Relation of protein nutrition to the reduction of red blood cells induced by physical training

Sports anemia induced by tennis training or exercising on a bicycle ergometer was studied in healthy male students. Since the anemia has been attributed to an increased susceptibility of red blood cells to lysis during exercise and influence by the nutritional status of the individuals has been suggested, the relation of sports anemia to the nutritional conditions of the subjects and to osmotic fragility of red cells were studied in groups by controlling protein levels in diets. Anemia was most pronounced and the recovery from it was most prolonged in subjects with low protein diets, while it was least pronounced and the recovery was most rapid in subjects with high protein diets. The extent of increase in osmotic fragility of red cells was highest in subjects with low protein diets, and lowest in subjects with high protein diets. The erythropoietic responses to the exercise were different among the dietary groups; i.e., an early increase in blood reticulocytes in subjects with high protein diets and a late increase in subjects with low protein diets were observed during the course of training. From above observations, we conclude that the extent of anemia is closely related to protein intake from the diets and that it is one of adaptive processes of individuals to stenuous physical training rather than an exaggeration of the physiological process of erythrocyte destruction.