Physical training and copper, iron, and zinc status of swimmers

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.