Document Detail


Effect of acute hypoxia on heart rate variability at rest and during exercise.
MedLine Citation:
PMID:  15162245     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of this study was to investigate sympathovagal balance as inferred from heart rate variability (HRV) responses to acute hypoxia at rest and during exercise. HRV was evaluated in 12 healthy subjects during a standardized hypoxic tolerance test which consists of four periods alternating rest and moderate exercise (50 % V.O (2)max) in normoxic and hypoxic conditions. Ventilatory responses were determined and HRV indexes were calculated for the last 5 min of each period. In well-tolerant subjects, hypoxia at rest induced a decrease of root-mean-square of successive normal R-R interval differences (RMSSD) (p < 0.05) and of absolute high frequency (HF) power (p < 0.001). All absolute HRV indexes were strongly reduced during exercise (p < 0.001) with no further changes under the additional stimulus of hypoxia. A significant increase (p < 0.05) in the HF/(LF+HF) ratio (where LF is low frequency power) was found during exercise in hypoxia compared to exercise in normoxia, associated with similar mean changes in ventilation and tidal volume. These results indicate a vagal control withdrawal under hypoxia at rest. During exercise at 50 % V.O (2)max, HRV indexes cannot adequately represent cardiac autonomic adaptation to acute hypoxia, or possibly to other additional stimuli, due to the dominant effect of exercise and the eventual influence of confounding factors.
Authors:
M Buchheit; R Richard; S Doutreleau; E Lonsdorfer-Wolf; G Brandenberger; C Simon
Related Documents :
19107505 - Effect of high intensity intermittent training on heart rate variability in prepubescen...
8787165 - The presence of coherence in sympathetic and phrenic activities in a developing mammal.
16859975 - Feasibility study on identification of green, black and oolong teas using near-infrared...
20097685 - Chronotropic incompetence and autonomic dysfunction in patients without structural hear...
16696585 - The role of antihistamines in asthma management.
22155655 - Spatial memory is improved by aerobic and resistance exercise through divergent molecul...
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article    
Journal Detail:
Title:  International journal of sports medicine     Volume:  25     ISSN:  0172-4622     ISO Abbreviation:  Int J Sports Med     Publication Date:  2004 May 
Date Detail:
Created Date:  2004-05-26     Completed Date:  2004-09-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8008349     Medline TA:  Int J Sports Med     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  264-9     Citation Subset:  IM    
Affiliation:
Laboratoire des Régulations Physiologiques et des Rythmes Biologiques chez l'Homme, Strasbourg, France. Martin.Buchheit@physio-ulp.u-strasbg.fr
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / physiology
Adult
Anoxia / physiopathology*
Exercise / physiology*
Heart Rate / physiology*
Humans
Male
Pulmonary Ventilation / physiology
Respiration
Rest / physiology*

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


Previous Document:  Concomitant abuse of anabolic androgenic steroids and human chorionic gonadotrophin impairs spermato...
Next Document:  Influence of aerobic fitness level on measured and estimated perceived exertion during exhausting ru...