By Victor Conte Updated on October 27, 2022

Grow As You Sleep

Picture for Grow As You Sleep
Original article: Muscular Development

by Victor Conte

ZMA is an effective new sports performance product that has been clinically proven to increase anabolic hormone levels and muscle strength in trained athletes. (1,2) ZMA is the first "nighttime anabolic formula" developed specifically to enhance recovery by improving sleep efficiency. Many athletes fail to realize how important it is to get a deep and restful sleep. Healing, tissue repair, anabolic hormone production and muscle growth are maximized during sleep, so quality sleep is extremely important to athletes.

What is ZMA?

ZMA is a scientifically designed, university laboratory tested anabolic mineral support formula. ZMA contains zinc monomethionine aspartate plus magnesium aspartate and vitamin B-6 in precise ratios and is recommended to be taken 30-60 minutes before bedtime. ZMA is patent pending all natural product that is manufactured utilizing a unique proprietary process, which significantly enhances the absorption and utilization of both the zinc and magnesium.

Do world-class athletes use ZMA?

World class athletes are reporting tremendous benefits from ZMA, in the gym, as well as on the athletic field. For example, more than 250 NFL players are currently taking ZMA. Lester Archambeau, starting defensive end for last year's NFC Champion Atlanta Falcons, says he is "extremely satisfied with ZMA. ZMA definitely helps me recover! I can tell when I take it and when I don't. There is no doubt that it makes me sleep better." And when it comes to the gym, the big Falcon claims, "I have much better endurance when taking ZMA." Bryce Paup, Jacksonville Jaguar's multi-All Pro defensive end and 1995 Defensive Player of the Year (he led the NFL with 17.5 sacks) has also been taking advantage of ZMA. Paup says, "When I take ZMA, I sleep better and more soundly, and I feel more rested when I wake up." And when it comes to the football field, Paup claims, "The more I rest and the better I sleep, the better I perform on the field."

In addition to the professional football players, more than 25 IFBB pro bodybuilders have benefited from using ZMA. Flex Wheeler (1999 Arnold Schwarzenegger Classic Champion) says "I can't believe how much better I feel using ZMA. I have greater output. I'm stronger in everything. I wake up very well rested, and my workouts have gone better!" Michael Ashley (1990 Arnold Schwarzenegger Classic Champion) claims "ZMA is the most effective recovery supplement I've used in my entire bodybuilding career! A deep and restful sleep is the secret to maximizing the anabolic process."

Does exercise effect sleep?

Studies involving the effects of different types and duration of exercise on sleep efficiency have yielded conflicting results. However, in a study of the effects of power exercise on the sleep of a group of trained power lifters, the tendency was for this type of more strenuous exercise to affect sleep adversely. (3) Excessive training has also been reported to cause sleep disturbances as well as mood changes, and the sleep disruption was greater at higher training volumes. (4) In addition, long duration daytime exercise of moderate intensity has been shown to decrease GH and testosterone production during nighttime sleep. (5)

Does age effect sleep?

Sleep quality declines with age, with progressively less time in deep or slow wave sleep (SWS), which occurs during the initial part of sleep. Age related declines also occur in lean body mass, growth hormone (GH) and insulin-like growth factor 1 (IGF-1). (6) In normal young adults, a major burst of growth hormone occurs shortly after sleep onset, in association with the first period of slow wave sleep. In men, approximately 70% of the daily GH output occurs during this period of early sleep throughout adulthood. (7) Extensive evidence also indicates the existence of a consistent relationship between increased SW sleep (stages 3 and 4) and increased GH secretion and, conversely, between awakenings and decreased GH release. Pharmacological stimulation of SW sleep results in increased GH release, and compounds which increase SW sleep represent a new class of GH secretion stimulators.

How does ZMA effect sleep?

In a study of patients with mild or moderate insomnia, it was found that sleep efficiency was significantly improved with oral magnesium therapy. (8) Researchers have also reported that chronic sleep deprivation causes magnesium deficiency as well as decreased exercise tolerance. However, these researchers also found that that the decreased exercise tolerance observed as a result of sleep deprivation could be significantly improved by oral magnesium administration. (9) ZMA contains magnesium aspartate, which is highly bioavailable, and studies have shown this form to have a superior rate of absorption compared to other forms. (10)

Does exercise effect testosterone levels?

First of all, it's a widely held misconception that exercise increases testosterone levels. In fact, prolonged exercise decreases the production of testosterone by approximately 10%.(11) Many studies have reported post-exercise increases in serum testosterone levels, however, what they're measuring is only a temporary false elevation. This is because exercise causes significant decreases in plasma volume, hepatic plasma flow and the metabolic clearance rate of testosterone. This is the reason it's extremely important to measure testosterone levels in a rested state during the early morning as opposed to post exercise. A large percentage of the testosterone secreted daily occurs during sleep and levels peak during the early morning and decrease throughout the day by 25% to an evening minimum. (12)

The following analogy may be helpful in explaining the effect of exercise on testosterone levels. Imagine that there's a hose bringing testosterone into a bathtub, which represents testosterone production, and you decrease the flow of the hose by 10%, which represents the effects of exercise. If you restrict the drain flow at the same time by 30%-a reduction in metabolic clearance rate of testosterone-the level of testosterone will briefly appear to be elevated. However, this is only a short-term effect of exercise and clearly represents a false elevation.

Does age effect testosterone levels?

Testosterone levels significantly decline with age. Serum testosterone concentrations were examined from over 4,000 military veterans and their testosterone levels dropped by more than 30% from age 32 to age 44. (13) In another study of over 1,400 men aged 20-60 years old, testosterone levels showed a significant stepwise decrease with age (p < 0.001) starting with the early adult years. (14)

How does ZMA effect testosterone levels?

The connection between zinc and testosterone has been known for more than 15 years now. For example, in a study published back in 1982, kidney failure patients, who are typically zinc deficient, were supplemented with zinc for a period of six months, and their testosterone levels increased by 85%. (15) In a more recent study conducted in 1996 called "Zinc Status and Serum Testosterone Levels of Healthy Adults", the researchers found that 30 mg per day of zinc supplemented to the diets of healthy American men experiencing moderate zinc deficiencies doubled their testosterone levels in 6 months. (16)

An independent study of ZMA was recently conducted at Western Washington University under the direction of sports performance researcher, Lorrie Brilla, Ph.D. A group of 12 competitive NCAA football players who took ZMA nightly during an 8 week spring training program had over 30% increases in free and total testosterone levels compared to more than 10% decreases in the placebo group of 15. (1)

Does exercise effect growth hormone levels?

Single measurements of growth hormone are not very useful, so insulin-like growth factor 1 (IGF-1) levels, which are protein bound and more stable, are usually measured as an indicator of growth hormone status. Prolonged intensive exercise leads to significantly reduced IGF-1 levels. In a study of 9 subjects training as gymnasts, a 24% decrease in the IGF-1 concentrations were found after 3 days of intensive exercise. (17) In another study of 38 young males involved in a 5 week program of intense physical training, the subjects IGF-1 levels decreased by an average of 12%. (18)

Does age effect growth hormone levels?

Growth hormone levels significantly decline with age. It has been published that growth hormone levels decline by 50% every seven years from age 21. (19) For example, if your IGF-1 level at age 21 was 400 ng/mL, then it would be at 200 ng/mL at age 28 , 100 ng/mL at age 35, and 50 ng/mL at age 42. So at age 42, your IGF-1 level would be about 1/8 th of the level it was at 21 years old.

How does ZMA effect growth hormone levels?

The chief synergists of growth hormone include zinc, magnesium, testosterone and insulin, whereas its chief antagonist is cortisol. (20) Zinc and magnesium supplementation have both been reported to significantly reduce plasma levels of the catabolic "stress" hormone cortisol by 59% and 25%, respectively. (21, 22) Zinc supplementation has also been reported to have a very positive effect upon IGF-1 levels in humans. For example, in a study of growth retarded children, the zinc treated children's IGF-1 levels increased by 47% after 1 month and 70% after 5 months of supplementation. (23) In the recent ZMA study conducted by Dr. Brilla, the NCAA football players who took ZMA nightly had a 3.6% increase in IGF-1 levels compared to a substantial 21.5% decrease in the placebo group. (1)

How does ZMA effect muscle strength?

In addition to measuring the anabolic hormone increases in the football players, Dr. Brilla measured their muscle strength and functional power increases. Pre and post leg strength and power measurements were made using a Biodex isokinetic dynamometer. The players who took ZMA nightly during the 8 week period of intensive training had 2.5 times greater strength gains than the placebo group. The muscle strength of the ZMA group increased 11.6% compared to a 4.6% increase in the placebo group. The ZMA group also had two times greater functional power gains compared to the placebo group. The functional power of the ZMA group increased 18.2%, in contrast to 9.4% for the placebo group. (1,2)

How prevalent are zinc and magnesium deficiencies in athletes?

Zinc and magnesium deficiencies are common in the general population and even more prevalent in athletes. Through an extensive search of worldwide medical research data, we discovered that rigorous exercise and stress results in significant bodily losses of zinc and magnesium.

For example, in a study called "Serum Zinc in Athletes in Training," serum zinc was determined in 160 training athletes-103 males and 57 females. In 23.3% of the males and 43% of the female athletes, serum zinc was significantly below the "normal range."(24)

In addition, in a study called "Biochemical Indices of Selected Trace Minerals in Men: Effect of Stress," blood (plasma) levels of zinc and other trace minerals were determined in 66 men before and after a 5 day period of sustained physical and psychological stress. Zinc levels decreased by 33%! (25)

In another study called "Magnesium, Zinc and Copper status of 270 US Navy Sea, Air and Land (SEAL) trainees" conducted by the US Department of Military Medicine, it was shown that the blood concentrations of magnesium and zinc were significantly below the "normal range" for 23% and 24% of the trainees, respectively.(26)

Furthermore, in 1998, BALCO Laboratories tested the mineral status of over 250 NFL players, including the entire Denver Broncos Super Bowl championship team, as well as the entire Miami Dolphin team. Over 70% of the players were either 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. (1)

Don't athletes get enough zinc and magnesium from foods?

The main reason for baseline deficiencies in the 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% of self-selected diets contain less than two thirds of the RDA for zinc (27) and 39% contain less than two-thirds of the RDA for magnesium. (28) 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.

Don't athletes get sufficient zinc and magnesium from their multiple vitamin/mineral supplements?

In a study called "The effect of 7 to 8 months of vitamin/mineral supplementation on the vitamin and mineral status of athletes," blood indicators of eight vitamins (B1, B2, B6, C, E, A, B12, folate) and six minerals (Cu, Mg, Zn, Ca, P) were measured in 86 athletes before and after a 7-to 8 month period of training. (29) During this period, half consumed a multi-vitamin/mineral supplement and a matched group took a placebo. Following the supplementation period, blood indicators of B1, B6, B12 and folate status all increased, but there were no effects of supplementation on the blood levels of any of the minerals. Zero effect! This is because of the competitive and antagonistic interactions that prevented absorption. The authors concluded that "7 to 8 months of multi-vitamin/mineral supplementation did not effect any of the blood mineral levels".


ZMA is rapidly becoming the preferred natural testosterone boosting supplement by many strength athletes. As more athletes begin to truly understand the processes of maximizing recovery, healing, tissue repair, anabolic hormone production and muscle growth, they'll join those already spreading the ZMA gospel "You Grow As You Sleep!"

Please be advised that imitation Zinc Magnesium Aspartate products are NOT THE SAME AS ZMA and may not produce the same results obtained in the ZMA study.

ZMA was developed by Victor Conte, founder and director of BALCO Laboratories in Burlingame, California, which has been in existence for more than 18 years. BALCO specializes in mineral and trace element assessment and performs research with elite Olympic and professional athletes. Victor routinely provides consultation for several hundred elite athletes from a variety of sports including football, baseball, bodybuilding, basketball, tennis, hockey, track and field, swimming and soccer.


1. Brilla LR, Conte, V. A novel zinc and magnesium formulation (ZMA) increases anabolic hormones and strength in athletes. Sport Med Train and Rehab (in press). Abstract presented November 14, 1998 at the 18th Annual Meeting of the S.W. Chapter of the ACSM.
2. Brilla LR, Conte, V. Effects of zinc-magnesium (ZMA) supplementation on muscle attributes of football players. Med and Sci in Sports and Exercise, Vol. 31, No. 5, May 1999
3. Montgomery I, et al. Acta Physio Scand Suppl, 1998, 574: 36-40.
4. Taylor SR, et al. Med Sci Sprts Ecrtc, 1997 May, 29:5, 688-93.
5. Kern W, et al. J Appl Physiol, 1995 Nov, 79:5, 1461-8.
6. Prinz PN, et al. J Gerontol A Biol Sci Med Sci, 1995 July, 50:4, M222-6.
7. Van Cauter E, et al. Sleep, 1998 Sep, 21:6,553-66.
8. Hornyak M, et al. Sleep, 1998 Aug, 21:5,501-5.
9. Tanabe K, et al. Jpn Circ J, 1998 May, 62:5, 341-6.
10. Disch G, et al. Arzneimittelforschung, 1994, 44.5:647-650.
11. Cadoux-Hudson TA, et al. Eur J Appl Physiol, 1985, 54 (3): 321-5.
12. Tietz N. Clinical guide to laboratory tests. W.B. Saunders, 1995, page 579.
13. Dabbs J. Chronobiol Int, 1990, 7:3, 245-9.
14. Simon D, et al. Am J epidemiol, 1992 Apr, 135:7, 783-91.
15. Mahajan, SK, et al. Ann Intern Med, 1982, 97.3, 357-61.
16. Prasad A, et al. Nutrition, 1996, 12.5:344-48.
17. Jahresis G, et al. Growth Regul, 1991 Sep,1:3,95-9.
18. Eliakim A, et al. Am J Physiol, 1998 July, 275:1 Pt 2, R308-14.
19. Veldhuis JD, et al. Sleep, 1996 Dec, 19:10 Suppl, S221-4.
20. Kutsky RJ. Handbook of vitamins, minerals and hormones. Van Nostrand. Pgs. 307-13.
21. Brandao-Neto J, et al. Bio Trace Elem Res, 1990, Vol 24, 83-89.
22. Golf SW, et al. Clen Chem Cen Biochem, 1984, Vol. 22, 717-21.
23. Ninh NX, et al. Am J Clin Nutr, 1996, 63:514-19.
24. Haralambie G, et al. Int J Sports Med, 1981, 2:135-138.
25. Singh A, et al. Am J Clin Nutr, 1991, 53:126-31.
26. Singh A, et al. Am J Clin Nutr, 1989 Apr, 49:695:700.
27. Holden JM, et al. J Am Diet Asso, 1979, 75.1:23-28.
28. Morgan KJ, et al. J Am Coll Nutr, 1985, 4.2:195-206.
29. Telfoed RD, et al. Int J Sport Nutr, 1992 Jun, 2:2,123-34.


About Author
Grow As You Sleep
SNAC founder Victor Conte has changed the world of sports nutrition forever.  ESPN magazine ranked him as the #1 pioneering sports scientist based on his work with world-class athletes for more than three decades. His dedication to science and innovation led to the development of ZMA, a groundbreaking nighttime recovery supplement that’s licensed by more than 140 brands around the globe.