Effects of exercise training on human copper and zinc nutriture.

The findings of our three studies indicate no significant decreases in blood biochemical indices of copper and zinc nutritional status among female and male swimmers during physical training when dietary intakes of these trace elements are adequate (greater than or equal to 67% recommended safe and adequate intake). At these intakes, erythrocyte superoxide dismutase activity increased after physical training indicating a biochemical adaptation of human copper metabolism associated with exercise training. It is noteworthy that this increase in superoxide dismutase activity occurred without an apparent increase in daily copper intake. The calculated copper intakes were 1.3-1.4 and 1.6-1.9 mg/d in the female and male swimmers, respectively. These intakes are less than the suggested value of 2.0 mg/d (Committee on Dietary Allowances, 1980), but they are similar to the reported intakes of other groups in the United States (Klevay et al., 1979). In conclusion, these findings do not appear to support the belief that physical training per se produces adverse effects on copper and zinc nutriture.