This study was performed to assess how 4 weeks of magnesium supplementation and exercise affect the free and total plasma testosterone levels of sportsmen practicing tae kwon do and sedentary controls at rest and after exhaustion. The testosterone levels were determined at four different periods: resting before supplementation, exhaustion before supplementation, resting after supplementation, and exhaustion after supplementation in three study groups, which are as follows: Group 1-sedentary controls supplemented with 10 mg magnesium per kilogram body weight. Group 2-tae kwon do athletes practicing 90-120 min/day supplemented with 10 mg magnesium per kilogram body weight. Group 3-tae kwon do athletes practicing 90-120 min/day receiving no magnesium supplements. The free plasma testosterone levels increased at exhaustion before and after supplementation compared to resting levels. Exercise also increased testosterone levels relative to sedentary subjects. Similar increases were observed for total testosterone. Our results show that supplementation with magnesium increases free and total testosterone values in sedentary and in athletes. The increases are higher in those who exercise than in sedentary individuals.

BackgroundChromium histidinate (CrHis) and biotin are micronutrients commonly used to improve health by athletes and control glycaemia by patients with diabetes. This study investigates the effects of 8-week regular exercise training in rats together with dietary CrHis and biotin supplementation on glucose, lipids and transaminases levels, as well as protein expression levels of peroxisome proliferator-activated receptor gamma (PPAR-γ), insulin receptor substrate-1 (IRS-1) and nuclear transcription factor kappa B (NF-κB).MethodsA total of 56 male Wistar rats were randomly divided into 8 groups of 7 animals each and treated as follows: Control, CrHis, Biotin, CrHis+Biotin, Exercise, CrHis+Exercise, Biotin+Exercise, and CrHis+Biotin+Exercise. The doses of CrHis and biotin were 400 μg/kg and 6 mg/kg of diet, respectively. The training program consisted of running at 30 m/min for 30 min/day at 0% grade level, 5 days per week, once a day for 6 weeks. Serum glucose, total cholesterol (TC), high-density lipoprotein cholesterol (HDL), triglycerides (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured with an automatic biochemical analyzer. Muscle and liver PPAR-γ, IRS-1 and NF-κB expressions were detected with real-time polymerase chain reaction.ResultsRegular exercise significantly (p < 0.001) decreased glucose, TC and TG levels, but increased HDL cholesterol. Dietary CrHis and biotin supplementation exhibited a significant (p < 0.001) decrease in glucose (effect size = large; ƞ2 = 0.773) and TG (effect size = large; ƞ2 = 0.802) levels, and increase in HDL cholesterol compared with the exercise group. No significant change in AST and ALT (effect size = none) levels was recorded in all groups (p > 0.05). CrHis/biotin improves the proteins expression levels of IRS-1, PPAR-γ, and NF-κB (effect size: large for all) in the liver and muscle of sedentary and regular exercise-trained rats (p < 0.001).ConclusionsCrHis/biotin supplementation improved serum glucose and lipid levels as well as proteins expression levels of PPAR-γ, IRS-1 and NF-κB in the liver and muscle of exercise-trained rats, with the highest efficiency when administered together. CrHis/biotin may represent an effective nutritional therapy to improve health.

Aim. The objective of this study is to investigate the effectiveness of Crossfit training in order to minimize performance loss of elite wrestlers during 30-day rest period. Materials and Methods. Total 23 elite male wrestlers who competed at the last national championship participated in this study. The participants were divided into two groups as Crossfit and control group. The Crossfit group performed 5 pull-ups, 10 push-ups and 15 squat exercises consecutively (Crossfit-Cindy) for total 20-min, during the 30-day period, 6 days per week. The Control group did not perform any exercise programs during this period. Before and after the 30-day period, athletes were applied anthropometric measurements as well as VO2max (aerobic capacity), bench press and squat (maximal dynamic strength), leg and handgrip strength (isometric strength), pull-up and push-up (strength endurance) tests. Results. After the 30-day period in the control group, body weight and body fat percentage (BF %) increased significantly, whereas all performance variables decreased significantly. Maximal dynamic strength and aerobic capacity values decreased significantly in the Crossfit group, while body weight, body fat percentage, isometric strength and strength endurance values were maintained. Moreover, the decrease in VO2max and bench press tests was higher in the control group than in the Crossfit group. Conclusion: Consequently, the present study showed that 20-min Crossfit training was highly effective in maintaining the form of elite wrestlers during a 30-day rest period

The effects of a 1-month exercise program and magnesium supplementation on the adrenocorticotropic hormone and cortisol levels were studied in young tae-kwon-do and sedentary subjects both at rest and exhaustion. The hormone levels were compared before and after supplementation with 10 mg of magnesium (as magnesium sulfate) per kilogram of body weight. Both exercise and magnesium supplements caused significant increases of the adrenocorticotropic hormone (p < 0.05). The cortisol levels were increased in training subjects receiving supplements (p < 0.05) but not so in subjects that either trained or received magnesium supplements in an independent manner. The cortisol levels measured in resting individuals were higher in the supplemented and non-supplemented athletes than those in sedentary subjects (p < 0.05). The results of this study show that exercise and/or magnesium supplementation causes a rise of the adrenocorticotropic hormone, whereas cortisol is increased only as a result of combined exhaustion and magnesium supplements.