ZMA is a combination of zinc, magnesium and vitamin B6 taken by many athletes and bodybuilders. The most prominent reason for taking ZMA is the increase in muscle mass and strength that users report. Increased mass and strength found by users was confirmed by an independent double-blind study. Dr. Lorrie Brilla of Western Washington University found that those taking ZMA compared to the placebo group had 2.5 times greater muscle strength gains. Let's take a look at each of the individual components of ZMA, and why each is important to build muscle mass.