Effects of exercise in normobaric hypoxia on hemodynamics during muscle metaboreflex activation in normoxia.

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Serval ID
serval:BIB_AC0F722F5856
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Effects of exercise in normobaric hypoxia on hemodynamics during muscle metaboreflex activation in normoxia.
Journal
European journal of applied physiology
Author(s)
Mulliri G., Sainas G., Magnani S., Roberto S., Ghiani G., Mannoni M., Pinna V., Willis S.J., Millet G.P., Doneddu A., Crisafulli A.
ISSN
1439-6327 (Electronic)
ISSN-L
1439-6319
Publication state
Published
Issued date
05/2019
Peer-reviewed
Oui
Volume
119
Number
5
Pages
1137-1148
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
Little is known about the cardiovascular effects of the transition from exercise in hypoxia (EH) to normoxia. This investigation aimed to assess hemodynamics during the metaboreflex elicited in normoxia after EH.
Ten trained athletes (four females and six males, age 35.6 ± 8.4 years) completed a cardiopulmonary test to determine the workload at anaerobic threshold (AT). On separate days, participants performed three randomly assigned exercise sessions (10 min pedalling at 80% of AT): (1) one in normoxia (EN); (2) one in normobaric hypoxia with FiO <sub>2</sub> 15.5% (EH15.5%); and (3) one in normobaric hypoxia with FiO <sub>2</sub> 13.5% (EH13.5%). After each session, the following protocol was randomly assigned: either (1) post-exercise muscle ischemia after cycling for 3 min, to study the metaboreflex, or (2) a control exercise recovery (CER) session, without any metaboreflex stimulation.
The main result were that both EH15.5% and EH13.5% impaired (p < 0.05) the ventricular filling rate response during the metaboreflex (- 18 ± 32 and - 20 ± 27 ml s <sup>-1</sup> ), when compared to EN (+ 29 ± 32 ml s <sup>-1</sup> ), thereby causing a reduction in stroke volume response (- 9.1 ± 3.2, - 10.6 ± 8.7, and + 5 ± 5.7 ml for EH15.5%, EH13.5% and EN test, respectively, p < 0.05). Moreover, systemic vascular resistance was increased after the EH15.5% and the EH13.5% in comparison with the EN test.
These data demonstrate that moderate exercise in hypoxia impairs the capacity to enhance venous return during the metaboreflex stimulated in normoxia. Overall, there is a functional shift from a flow to vasoconstriction-mediated mechanism for maintaining the target blood pressure during the metaboreflex.
Keywords
Adult, Anaerobic Threshold, Female, Hemodynamics, Humans, Hypoxia/physiopathology, Male, Muscle, Skeletal/physiology, Physical Conditioning, Human/adverse effects, Physical Conditioning, Human/methods, Random Allocation, Reflex, Blood pressure, Cardiac output, Cardiac pre-load, Stroke volume, Venous return
Pubmed
Web of science
Create date
25/03/2019 20:11
Last modification date
16/02/2021 7:26
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