Improved work capacity at altitude by transfusional polycythemia

Six tennis players from Mar del Plata (sea level) were sent to La Paz (3,600 mts.). Previously the oxygen capacity of blood of three of them was sharply increased by transfusion up to a meap Hb-level of 19.83 g.%. This group was not only polycythemrnic when compared to the controls, but also when compared to the residents of La Paz. The overcompensative polycythemia was well tolerated. There was a striking improvement of subjective wqrk capacity, and when estimated on the basis of dyspnea and pulse rate.