ZMA (Zinc monomethionine aspartate and Magnesium Aspartate) is a supplement used by bodybuilders and athletes. It was developed by Victor Conte (founder of BALCO Laboratories in Burlingame, California) and is a combination of zinc, magnesium and vitamin B6. The formula is "patent pending" and the name "ZMA" trademarked by SNAC System Inc, also founded by Victor Conte. ZMA is claimed to raise testosterone and IGF-1 levels which may aid in gaining muscle size and strength.
ZMA is a combination of two minerals, zinc and magnesium, and Vitamin B-6 or pyridoxine. All three of these compounds are important in biological processes, and while studies have shown that most Americans get enough zinc and Vitamin B6, more than 50% are deficient in magnesium.
An increase in exercise can lead to the loss of vitamins and minerals making it particularly important for bodybuilding due to the blood sugar level rises and urination increases, increasing the loss of magnesium, zinc, B12, B6, folic acid, and many other nutrients. Although drinking water re-hydrates an athlete, fruit juice, sports drinks or foods high in water such as vegetables are needed to replenish water-soluble nutrients.
The proportion of ingredients generally used in products is 20-30 mg Zinc, 400-500 mg Magnesium and ~10mg B6. According to the label directions, ZMA should be taken before bed on an empty stomach (2 hours after eating your last meal and at least 30 minutes prior to any other supplements). The product should not be taken with calcium (cheese,milk,etc.), the reason being that calcium blocks the absorption of zinc.
A 1999 study was undertaken on NCAA Football players during an 8 week spring training program. The control group was told to cease taking any nutritional supplements. Those who took the ZMA tablets showed greater increases in muscle strength, free testosterone levels, and IGF-1 levels. This study was funded by SNAC Systems Inc. (the patent holders) and one of the study's authors (Victor Conte) has equity in this company.
Another study in 2004 conducted jointly by the Exercise & Sport Nutrition Lab of Baylor University, IMAGINutrition, and the Journal of the International Society of Sports Nutrition, found that ZMA has no effect on strength, hormone levels, or anaerobic capacity.
So, who do we believe? We know that magnesium provides great rewards in helping to reduce anxiety and promote deep sleep. Has anyone out there used ZMA and found there to be benefits?
