Document Detail


Exercise breathing pattern during chronic altitude exposure.
MedLine Citation:
PMID:  2007398     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Breathing pattern in response to maximal exercise was examined in four subjects during a 7-day acclimatisation to a simulated altitude of 4247 m (barometric pressure, PB = 59.5 kPa). Graded exercise tests to exhaustion were performed during normoxia (day 0), and on days 2 and 7 of hypoxia, respectively. Ventilation was significantly augmented in the hypoxic environment, as were both the mean inspiratory flow (VT/TI) and inspiratory duty cycle (TI/TTOT) components of it. VI/TI was increased due to a significant increase in tidal volume (VT) and a corresponding decrease in inspiratory time duration (TI). Throughout a range of exercise ventilation, TI/TTOT was increased due to an apparently greater decrease in expiratory time duration (TE) with respect to TI. In all cases, the relation between VT and TI displayed a typical range 2 behaviour, with evidence of a range 3 occurring at very high ventilatory rates. There was essentially no difference observed in the VT-TI relation during exercise between the normoxic and hypoxic conditions. No significant changes were observed in the breathing pattern in response to exercise within the exposure period (from day 2 to day 7), although there was a discernible tendency to a higher stage 3 plateau by day 7 of altitude exposure.
Authors:
I B Mekjavic; C Moric; S V Goldberg; J B Morrison; M L Walsh; E W Banister; R B Schoene
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  European journal of applied physiology and occupational physiology     Volume:  62     ISSN:  0301-5548     ISO Abbreviation:  Eur J Appl Physiol Occup Physiol     Publication Date:  1991  
Date Detail:
Created Date:  1991-05-02     Completed Date:  1991-05-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0410266     Medline TA:  Eur J Appl Physiol Occup Physiol     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  61-5     Citation Subset:  IM; S    
Affiliation:
School of Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.
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MeSH Terms
Descriptor/Qualifier:
Acclimatization / physiology
Adult
Altitude*
Anoxia / physiopathology
Breathing Exercises*
Exercise / physiology
Humans
Male
Respiration / physiology*
Time Factors

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


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