Oxygen Uptake Kinetics During Supra V·O_2max Treadmill Running in Humans

Abstract

Accurate classification of V·O₂ kinetics is essential to correctly interpret its control mechanisms. The purpose of this study was to examine V·O₂ kinetics in severe and supra-maximal intensity running exercise using two modelling techniques. Nine subjects (mean ± S.D: age, 27 ± 7 years; mass, 69.8 ± 9.0 kg; V·O_2max, 59.1 ± 1.8 mL · kg · min^-1) performed a series of “square-wave” exercise transitions to exhaustion at running speeds equivalent to 80 % of the difference between the V·O₂ at LT and V·O_2max (Δ), and at 100 %, 110 % and 120 % V·O_2max. The V·O₂ response was modelled with an exponential model and with a semi-logarithmic transformation, the latter assuming a certain steady state V·O₂. With the exponential model there was a significant reduction in the “gain” of the primary component in supra-maximal exercise (167 ± 5 mL · kg^-1 · km^-1 at 80 % Δ to 142 ± 5 mL · kg^-1 · km^-1 at 120 % V·O_2max, p = 0.005). The time constant of the primary component also reduced significantly with increasing intensity (17.8 ± 1.1 s at 80 % Δ to 12.5 ± 1.2 s at 120 % V·O_2max, p < 0.05). However, in contrast, using the semi-log model, the time constant significantly increased with intensity (30.9 ± 13.5 s at 80 % Δ to 72.2 ± 23.9 s at 120 % V·O_2max, p < 0.05). Not withstanding the need for careful interpretation of mathematically modelled data, these results demonstrate that neither the gain nor the time constant of the V·O₂ primary component during treadmill running are invariant across the severe and supra-maximal exercise intensity domains when fit with an exponential model. This suggests the need for a reappraisal of the V·O₂/work rate relationship in running exercise.

Exponential modelling - semi-logarithmic transformation - exercise intensity domains - time to exhaustion

References

• 1 Barstow T J, Jones A M, Nguyen P H, Casaburi R. Influence of muscle fiber type and pedal frequency on oxygen uptake kinetics of heavy exercise.  J Appl Physiol. 1996;  81 1642-1650
• 2 Barstow T J, Mole P A. Linear and nonlinear characteristics of oxygen uptake kinetics during heavy exercise.  J Appl Physiol. 1991;  71 2099-2106
• 3 Billat L V, Koralsztein J P. Significance of the velocity at V·O_2max and time to exhaustion at this velocity.  Sports Med. 1996;  22 90-108
• 4 Borrani F, Candau R, Millet G Y, Perrey S, Fuchslocher J, Rouillon J D. Is the V·O₂ slow component dependent on progressive recruitment of fast-twitch fibers in trained runners?.  J Appl Physiol. 2001;  90 2212-2220
• 5 Carter H, Jones A M, Barstow T J, Burnley M, Williams C A, Doust J H. Oxygen uptake kinetics in treadmill running and cycle ergometry: a comparison.  J Appl Physiol. 2000;  89 899-907
• 6 Carter H, Jones A M, Maxwell N S, Doust J H. The effect of interdian and diurnal variation on oxygen uptake kinetics during treadmill running.  J Sports Sci. 2002;  20 901-909
• 7 Carter H, Pringle J S, Jones A M, Doust J H. Oxygen uptake kinetics during treadmill running across exercise intensity domains.  Eur J Appl Physiol. 2002;  86 347-354
• 8 Carter H, Grice Y, Dekerle J, Brickley G, Hammond A JP, Pringle J SM. The effect of prior exercise above and below critical power on exercise to exhaustion.  Med Sci Sport Exerc. 2005;  37 775-781
• 9 Demarle A P, Slawinski J J, Laffite L P, Bocquet V G, Koralsztein J P, Billat V L. Decrease of O(2) deficit is a potential factor in increased time to exhaustion after specific endurance training.  J Appl Physiol. 2001;  90 947-953
• 10 Grassi B. Skeletal muscle V·O₂ on-kinetics: set by O₂ delivery or by O₂ utilization? New insights into an old issue.  Med Sci Sports Exerc. 2000;  32 108-116
• 11 Grassi B, Gladden L B, Samaja M, Stary C M, Hogan M C. Faster adjustment of O₂ delivery does not affect V(O2) on-kinetics in isolated in situ canine muscle.  J Appl Physiol. 1998;  85 1394-1403
• 12 Grassi B. Regulation of oxygen consumption at exercise onset: Is it really controversial?.  Exerc Sport Sci Rev. 2001;  29 134-138
• 13 Hebestreit H, Kriemler S, Hughson R L, Bar-Or O. Kinetics of oxygen uptake at the onset of exercise in boys and men.  J Appl Physiol. 1998;  85 1833-1841
• 14 Hill D W, Halcomb J N, Stevens E C. Oxygen uptake kinetics during severe intensity running and cycling.  Eur J Appl Physiol. 2003;  89 612-618
• 15 Hughson R L, O'Leary D D, Betik A C, Hebestreit H. Kinetics of oxygen uptake at the onset of exercise near or above peak oxygen uptake.  J Appl Physiol. 2000;  88 1812-1819
• 16 Hughson R L, Tschakovsky M E, Houston M E. Regulation of oxygen consumption at the onset of exercise.  Exerc Sport Sci Rev. 2001;  29 129-133
• 17 Jones A M, Carter H, Pringle J S, Campbell I T. Effect of creatine supplementation on oxygen uptake kinetics during submaximal cycle exercise.  J Appl Physiol. 2002;  92 2571-2577
• 18 Jones A M, Wilkerson D P, Burnley M, Koppo K. Prior heavy exercise enhances performance during subsequent perimaximal exercise.  Med Sci Sports Exerc. 2003;  35 2085-2092
• 19 Koga S, Barstow T J, Shiojiri T, Takaishi T, Fukuba Y, Kondo N, Shibasaki M, Poole D C. Effect of muscle mass on V·O₂ kinetics at the onset of work.  J Appl Physiol. 2001;  90 461-468
• 20 Koga S, Shiojiri T, Shibasaki M, Kondo N, Fukuba Y, Barstow T J. Kinetics of oxygen uptake during supine and upright heavy exercise.  J Appl Physiol. 1999;  87 253-260
• 21 Koppo K, Bouckaert J. The Decrease in the V·O₂ slow component induced by prior exercise does not affect the time to exhaustion.  Int J Sports Med. 2002;  23 262-267
• 22 Lamarra N, Whipp B J, Ward S A, Wasserman K. Effect of interbreath fluctuations on characterizing exercise gas exchange kinetics.  J Appl Physiol. 1987;  62 2003-2012
• 23 Macdonald M, Pedersen P K, Hughson R L. Acceleration of V·O₂ kinetics in heavy submaximal exercise by hyperoxia and prior high-intensity exercise.  J Appl Physiol. 1997;  83 1318-1325
• 24 MacDonald M J, Shoemaker J K, Tschakovsky M E, Hughson R L. Alveolar oxygen uptake and femoral artery blood flow dynamics in upright and supine leg exercise in humans.  J Appl Physiol. 1998;  85 1622-1628
• 25 Medbo J I, Mohn A C, Tabata I, Bahr R, Vaage O, Sejersted O M. Anaerobic capacity determined by maximal accumulated O₂ deficit (see comments).  J Appl Physiol. 1988;  64 50-60
• 26 Motulsky H J, Ransnas L A. Fitting curves to data using nonlinear regression: a practical and nonmathematical review.  Faseb J. 1987;  1 365-374
• 27 Ozyener F, Rossiter H B, Ward S A, Whipp B J. Negative accumulated oxygen deficit during heavy and very heavy intensity cycle ergometry in humans.  Eur J Appl Physiol. 2003;  90 185-190
• 28 Paterson D H, Whipp B J. Asymmetries of oxygen uptake transients at the on- and offset of heavy exercise in humans.  J Physiol (Lond). 1991;  443 575-586
• 29 Perrey S, Candau R, Borrani F, Millet G Y, Rouillon J D. Recovery kinetics of oxygen uptake following severe-intensity exercise in runners.  J Sports Med Phys Fitness. 2002;  42 381-388
• 30 Poole D C, Richardson R S. Determinants of oxygen uptake. Implications for exercise testing.  Sports Med. 1997;  24 308-320
• 31 Pringle J S, Doust J H, Carter H, Tolfrey K, Campbell I T, Jones A M. Oxygen uptake kinetics during moderate, heavy and severe intensity “submaximal” exercise in humans: the influence of muscle fibre type and capillarisation.  Eur J Appl Physiol. 2003;  89 289-300
• 32 Scheuermann B W, Barstow T J. O₂ uptake kinetics during exercise at peak O₂ uptake.  J Appl Physiol. 2003;  95 2014-2022
• 33 Whipp B J. Rate constant for the kinetics of oxygen uptake during light exercise.  J Appl Physiol. 1971;  30 261-263
• 34 Whipp B J. The slow component of O₂ uptake kinetics during heavy exercise (published erratum appears in Med Sci Sports Exerc 1995; 27: 298).  Med Sci Sports Exerc. 1994;  26 1319-1326