Article Text

Download PDFPDF
Continuous and intermittent exposure to the hypoxia of altitude: implications for glutamine metabolism and exercise performance
  1. D M Bailey1,
  2. L M Castell2,
  3. E A Newsholme2,
  4. B Davies1
  1. 1Hypoxia Research Unit, Health and Exercise Sciences Research Laboratory, University of Glamorgan, Pontypridd CF37 1DL, United Kingdom
  2. 2Cellular Nutrition Research Group, University Department of Biochemistry, Oxford OX1 3QU, United Kingdom
  1. Correspondence to: Dr D M Bailey, Hypoxia Research Unit, Health and Exercise Sciences Research Laboratory, School of Applied Sciences, University of Glamorgan, Pontypridd CF37 1DL, United Kingdom

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Take home message

The duration of exposure to environmental hypoxia during physical exercise is a potential mediator of immune function and athletic performance. Continuous hypoxic training resulted in overt immunodepression whereas intermittent hypoxic training increased physical exercise performance considerably.

Although most elite athletes invest a considerable amount of time and resources training at altitude, the practical benefits gained remain to be clearly established despite almost half a century of investigation. Elucidating the potential factors that affect physical performance after return to sea level has been the subject of much interest and controversy.

The time spent exposed to the hypoxia of altitude would appear to be an important mediator of sea level performance. A combination of physical exercise and intermittent hypoxia (defined as an exposure time of 30 minutes to 12 hours a day) has been shown to accelerate the normal adaptations invoked by a comparable programme of normoxic training with cardioprotective and performance enhancing benefits.1 In contrast, increased free radical mediated oxidative stress,2 decreased cell mediated immunity,3 and increased incidence of infectious episodes4 have been reported in continuous hypoxia (defined as an exposure time of 24 hours a day). We have previously reported two cases of infectious mononucleosis following chronic exposure to 1500–2000 m.5

Glutamine has been identified as a conditionally essential amino acid required for lymphocyte proliferation and macrophage phagocytosis, and it has been suggested that any physiological decrease in plasma glutamine may impair the host's defence against opportunistic infections.6 In the light of these findings, …

View Full Text