| The effects of breathing a helium-oxygen gas mixture on maximal pulmonary ventilation and maximal oxygen consumption during exercise in acute moderate hypobaric hypoxia. | |
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MedLine Citation:
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PMID: 20623231 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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To test the hypothesis that maximal exercise pulmonary ventilation (VE max) is a limiting factor affecting maximal oxygen uptake (VO2 max) in moderate hypobaric hypoxia (H), we examined the effect of breathing a helium-oxygen gas mixture (He-O(2); 20.9% O(2)), which would reduce air density and would be expected to increase VE max. 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-O(2), H with normal air and N] in random order. VO2 max and arterial oxy-hemoglobin saturation (SaO(2)) were, respectively, 15.2, 7.5 and 4.0% higher (all p < 0.05) with He-O(2) than with normal air (VE max, 171.9 ± 16.1 vs. 150.1 ± 16.9 L/min; VO2 max, 52.50 ± 9.13 vs. 48.72 ± 5.35 mL/kg/min; arterial oxyhemoglobin saturation (SaO(2)), 79 ± 3 vs. 76 ± 3%). There was a linear relationship between the increment in VE max and the increment in VO2 max in H (r = 0.77; p < 0.05). When subjects were divided into two groups based on their VO2 max, both groups showed increased VE max and SaO(2) in H with He-O(2), but VO2 max was increased only in the high VO2 max group. These findings suggest that in acute moderate hypobaric hypoxia, air-flow resistance can be a limiting factor affecting VE max; consequently, VO2 max is limited in part by VE max especially in subjects with high VO2 max. |
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Authors:
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Takeshi Ogawa; Jose A L Calbet; Yasushi Honda; Naoto Fujii; Takeshi Nishiyasu |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-07-10 |
Journal Detail:
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Title: European journal of applied physiology Volume: 110 ISSN: 1439-6327 ISO Abbreviation: Eur. J. Appl. Physiol. Publication Date: 2010 Nov |
Date Detail:
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Created Date: 2010-10-20 Completed Date: 2010-12-10 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 100954790 Medline TA: Eur J Appl Physiol Country: Germany |
Other Details:
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Languages: eng Pagination: 853-61 Citation Subset: IM |
Affiliation:
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Institute of Health and Sports Science, University of Tsukuba, Tsukuba, Ibaraki, 305-8574, Japan. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Abdomen, Acute Adult Altitude Anoxia / physiopathology* Atmospheric Pressure Exercise / physiology* Exercise Test Helium* Humans Male Models, Biological Oxygen / blood* Oxygen Consumption / physiology* Oxyhemoglobins / metabolism Pulmonary Ventilation / physiology* Young Adult |
| Chemical | |
Reg. No./Substance:
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0/Oxyhemoglobins; 7440-59-7/Helium; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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