Document Detail


Training in normobaric hypoxia and its effects on acute mountain sickness after rapid ascent to 4559 m.
MedLine Citation:
PMID:  20367484     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In a randomized, placebo-controlled, double-blind study, we tested a 4-week program in normobaric hypoxia that is commercially offered for the prevention of acute mountain sickness (AMS). Twenty-two male and 18 female healthy subjects [mean age 33 +/- 7 (SD) years] exercised 70 min, 3 x /week for 3 weeks on a bicycle ergometer at workloads of 60% VO2max either in normoxia (normoxia group, NG) or in normobaric hypoxia (hypoxia group, HG), corresponding to altitudes of 2500, 3000, and 3500 m during weeks 1, 2, and 3, respectively. Four passive exposures of 90 min in normoxia (NG) or hypoxia corresponding to 4500 m (HG) followed in week 4. Five days after the last session, subjects ascended within 24 h from sea level to 4559 m (one overnight stay at 3611 m) and stayed there for 24 h. AMS was defined as LL (Lake Louise score) > or =5 and AMS-C > or =0.70. The AMS incidence (70% in NG vs. 60% in HG, p = 0.74), LL scores (7.1 +/- 4.3 vs. 5.9 +/- 3.4, p = 0.34), and AMS-C scores (1.50 +/- 1.22 vs. 0.93 +/- 0.81, p = 0.25) at the study endpoint were not significantly different between the groups. However, the incidence of AMS at 3611 m (6% vs. 47%, p = 0.01) and the functional LL score at 4559 m were lower in HG. SpO2 at 3611 m, heart rate during ascents, and arterial blood gases at 4559 m were not different between groups. We conclude that the tested program does not reduce the incidence of AMS within a rapid ascent to 4559 m, but our data show that it prevents AMS at lower altitudes. Whether such a program would prevent AMS at higher altitudes, but with slower ascent, remains to be tested.
Authors:
Kai Schommer; Neele Wiesegart; Elmar Menold; Ute Haas; Katrin Lahr; Hermann Buhl; Peter Bärtsch; Christoph Dehnert
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  High altitude medicine & biology     Volume:  11     ISSN:  1557-8682     ISO Abbreviation:  High Alt. Med. Biol.     Publication Date:  2010  
Date Detail:
Created Date:  2010-04-06     Completed Date:  2010-07-15     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901183     Medline TA:  High Alt Med Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  19-25     Citation Subset:  IM; S    
Affiliation:
Department of Sports Medicine, Medical Clinic, University Hospital Heidelberg, Heidelberg, Germany. kai.schommer@med.uni-heidelberg.de
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MeSH Terms
Descriptor/Qualifier:
Acclimatization*
Adult
Altitude Sickness / epidemiology,  prevention & control*
Anoxia*
Blood Gas Analysis
Double-Blind Method
Female
Heart Rate
Hematocrit
Hemoglobins / analysis
Humans
Lactic Acid / blood
Male
Oximetry
Physical Education and Training / methods*
Chemical
Reg. No./Substance:
0/Hemoglobins; 50-21-5/Lactic Acid

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


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