Peripheral fatigue is not critically regulated during maximal, intermittent, dynamic leg extensions.

Details

Serval ID
serval:BIB_D36294B5634F
Type
Article: article from journal or magazin.
Collection
Publications
Title
Peripheral fatigue is not critically regulated during maximal, intermittent, dynamic leg extensions.
Journal
Journal of Applied Physiology
Author(s)
Christian R.J., Bishop D.J., Billaut F., Girard O.
ISSN
1522-1601
ISSN-L
0161-7567
Publication state
Published
Issued date
2014
Volume
117
Number
9
Pages
1063-1073
Language
english
Notes
Publication types: Publication Status: ppublish
Abstract
Central motor drive to active muscles is believed to be reduced during numerous exercise tasks to prevent excessive peripheral fatigue development. The purpose of the present study was to use hypoxia to exacerbate physiological perturbations during a novel, intermittent exercise task and to explore the time-course and interplay between central and peripheral neuromuscular adjustments. On separate days, 14 healthy men performed four sets of 6 × 5 maximal-intensity, isokinetic leg extensions (1 repetition lasting ∼7 s) at 300°/s (15 and 100 s of passive rest between repetitions and sets, respectively) under normoxia (NM, fraction of inspired O2 0.21), moderate (MH, 0.14), and severe normobaric hypoxia (SH, 0.10). Neuromuscular assessments of the knee extensors were conducted before and immediately after each set. There was an interaction between time and condition on the mean peak torque produced during each set (P < 0.05). RMS/M-wave activity of the rectus femoris decreased across the four sets of exercise, but there was no difference between conditions (8.3 ± 5.1% all conditions compounded, P > 0.05). Potentiated twitch torque decreased post set 1 in all conditions (all P < 0.05) with greater reductions following each set in SH compared with NM but not MH (end-exercise reductions 41.3 ± 3.0% vs. 28.0 ± 3.2%, P < 0.05 and 32.1 ± 3.3%, P > 0.05). In conclusion, severe hypoxia exacerbates both peripheral fatigue development and performance decrements during maximal, intermittent, dynamic leg extensions. In contrast to observations with other exercise modes, during exercise involving a single muscle group the attenuation of central motor drive does not appear to independently regulate the development of peripheral muscle fatigue.
Pubmed
Web of science
Create date
18/12/2014 18:39
Last modification date
20/08/2019 15:53
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