Original article: Muscular Development
By Bob Lefavi, PhD, CSCS, CHES
In order to understand the history of ZMA, I recently interviewed the inventor, nutritionist/scientist Victor Conte.
BL: Victor, why don't you tell us about yourself and provide some background on BALCO Laboratories.
VC: I'm the founder and director of BALCO Laboratories in Burlingame, California. BALCO has been in existence for about 15 years. We specialize in mineral and trace element assessment and do research with elite Olympic and professional athletes.
BL: In what capacity do you work with these elite athletes?
VC: We provide a comprehensive mineral and trace element assessment and, based upon the athletes' test results; we make specific nutritional supplementation recommendations.
BL: And I understand you've also worked with some of the players on the Denver Broncos?
VC: Yes. We've provided testing and consultation for over 250 NFL players, including the entire Denver Broncos Super Bowl championship team, as well the entire Miami Dolphins team, including their coaches and trainers.
BL: Did you find that many of the professional football players had mineral deficiencies?
VC: Absolutely! For example, more than 70 percent of the 250 NFL players we tested were depleted or deficient in both zinc and magnesium. The NCAA football players in the ZMA study also had reduced baseline blood levels of both zinc and magnesium. However, eight weeks of ZMA supplementation was very effective in optimizing their levels of these elements, which resulted in dramatic increases in the anabolic hormone levels and muscle strength of the athletes.
BL: Don't we get plenty of zinc and magnesium in common foods?
VC: The main reason for baseline deficiencies in both the general population and in serious athletes is that it's difficult to get proper amounts solely through the intake of whole foods. USDA studies show that 68 percent of self-selected diets contain less than two-thirds of the RDA for zinc and 39 percent contain less than two-thirds of the RDA for magnesium. While zinc and magnesium are contained in a wide variety of foods, it's been my experience that athletes don't acquire sufficient quantities through their normal diets. One reason may be that foods high in these minerals aren't necessarily the most desirable. For example, the best food sources for zinc include oysters and beef liver. These foods just aren't consumed by most athletes, nor should they be.
BL: Most athletes take a daily multiple vitamin/mineral supplement. Don't they get the additional zinc and magnesium that we need from this source?
VC: Probably not! In a study called "The effect of seven to eight months of vitamin/mineral supplementation on the vitamin and mineral status of athletes," blood indicators of eight vitamins (Bl, B2, B6, C, E, A, B12, folate) and six minerals (Cu, Mg, Zn, Ca, P) were measured in 86 athletes before and after a seven- to eight-month period of training. During this period, half consumed a multi-vitamin/mineral supplement and a matched group took a placebo.
Following the supplementation period, blood indicators of vitamins Bl, B6, B12 and folate status all increased, but there were no effects of supplementation of any of the minerals on the blood levels. Zero effect! This is because of the competitive and antagonistic interactions that prevented adequate absorption. In their study, the authors concluded that "seven to eight months of multi-vitamin/mineral supplementation did not affect any of the blood mineral levels."
BL: What about the tendency for athletes to be excessive with their supplementation? I know that zinc can be toxic in high dosages.
VC: That's a very good point. This is the reason ZMA contains a daily dosage of 30 milligrams of zinc for men. A dosage of zinc greater than 50 milligrams per day can lower HDL cholesterol levels, copper levels, and super oxide dismutase [SOD] levels in as short a time as 14 days. What I'm saying is that too much zinc can be just as bad as not enough. So, it's very important to take a safe and appropriate daily dosage of zinc.
So, is ZMA FUEL the next "creatine"? Who knows? But one thing's for sure - The research is headed in the right direction!
Dr. Bob Lefavi, Certified Strength and Conditioning Specialist and Certified Health Education Specialist, is a professor in the College of Health Professions, Armstrong Atlantic State University, Savannah, Ga.