[Adaptation to chronic hypoxia at various altitudes].

A comparison is made between the results obtained and the examinations carried out in the study of adaptation to chronic altitude hypoxia at 2500 m (19th Olympic Games, Mexico City), and 5350 m (base camp, 1973 Italian Mt. Everest Expedition). An assessment is made of circulation, respiration, and blood changes, and their influence on maximum aerobic effort capacity per unit of time, i.e. VO2max (maximum oxygen consumption). The fall in this capacity is greater than might be supposed from the compensatory mechanisms. Lastly, a comparison is made between recently acclimatised chronically hypoxic subjects and high-altitude natives, and suggestions are put forward to explain the better muscle performance of the latter.