[Physical work capacity of Alpinists under conditions of extremely low pO2 in inspired air]

It is shown that high-trained Alpinists retain relatively high working capacity under conditions of extremely low piO2. Maximal oxygen uptake with extremely low piO2 decreases in high-trained Alpinists less than the working capacity which under conditions of extremely low piO2, is, mainly, limited by decreased potentiality to utilize oxygen by cardiac and skeletal muscles because of paO2 and pvO2 fall below critical values. Low paO2 promotes a decrease in the rate of oxygen diffusion from blood of capillaries into cells, fall of oxygen tension in tissues and lowering of the oxidative processes' rate. Changes in the working capacity of high-trained Alpinists under conditions of extremely low piO2 depend on individual peculiarities of the organism, alpinist length of training which promote high reactivity of the respiration in response to low piO2, economization of the respiration function, development of adaptation mechanisms to low pO2 in the cerebral tissues, skeletal muscles and heart.