Iron deficiency in adolescent endurance athletes.

Iron deficiency with or without anemia may impair athletic performance. Although previous reports suggest a high incidence of iron deficiency in adolescent athletes, the recommendations for routine screening are unclear. In this study, high school male and female cross-country runners were evaluated by determining serum ferritin, hemoglobin, and red blood cell indexes during an 11-week competitive season. At the beginning of the season one of 30 males and eight of 20 females had iron deficiency, defined as a ferritin level greater than or equal to 12 ng/ml. By the end of the season four additional males and another female became iron deficient, for an overall incidence of 17% in males and 45% in females. Of the 26 runners who were evaluated throughout the season, ferritin levels fell in all nine females and in 14 of 17 males. Iron-deficiency anemia was not observed in any subject. These findings suggest that nonanemic iron deficiency is common in adolescent runners. Although iron deficiency is more common in females, one of every five males was iron depleted by the close of the season. Preseason screening alone is shown to be inadequate for detecting iron-deficient athletes as five runners with low ferritin levels were not identified on the initial evaluation.