The effect of physiological and pharmacological dose zinc supplementation on elite athletes' element metabolism and fatigue

The purpose of this study is to research the effect of physiological and pharmacological dose zinc application on elite athletes on their element metabolism and fatigue. The research was performed on a total of 20 female athletes who play in volleyball teams of Gazi University Sports Club and whose average age, body weight and height are as such; 15.1±1.07 year (14-17), 59.9±6.4 kg (50.4-72.2), 175.3±6.5 cm (163-185), respectively. The study protocol was approved by the Ethics Committee of Selçuk University School of Physical Education and Sports. The athletes included in the study were divided into 2 groups with equal numbers: Group 1 Physiological dose zinc applied group: The group that continued to their daily routine training programs (6 days/week) and on which 220 mg/day zinc sulfate was applied for 4 weeks during the study period. Group 2 Pharmacological dose zinc applied group: The group that continued to their daily routine training programs (6 days/week) and on which 440 mg/day zinc sulfate was applied for 4 weeks during the study period. From all the athletes participating in the study, blood and urine samples were taken a total of 7 times such as; before the start of zinc applications during the resting and post-exercise, as well as within one-week time slices after 4-week zinc supplementations start, after the supplementations finish and post-exercise. Besides, faeces samples were taken a total of 5 times only during the resting. Zinc, magnesium, phosphorus, calcium, iron, copper and selenium levels in the athletes? serum, urine and faeces samples were determined on ICP-MS device while their plasma lactate levels were determined on the auto-analyzer device. Both post-exercise and the zinc supplementation significantly increased the levels of magnesium, calcium, iron and zinc in serum within one-week time slices for 4 weeks. While training increased the levels of serum copper and selenium, zinc supplementation reduced serum levels of the same parameters. The exercise before and after physiological dose zinc supplementations, and the exercise before and after the pharmacological dose zinc supplementations of magnesium, calcium and phosphorus did not effect the excretion of calcium, copper, selenium and phosphorus through urine but nonetheless, the exercise before and after zinc supplementations (physiological and pharmacological doses) caused the decline of urine and zinc levels. While physiological and pharmacological dose zinc supplementations significantly decreased the excretion of magnesium, copper and phosphorus, regularly increased the excretion of zinc through faeces. In the study, training before zinc supplementations significantly increased the levels of plasma lactate. Both physiological and pharmacological dose zinc supplementations reduced the levels of plasma lactate. As a conclusion, physiological dose zinc supplementations to the athletes for 4 weeks may be beneficial on sportive performance.