Background: Zinc is involved in numerous metabolic roles, including energy metabolism, immunity, and antioxidative effects. Zinc losses during exercise, in particular through sweat, are well documented. However, conflicting results have been reported for changes in circulating and tissue zinc concentration as a result of exercise. The purpose of this article is to quantify the immediate effect of aerobic exercise on plasma or serum zinc levels, in healthy participants.
Methods: We conducted a systematic review of peer-reviewed articles published up to December 20, 2014, to identify studies that investigated the acute effects of exercise on selected indices of zinc status. Meta-analyses were conducted to determine the change in serum zinc concentration immediately after a bout of aerobic exercise.
Results: Forty-five studies were included in the systematic literature review. Of the included studies, sufficient data were available from 34 studies (providing 46 comparisons) to quantify the change in serum zinc concentration after exercise. Serum zinc concentration was significantly higher immediately after exercise (0.45 ± 0.12 μmol·L(-1), P < 0.001; mean ± SE). Secondary analyses showed greater increase in serum zinc for untrained individuals and exercise sessions that involved running or maximal intensity. Insufficient data were available to determine the effects of exercise on urinary, sweat, and erythrocyte zinc.
Conclusions: The present systematic review and meta-analysis indicated significant increase in serum zinc concentration immediately after an aerobic exercise session, suggesting acute perturbations in zinc homeostasis. Further research is required to ascertain the long-term effects of exercise on zinc metabolism and potential consequences for dietary zinc requirement for physically active populations.