RESUMEN
The hypothesis that blood biochemical measurements of iron (Fe), copper (Cu), magnesium (Mg) and zinc (Zn) nutritional status and dietary intakes of these minerals are useful predictors of 100-yd free-style swimming performance during actual competition was examined in five female and five male collegiate swimmers. Dietary intakes of Fe, Cu, Mg, and Zn exceeded 70% of daily recommended or estimated safe and adequate intakes. Anemia was not present but body iron stores, assessed with serum ferritin concentration, were reduced in female swimmers who had significantly increased erythrocyte Mg and superoxide dismutase activity which suggest a biochemical 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 important role of mineral nutritional status in facilitating the development of peak physical performance and support the hypothesis that mineral element nutritional status is one factor contributing to attainment of optimal human physiological function.
Asunto(s)
Cobre/sangre , Dieta , Hierro/sangre , Magnesio/sangre , Estado Nutricional , Natación/fisiología , Zinc/sangre , Adulto , Femenino , Humanos , MasculinoRESUMEN
The influence of physical training on copper, iron, and zinc nutriture was studied before and at the end of a competitive season in 16 female and 13 male swimmers and in 13 female and 15 nontraining control subjects. Mean daily energy, protein, and carbohydrate intakes increased (p less than 0.05) in the swimmers. Estimated copper, iron, and zinc intakes increased (p less than 0.05) in the male swimmers. Hematocrit and hemoglobin did not change but ferritin increased (p less than 0.05) in male swimmers. Plasma copper, iron and zinc were within the ranges of normal values and did not change. Erythrocyte superoxide dismutase (SOD) activity increased (p less than 0.01) after training. The findings indicate that copper, iron, and zinc nutriture is not adversely affected by physical training when dietary intakes are adequate, and that increases in red blood cell SOD activity without an increase in dietary copper are a functional adaptation of copper metabolism to aerobic training.