How does ZMA affect testosterone levels?
The connection between zinc and testosterone has been known for more than 15 years. In a study published in 1982, kidney failure patients, who are typically zinc deficient, were supplemented with zinc for a period of six months. Amazingly, their testosterone levels increased by an incredible 85%.(15) In a more recent study conducted in 1996, called “Zinc Status and Serum Testosterone Levels of Healthy Adults,” researchers found that adding 30 mg per day of zinc to the diets of healthy American men who were experiencing moderate zinc deficiencies actually doubled their testosterone levels within six months.(16) An independent study of ZMA was recently conducted at Western Washington University under the direction of sports performance researcher, Lorrie Brilla, Ph.D. A group of 12 competitive NCAA football players who took ZMA nightly during an eight-week spring training program had over 30% increases in free and total testosterone levels compared to more than 10% decreases in the place
