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Human muscle structure after exposure to extreme altitude
H Hoppeler1, H Howald, P Cerretelli
1Department of Anatomy, University of Bern, Switzerland.
Experientia
|December 1, 1990
Summary
Mountaineering in the Himalayas caused muscle fiber size and oxidative capacity to decrease significantly. However, improved oxygen supply to muscle mitochondria was observed after high altitude exposure.
Area of Science:
- Physiology
- Altitude Medicine
- Exercise Science
Background:
- Mountaineering expeditions to high altitudes present physiological challenges.
- Understanding muscle adaptations to extreme environments is crucial for athlete health and performance.
Purpose of the Study:
- To investigate structural and functional changes in skeletal muscle following Himalayan mountaineering.
- To assess the impact of high altitude exposure on muscle fiber characteristics and oxidative capacity.
Main Methods:
- Muscle biopsies were obtained from mountaineers.
- Analysis of muscle fiber size and oxidative capacity was performed.
- Capillary network changes were evaluated.
Main Results:
- A significant reduction in muscle fiber size (approximately -20%) was observed.
- Muscle oxidative capacity decreased significantly (approximately -25%).
- The muscle capillary network remained unaffected by the catabolic processes.
Conclusions:
- High altitude exposure leads to muscle atrophy and reduced oxidative function.
- Despite structural changes, the capillary network's integrity suggests enhanced oxygen supply to mitochondria.
- This adaptation may improve mitochondrial oxygen utilization post-expedition.