Endurance sports may also raise the risk for iron deficiency anemia by increasing the amount of iron lost in the sweat, as well as by causing hemolysis (the destruction of red blood cells) due to the mechanical trauma caused by repetitive foot strikes during running, though it can also occur during cycling, swimming, rowing, and strength training.[1] For these reasons, the iron needs of athletes (especially of those who are menstruating) may be higher compared to the general population.