Submitted to: International Journal of Sports Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/1996
Publication Date: N/A
Interpretive Summary: Human physical performance depends on many factors including skill, motivation, concentration, muscle mass, and nutritional components. Although the roles of water and carbohydrate are well established in promoting peak performance, there is limited information regarding the importance of the mineral elements in development of top levels of athletic performance. We studied a group of five female and five male collegiate swimmers and examined how well prediction equations, derived from another group of collegiate swimmers and based on estimates of iron, copper, magnesium, and zinc intake and blood biochemical measurements of nutritional status of these mineral elements, would relate to swim times measured during competition. We found no difference between 100-yd free- style times determined during championship competition and those predicted with the equations. This finding indicates the important, and previously unrecognized, role that trace element nutritional status plays in optimizing human physical performance. This information will be useful to dietitians and nutritionists who work with physically active people. It indicates that proper nutrition can be achieved by selecting nutritious foods and that nutritional supplements are not needed for optimal performance when a balanced diet is consumed.
Technical Abstract: The validity of previously derived models utilizing blood biochemical measurements of iron, copper, magnesium and zinc nutritional status and dietary intakes of these minerals to estimate 100-yd free-style swimming performance during the competitive season was examined in five female and five male collegiate swimmers. Dietary intakes of iron, copper, magnesium, and zinc exceeded 70% of recommended or estimated safe and adequate intakes. Anemia was not present but body iron stores, assessed with serum ferritin concentration, were low in female swimmers who had significantly increased erythrocyte magnesium concentration and superoxide dismutase activity which suggests an adaptation to physical training. Actual 100-yd freestyle times (53.1 +/- 1.4 sec; mean +/- SE) measured during competition were similar to values (52.6 +/- 1.4 sec) predicted with models previously derived from other groups of swimmers. These findings indicate the validity of the prediction models and emphasize the important role of mineral nutritional status in facilitating the development of peak physical performance. Therefore, nutritional status is one of a series of factors contributing to attainment of optimal human function.