Iron Deficiency in Athletes

Adequate body stores of iron are necessary for optimal endurance exercise performance. Severe iron depletion resulting in overt iron-deficiency anemia clearly depresses endurance fitness, but it is not clear if milder degrees of iron deficiency (low serum ferritin with normal hemoglobin levels) impair physical capacity. The question is an important one for athletes, particularly females, who are particularly prone to iron deficiency without anemia. This review examines research data, in both animals and humans, which have addressed this issue. Constructing guidelines based on this often-conflicting body of information is difficult. Routine screening is advocated for at-risk athletes, particularly elite-level female competitors in distance sports, and, although controversial, many authorities recommend iron treatment for athletes with hypoferritemia (ferritin <12-20 ng/mL), even without overt anemia. However, “blind” supplementation with oral iron by athletes is not recommended.