Neuromuscular evaluation of arm-cycling repeated sprints under hypoxia and/or blood flow restriction.

Details

Serval ID
serval:BIB_F43DA72FAAFA
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Neuromuscular evaluation of arm-cycling repeated sprints under hypoxia and/or blood flow restriction.
Journal
European journal of applied physiology
Author(s)
Peyrard A., Willis S.J., Place N., Millet G.P., Borrani F., Rupp T.
ISSN
1439-6327 (Electronic)
ISSN-L
1439-6319
Publication state
Published
Issued date
07/2019
Peer-reviewed
Oui
Volume
119
Number
7
Pages
1533-1545
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
This study aimed to determine the effects of hypoxia and/or blood flow restriction (BFR) on an arm-cycling repeated sprint ability test (aRSA) and its impact on elbow flexor neuromuscular function.
Fourteen volunteers performed an aRSA (10 s sprint/20 s recovery) to exhaustion in four randomized conditions: normoxia (NOR), normoxia plus BFR (N <sub>BFR</sub> ), hypoxia (FiO <sub>2</sub> = 0.13, HYP) and hypoxia plus BFR (H <sub>BFR</sub> ). Maximal voluntary contraction (MVC), resting twitch force (Db10), and electromyographic responses from the elbow flexors [biceps brachii (BB)] to electrical and transcranial magnetic stimulation were obtained to assess neuromuscular function. Main effects of hypoxia, BFR, and interaction were analyzed on delta values from pre- to post-exercise.
BFR and hypoxia decreased the number of sprints during aRSA with no significant cumulative effect (NOR 16 ± 8; N <sub>BFR</sub> 12 ± 4; HYP 10 ± 3 and H <sub>BFR</sub> 8 ± 3; P < 0.01). MVC decrease from pre- to post-exercise was comparable whatever the condition. M-wave amplitude (- 9.4 ± 1.9% vs. + 0.8 ± 2.0%, P < 0.01) and Db10 force (- 41.8 ± 4.7% vs. - 27.9 ± 4.5%, P < 0.01) were more altered after aRSA with BFR compared to without BFR. The exercise-induced increase in corticospinal excitability was significantly lower in hypoxic vs. normoxic conditions (e.g., BB motor evoked potential at 75% of MVC: - 2.4 ± 4.2% vs. + 16.0 ± 5.9%, respectively, P = 0.03).
BFR and hypoxia led to comparable aRSA performance impairments but with distinct fatigue etiology. BFR impaired the muscle excitation-contraction coupling whereas hypoxia predominantly affected corticospinal excitability indicating incapacity of the corticospinal pathway to adapt to fatigue as in normoxia.
Keywords
Adult, Arm/blood supply, Arm/physiopathology, Exercise, Female, Humans, Hypoxia/physiopathology, Ischemia/physiopathology, Male, Muscle Contraction, Muscle Fatigue, Muscle, Skeletal/blood supply, Muscle, Skeletal/innervation, Muscle, Skeletal/physiopathology, Pyramidal Tracts/physiopathology, Random Allocation, BFR, Corticospinal excitability, Neuromuscular fatigue, Occlusion, Transcranial magnetic stimulation
Pubmed
Web of science
Create date
03/05/2019 17:18
Last modification date
16/12/2019 7:19
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