Dynamic responses of oxygen uptake at the onset and end of moderate and heavy exercise in trained subjects.
Details
Serval ID
serval:BIB_37624
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Dynamic responses of oxygen uptake at the onset and end of moderate and heavy exercise in trained subjects.
Journal
Canadian Journal of Applied Physiology
ISSN
1066-7814 (Print)
ISSN-L
1066-7814
Publication state
Published
Issued date
2004
Peer-reviewed
Oui
Volume
29
Number
1
Pages
32-44
Language
english
Abstract
Inconsistencies about dynamic asymmetry between the on- and off-transient responses in VO2 are found in the literature. Therefore the purpose of this study was to examine VO2 on- and off-transients during moderate- and heavy-intensity cycling exercise in trained subjects. Ten men underwent an initial incremental test for the estimation of ventilatory threshold (VT) and, on different days, two bouts of square-wave exercise at moderate (<VT) and heavy (>VT) intensities. VO2 kinetics in exercise and recovery were better described by a single exponential model (<VT), or by a double exponential with two time delays (>VT). For moderate exercise, we found a symmetry of VO2 kinetics between the on- and off-transients (i.e., fundamental component), consistent with a system manifesting linear control dynamics. For heavy exercise, a slow component superimposed on the fundamental phase was expressed in both the exercise and recovery, with similar parameter estimates. But the on-transient values of the time constant were appreciably faster than the associated off-transient, and independent of the work rate imposed (<VT and >VT). Our results do not support a dynamically linear system model of VO2 during cycling exercise in the heavy-intensity domain.
Keywords
Adolescent, Adult, Analysis of Variance, Bicycling/physiology, Humans, Kinetics, Least-Squares Analysis, Male, Models, Biological, Oxygen Consumption, Physical Education and Training, Physical Endurance, Pulmonary Gas Exchange
OAI-PMH
Pubmed
Web of science
Create date
19/11/2007 11:12
Last modification date
20/08/2019 14:25