with  although  i n d i c e s provided  to  correlation  indices  an  four separate  correlated  threshold.  0.83,  Dlot,  Ve/VO£) t o determine the v e n t i l a t o r y  was  retest  sudective determination  d e t e c t i o n were s t u d i e d  determination  and  each  being  ventilatory  threshold'  investigators  the  lactate  t o determine which  reliable  R,  blood  measure,  common  'anaerobic  -  from a time-based  increased  The  is  31  able t o reproduce  concluded  minutes,  high  that  the  lactate  by  nas  exchange  determined a slightly  the  different and  protocol,  a blood  lactate  sampling  rate  reference), 0.63)  of  these  between  V e / V O £ and  once  investigators  the  through  transition blood  Approximately the  working  will  be  1986).  90  muscle  minutes  found  (their  a noor  criterion  correlation  t h r e s h o l d when d e t e r m i n e d  (r =  through  lactate.  -  Excess  C0£  acid  additional  lactic  production  fashion VCO£ The EXCO£  rapidly  after  producing  a  (RQrest  *  Clode, reported EXCQ£.  not  Clark  yet and  high  and  water  generated  long as t h e  as  there  increasing  continue to rise,  the t r a n s i t i o n relative  system  increase i n excess  be In a  workloads  s l o w l y at  threshold in a  rate  will  (Wasserman e t a l , 1936). with  acid  (Wasserman e t a l ,  as  increasing  (PIT)  will  between  Campbell  correlations  permits  reasonable  test  lactic  bicarbonate buffering  first  curvilinear  C0£  LEXC02 =  muscle  cell  the  blood stream,  in  the  The  readily  capillary  (1961) and between  lactate  accumulation  although  early  I s s e k u t z and the  i n blood hydrogen  diffuse  enhanced  by t h e  endothelial  research  Rodahl  by  (1961)  that  the  calculation  lactate  t o be d e t e c t e d  i o n and  C0£  produced  presence  of carbonic  The  lactate  with  within  a c r o s s t h e m u s c l e memnrane  cells.  and  l a c t a t e t h r e s h o l d and  i n v e s t i g a t i o n s suggest  changes  accuracy.  the  blood  been d e t e r m i n e d ,  These e a r l i e r  EXCO£  is  of  within  VO£)D.  relationship has  be  ion to buffer  intensity  i o n produced  the d i s s o c i a t i o n  (excess) CD£  production  progressive  then  from  (EXCO£) w i l l  hydrogen  acid  % o f t h e hydogen  b u f f e r e d by t h e  non-metabolic  lactic  and  94  mass  immediately  producing  of  three  Non-Met abol_ i c _ C O £ _ a n d _ P e r f orioa^ce  £_  of  every  into  anhycrase molecule,  however, active  may muscle  hinderance  be  detected  lactate  accurate  during  The  related  found a  which  is  1981  expired  is  the  cell  the  may  point  onset by  Hearst  EXCO£  accumulation  and  the that  is  through  of  COS  anaerobic  transition threshold  that  the running  speed  c o u l d be  These a u t h o r s  at  used  found  a  <r=.94, P<3.81) between p r e d i c t e d  indication  the rapid  of the c r i t i c a l occurs.  unpublished  highly  at f o u r s p e c i f i c  index  training.  performance.  anaerobisis  correlated  C0£  buffering capacity.  threshold  suggesting that  (198£,  allows  increase i n excess  this  of  anaerobic  production  i n e x p i r e d EXCO£ occured  correlation  of  the excess  a consistent or  is  cellular  test  subject's  the organism's  running  be an  lactate  t h e measurement  lactate  McKenzie found  marathon t i m e s  EXCD£  supported  and  a  that  the s u b j e c t ' s s t a t e of  marathon  actual  which  across  consumption  of  thought  surpassed,  significant  expired  translocation  i n blood  that  oxygen  intensity,  breakaway  predict  and  a  w i t h i n the  ( I s s e k u t z e t a l , 1961).  determination  Rhodes and  rise  suggested  maximal  there  critical  a  highly  a  al  pathways  d e p e n d s on  In  has  movement  t o the magnitude o f  that  metabolism, point  fibers  a more a c c u r a t e p r e d i c t i o n o f  investigators  glycolytic  when  to  accumulation et  noninvasive  directly  They  and  a significant  offer  Volkov  C0£  power.  oxidative  1986)  1986)  before  E X C O £ may  1975  excess  the  (Brooks,  p r o d u c t i o n and  In  to  bed  by  B e c a u s e o f t h e s e mechanisms i n c r e a s e s i n e x p i r e d E X C O £  detected;  the  removed  (Stainsby,  membrane. may  be  These thesis)  (r=.89)  running  speeds.  with  increase in intensity  results who  found  blood  at  were that  lactate  -  3__  £SQIS£QL§_FOR_£LyCID@IING_TR Underlying  progressive  investigations  intensity  described  the  different  forcing  transition  tests  responses  one  functions.  threshold  increases  in  C02 p r o d u c t i o n .  accomplished  causing even  of  Whipp,  those  arterial  unable  a  PC02  blood  I n 1975 Wasserman and w n i p p expect  t o o b t a i n when  which  for  mediated fall  compensate  by  are proportional to the  metabolic  by while  and  is  increases  in  C02  production  pH r e m a i n s unchanged, fit  +) i n c r e a s e s  blood  acidosis  high  increased  f o r increases  bicarbonate  using  a t work r a t e s D e l o w t h e  disproprtionally  to  threshold a r e  pH and PC02 a r e m a i n t a i n e d  work r a t e s y e t ( 8 0 % max to  transition  Pit work r a t e s a b o v e t h e t r a n s i t i o n  compensation  over  greater  loss  ventilation  through  ventilation  could  mean a r t e r i a l  alveolar  the  the  In g e n e r a l ,  in  threshold  of  (PIT).  increases  are  34 -  in ventilation  i n blood  pH f a l l s .  pH due t o t h e (Wasst=rman and  1975)  During  a  progressive  intensity  increments the f o l l o w i n g trends 1.  VQ2  test  with  linearly  maximal v a l u e  i s reached  a t w h i c h V02 w i l l  2.  and VC02 w i l l  critical acid  intensity,  i s produced 3.  Ve  increases greater 4.  will in  than  Ve  throughout  increase  the anaerobic  causing  equal  increases  4 minute  threshold,  in  with  until  a  V02 up t o a  at whicn  faster  i n proportion  increases  the test  plateau.  linearly  VC02 t o i n c r e a s e  increase  -  may be o b s e r v e d :  increases  Ve  i  t h a n V02.  t o VC02,  VC02  lactic  whicn  therefore a r e both  i n V02.  R increases since  increases  i n VC02 a r e o r e a t e r  than  increases The 4  in  difference minutes,  will  between t h e two  i s that while  increase  remains  V0£.  at  the  constant,  increases  at  decreases.  using  anaerobic  and  intensity  tests  advantages  over  determination objective.  using of  one four  the  1.  1  definition 2.  4.  PCO£  end-tidal  end-tidal  P0£ PC02  based  that  increments  increments  had  when  threshold' on  increments  progressive  five  several  noninvasive  was  a  major  major p o i n t s :  allowed  a  more  specific  i s much s h o r t e r .  lactate  allowing  while  P02  of the anaerobic threshold.  the test  3.  minute  'anaerobic  minute  increments  concluded  minute  T h i s c o n c l u s i o n was  end-tidal  1975)  (1975)  using  functions, 1 or  threshold while end-tidal  threshold  Whipp,  Whipp  forcing  increments  using 4 minute  (Wasserman and  Wasserman  1 minute  anaerobic  while  the  different  values  do  quicker recovery is  easier  to  the  'anaerobic  from reach  not  reach  such  high  values  exhaustive exercise. and  determine  the maxVO£  i f so  desired. 5. a V0£ It  values  o r work r a t e w i t h o u t  appears  readily  t h r e s h o l d ' can  from  that tests  inbetween,  responses reported (Wasserman  occur. during et  the using  as  tests al,  transition  as  one  t h r e s h o l d can  recognizes  transition  using 1975:  1 and  be  either  discerned  increments, that  1935).  or  different  t h r e s h o l d v a l u e s have  4 minute workload  Yoshida,  as  in estimation.  1 or 4 minute workload  long  Similar  large errors  be e x p r e s s e d  been  increments  McLellan  (1987)  attributes in  threshold  exchange determine and  much o f t h e c o n f l i c t i n g detection,  parameters  using  observed  changes in  the anaerobic threshold  v i sa-versa.  data to methodological  a  in ventilatory  'fast'  during a  increment  'slow'  errors ana  pas  test  increment  to  test  - 37 -  4..0  CONCLUSIONS Amidst  the  and-effect  relationship  transition phenomena Many  (McLellan,  there  is  large  area  are s t i l l  et  al,  question  i n c o n c l u s i v e evidence  part  intracellular the  still  the  due  to  events,  utilizing  t h e e q u a l i t y and c a u s e -  ventilatory many f i r m  and  lactate  believers i nthe  1987; Wasserman e t a l , 1986; D a v i s ,  (Hughson  however,  surrounding of  thresholds there  reviewers  1985),  controversy  an  1987;  Brooks,  the relationship. supporting  insufficient  suggesting  some o f t h e new  a need  either  method  i985; It  1985).  Stainsby  a D o e a r s  that  position,  in a  of  determining  f o r further research i n  technologies.  38 -  CHAPTER METHOD AND  THREE PROCEDURES  -  40 -  _iIHQDS_BNO_ERQQiDyRES  Subjects  Twenty-one  period  subjects to  team  cyclists  (15 males arid fa females)  i n t h e s t u d y . The s u b j e c t s were t e s t e d over'a  participated day  national  just  prior  to  the  tnree  n a t i o n a l team time t r i a l s : a l l  were i n a h i g h l y t r a i n e d s t a t e . The s u o j e c t s were asked  refrain  from  heavy  e x e r c i s e £ 4 hours o r i o r t o the t e s t and  perform on an empty stomach. Test_ng_Procedures  The  baseline  measures o f height  and weinht were taken  orior  to t e s t i n g . Testing and  was performed at U. B. C.  Research  prior  to  Center.  Peine  Subjects  tested,  i n t h e J .tt.Buchanan F i t n e s s  were asked t o warm up 15 minutes  and were allowed only a l i m i t e d war roup  with t h e t e s t i n g apparatus i n p l a c e . The  test  intensity  test  warmup  minute cyclists  The where  ft  the  frequency.  at  with  cadence  test  was  consisted  of  a  continuous  progressive  on a Monarch s t a t i o n a r y b i c y c l e . F o i l o w i n n  pedalled  (female/male) 1.0).  protocol  a  work  against  an i n i t i a l  r e s i s t a n c e o f 180 o r 158w (figure  98 rpm was maintained throughout t n e t e s t .  terminated  athlete  r a t e o f 58 o r 188w (female/male) t n e  i n c r e a s e s o f £ 5 W every second minute of  a two  was  upon  volitional  unaole t o m a i n t a i n  fat icue: that  point  o r r e g a i n t n s 98 RPM  — Table  1. 0 Th  stage  *• i  rne  work  < rn i n)  -  0  wmuD  i  2  2  4  3  6  4  a  5  10  S  12  7  14  —  ma  41  sivs  l o a d i n g s e n erne.  rate  (w)  i e  frequency (RPM)  female  2  100  58  4  150  108  98  6  175  125  98  a  283  158  93  10  225  175  93  12  258  230  33  14  275  225  98  16  380  253  98  etc.  Testing lactate  and  monitored a  measures HR.  online  Hewlett  included Respiratory  Data  determined  or c a l c u l a t e d  HR  monitored  through  the  Blood minute  use  in  intervals  were  V5  EC3  the  samples  rseamolysed  using  cooled  S43.  last  throughout The  was  second  blood  time 18  determined  using  aiood  variaaies  were  interefaced  with  Variables  were  intervals.  seconds  of eacn  minute  recording. tio  duration  P e r c h l o r i c  EXC02,  System.  ta;<en v i a f i n g e r  test.  Analyzer  the  of a t h r e e lead  samples  lactate  15  R.  VC02,  exchange  Acquisition  over  intensity  blood  gas  VE,  u s i n g a Beckman M e t a b o l i c C a r t  Packard  was  V02,  were acid,  v e n o u s  of  the  taken. and  a Kontron  sampling  at  procressive immediately  analysed.  Total  Medica1 L a c t a t e  The  breakaway  threshold  points  indepencant  oaservers  WTT  LftTT  curves.  bach  while  the  subjects  and  separately proposed  areakaway  discussed point  by  was  points,  upon.  were  three  VE/VD2)  and  visual set  of  curves  identity  or t r a n s i t i o n  one  dependent  tnree  of tne  EXTT,  analysed  were  was  withheld.  thresholds, and  an  variaale  were  exact  v a r i a a l e s (blood  independant  ay  Determined  inspect ion  group o f t h r e e o b s e r v e r s  agreed  There and  the  through  were  The then  brsaxaway  lactate.  (progressive  EXC02  intensity  test). P)  r e g r e s s i o n a n a l y s i s was  EXTT  and  WTT,  LftTT and  value  were o a t a i n e d  Significant measures using  post  The  hoc  values  for  coefficient threshold.  f o r the  ft  comparing  EXTT and  Correlation coefficients  and  LftTT, an  r*  data. were  significant  determined  F value  was  a  using  repeated  further investipated  procedures.  decree  investigated  WTT.  differences  ftiMOVft.  performed  by five was  to  which  graphing minutes  the  curves  average pre  determined  absolute  a n d post for  paralleled  each o t h e r w a s  EXCG2  and  lactate  t h r e s h o l d . ft c o r r e l a t i o n  a l l . data  points  pre/post  CHAPTER RESULTS AND  FOUR DISCUSSION  - 44  -  BliyLIi  Twenty-one in  this  trials.  Canad i am  study  just  National  prior  to  caliper cyclists  p a r t  iciDated  the Canadian N a t i o n a l team time  The d e s c r i p t i v e s u b j e c t data i s presented  i n T a o l e 1.  T A B L E 1. D e s c r i p t i v e s u b j e c t data f o r a l l s u b j e c t s grouped, males and females GROUP N = £1 £3.19 + 3. 34 70.10 + 8.46 175.5 + 1.57 63.41 +  : Ape : (yr). : Wei qht : ~ <kp>. : Height : : : MaxVO£  JaU*B_*i0iDl_5_3  Aerobic determined blood  by  ; : : • : : i  MALE n = 15 £3. £6 + £.79 73.57 + 7.30 177.9 + 6. 90 65.38 + 5_8  anaerobic using  lactate,  equivalent  :  for  FEMALE n = 6. £3.00 + . 1.95 " 61.43 + 3. 34 169.6 + . 1.59 58.50 +  ._  5_jt  transition  each  of  EXTT  -  V0£,  VE/VO£).  : : : : : : : : :  .  \_  threshold  values  three s i n g l e indices  excess  CC£, The  and WTT mean  were  ( i e . LATT -  - the v e n t i l a t o r y  threshold  V0£  values  (+S.D.)  f o r each method of AT d e t e c t i o n , r e p o r t e d i n I/min, were  3.65  0.57,  +  EXTT,  and  3.46  WTT  +  0. 6£,  respectively.  and  3.53  Table  + ©.51 £  f o r each of LATT,  presents a c o r r e l a t i o n  matrix f o r the r e p o r t e d i n d i c e s . Diagrams 1 throuch  3  T A B L E . 2. A c o r r e l a t i o n matrix between a b s o l u t e VOc AnT v a l u e s as determined throuch d i f f e r e n t method* LATT EXTT WTT  :  LATT 1.3 3. 95 * 0.91 *  * sionificant  EX .  s  T  WTT  1.0 0.  at s-'<3.00:  9£ *  i.  0  represent  plots  repression  the  three  indices  anc  report  the  ecuat ions. The h i g h e s t c o r r e l a t i o n set ween t r a n s i t i o n  thresholds between  comparing  determined LATT  correlation  and  through EXTT  (r  different =  8. 95,  methods  ?<8.881).  was The  found lowest  between two measures was found Petween LATT and  WTT  (r = 12.91, P<8. 881).  4. 5: 4. £: X 3.9!  m i  E I G U R E _ 1 _ LATT <mmoi/i) vs £XTT (mi/kc/min) fi = £1 R = 8.95 P(R)<8.881  ... •  T T 3. 6:  3. 3:  / 3. 0: k g £.7: / m £.4; i n  X = 8. 8Sl3*Y + .6653  £.4  3.8  3. 6 4. £ LATT (rnmol/1)  4. 8  i_ATT (rnmoi/I) vs WTT <V£/vu£)  EISU_E_£_  = £1 R = 8.91 P(R) <8.881  H  X = 1.8£5b*Y - . 0 £ 9  £. 4  £.8  £. 8 • LATT  3. 6 <mmol/l)  4. 4  - 4to -  EI§yEI_3s_ EXTT (ml/ka/'min) vs (VE/V02)  WTT  = £1 = 8.92 P < R) <8. 881  N  5?  Y = .?462*X + .9974  >. 8 EXTT  2. 8  The  equality  (I/rnin)  was  of  3.6 <ml/kn/min>  the  determined  three  4.4  transition  through  threshold  t h e use o f a repeated measures  ANOVA  which r e v e a l e d  (F  8.41, P<8.881). Post hoc cornoar i s i o n s r e v e a l e d  =  differences between  a significant  EXTT  and  WTT  difference  means  3 ) . There was a general  WTT,  which  i n 19 of 21  V02  means  significant  trend  =  2.212,  P<8.825),  t h e LATT and WTT  but  (1/rnin)  the  trend  a  means <see  f o r t h e EX i'7 t o preceded t h e  preceded t h e LATT. Although t h e t r e n d s f o r t h e  inconsistent,  As  (t  between  TABLE  held true  d i f f e r e n c e oe-cween c e i l  between LATT and EXTT means (t = 4.287, P<8.881) and  nonsignificant  were  V02 v a l u e s  f o r t h e EXTT t o precede The  WTT LATT  subjects. and  time  are l i n e a r l y r e l a t e d  differences  - 47 between  V02  represented the  means as  transition (LATT),  (WTT).  Using  EXTT  compared through  (minutes). The mean times  t-Tests  (t =  threshold  the  were  approximately  12 + 3  s i g n i f i c a n t d i f f e r e n c e s were  LATT and EXTT means (t = 5.81. P<8.881) and  means  to  occured  (min) at which  10.5 + 3 minutes (EXTT), and 11.5 ± £ . 5 minutes  both  WTT  transition  time  correlated  between and  a  thresholds  minutes  found  r e p r e s e n t d i f f e r e n c e s between t n e means when  £ . 8 8 , P, 8.858). The blood  (LATT)  was  the v e n t i l a t o r y increased  significantly  transition  release of EXCO£  lactate  delayed,  threshold  as  detected  i n e x p i r e d a i r , with an  average time d e l a y o f 1.4 minutes.  TABLE_3_ RM ANOVA and Post Hoc comparisions o f t h e t h r e s h o l d V 0 £ v a l u e s (1/min) as d e t e c t e d through d i f f e r e n t means TT INDEX LATT EXTT WTT ANOVA  . POST HOC CORRELATED T-TESTS. N LATT . EXTT . WTT £1 t=4.£9 . t= 1.33 . P (8.881 . . t= £ . £1 £1 . P>8. 85* .P <8. 8 £ 5 . £1 .F=8.41 .P<8. 881 . df —  —  * nonsignificant Individual time  .  MEAN VQ2 (1/min) . 3.65 +8.57 . . 3. 46 +8. 63 . . 3.58 +8.51 ,.  difference  subjects  were compared over a r e l a t i v e p e r i o d o f  pre and post t h r e s h o l d s , using t h e E X C O £ and blood  threshold  points  procedure  also  appearance expired compared threshold  of  EXC02 over  as  allowed blood volume a  relative for  points  of  comparision.  This  t h e s i g n i f i c a n t time d e l a y i n t h e  l a c t a t e t o be accounted and  lactate  blood  lactate  f o r . The s u b j e c t ' s  concent r a t i ons  were  f i v e minute pre t h r e s h o l d and f i v e minute post  p e r i o d , f o r a t o t a l o f e l e v e n minutes. A p s o l u t e v a l u e s  -  of  lactate  (rnmoi/I)  s i g n i f icarit l y minute  ranee-  variance in  blood  8. 69,  With  an  lactate  excess  ccrnparision. produced  =  i n blood  expired  .95,  (r  arid  P<8.881), lactate  excess P <0. 801)  r*  of  levels  CG2  (ml/kc/rsin)  c o r r a l atsc  ( s e e DI AGRA*! 4) o v e r t h i s  0.48,  approximately  c a n be a c c o u n t e d  correlations  significant with being  correlations  approximately accounted  influences  o f both  individual  rnay a c c o u n t  f o r t h e lower  o v e r ztis  f o r by  cnances  point f o r  same t i m e  period  ( r a n g i n g from  .82 t o  88 - 98'/. o f t h e v a r i a t i o n i n  f o r through differences  grouped  1:  58?C o f t h e  C02 when u s i n g t h e TT a s a r e l a t i v e  Individual  highly  43 -  changes  i n EXCQ2. The  and g e n d e r  correlation  differences  obtained.  FIGURE_4_ L a c t a t e (mrnol/1) v s e x p i r e d e x c e s s C02 (ml/kg) o v e r an 11 m i n u t e r a n g e (5 min. p r e & post AT) u s i n g t h e AT a s a r e l a t i v e point of reference n = £24 R = 8.69 P<8.881 X = .4391*Y - 1.7895  LACTATE  (rnmol/1)  - 43 Changes levels the  nature  of  Both  threshold  increased individual period  EXC02  appear  when t h e t h r e s h o l d s  gender. pre  in  at  to track  a r e used  this relationship  a v e r a g e m a l e and after an  which  increased  correlations  between  lactate  of  o f t i m e s u g g e s t t h e two  blood are  lactate  individuals  lactate  o v e r t h e male's. and  interrelated.  lactate although  v a l u e s were  the female's blood rate  i n piood  as r e l a t i v e p o i n t s ,  varies  female  changes  The  and  similar  and  EXC02  significant  EXC02 over  this  DISCUSSION  While 1376;  previous  Wasserman  demonstrated lactate  studies  et  a  al,  (Caiozzo  1973;  Wasserman  relationship  thresholds,  and  reflect  between  earlier  may  1351;  C l o d e e t a l , 1361), t h e e x a c t  elucidated.  C02 The  relationship  the  purpose  lactate  erg©meter  has  not  specific subject  The  correlations  lactate).  and  blood  suggested  that  (Issekutz  et a l ,  between  excess,  t o determine the  EXC02  throughout level  studies  (EXCD2, have  threshold  and  an e x t e n s i v e  any p r e v i o u s  between VE/V02)  examined  utilizing  studies  measures o r u t i l i z i n g  a  cyclists,  on t h e r e l a t i o n s h i p  ventilatory  of  this  study  between  each  of  the ft  transition  correlation  VE/VC2 t h r e s h o l d s , ai,  have  a  the  bicycle  review of the investigating such  an  elite  pool.  results  determining  and  intensity test,  ventilatory  was  i n twenty-one e l i t e  many  revealed  lactate  study  placed  1364)  a c c u m u l a t i o n h a s y e t t o be  lactate  the  transition  progressive  literature these  and  Although  aerobic-anaerobic  et  test  have  relationship  this  p a r t i c u l a r e m p h a s i s was  thresholds.  and  of  al,  ventilatory  blood  lactate  blood  intensity  blood  level  blood  between  progressive while  and  in  et  studies  EXC02  non-metabolic  changes  e t a i , 1932; D a v i s e t a l ,  1932;  Davis  the  threshold  o f r=0.91 was  consistent s t a l , 1376;  with  demonstrated three  indices  (EXCQ2, found  significant used  VE/VQ2, and  between t h e  e a r l i e r findings'  in  blood  lactate (Caiozzo  Wasserman e t a l , 1 9 7 3 ) .  These  previous  authors  sensitive  measure o f t h e l a c t a t e t h r e s h o l d .  This  study  have  found  the  lactate threshold  not  represent  significant EXCD2  (r=8.95),  actual  the  appearance  point  did  threshold  point  (P>8. 8 5 ) ,  is  an  have  abrupt  although  difference  threshold  researchers  not  of  measure  must  suggested lactate 1936).  have  be  that  blood  blood  in  blood  Although.  reflect  at  VE/V02  similar  non-significant  In  13  turnpoint to  VE/V02  be u t i l i z e d , the point  2  min.  caution.  turnpoint  was  previous  at which  there  e t a l , 1982;  may  not  Recent  criterion  studies  have  reflect  intracellular  (Stainsby,  1986; B r o o k s ,  lactate  h a v e been f o u n d t o  these s i m i l a r i t i e s  may  i n no way  l a c t a t e . In t h i s  while  in  8  was e q u a l of  21  a f t e r the lactate turnpoint post  as  study  d i f f e r e n c e may  VE/V02 and l a c t a t e t u r n p o i n t r e l a t i o n s h i p .  turnpoint,  occured  VE/V02  from t h e l a c t a t e  l a c t a t e as t h e i r  o f 21 c a s e s t h e VE/V02 t u r n p o i n t  lactate  time  1973).  blood  points,  the  l a c t a t e (Caiozzo  concentration and  fts  VE/VQ2 and l a c t a t e t u r n p o i n t  due t o t h e e r r a t i c  pre  may  blood with  by a 1.35 m i n u t e  differ  the accumulation of i n t r a c e l l u l a r  be  the  used  between t h e a v e r a g e  lactate.  to reflect  lactate  or  was f o u n d  VE/V02  interpreted  production  breakaway  the  which  with  t h e EXCDS t h r e s h o l d d i d  significantly  suggested,  increase  tins most  t o c o r r e l a t e best  represented  D a v i s e t a l , 1976; Wasserman e t a l , Studies  VE/VQ2 may o f f e r  o c c u r a n c e o f t h e l a c t a t e t h r e s n o l d . ft  lactate thresholds,  in  that  t h e EXC02 t h r e s h o l d  (P<8.881)  and  delay  the  suggested  lactate not  turnpoint).  significantly  t o o r preceded  cases  t h e VE/V02  (a r a n g e o f 3 min.  Although different  the average from  the  average  lactate  values,  turnpoint,  spanning  the  the  wide range of VE/V02 t u r n p o i n t  lactate  turnpoint,  may  be  largely  r e s p o n s i b l e f o r t h i s finding.. EXC02  tumpoints  were found t o be more c o n s i s t e n t l y  to  the  lactate tumpoints,  of  £1  cases.  Not  significantly found  them  diffuses  across  lactate  molecule of  hypothesis Caiozzo  the  muscle  is  is  further  al  by  found the  preceded the  the  s i g n i f i c a n c e of such a d i f f e r e n c e mean  (+0.829), results  would  recognized  suggest  (Stegrnann  determination mmol/1  of  the  (Kindermann  possible, The  over  a  1.72  that et  the  was  al,  al,  not  relationship over  turnpoint)  in  the  the  EXC02  and  for  comparision.  an  eleven  present  lactate when  5.30  supporting 1988). T h i s  scual  by to,  although  and  that  at a set et  mmol/1  range. These  differences  Sjodin  blood  the  investigated.  rnmol/1  f a c t o r s of  between  cell,  found to. be 3.35  1981),  1979;  EXC02  than  lb subjects,  individual  being s u b j e c t t o l a r g e  investigated  -  was  r e s u l t s documented  i n 13 of  lactate threshold  et  the  (Stainsby,  a b s o l u t e l a c t a t e v a l u e was  occur ing  readily  VCD2 t u r n p o i n t was  or  The  more  mechanism  lactate turnpoint  19  turnpoints  suggests that  from w i t h i n  supported  (1982) who  data  membrane  translocation  lactate  in  a significant difference  This  released  lactate turnpoint  EXC02 and  (r=i2. 95)  (P<0.f2(21).  the  a  et  were  correlated  between  evidence  only  preceding the  related  must  be  individual  v a l u e of 2 or a l , 1981)  4  i s not  error.  lactate  minute range  and  (5 min.  EXC02 pre  and  was post  study. In order t o compare s u b j e c t s  t u m p o i n t s were used as r e l a t i v e p o i n t s the  two  curves  were  compared  in t h i s  manner  it  changes  in  different  in  changes  relative  both  males and  in  expired of  (P<0.081).  concentration  same  the  c l o s e l y tracked  r e i a t ionshin  and  et  much  and  Rodahl  (r=0. 92,.  for  the group  (r=0. 69,  is  al  in  P<3.081).  agreement  (1966)  who  between  changes  is  in  with the e a r l i e r  found  changes  excess COS,  a  in  correlation  blood  1961).  The  lower c o r r e l a t i o n  i n t h i s study was  error  blood  Previous  lactate  also  while be  have  technique  influenced  lactate  the  C02  acknowledged  factor.  concentrations  The  by pooled  that  does  expired  production,  as  differance  s t o r a g e c a p a c i t y of the (Clode  et  ai,  19S7>.  suggested however, t h a t the use o f a allow  Bouhuys et a l , 1966;  significant  by the  (male r=8.7£,. female r=8.73), w h i l e  EXC02  CDS  changes i n blood l a c t a t e t o be  with r e a s o n a b l e accuracy  1967;  suggests  1986),  studies  determined  coefficient  l a c t a t e l e v e l s must be acknowledged as a source o f  must  balancing  al,  intracellular  (Brooks,  individual  sexes  largely  a l (1966) found age t o be an i n f l u e n c i n g  venous  grouped  lower than those r e s u l t s found by I s s e k u t z  Bouhuys  of  lactate  although the  o f the two  reflection  Individual from'0.82 t o  combination et  was  when using the t u r n p o i n t 5 as  p e r i o d o f time ranged  data  r=8.80  correlation  found  EXCOS  females. Approximately 5054 of the  excess COS  the This  of  although  reference  Bouhuys  coefficient  in  l a c t a t e c o n c e n t r a t i o n c o u l d bs accounted f o r  over  of  changes  lactate,  points  findings  that  blood  blood  correlations 3.96  found  for  variance by  was  (Clode et a l , 1969;  I s s e k u t z et a l , 1961).  Clode et  T h i s study  may  be  reflecting  intracellular  suggested  by  Volkov et a i (1975).  The  between an i n c r e a s e i n e x p i r e d EX-COS and  -  blood  lactate  lactate  into  across the  the  rapid  suggested the  accumulation t h e blood  cell  delay, and  would  may  stream,  of  by S t a i n s b y  reflect  the delayed  release of  w h i l e EXC02 i s f r e e l y  diffusable  lactate  (1986).  site  during  -  membrane a t r a n s l o c a t i o n  diffusion  collection  54  must  strenous  across  Although  the  cell  may  t h e blood t r a n s i t  the transit  time  f o r a very small portion  prevent  membrane a s  be c o n s i d e r e d a s c o n t r i b u t i n g  exercise  o n l y account  hinderance  time t o t o the  i s decreased  o f t h e observed  difference. The  average  (+2.7S).  The  threshold  point  with  Hearst  values,  excess. mean  COS  t h r e h o l d v a l u e was 14.04 ml/kg/min  absolute  was  3.35  mmol/1  (198S u n p u b l i s h e d  1.7S  -  upon  the  threshold  values  (+0.8S9),  suggests  individual  would  concentration i n close  d a t a ) . The w i d e r a n g e  5.3® mmol/1,  dependent  lactate  not  that  this  and t h e s e t t i n g  allow  for  this  the  agreement  of threshold  point of  at  i s highly  predetermined  inter-individual  variation. Previous EXCOS  studies  production  Rhodes  et  al,  significant variables. EXCOS  and  et  does  the  relationship  (Hearst, al,  1975)  exsist  through capacity.  metabolic turnpoint  related the  to  the  glycolytic  between  unpublished have found  between  The p r e v i o u s s t u d i e s have s u g g e s t e d  production  the  Volkov  relationship  directly  of  performance  1981;  is  buffering  investigating  magnitude  that of  198S; that  these  a  two  t h e index o f lactic  p a t h w a y s and t h e  acid  organism's  The EXCOS t u r n a o i n t may r e p r e s e n t t h e o n s e t  acidosis,  as suggested  and p e r f o r m a n c e  by t h e r e l a t i o n s h i p  variables,  between  while the r e l a t i o n s h i p  between  metabolic  a c i d o s i s and f a t i g u e h a s been w e l l  documented  (w'enger e t a l , 1975). VE/V02  threshold  threshold  points  in  the  are  lactate  threshold  degree  of  accuracy.  method  of  determining  points  EXC02 the  harder  expired  T h e VE/V02 t h r e s h o l d  accumulation. blood  points  may  EXC02  to  be  offer  point  a  where  metabolic  acidosis between  the  of  release  determined  with  technologies documented  will  Further  intra-cel1ular  EXC02  may  allow  greater  care  allow  this  i n the future.  Plood  predicted  and c o n s u m p t i o n a r e u n b a l a n c e d  relationship  and  than  p o i n t s do, however,  production  occurs.  to ciscem  allow  trie  a high  noninvasive  intracellular  lactate  and t h e r a p i d o n s e t o f  investigation lactic  acid  performance and  lactate  with  valuable  those  accuracy.  relationship  into  the  p r o d u c t i o n and v a r i a b l e s t o be New to  research be  better  -  56  CHAPTER SUMMARY AND  -  FIVE: CONCLUSIONS  - 57 -  SUMMARY Significant points  as  lactate,  any  threshold the  r=®.9i blood  determined  were  through  found  between t h e t h r e s h o l d  t h r e e independent  indices  (blood  excess C02, and t h e r a t i o VE/V02). The best c o r r e l a t i o n  between  and  correlations  two  of  the threshold  points  as  determined through t h e blood l a c t a t e  excess  between  C02 the  index  p o i n t s was found between t h e index  (r=0.95). ft c o r r e l a t i o n was found o f  threshold  p o i n t s as determined through t h e  l a c t a t e index and t h e VE/V02 index, w h i l e a c o r r e l a t i o n o f  r=0.92  was  found  between  the  VE/V02 index and t h e excess C02  index. A  significant  points  as  (F=8.41,  determined  between  lactate  excess  CD2  mean was  values  the  and  difference  VE/V02 i n d i c e s The  Post  hoc  three  tests  threshold  independent  revealed  a  indices  significant  p o i n t s as determined  t h e VE/V02 index found  through  between  (P<0.025). There was no the  blood  lactate  and  (P>0.05). absolute  3.35  varied  the  the threshold  and through excess C02 (P<0.001), and between t h e  index  significant  point  through  P<0.001).  difference blood  F r a t i o was found when comparing  lactate  mrnol/1 from  1.72  concentration  (+0.829),  at t h e t h r e s h o l d  w h i l e t h e range of t h r e s h o l d  - 5 . 3 0 mmol/1. The average excess C02  t h r e s h o l d v a l u e was 14.04 ml/kg/rnin (+2.72). Blood (r=0.69,  lactate P<0.001)  concentration with  expired  correlated  excess  C02  significantly  volume over an 11  - 5-3 -  minute  range  correlation the  across  coefficients  independent  blood  nature  p o i n t s . Higher  obtained of  the  f o r each  excess  throughout CG2  (P<0.001)  the  volume  than  progressive  increased  at  a  <©.S2 - ®«3S)  individual  relationship  l a c t a t e . Excess C02 volume appeared  levels  the  the threshold  express  between EXCQ2 and  t o t r a c k blood  intensity  test,  significantly  lactate although  lower l e v e l  d i d blood l a c t a t e , with an average time d e l a y i n  appearance  o f blood l a c t a t e o f 1.35 minutes  (V02 d i f f e r e n c e  of 0.133 l/min>. The lactate (n=6)  relationship concentration had  a  lower  concentration a  relative  determined between  between e x p i r e d excess CQ2 volume and blood  as scale,  appeared t o be sex dependant. excess  The females  C02 volume f o r each unit o f l a c t a t e  compared t o t h e males (n=15).  When compared on  with t h e zero point at t h e t h r e s h o l d  through  each  of  the  two i n d i c e s ,  point as  the r e l a t i o n s h i p  blood l a c t a t e c o n c e n t r a t i o n and e x c e s s C02 volume can be  visualized.  T a b l e 1. Hypotheses: variables  :  LATT vs EXA7 : EXTT vs WTT : WTT vs LATT :  s__. c o r r e l a t i o n  si_./non significant signi ficant significant  : P : :P<0. 001: :P<0. 001: :P<0.001:  s__. d i f f e r e n c e  si_./non « P s s i g n i f i c a n t :P<0. 001: s i gni f i c a n t :P<0. 025: n o n - s i g n i f . :P>0. 050:  Changes i n e x p i r e d excess C02 volume appear t o t r a c k changes i n blood lactate c o n c e n t r a t i o n (r=0.63) when t h e two v a r i a b l e s a r e put on a r e l a t i v e s c a l e (accounting f o r t h e s i g n i f i c a n t time difference between t h e two t h r e s h o l d p o i n t s ) , aithougn t h e r e i s a wide v a r i a t ion -.between i n d i v i d u a l s i n t h e exact n a t u r e o f t h i s relationship i e . blood l a c t a t e can not be p r e d i c t e d from excess QQS^ilh-lCE^2'D§ihlE-^££ J'£^£li l  - 59 -  CONCLUSIONS  1.  There  is a  strong r e l a t i o n s h i p  (r=0.31 - 0.95) between t h e  t r a n s i t i o n t h r e s h o l d s as determined through t h e t h r e e £.  Changes i n e x p i r e d excess  C0£ volume precede changes i n blood  l a c t a t e c o n c e n t r a t i o n and t h e v e n t i l a t o r y 3.  Changes  in  blood  exact  lactate  nature  Blood  lactate  Further  concentration  may  blood  vary  C0£ volume. is  required  intra-cel1ular  between  i n blood  changes  in  lactate  thresholds  acidosis. lactate blood  individuals  suspect  the  c o n c e n t r a t i o n and  Excess production  (3.35 mmol/1 +0.8£3), and  value.  l a c t a t e c o n c e n t r a t i o n may not be r e f l e c t i n g  intra-cellular  lactate  lactate  determine  l a c t a t e c o n c e n t r a t i o n at t h e t r a n s i t i o n t h r e s h o l d  widely  Changes  to  C0£ volume.  should not be s e t at a predetermined 7.  although t h e  c o n c e n t r a t i o n can not be a c c u r a t e l y p r e d i c t e d  between  e x p i r e d excess  The  <r=8.69, P<0.001),  by gender.  investigation  relationship  6.  (VE/VO£).  o f t h i s r e l a t i o n s h i p depends on t h e i n d i v i d u a l and  from e x p i r e d excess 5.  equivalent  i n e x p i r e d excess C0£ volume appear t o t r a c k changes  appears t o be i n f l u e c e d 4.  indices.  lactate  concentration,  not  r e f l e c t i n g the rapid  C0£  may  with  threshold  reflect  increased  g r e a t e r accuracy, points  t o wide margins o f e r r o r .  as  onset  their  with  blood  o f metabolic  intra-cellular  making s t u d i e s using c r i t e r i o n reference  - SiZi -  BIBLIOGRAPHY  - 61  -  REFERENCES  ftlpert, N. R. Lactate p r o d u c t i o n and removal and of metabolism. AnnaJ,s___Y^_Acad__S^i 11.9(3): 995 i  Asmussen, E. Control of v e n t i l a t i o n Rey_ 11: 24 - 54, 1.983.  the r e g u l a t i o n 1011, ~ 1965.  i n e x e r c i s e . Ex..  Spt__Sc_  i-  Aunola, S., and H. Rusko.- R e p r o d u c i b i l i t y o f aerobic and anaerobic thresholds i n 20-50 year old men. 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Methodology o f l a c t i c a c i d assay. L„ctate_in __________________ Int. Symp. , B a s e l . 1978, pp. 20 - 28. Lockwood,  L. ,  B_____§___  119: 854 - 865, 1965.  D.  Yoder and M. Z i e n t y . L a c t i c a c i d .  B__________  Margaria, R., H . Edwards, and D. D i l l . The p o s s i b l e mechanisms o f c o n t r a c t i n g and paying t h e oxygen debt and t h e r o l e o f l a c t i c acid i n muscular c o n t r a c t i o n . ftm. J . P h _ _ _ _ l _ 106: 689 - 715, 1933. McLellan, T. The a n a e r o b i c t h r e s h o l d : concept and c o n t r o v e r s y . E__-_r_____S_________§_____ 19(2): 3 - 8 , 1987. McLellan, T., and Skinner, J . The use o f t h e a e r o b i c t h r e s h o l d as a b a s i s o f t r a i n i n g . Cart. J ; B 2 _ I i ____.: S c i _ 6: 197 - 201, 1981.  Naimark, ft., K. Wasserman, and M.B. M c l l r o y . Continuous measurement o f v e n t i l a t o r y exchange r a t i o during e x e r c i s e . J.. B_____E_______ 19(4): 644 - 652, 1964. Noll, F. L-( + ) - l a c t a t e :IN H. U. Bergmeyer, Met hods_gf _Enzymat_ic finaly.si.5j 3rd. ed._ V o l . VI, M e t a b o l i t e s 1: Carbohydrates. V e r l e g Chemie, Weinham, B a s e l . 1984.  - 65 Owles, W.H. A l t e r a t i o n s i n t h e l a c t i c a c i d c o n t e n t o f t h e blood as a r e s u l t of light e x e r c i s e , and a s s o c i a t e d changes i n C02 combining power o f t h e blood a n d i n t o a l v e o l a r C0£ pressure. J_ Et3Ysi£ l__iL£ D_£'I ii £14 - £37, 1930. ,  ,  l  Ponton, L. et.al.. V a l i d i t y and r e p r o d u c i b i 1 i t y of the l a c a t e threshold f o r a continuous p r o t o c o l on the t r e a d m i l l . Med__Sci. Sst__Exerc_ 14<£): 160 - 161, 1982. Powers, S.K., and. R.E. subrnaximal exercise: a 65, 1985.  Beadle. C o n t r o l of v e n t i l a t i o n d u r i n g b r i e f review. J; § D g r t s _ _ c _ _ 3 ( 1 ) : 51 -  Powers, S., S. Dodd, and R. Garner. 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E f f e c t s of glycogen d e p l e t i o n and workload on p o s t e x e r c i s e D£ consumption a n d blood l a c t a t e . J_ S 2 B l _ _ E t 3 _ s l _ l i . 47: 51 £ - 514, 1979. Simon, J . e t . a l . and respiratory 13 - 17, 1983.  L a c t a t e accumulation r e l a t i v e t o t h e anaerobic compensation t h r e s h o l d s . J. A_p___Phys_o__ 54:  Sjodin, B. L a c t a t e dehydrogenase i n human s k e l e t a l muscle. Acta;. P h y s i o l ; Sca_d__ 436 (Suppl. ) : 1 - 32, 1976. Sjodin, B., and Jacobs, I. Onset of blood l a c t a t e accumulation and marathon running performance. Int. J. Sp_orts_Med, £: £3 26, 1981. L  Skinner, J.S. and T.M. McLellan. The t r a n s i t i o n from a e r o b i c t o anaerobic metabolism. Res_ 0 u § C _ j L _ l l l s r _ i 5 e _ S D o r t _ 5 1 ( 1 ) : £34 £48, 1980. Stainsby, Ui. p r o d u c t i o n . Med.  Biochemical and S c i . Spt. Exerc.  p h y s i o l o g i c a l bases f o r l a c t a t e 18(3): 341 - 343, 1986.  - 66 Stegmann, H. , W. Kinderrnann, arid A. Schnabel. L a c t a t e k i n e t i c s arid individual anaerobic t h r e s h o l d . I _ t . J ; ___12_______ £ ( 3 ) : 160 - 165, 1981. Sucec, ft. e t . a l . The r e p r o d u c i b i l i t y of the ftT by venous blood lactate and gas exchange measurements. Med. Sci.. S _ t . E x e r c ^ 14(2): 127, 1982. S u t t o n , J . R. , and N. L. Jones. C o n t r o l of pulmonary v e n t i l a t i o n d u r i n g e x e r c i s e and mediators i n the b l o o d : C02 and hydrogen i o n . ' Med-__Sci__§e_rts_ 11(2): 198 - 203, 1979. Swanson, G. Overview of v e n t i l a t o r y c o n t r o l during e x e r c i s e . M_d__S_i____orts_ 11(2): 221 - 228, 1979. Tanaka, K. et.al. R e l a t i o n s h i p s o f anaerobic t h r e s h o l d and onset of blood l a c t a t e accumulation with endurance performance. i _ r _ _ _ _ _ 8 _ _ l _ _ S _ _ _ l o l _ 52: 51 — 56, 1983. Tesch, P. ft., D. Sharp, and W. D a n i e l s . I n f l u e n c e of f i b e r type composition and c a p p i l a r y d e n s i t y on the onset o f blood l a c t a t e accumulation. I n t . J . Sport s_M_d._ 2 ( 4 ) : 252 - 255, 1981. Turrell, E. , and Robinson, S. The a c i d - b a s e e q u i l i b r i u m o f the blood i n e x e r c i s e , Amer. J'. Eb__io__ 137: 742, 1942. Volkov, N. et.al. Assessment of a e r o b i c and anaerobic c a p a c i t y of athletes i n t r e a d m i l l r u n n i n g . Eur. J . A p g l . Physigl._ 34(2): 121 - 130, 1975. Wasserman, K. Coupling of e x t e r n a l t o i n t e r n a l r e s p i r a t i o n , ftm.. Rey__Res_ir__Di.5_ 129 (suppl.) : S21 - S24, 1984. Wasserman, K. , Beaver, W., and Whipp, B. Mechanisms p a t t e r n s of blood l a c t a t e : i n c r e a s e during e x e r c i s e i n man. Sci__Sp.t__Exerc._ 18(3): 344 - 352, 1986..  and Med._  Wasserman, K., and M c l l r o y , M. 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Ward. muscular e x e r c i s e i n man. 1930.  Environ.  §_sr£ise_Physio3._  Ventilatory  control  * <t^_J^_Sggrts_Meti r  SL  5 0 : £17 -  dynamics d u r i n g 1: 146 - 159,  Yeh, M. , M. G a r d n e r , T. ftdarns, F. Y a n o w i t z , a n d R. C r a p o . "Anaerobic t h r e s h o l d : " p r o b l e m s o f d e t e r m i n a t i o n and v a l i d a t i o n .  ___9__1__E_______ 5 5 : 1173 - 1186, Yoshida, 7. Effect threshold and onset incremental exercise. 1984.  1983.  of dietary m o d i f i c a t i o n s on lactate o f blood lactate accumulation during E u r _ J _ 9 _ _ i _ _ E Y _ _ _ I i . 5 3 : £00 - £05, h  Yoshida, T. E f f e c t of exercise duration during incremental exercise on t h e d e t e r m i n a t i o n o f a n a e r o b i c t h r e s h o l d and t h e onset o f blood l a c t a t e accumulation. Eur__J__ftDpl__Physiol. 53: 196 - 199,: 1984. i  Yudkin, J . a n d R . D . Cohen. T h e c o n t r i b u t i o n o f t h e k i d n e y t o t h e removal o f a l a c t i c acid: load under normal a c i d o t i c c o n d i t i o n s in t h e c o n s c i o u s r a t . C l i n . S c i . _£2l____§!_i_ed._ 4 8 : 1.21 — 1 3 1 , 1975.  - 68 -  APPENDIX P,  -  69  -  LACTATE THRESHOLDS: A SUMMARY OF OBSERVER ESTIMATES EXPRESSED IN MINUTES  N=21 #  OBSERVER  ACCEPTED  RANGE  #1  #2  #3  I.  13.0  13.0  13.0  13. 0  0. 0  2  18.5  18.0  18.0  18. 0  0.5  3  10.5  10.0  10.0  10. 0  0. 5  4  15.5  15.5  15.0  15.5  0.5,  5  14.0  14.5  14.5  0. 5  6  10.5  10.5  10. 5  0.0  7  13. 0  13. 0  13. 0  0. 0  a  15.5  13.5  14.5  15. 0  2.-0  9  16.5  16.5  17.0  16. 5  0. 5  10  7.0  7.5  7. 5  0. 5  11  14.5  14.5  14.5  14.5  0. 0  12:  12.5  12.5  12.5  12.5  0. 0  13  11.5  12.0  11.5  11.5  0. 0  14  10.0  10.5  11.0  10. 5  0. 5  15  11.0  10.5  10. 5  0. 5  16  9.0  9.0  8. 5  9.0  0. 5  17  10.0  10.0  9. 5  10. 0  0. 5  18  10.0  10.0  10.0  0. 0  19  12.0  12.0  12.5  12. 0  0. 5  2©  9.0  9.0  10.0  9. 0  1. 0  21  10.0  10.0  10.0  10. 0  10.5  VALUE  (MIN)  WIDTH  _____  AVERAGE  <0.5  - 70 EXC02 THRESHOLDS: A SUMMARY OF OBSERVER ESTIMATES EXPRESSED IN MINUTES  OBSERVER  RANGE  VALUE (MIN)  WIDTH  9.5  11.0  2. 0  ia. 0 ia.0  18.0  0. 5  #1  #2  11.0  11.5  ia.5 9. 0  ACCEPTED  9. 0  #3  8. 5  0. 5  9. 0  12.0  12.0  12.0  12.0  0. 0  11.5  ll.,5  11.5  11.5  0. 0  10.5  10.5  10.5  10.5  0.0  12.5  12.5  12.5  12.5  0. 0  14. 0  14. 5  14.5  2.0  15.0  15.0  15.0  15.0  0. 0  5.0  5.0  4.5  5.0  0. 5  13.0-  13.0  12.5  13.0  0. 5  11.5  12.0  11..0  11.5  1. 0  10. 0  10. 0  10.0  0. 0  10.0  10.5  10.0  0. 5  9.0  9.0  9. 0  9. 0  0. 0  5.0  5.0  5.0  5. 0  0. 0  9.0  9.0  9. 0  9. 0  0. 0  9.0  9. 0  0. 0  9. 0  9. 5  1.0  8. 0  8. 0  0. O  9. 5  10. 0  9. 0 10.0 3. 0 9.5  9.0 9.0 8.0 10.0  12. 5  10.0  _____ AVERAGE  <0. 5  - 71 -  VE/VG2 THRESHOLDS: A SUMMARY OF OBSERVER ESTIMATES EXPRESSED IN MINUTES  OBSERVER  N=21  ACCEPTED  RANGE  #1  #2  #3  VALUE (MIN)  WIDTH  1  12.0  12.0  11.5  12. 0  8. 5  2.  18.5  18."5  18.5  18. 5  8. 8  3  9.0  9.0  9.0  0. 8  4  13.0  13.0  12.5  13.0  0. 5  5.  1.1.5  12.0  11.5  11.5  0.5  6  12.5  13.0  12.5  12. 5  0.5  7  12.0  13.0  12.5  12.5  1.0  a  12.0  12.0  11.5  12.0  0.5  9  15..5  15.0  14.5  14. 5  1.0  10  7.0  7.0  7.0  7. 0  8. 8  13. 0  0. 5  #  11  12.5. 13.0  12  13.0  13.5  15.5  13. 5  2. 5  13  10.0  9.5  9.5  9. 5  0. 5  14  9. 0  9. iZ  11.5  9. 0  2. 5  15  11.0  11.5  11.5  11.5  0. 5  16  6.0  9.0  9.0  9.0  3. 8  17  9. 0  8.0  8.0  8. 5  1. 8  ia  11.5  12.0  11.5  11.5  8. 5  19  11.0  11.0  11.0  11.0  8. 8  20  10.0  18.0  12.0  18. 0  2. 8  £1  10.0  10.0  9.5  10. 8 AVERftGE  <i.8  -  72  -  APPENDIX B  - 73 -  )—  i  i  1  1  1  1  1  Workload or time  1  T  r  - 74  APPENDIX  - 75 -  ExC0  2  and blood lactate  Workload or time  - 76  APPENDIX  - 77 8 L 0 0 0 LACTATE (mmol/l)  - 78 BLOOD LACTATE (mmol/l)  TIME (min)  EXCESS C02  PROFILE  MALE #6  c  E CI  O U X u oo  i  "1  I  I  I  I  I  1  1  1  1  1  1  1  r  10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 TIME ( m i n )  EXCESS C02  PROFILE  MALE #12  1  2  3  4  5  6  7  8  9  10  11  12  13  TIME (min)  14  15  16  17  1fl  19  20  21  2?  23  24  25  - 83 -  VE/V02  (l/min/ml)  - 86 -  APPENDIX E  AVERAGE EXC02 VALUES 24 -j 23 22 -  PRE AND POST THRESHOLD  AVERAGE  LACTATE  VALUES  PRE AND POST THRESHOLD  \  O £ E  u 00 CO  •  OVERALL LA AV.  TIME (min p r e / p o a t threahold) +-.. MALE LA AV.  O  FEMALE LA AV.  

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