[Effect of zinc and selenium supplementation on serum testosterone and plasma lactate in cyclists after one bout of exhaustive exercise]

Introduction: The purpose of this study was to investigate how exhaustion exercise affects testosterone levels and plasma lactates in road cyclists supplemented with oral zinc and selenium for 4 weeks

Materials and Methods: Twenty-four male road cyclists volunteers, were selected from the Tehran Traffic team, and based on BMI were divided into three groups; the selenium, zinc, and controls. The status of zinc and selenium in subjects was assessed at baseline. After 4 weeks of supplementation free, total testosterone, and lactate levels of all subjects were determined before and after exercise. Data was analyzed according to repeated measures ANOVA, and the Bonfferoni post hoc test, with a significance level of P<0.05

Results: Resting total, free testosterone, and lactate levels did not differ significantly between groups, and were increased by exercise [P>0.05]. Total testosterone levels in the Zn group were higher than in the Se group after exercise [P<0.05]. Free testosterone levels in the Zn group were higher than the other groups [P<0.05]. There was an insignificant difference between levels of lactate in the three groups after exercise [P>0.05]

Conclusion: According to this study, 4-week selenium and zinc supplementation had no significant effect on testosterone or lactate levels of subjects who had a zinc and selenium sufficient diet. Zinc supplementation increased levels of total testosterone in contrast with selenium group, and also increased free testosterone versus the other groups, whereas there was no change in the levels of lactate in the three groups post-test

[Effect of Zinc supplementation on serum testosterone and plasma lactate in male cyclist after one bout of exhaustive exercise]

There is fairly scarce information about the effects of zinc, an essential trace element, on exercise performance. Studies concentrate mostly on the distribution of this element in the body in response to exercise. The purpose of this study was to investigate the effect of exhaustion exercise on the testosterone levels and plasma lactates in road cyclists who are supplemented with oral zinc for 4 weeks. In this semi experimental sixteen male road cyclists, who were healthy in the first evaluation were selected from the Tehran traffic team and were divided into two groups according to mass body index; zinc group and control group. After 4 weeks zinc supplementation [30 mg/day], blood samples were collected from each subject before and after an exhaustive exercise bout. Data were analyzed by independent and paired sample t test. Total testosterone, free testosterione and lactate levels in two groups were increased by exercise [P<0.05] and there was no significant differences between total testosterone and lactate levels in two groups before and after exhaustion exercise [P>0.05]. There was a significant difference between effects of exhaustion exercise on free testosterone levels between two groups [P<0.05]. According to this study, zinc supplementation has no significant effects on testosterone and lactate levels in response to exercise in subjects with a balance diet. However, free testosterone levels were increased by exercise after zinc supplementation