Document Detail


Training in hypoxia fails to further enhance endurance performance and lactate clearance in well-trained men and impairs glucose metabolism during prolonged exercise.
MedLine Citation:
PMID:  19897566     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The aim of this study was to investigate the synergistic effects of endurance training and hypoxia on endurance performance in normoxic and hypoxic conditions (approximately 3000 m above sea level) as well as on lactate and glucose metabolism during prolonged exercise. For this purpose, 14 well-trained cyclists performed 12 training sessions in conditions of normobaric hypoxia (HYP group, n = 7) or normoxia (NOR group, n = 7) over 4 weeks. Before and after training, lactate and glucose turnover rates were measured by infusion of exogenous lactate and stable isotope tracers. Endurance performance was assessed during incremental tests performed in normoxia and hypoxia and a 40 km time trial performed in normoxia. After training, performance was similarly and significantly improved in the NOR and HYP groups (training, P < 0.001) in normoxic conditions. No further effect of hypoxic training was found on markers of endurance performance in hypoxia (training x hypoxia interaction, n.s.). In addition, training and hypoxia had no significant effect on lactate turnover rate. In contrast, there was a significant interaction of training and hypoxia (P < 0.05) on glucose metabolism, as follows: plasma insulin and glucose concentrations were significantly increased; glucose metabolic clearance rate was decreased; and the insulin to glucagon ratio was increased after training in the HYP group. In conclusion, our results show that, compared with training in normoxia, training in hypoxia has no further effect on endurance performance in both normoxic and hypoxic conditions or on lactate metabolic clearance rate. Additionally, these findings suggest that training in hypoxia impairs blood glucose regulation in endurance-trained subjects during exercise.
Authors:
Virgile Lecoultre; Andreas Boss; Luc Tappy; Fabio Borrani; Christel Tran; Philippe Schneiter; Yves Schutz
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-11-06
Journal Detail:
Title:  Experimental physiology     Volume:  95     ISSN:  1469-445X     ISO Abbreviation:  Exp. Physiol.     Publication Date:  2010 Feb 
Date Detail:
Created Date:  2010-02-12     Completed Date:  2010-05-06     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9002940     Medline TA:  Exp Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  315-30     Citation Subset:  IM    
Affiliation:
Department of Physiology, University of Lausanne, Bugnon 7, CH-1005 Lausanne, Switzerland. virgile.lecoultre@unil.ch
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MeSH Terms
Descriptor/Qualifier:
Adult
Altitude
Anoxia / physiopathology*
Blood Glucose / metabolism*
Exercise Tolerance*
Humans
Lactic Acid / blood*
Male
Metabolic Clearance Rate
Physical Exertion*
Physical Fitness*
Task Performance and Analysis*
Chemical
Reg. No./Substance:
0/Blood Glucose; 50-21-5/Lactic Acid

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


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