ZMA is a popular supplement for aiding hormone production and improving recovery from hard training sessions. The 'Z' in ZMA stands for Zinc, which is responsible for test production, helping to increase muscle mass and strength. Interestingly, many males are actually deficient in Zinc! The 'M' in ZMA stands for Magnesium, which increases quality of sleep, leading to improved recovery times. ZMA is a powerful, all-natural dietary supplement clinically proven to increase male hormone and insulin-like growth factor (IGF-1) levels and enhance muscle strength in training athletes. ZMA increases hormone levels Increases insulin-like growth factor (IGF-1)* Increases muscle strength Induces better sleep Improves recovery ZMA was designed to optimize the absorption and availability of zinc and magnesium during peak times of growth and repair. Both zinc l-monomethionine (L-OptiZinc) and zinc/magnesium aspartate are unique and highly bioavailable forms of these minerals. The zinc l-monomethionine is absorbed in the front part of the small intestine at the mineral "receptor sites," while the zinc/magnesium aspartate is absorbed in the back of the small intestine via an "active transport" mechanism. In addition, the zinc/magnesium aspartate in ZMA consists of a unique complex of zinc, magnesium and aspartic acid, which enables the magnesium and zinc to reach the blood stream at the same time.

Proponents of ZMA supplements claim that it provides a number of benefits to athletes and body builders; these include better sleep and faster recovery, and more specifically, increased endurance and strength, as well as higher testosterone levels. In addition to these benefits, because ZMA is a natural testosterone boosting supplement, it is not banned by athletic organizations and is therefore a preferred substitute for athletes who wish to improve their performance without having to fear legal scrutiny.

Lorrie Brilla, PhD, of Western Washington University and Victor Conte of Balco Labs in Burlingame, California conducted studies that sought to determine the effects of ZMA on strength and testosterone levels, the results of which supported the proposed claims. However, it's important to note that Conte himself developed ZMA and SNAC Systems, who happen to be patent holders of the ZMA brand and who funded the study. Contrary to their findings, independent studies conducted by Baylor University in Texas concluded that ZMA supplementation during training has no significant impact on muscle gain and athletic performance. Furthermore, according to research led by experts at the German Sport University of Cologne, “No significant changes in serum total and serum free testosterone were observed in response to ZMA use.”

In spite of in-congruent evidence, the intrinsic benefits of consuming ZMA -- apart from those associated with athletic performance -- should not be discarded. Vegetarians, pregnant women, gastrointestinal disease sufferers, the elderly and diabetics may benefit from consuming ZMA in order to combat deficiencies in any of its constituents. All of this, of course, merely goes to say that it's probably more appropriate to consider the benefits of ZMA as a dietary supplement, rather than as a performance enhancement.