You are not logged in.

Severe hypoxia affects exercise performance independently of afferent feedback and peripheral fatigue

Millet, Guillaume Y., Muthalib, Makii, Jubeau, Marc, Laursen, Paul B. and Nosaka, Kazunori 2012, Severe hypoxia affects exercise performance independently of afferent feedback and peripheral fatigue, Journal of applied physiology, vol. 112, no. 8, pp. 1335-1344, doi: 10.1152/japplphysiol.00804.2011.

Attached Files
Name Description MIMEType Size Downloads

Title Severe hypoxia affects exercise performance independently of afferent feedback and peripheral fatigue
Author(s) Millet, Guillaume Y.
Muthalib, Makii
Jubeau, Marc
Laursen, Paul B.
Nosaka, Kazunori
Journal name Journal of applied physiology
Volume number 112
Issue number 8
Start page 1335
End page 1344
Total pages 10
Publisher American Physiological Society
Place of publication Bethesda, Md.
Publication date 2012-04-15
ISSN 8750-7587
1522-1601
Keyword(s) central nervous system
altitude
transcranial magnetic stimulation
electrical stimulation
near-infrared spectroscopy
Adult
Afferent Pathways
Electric Stimulation
Evoked Potentials, Motor
Exercise
Feedback, Physiological
Humans
Hypoxia
Male
Motor Cortex
Muscle Contraction
Muscle Fatigue
Muscle, Skeletal
Oxygen
Peripheral Nervous System
Physical Endurance
Summary To test the hypothesis that hypoxia centrally affects performance independently of afferent feedback and peripheral fatigue, we conducted two experiments under complete vascular occlusion of the exercising muscle under different systemic Oenvironmental conditions. In experiment 1, 12 subjects performed repeated submaximal isometric contractions of the elbow flexor to exhaustion (RCTE) with inspired O2 fraction fixed at 9% (severe hypoxia, SevHyp), 14% (moderate hypoxia, ModHyp), 21% (normoxia, Norm), or 30% (hyperoxia, Hyper). The number of contractions (performance), muscle (biceps brachii), and prefrontal near-infrared spectroscopy (NIRS) parameters and high-frequency paired-pulse (PS100) evoked responses to electrical muscle stimulation were monitored. In experiment 2, 10 subjects performed another RCTE in SevHyp and Norm conditions in which the number of contractions, biceps brachii electromyography responses to electrical nerve stimulation (M wave), and transcranial magnetic stimulation responses (motor-evoked potentials, MEP, and cortical silent period, CSP) were recorded. Performance during RCTE was significantly reduced by 10-15% in SevHyp (arterial O2 saturation, SpO2 = ∼75%) compared with ModHyp (SpO2 = ∼90%) or Norm/Hyper (SpO2 > 97%). Performance reduction in SevHyp occurred despite similar 1) metabolic (muscle NIRS parameters) and functional (changes in PS100 and M wave) muscle states and 2) MEP and CSP responses, suggesting comparable corticospinal excitability and spinal and cortical inhibition between SevHyp and Norm. It is concluded that, in SevHyp, performance and central drive can be altered independently of afferent feedback and peripheral fatigue. It is concluded that submaximal performance in SevHyp is partly reduced by a mechanism related directly to brain oxygenation.
Language eng
DOI 10.1152/japplphysiol.00804.2011
Field of Research 110699 Human Movement and Sports Science not elsewhere classified
Socio Economic Objective 970111 Expanding Knowledge in the Medical and Health Sciences
HERDC Research category C1.1 Refereed article in a scholarly journal
ERA Research output type C Journal article
Copyright notice ©2012, American Physiological Society
Persistent URL http://hdl.handle.net/10536/DRO/DU:30090067

Connect to link resolver
 
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 29 times in TR Web of Science
Scopus Citation Count Cited 30 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 8 Abstract Views, 0 File Downloads  -  Detailed Statistics
Created: Mon, 05 Dec 2016, 14:35:51 EST

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact drosupport@deakin.edu.au.