Effects of two types of fatigue on the VO(2) slow component.

Details

Serval ID
serval:BIB_37620
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Effects of two types of fatigue on the VO(2) slow component.
Journal
International Journal of Sports Medicine
Author(s)
Deley G., Millet G.Y., Borrani F., Lattier G., Brondel L.
ISSN
0172-4622 (Print)
ISSN-L
0172-4622
Publication state
Published
Issued date
2006
Peer-reviewed
Oui
Volume
27
Number
6
Pages
475-482
Language
english
Abstract
The aim of the study was to test the hypothesis of the involvement of type II fibres in the V.O (2) slow component phenomenon by using two prior fatiguing protocols on the knee extensor muscles. Nine subjects performed three constant-load cycling exercises at a work rate corresponding to 80 % of their V.O (2) max: (i) preceded by a 20-min fatiguing protocol using electromyostimulation (EMS), (ii) preceded by a 20-min fatiguing protocol using voluntary contractions (VOL), and (iii) without fatiguing protocol (NFP). Voluntary and evoked neuromuscular properties of the knee extensor muscles were tested before (PRE) and after (POST) the two fatiguing protocols. Results show a significant reduction in voluntary force after both fatiguing protocols (-19.9 % and -11.8 %, in EMS and VOL, respectively p<0.01). After EMS, this decrease was greater than after VOL (p<0.05) and was combined with a slackening of muscle contractile properties which was absent after VOL (p<0.05). Regarding the effects on oxygen uptake kinetics, the appearance of the slow component was delayed after EMS and its amplitude was lower than those obtained in VOL and NFP conditions (0.48+/-0.07 vs. 0.75+/-0.09 and 0.69+/-0.08 L . min (-1), respectively; p<0.05). It can thus be concluded that exercises dedicated to preferentially fatiguing type II fibres may alter V.O (2) kinetics.
Keywords
Adult, Electric Stimulation, Electromyography, Exercise Test/methods, Humans, Knee/physiology, Male, Muscle Contraction/physiology, Muscle Fatigue/physiology, Muscle Fibers, Fast-Twitch/physiology, Oxygen Consumption/physiology, Weight-Bearing/physiology
Pubmed
Web of science
Create date
19/11/2007 11:12
Last modification date
20/08/2019 14:25
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