Exercise and iron status.

Total iron losses in feces, urine and sweat in endurance-trained athletes are approximately 1.75 mg/d (compared with the reference value of 1 mg/d) in males and approximately 2.3 mg/d (compared with the reference value of 1.4 mg/d) in females because of the additional iron losses with menses. Therefore, it is not surprising that many investigators report that iron deficiency is a common problem in athletes who do not increase their iron intake above that of the general population. Recently, several observations of iron deficiency associated with mild exercise have been reported. Investigation of the extent of iron loss and utilization in individuals exercising for fitness is needed. Because compromised iron status can affect athletic performance as well as general health, including immune functions, cognitive development and ability to thermoregulate, it is advisable to emphasize meeting the recommended dietary allowances for iron during exercise training.