Influence of increment magnitude and exercise intensity on VO2 kinetics, time to steady state, and muscle oxygenation

McNulty, C.A, Robergs, R.A., & Morris, D.B (2015) Influence of increment magnitude and exercise intensity on VO2 kinetics, time to steady state, and muscle oxygenation. Journal of Exercise Physiology Online, 18(5), pp. 37-58.

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The purpose of this study was to quantify the oxygen uptake (VO2) kinetics to steady state across the full range of sub-ventilatory threshold (VT) work rates. Twelve trained males participated in two separate series of five bouts of cycling. One trial (DM) involved 10 min at a percentage of their VT. The second trial involved five bouts at an increasing baseline intensity for 5 min (SM1), followed by an increase of 30% of VT for 10 min (SM2). The VO2 kinetics was quantified by the mono-exponential time constant (tau, τ) as well as a new method for time to steady state (TTSS). For DM, τ increased significantly from 30% and 45%VT (31 ± 22 and 33 ± 15 sec, respectively) between 60% to 90%VT (42 ± 16, 53 ± 29, 74 ± 25 sec for 60%, 75%, and 90%VT, respectively). For SM1, τ increased significantly from 40% (41 ± 16 sec) to 60%VT (74 ± 25 sec). For SM2, τ increased significantly between 60% (44 ± 11 sec) to 80%, and 90%VT (92 ± 41 and 151 ± 83 sec, respectively), and from 70% (54 ± 38 sec) to 90%VT (151 ± 83 sec). The data revealed a clear increase in τ as intensity increased, revealing a more complex VO2 response than previously documented.

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ID Code: 96751
Item Type: Journal Article
Refereed: Yes
Keywords: Mono-exponential, Near-infrared spectroscopy, Steady state VO2, VO2 kinetics
ISSN: 1097-9751
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Schools > School of Exercise & Nutrition Sciences
Copyright Owner: Copyright 2015 American Society of Exercise Physiologists
Deposited On: 22 Jul 2016 01:07
Last Modified: 25 Jul 2016 01:23

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