ABSTRACT
Altitude acclimatization is the physiological process which takes place in the body on exposure to hypoxia at altitude (or in a chamber). It comprises a number of responses by different systems in the body, which mitigate, to a degree, the effects of the fall in oxygen partial pressure so that the tissues of the body are defended against this fall to a remarkable degree. Advantageous though this process is, it does not restore performance to that at sea level. Probably the most important change is the increase in breathing (minute ventilation) due to stimulation of the peripheral chemoreceptor (carotid bodies) by hypoxia and changes in the chemical control of breathing. Another is the well-known increase in haemoglobin concentration in the blood. The time courses of these responses vary but most of the changes take place over a period of days up to a few weeks. Individuals vary in the speed and extent to which they can acclimatize. Apart from past history of acclimatization there are no good predictors of future performance. A recent interest is in the effect of intermittent hypoxia. Intermittent hypoxia, in sufficient dose, can produce some of the changes of acclimatization.
