Document Detail


Exercise intensity typical of mountain climbing does not exacerbate acute mountain sickness in normobaric hypoxia.
MedLine Citation:
PMID:  22858630     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Physical exertion is thought to exacerbate acute mountain sickness (AMS). In this prospective, randomized, crossover trial, we investigated whether moderate exercise worsens AMS in normobaric hypoxia (12% oxygen, equivalent to 4,500 m). Sixteen subjects were exposed to altitude twice: once with exercise [3 × 45 min within the first 4 h on a bicycle ergometer at 50% of their altitude-specific maximal workload (maximal oxygen uptake)], and once without. AMS was evaluated by the Lake Louise score and the AMS-C score of the Environmental Symptom Questionnaire. There was no significant difference in AMS between the exposures with and without exercise, neither after 5, 8, nor 18 h (incidence: 64 and 43%; LLS: 6.5 ± 0.7 and 5.1 ± 0.8; AMS-C score: 1.2 ± 0.3 and 1.1 ± 0.3 for exercise vs. rest at 18 h; all P > 0.05). Exercise decreased capillary Po(2) (from 36 ± 1 Torr at rest to 31 ± 1 Torr), capillary arterial oxygen saturation (from 72% at rest to 67 ± 2%), and cerebral oxygen saturation (from 49 ± 2% at rest to 42 ± 1%, as assessed by near-infrared spectroscopy; P < 0.05), and increased ventilation (capillary Pco(2) 27 ± 1 Torr; P < 0.05). After exercise, the increase in ventilation persisted for several hours and was associated with similar levels of capillary and cerebral oxygenation at the exercise and rest day. We conclude that moderate exercise at ~50% maximal oxygen uptake does not increase AMS in normobaric hypoxia. These data do not exclude that considerably higher exercise intensities exacerbate AMS.
Authors:
Kai Schommer; Moritz Hammer; Lorenz Hotz; Elmar Menold; Peter Bärtsch; Marc M Berger
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial     Date:  2012-08-02
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  113     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2012 Oct 
Date Detail:
Created Date:  2012-10-02     Completed Date:  2013-05-23     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1068-74     Citation Subset:  IM    
Affiliation:
Department of Internal Medicine VII, Division of Sports Medicine, University of Heidelberg, Im Neuenheimer Feld 110, Heidelberg, Germany.
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MeSH Terms
Descriptor/Qualifier:
Acute Disease
Adult
Altitude
Altitude Sickness / metabolism,  physiopathology*
Anoxia / metabolism,  physiopathology*
Cross-Over Studies
Female
Hemodynamics / physiology
Humans
Male
Oxygen / metabolism
Oxygen Consumption / physiology
Physical Exertion / physiology*
Prospective Studies
Pulmonary Gas Exchange / physiology*
Respiration
Rest / physiology
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

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


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