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Peak oxygen uptake and regional oxygenation in response to a 10‐day confinement to normobaric hypoxia
Author(s) -
Kounalakis S. N.,
Keramidas M. E.,
Eiken O.,
Jaki Mekjavic P.,
Mekjavic I. B.
Publication year - 2013
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12067
Subject(s) - oxygenation , hypoxia (environmental) , oxygen , anesthesia , medicine , zoology , chemistry , biology , organic chemistry
We investigated the effect of hypoxic acclimatization per se , without any concomitant influence of strenuous physical activity on muscle and cerebral oxygenation. Eight healthy male subjects participated in a crossover‐designed study. In random order, they conducted a 10‐day normoxic ( CON ) and a 10‐day hypoxic ( EXP ) confinement. Pre and post both CON and EXP confinements, subjects conducted two incremental‐load cycling exercises to exhaustion; one under normoxic, and the other under hypoxic ( F I O 2 = 0.154) conditions. Oxygen uptake ( V ˙ O 2 ), ventilation (V ˙ E ), and relative changes in regional hemoglobin oxygenation (Δ([ HbO 2 ]) in the cerebral cortex and in the serratus anterior ( SA ) and vastus lateralis ( VL ) muscles were measured. No changes were observed in the CON confinement. Peak work rate andV ˙ O 2 p e a kwere similar pre and post in the EXP confinement, whereasV ˙ Eincreased in the EXP post normoxic and hypoxic trials ( P < 0.05). The exercise‐induced drop in VL Δ[ HbO 2 ] was less in the post‐ than pre‐ EXP trial by 4.0 ± 0.4 and 4.2 ± 0.6 μM during normoxic and hypoxic exercise, respectively. No major changes were observed in cerebral or SA oxygenation. These results demonstrate that a 10‐day hypoxic exposure without any concomitant physical activity had no effect on normoxic or hypoxicV ˙ O 2 p e a k, despite the enhanced VL oxygenation.