Zinc monomethionine aspartate (ZMA) - Health Effects

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 III. ZMA does claim to raise strength levels, although studies show inconsistent results.

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.ZMA is a combination of two minerals, zinc and magnesium, and Vitamin B₆ 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% don't meet the U.S. government's recommendation for magnesium.

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.

This study examined whether supplementing the diet with a commercial supplement containing zinc magnesium aspartate (ZMA) during training affects zinc and magnesium status, anabolic and catabolic hormone profiles, and/or training adaptations. Forty-two resistance trained males (27 ± 9 yrs; 178 ± 8 cm, 85 ± 15 kg, 18.6 ± 6% body fat) were matched according to fat free mass and randomly assigned to ingest in a double blind manner either a dextrose placebo (P) or ZMA 30–60 minutes prior to going to sleep during 8-weeks of standardized resistance-training. Subjects completed testing sessions at 0, 4, and 8 weeks that included body composition assessment as determined by dual energy X-ray absorptiometry, 1-RM and muscular endurance tests on the bench and leg press, a Wingate anaerobic power test, and blood analysis to assess anabolic/catabolic status as well as markers of health. Data were analyzed using repeated measures ANOVA. Results indicated that ZMA supplementation non-significantly increased serum zinc levels by 11 – 17% (p = 0.12). However, no significant differences were observed between groups in anabolic or catabolic hormone status, body composition, 1-RM bench press and leg press, upper or lower body muscular endurance, or cycling anaerobic capacity. Results indicate that ZMA supplementation during training does not appear to enhance training adaptations in resistance trained populations.