[Sport-anemia: studies on hematological status in high school boy athletes]

High prevalence of anemia and iron deficiency state are found among athletes. To determine the influence of sports activities on the hematological state, we have performed hematological tests and examined the iron metabolism, in addition to some serum enzyme activities and some characters of red blood cells before and after exercise in high school boy athletes. The red blood cell count, hemoglobin level, and hematocrit value were significantly lower than those in the non-athletes boy students. The serum ferritin level in the athletes was significantly lower than that in the control group and healthy adults. Iron deficiency anemia was found in 12% of the athletes. The serum haptoglobin level in the athletes was significantly lower than that in the control group and the level before exercise, suggesting intravascular hemolysis, but the serum hemopexin level showed no difference before and after exercise, suggesting that the hemolysis was not so severe. The serum CPK and myoglobin levels showed a significant increase after exercise, but those levels were quite lower than that of muscle diseases. These findings suggest that daily exercise is closely associated with the increased risk of iron deficiency state, particularly in the high school boy athletes. The mechanism of hemolysis in athletes may partly depend on the increased fragility of iron deficiency red blood cells on mechanical strength.