Long-Term Intermittent Hypoxia Increases O2-Transport Capacity but Not VO2max
| Autor: | Jorge Cajigal, Katja Heinicke, Nicole Prommer, Walter Schmidt, Claus Behn, Teresa Viola |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Adult
Male Meteorology Physiology Altitude Sickness Biology Hemoglobins Oxygen Consumption Altitude Animal science Acute hypoxia Humans Chile Hypoxia Erythropoietin Sea level Erythrocyte Volume Analysis of Variance Blood Volume Public Health Environmental and Occupational Health Intermittent hypoxia General Medicine Adaptation Physiological Military Personnel Physical performance South american Erythrocyte Count human activities |
| Zdroj: | High Altitude Medicine & Biology. 8:225-235 |
| ISSN: | 1557-8682 1527-0297 |
| DOI: | 10.1089/ham.2007.8309 |
| Popis: | Long-term intermittent hypoxia, characterized by several days or weeks at altitude with periodic stays at sea level, is a frequently occurring pattern of life in mountainous countries demanding a good state of physical performance. The aim of the study was to determine the effects of a typical South American type of long-term intermittent hypoxia on VO2max at altitude and at sea level. We therefore compared an intermittently exposed group of soldiers (IH) who regularly (6 months) performed hypoxic-normoxic cycles of 11 days at 3550 m and 3 days at sea level with a group of soldiers from sea level (SL, control group) at 0 m and in acute hypoxia at 3550 m. VO2max was determined in both groups 1 day after arrival at altitude and at sea level. At altitude, the decrease in VO2max was less pronounced in IH (10.6 +/- 4.2%) than in SL (14.1 +/- 4.7%). However, no significant differences in VO2max were found between the groups either at sea level or at altitude, although arterial oxygen content (Ca(O(2) )) at maximum exercise was elevated (p0.001) in IH compared to SL by 11.7% at sea level and by 8.9% at altitude. This higher Ca(O(2) ) mainly resulted from augmented hemoglobin mass (IH: 836 +/- 103 g, SL: 751 +/- 72 g, p0.05) and at altitude also from increased arterial O(2)-saturation. In conclusion, acclimatization to long-term intermittent hypoxia substantially increases Ca(O(2) ), but has no beneficial effects on physical performance either at altitude or at sea level. |
| Databáze: | OpenAIRE |
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