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.
Magnesium is the nutritional factor most people are likely to be deficient in. Some studies have indicated that as many as 60% of Americans are deficient. One reason is that people used to get much of their magnesium through drinking hard water, but hardly anyone does that anymore. Supplementing with magnesium is also crucial for treating chronic fatigue. (As discussed in my book.) Many forms of magnesium are poorly absorbed. Magnesium oxide is the form found most commonly such as in drugstores, and it has nearly zero absorption from the gut. So if you want to supplement, get a form that’s readily absorbed; magnesium citrate is best for this.