Iron status in athletes involved in intense physical activity.

Iron status was studied in 8 long distance runners. Training programs, diets, and general health were also investigated over a period of at least 2 years. Hemoglobin and serum iron did not differ from normals whereas bone marrow showed either an absence or only traces of iron indicating latent iron deficiency. Radio iron studies of heme and non-heme iron absorption and incorporation showed rather low values. However, they did not differ significantly from normal values. Whole body counting studies during 10 months showed increased elimination of radio iron corresponding to 2 mg iron/day. Due to a high daily iron intake, a balance was present. No signs of bleeding, hemolysis, or increased excretion of hemoglobin via the urine could be found. The low aborption and increased elimination of iron seems to be the explanation for the empty iron stores.