ZMA Supplements: Improve Sleep & Recovery

What Is ZMA?

 ZMA (zinc magnesium aspartate) is a supplement made up of zinc, magnesium, and vitamin B6. This combination may have benefits for sleep muscle growth and recovery.

Zinc is often paired with magnesium in supplemental form because they work synergistically, meaning each mineral helps the body absorb and utilize the other more effectively. Essentially, magnesium can help regulate zinc levels, while zinc can enhance the absorption of magnesium.²⁰

While magnesium is a ubiquitous element that plays a fundamental role in many cellular reactions, for our purposes here, there appears to be an inverse relationship between magnesium and cortisol, a hormone reported to have negative effects on strength gains and muscle mass during training.¹⁶ That is, some research suggests too little magnesium can help spike the steroid hormone cortisol, which is associated with reduced muscle strength and gains.²¹

Benefits of ZMA Supplements

Sleep

If you’re looking to boost your health and performance, a few recommendations rival one that’s absolutely free: Get a good night’s sleep. Sleep boosts muscle-protein synthesis and anabolism, makes you feel more energetic, reduces depression and improves memory, increases your athletic performance, and elevates your mood.¹ More zzzzz’s gets straight A’s when it comes to creating an optimal environment around which your body recovers from the stressors of life, including your workouts.

That apparently is easier said than done. The National Heart, Lung, and Blood Institute reports that 50-70 million Americans have chronic sleep disorders, and a 2024 Gallup Poll indicates only 26 percent of adults get eight hours of sleep nightly.^2,3 A 2022 study by Statistics Canada found poor sleep-facilitating behaviors “prevalent” among the sampled 18-64 age group, with 23 percent not meeting sleep duration recommendations and another 39 percent not meeting sleep quality guidelines.⁴

Concerning sleep quantity and quality, supplementation with zinc has shown positive results. A study by Cherasse et al (2017) said: “Recent research has concluded that zinc serum concentration varies with the amount of sleep, while orally administered zinc increases the amount and quality of sleep in mice and humans.”¹⁸  A 2024 systematic review suggests that zinc supplementation may lead to improvements in sleep quality.¹⁹

If our advice consisted of simply recommending you get a better night’s sleep, you’d have done it by now. Let’s take a closer look at what’s going on, and how one studied supplement can help.

Acute and chronic sleep deprivation is a potent catabolic stressor, increasing the risk of metabolic dysfunction and loss of muscle mass and function.⁵ Acute sleep deprivation has been found to decrease muscle-protein synthesis and promote a less anabolic hormonal environment.⁶

Further research has noted a lack of sleep with impaired maximal strength in compound (multi-joint) movements.⁷ An Australian study determined that “sleep restriction can have detrimental effects on the processes that maintain muscle mass… (which) help to explain previous reports of reduced muscle mass in those experiencing insufficient sleep.”⁸ 

None of which is good news if this aspect of your recovery is inadequate.

Testosterone and Muscle Growth

One of the primary functions of testosterone – among many — is to build muscle. Hormones are chemical messengers that tell your body how to work and what to do. Everyone makes testosterone, but men have levels about 10-20 times higher than women.⁹

What’s more, testosterone levels appear to be declining across the board worldwide, in part because of changes in body weight, physical activity, diet, alcohol consumption, sleep, and even environmental toxins (known more nefariously as endocrine-disrupting chemicals).¹⁰ 

Research suggests that insufficient sleep and sleep disorders negatively impact testosterone levels.¹¹ That may well be the mechanism linking sleep issues with suboptimal results in the gym.

One culprit here may be zinc, found in oysters, seafood, chicken, and red meat, an essential trace mineral involved in a range of biochemical processes, including testosterone production and immune and metabolic function. One study found that zinc deficiency can lead to low testosterone.¹² Adequate zinc levels are crucial for maintaining optimal testosterone levels and healthy sperm production, and zinc deficiency can lead to reduced testosterone and impaired fertility in men.¹³

In one study, serum zinc was positively correlated with total testosterone, and moderate supplementation played an important role in improving androgen.¹⁴ In another study, researchers noted: “Zinc may play an important role in modulating serum testosterone levels in normal men.”¹⁵

Exercise can deplete zinc, and regular activity can exacerbate the problem.¹⁶ A study by Kilic, et al (2006) examined the effect of intense exercise on professional athletes and its effect on thyroid and testosterone levels. The study determined that intense exercise led to a significant drop in both thyroid and testosterone levels. Further, the researchers found that a four-week course of oral zinc supplementation prevented this drop.¹⁷

Zinc and Magnesium Deficiency

Unfortunately, there’s a dearth of research specific to zinc and magnesium deficiency and how that affects the production of testosterone and insulin-like growth factor (IGF-1) and their effect on recovery, anabolism, and strength.⁸ In one study, Brilla and Conte (2000) reported that a zinc-magnesium formulation increased testosterone and IGF-1, leading to greater gains in football players.²²

Athletes have been reported to have lower levels of zinc and magnesium, possibly due to increased sweating while training or inadequate intake in their diets. Additionally, zinc and magnesium supplementation have been reported to have positive effects on resistance training athletes.⁸

Zinc and magnesium supplementation appears to be effective, most especially for those who are deficient, as they may well support both sleep and endogenous testosterone production. 

Should I Supplement With ZMA?

The decision to supplement starts with an evaluation of your diet and whether you’re consuming enough of the right kinds of whole foods while also considering your sleep habits and how a shortfall of some key micronutrients might adversely affect you. 

 Because deficiencies in zinc and magnesium are linked to declines in athletic performance and muscle mass, supplementation is a smart insurance policy to maximize gains and minimize losses. Read product labels as directed and do not take more than recommended.