Please use this identifier to cite or link to this item: http://hdl.handle.net/10553/50949
Title: The effects of breathing a helium-oxygen gas mixture on maximal pulmonary ventilation and maximal oxygen consumption during exercise in acute moderate hypobaric hypoxia
Authors: Ogawa, Takeshi
Calbet, Jose A.L. 
Honda, Yasushi
Fujii, Naoto
Nishiyasu, Takeshi
UNESCO Clasification: 241106 Fisiología del ejercicio
Keywords: Flow resistance
Ventilatory response
V˙O2max
Athletes Altitude
Issue Date: 2010
Publisher: 1439-6319
Journal: European Journal of Applied Physiology 
Abstract: To test the hypothesis that maximal exercise pulmonary ventilation ( V˙Emax ) is a limiting factor affecting maximal oxygen uptake ( V˙O2max ) in moderate hypobaric hypoxia (H), we examined the effect of breathing a helium–oxygen gas mixture (He–O2; 20.9% O2), which would reduce air density and would be expected to increase V˙Emax . Fourteen healthy young male subjects performed incremental treadmill running tests to exhaustion in normobaric normoxia (N; sea level) and in H (atmospheric pressure equivalent to 2,500 m above sea level). These exercise tests were carried out under three conditions [H with He–O2, H with normal air and N] in random order. V˙O2max and arterial oxy-hemoglobin saturation (SaO2) were, respectively, 15.2, 7.5 and 4.0% higher (all p < 0.05) with He–O2 than with normal air ( V˙Emax , 171.9 ± 16.1 vs. 150.1 ± 16.9 L/min; V˙O2max , 52.50 ± 9.13 vs. 48.72 ± 5.35 mL/kg/min; arterial oxyhemoglobin saturation (SaO2), 79 ± 3 vs. 76 ± 3%). There was a linear relationship between the increment in V˙Emax and the increment in V˙O2max in H (r = 0.77; p < 0.05). When subjects were divided into two groups based on their V˙O2max , both groups showed increased V˙Emax and SaO2 in H with He–O2, but V˙O2max was increased only in the high V˙O2max group. These findings suggest that in acute moderate hypobaric hypoxia, air-flow resistance can be a limiting factor affecting V˙Emax ; consequently, V˙O2max is limited in part by V˙Emax , especially in subjects with high V˙O2max .
URI: http://hdl.handle.net/10553/50949
ISSN: 1439-6319
DOI: 10.1007/s00421-010-1570-z
Source: European Journal of Applied Physiology[ISSN 1439-6319],v. 110, p. 853-861
Appears in Collections:Artículos
Show full item record

SCOPUSTM   
Citations

7
checked on May 9, 2021

WEB OF SCIENCETM
Citations

5
checked on May 9, 2021

Page view(s)

35
checked on May 11, 2021

Google ScholarTM

Check

Altmetric


Share



Export metadata



Items in accedaCRIS are protected by copyright, with all rights reserved, unless otherwise indicated.