Zinc is an essential mineral found in every cell in the body and is involved in more than 200 enzymatic reactions, substances that promote biochemical reactions in the body. Seventy-five to 80 percent of all the zinc in the body is found in skeletal muscle.
Current data indicate that people who are engaged in exercise increase the risk of developing exercise-induced deficiencies of this nutrient. Because it’s involved in the action of several hormones, up to and including insulin, growth hormone, testosterone and estrogen, trainees should give very strong consideration to supplementing with it.
Recently, Turkish researchers investigating exhaustion exercise and its effects on thyroid hormones and testosterone in elite athletes found that after four weeks of zinc supplementation—three milligrams per kilogram of bodyweight a day—free testosterone was much higher than before zinc supplementation. The researchers concluded that taking zinc benefits performance.
Kylie, M., et. al. (2006). The effect of exhaustion exercise on thyroid hormones and testosterone of elite athletes receiving oral zinc. Neuro Endocrinology Letters. 27(1-2): 247-252.