Abstract des Autors

As altitude increases, the partial pressure of oxygen decreases and results indecreased performance of those activities (aerobic) that depend on a steady supply of oxygen. The saturation of hemoglobin by oxygen in arterial blood is decreased. An initial response of the body to altitude is to decrease plasma volume so that red blood cells become more concentrated and blood can carry more oxygen. Later, an increased number of red cells may be produced. However,too high a concentration of red blood cells can impair blood flow due to increased viscosity of blood. Even after training at altitude for a number of weeks, performance generally remains impaired. Return to sea-level can soon result in return to normal performance levels, but there seems to be no advantage to training at altitude for sea-level contests. Verf.-Referat