Document Detail


Hypoxic ventilatory response is correlated with increased submaximal exercise ventilation after live high, train low.
MedLine Citation:
PMID:  15609029     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study tested the hypothesis that live high, train low (LHTL) would increase submaximal exercise ventilation (V(E)) in normoxia, and the increase would be related to enhanced hypoxic ventilatory response (HVR). Thirty-three cyclists/triathletes were divided into three groups: 20 consecutive nights of hypoxia (LHTLc, n = 12), 20 nights of intermittent hypoxia (4x5-night 'blocks' of hypoxia interspersed by two nights of normoxia, LHTLi, n = 10), or control (CON, n = 11). LHTLc and LHTLi slept 8-10 h per night in normobaric hypoxia (2,650 m), and CON slept under ambient conditions (600 m). Resting, isocapnic HVR (DeltaV(E)/Deltablood oxygen saturation) was measured in normoxia before (PRE) and after 15 nights (N15) hypoxia. Submaximal cycle ergometry was conducted PRE and after 4, 10, and 19 nights of hypoxia (N4, N10, and N19 respectively). Mean submaximal exercise V(E) was increased (P < 0.05) from PRE to N4 in LHTLc [74.4 (5.1) vs 80.0 (8.4) l min(-1); mean (SD)] and in LHTLi [69.0 (7.5) vs 76.9 (7.3) l min(-1)] and remained elevated in both groups thereafter, with no changes observed in CON at any time. Prior to LHTL, submaximal V(E) was not correlated with HVR, but this relationship was significant at N4 (r = 0.49, P = 0.03) and N19 (r = 0.77, P < 0.0001). Additionally, the increases in submaximal V(E) and HVR from PRE to N15-N19 were correlated (r = 0.51, P = 0.02) for the pooled data of LHTLc and LHTLi. These results suggest that enhanced hypoxic chemosensitivity contributes to increased exercise V(E) in normoxia following LHTL.
Authors:
Nathan E Townsend; Christopher J Gore; Allan G Hahn; Robert J Aughey; Sally A Clark; Tahnee A Kinsman; Michael J McKenna; John A Hawley; Chin-Moi Chow
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Publication Detail:
Type:  Clinical Trial; Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't     Date:  2004-12-18
Journal Detail:
Title:  European journal of applied physiology     Volume:  94     ISSN:  1439-6319     ISO Abbreviation:  Eur. J. Appl. Physiol.     Publication Date:  2005 May 
Date Detail:
Created Date:  2005-04-27     Completed Date:  2005-08-11     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  100954790     Medline TA:  Eur J Appl Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  207-15     Citation Subset:  IM    
Affiliation:
School of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, Australia. nathan.townsend@ausport.gov.au
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MeSH Terms
Descriptor/Qualifier:
Acclimatization / physiology
Adult
Altitude*
Humans
Male
Oxygen / metabolism*
Oxygen Consumption / physiology*
Physical Endurance / physiology*
Physical Exertion / physiology*
Pulmonary Ventilation / 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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