In an attempt to study the effect of a moderate work load on the concentration of serum erythropoietin and hemoglobin in young women, 8 female university students with a high hemoglobin content (group H), 7 female university students with a low hemoglobin content (group L) and 7 female university students with a tendency to be anemic (group A) were subjected to moderate work for 7 successive days in summer.
Each subject pedalled at a constant work load of 1.25kp at a cycling rate of 50rpm for 60min every day. Blood samples were drawn from the cubital vein under basal conditions on the day before training, the fourth day of training and the day after the training period. The results obtained were as follows; Group H showed a significantly higher erythropoietin concentration before training than groups L and A. The concentration of erythropoietin in group H decreased slightly during the training period, whereas those in groups L and A increased, although the differences were not statistically significant.
The concentration of serum iron in group H was significantly higher than that in group L before training. The former decreased significantly during the training period, whereas the latter was maintained at a lower level. The differences in blood constituents found among the three groups before training lessened after one week's moderate exercise.
The increase in Hb concentration in the subjects in groups L and A after training might have been induced by the augmented secretion of erythropoietin due to training for 7 successive days.