Abstract
Red blood cell indices, serum iron, and serum ferritin concentration were determined
in 45 marathon runners, 56 ultramarathon runners, and 32 healthy sedentary controls.
A significant reduction of hemoglobin concentration, hematocrit, mean corpuscular
hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular volume, serum
iron, and serum ferritin were found in marathon runners compared to control subjects.
The same variables were also reduced, but to a lesser extent, in the less trained
ultramarathon runners. The decreased hemoglobin concentration demonstrated in the
runners examined is related to both a reduced mean corpuscular hemoglobin concentration
and a reduced hematocrit and may depend on a reduction of the body iron stores.
Key words
aerobic training - hemoglobin - iron status - hematocrit - sports anemia - serum ferritin
