Document Detail


Long-term intermittent hypoxia increases O2-transport capacity but not VO2max.
MedLine Citation:
PMID:  17824823     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Long-term intermittent hypoxia, characterized by several days or weeks at altitude with periodic stays at sea level, is a frequently occurring pattern of life in mountainous countries demanding a good state of physical performance. The aim of the study was to determine the effects of a typical South American type of long-term intermittent hypoxia on VO2max at altitude and at sea level. We therefore compared an intermittently exposed group of soldiers (IH) who regularly (6 months) performed hypoxic-normoxic cycles of 11 days at 3550 m and 3 days at sea level with a group of soldiers from sea level (SL, control group) at 0 m and in acute hypoxia at 3550 m. VO2max was determined in both groups 1 day after arrival at altitude and at sea level. At altitude, the decrease in VO2max was less pronounced in IH (10.6 +/- 4.2%) than in SL (14.1 +/- 4.7%). However, no significant differences in VO2max were found between the groups either at sea level or at altitude, although arterial oxygen content (Ca(O(2) )) at maximum exercise was elevated (p < 0.001) in IH compared to SL by 11.7% at sea level and by 8.9% at altitude. This higher Ca(O(2) ) mainly resulted from augmented hemoglobin mass (IH: 836 +/- 103 g, SL: 751 +/- 72 g, p < 0.05) and at altitude also from increased arterial O(2)-saturation. In conclusion, acclimatization to long-term intermittent hypoxia substantially increases Ca(O(2) ), but has no beneficial effects on physical performance either at altitude or at sea level.
Authors:
Nicole Prommer; Katja Heinicke; Teresa Viola; Jorge Cajigal; Claus Behn; Walter F J Schmidt
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  High altitude medicine & biology     Volume:  8     ISSN:  1527-0297     ISO Abbreviation:  High Alt. Med. Biol.     Publication Date:  2007  
Date Detail:
Created Date:  2007-09-10     Completed Date:  2008-02-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901183     Medline TA:  High Alt Med Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  225-35     Citation Subset:  IM; S    
Affiliation:
Department of Sports Medicine and Sports Physiology, University of Bayreuth, Germany. nicole.prommer@uni-bayreuth.de
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological
Adult
Altitude*
Altitude Sickness / blood*
Analysis of Variance
Anoxia / blood*
Blood Volume
Chile
Erythrocyte Count
Erythrocyte Volume
Erythropoietin / blood
Hemoglobins / analysis
Humans
Male
Military Personnel*
Oxygen Consumption
Chemical
Reg. No./Substance:
0/Hemoglobins; 11096-26-7/Erythropoietin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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