ABSTRACT
One of the most important consequences of going to high altitude is a reduction in both maximal aerobic capacity and endurance exercise performance. In this chapter, the authors examine the physiology of oxygen transfer from the air to the mitochondria in the face of the reduced inspired PO2, specifically as it pertains to exercise at high altitude. Two of the most noteworthy features of exercise upon acute exposure to high altitude are the increased perception of effort with exercise (dyspnea on exertion) and the decrease in maximum exercise capacity. Exercise at high altitude is accompanied by very high levels of ventilation. Diffusion limitation of oxygen transfer in the lung is the primary reason for the consistent fall in the arterial PO2 and oxygen saturation during exercise at high altitude and is one of the chief limiting factors for maximal exercise at extremely high elevations.
