Int J Sports Med 2006; 27(2): 149-157
DOI: 10.1055/s-2005-873076
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Oxygen Uptake Kinetics During Supra V·O2max Treadmill Running in Humans

V·O2 Kinetics in Supra-Maximal RunningH. Carter1 , J. S. M. Pringle1 , T. J. Barstow2 , J. H. Doust3
  • 1Chelsea School Research Centre, University of Brighton, Eastbourne, UK
  • 2Department of Kinesiology, Kansas State University, IA Natatorium, Manhattan, KS, USA
  • 3Department of Sports and Exercise Science, University of Wales, Aberystwyth, Old College, Aberystwyth, Ceredigion, UK
Further Information

Publication History

Accepted after revision: November 25, 2005

Publication Date:
13 February 2006 (online)

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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·O2max, 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·O2max (Δ), and at 100 %, 110 % and 120 % V·O2max. 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·O2max, 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·O2max, 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·O2max, 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.

References

Dr. Helen Carter

Chelsea School Research Centre
University of Brighton

Gaudick Road

Eastbourne

BN20 7SP, UK

Phone: + 441273643743

Fax: + 44 12 73 64 37 04

Email: h.carter@bton.ac.uk