If you’ve been bodybuilding for more than a decade, you will likely remember the hype that surrounded a simple supplement known as ZMA at the turn of the millennium. A combination of zinc and magnesium aspartate plus vitamin [B.sub.6], ZMA was crowded out of the picture by supplements like creatine and nitric oxide boosters, which took off in popularity at around the same time.
And yet, we at FLEX never lost sight of the promise of ZMA. Backed up by clinical research that shows it to be an effective supplement for bodybuilders and other athletes, we have consistently recommended ZMA supplementation. In fact, this simple combination of essential minerals remains on our top 10 list of supplements for bodybuilders. Read on to understand why you need to give ZMA a place in your supplement regimen and how you can maximize its effects.
Zinc is an essential mineral and an antioxidant that stimulates the activity of many enzymes in the body, which are critical for a multitude of biochemical reactions. Zinc is critical for protein synthesis (the molecular mechanism of muscle growth) and tissue repair after injury. Like zinc, magnesium is an essential mineral also involved in numerous enzymatic reactions in the body. Magnesium is important for cardiovascular, metabolic and bone health.
These two minerals offer a multitude of physique benefits for bodybuilders. A plethora of research shows how zinc and magnesium enhance muscle mass, strength gains and fat loss, not to mention overall health and well-being.
The most well-known research on ZMA’s anabolic benefits was a 2000 study performed at Western Washington University (Bellingham). The researchers had NCAA football players take ZMA or a placebo nightly during an eight-week spring-training program. They discovered that the athletes taking the ZMA supplement experienced a greater than 30% increase in both free and total testosterone levels, and about a 4% increase in insulinlike growth factor-I levels, while those taking a placebo had a 10% decrease in both free and total testosterone levels and a 22% decrease in IGF-I. In addition to improvements in anabolic hormone levels and sleep quality, the ZMA athletes made significantly greater gains in strength and power compared to the placebo group. These benefits occurred despite the fact that analysis of the athletes’ diets found that they were all consuming well over the recommended intake for zinc.
Besides the Western Washington study, several others also find that zinc and magnesium offer potent anabolic properties. The most recent, a 2007 study from Selcuk University (Konya, Turkey) reported that four weeks of zinc supplementation in men increased both free and total testosterone levels at rest and after exercise. The same researchers found similar results for zinc supplementation on testosterone levels in an earlier study with competitive wrestlers. Researchers from the U.S. Department of Agriculture reported that zinc depletion decreased muscle endurance in the lower and upper body of subjects. This means that maintaining zinc levels is critical for your ability to complete a number of reps with a given weight, especially during a workout consisting of multiple sets. As far as magnesium goes, the Western Washington University researchers discovered in an earlier study that subjects taking a magnesium supplement while following a seven-week leg-training program increased their leg strength by 20% more than those taking a placebo.
Both zinc and magnesium supplements have been shown to significantly decrease the levels of the catabolic hormone cortisol. A study by researchers at Justus Liebig University (Giessen, Germany) revealed that triathletes taking a magnesium supplement for four weeks had significantly lower cortisol levels at rest and after a triathlon, as compared to athletes taking a placebo. Brazilian researchers also reported that subjects given a single dose of zinc experienced a significant drop in blood cortisol levels within two hours. Keeping cortisol lowered can be critical for muscle growth and strength gains, as cortisol competes with testosterone, decreasing anabolism and enhancing muscle breakdown.
In addition to boosting testosterone and IGF-I and blunting cortisol, ZMA may also indirectly enhance growth hormone levels. ZMA aids sleep quality because magnesium can normalize and extend stage 3 and 4 slow-wave sleep. This is critical, as deeper sleep can help to raise GH levels, which peak during the night. Better sleep quality also aids muscle recovery from tough workouts.
Zinc is critical for maintaining thyroid hormone production. This is important for keeping your metabolic rate (amount of calories you burn each day) up. Being low in zinc can interfere with thyroid hormone production–and compromised thyroid hormone function leads to a lower metabolic rate, which makes it harder to drop bodyfat.
Research confirms that when your diet is low in zinc, levels of thyroid hormones fall and resting metabolic rate drops. One study from the University of Massachusetts (Amherst) found that subjects placed on a lowzinc diet had significantly lowered metabolic rates. When they took a zinc supplement (25 milligrams) for 20 days, their metabolism bumped up to levels higher than they had been before they followed the low-zinc diet. The Selcuk University studies also showed that four weeks of zinc supplementation increased thyroid hormone levels in male wrestlers and sedentary men.
Zinc is not only critical for thyroid function, but it appears that it supports levels of the hormone leptin. This hormone is also important for maintaining metabolic rate, as well as keeping hunger down. A recent study from Andong National University (South Korea) showed that zinc deficiency significantly lowered amounts of leptin.
Zinc is well known to be critical for immune function, as it affects multiple aspects of the immune system. Research confirms that the incidence of acute lower respiratory tract infections decrease significantly following zinc supplementation. Zinc also has been found to significantly reduce the duration of fever and severity of pneumonia and other serious lower respiratory infections. Research from the Cleveland Clinic (Ohio) has shown that the length and severity of colds were cut in half for subjects receiving zinc at the onset of the illness. The researchers speculated that zinc may block the cold virus from combining with surface proteins that trigger symptoms.
Zinc also functions as an antioxidant. It not only activates an enzyme that helps to prevent diabetes, but also fights cancer by activating the tumor-suppressor endostatin, and it fights HIV by rendering inactive a protease essential for the HIV virus. In a nutshell, zinc’s antioxidant properties will not only enhance your health, but your recovery after workouts. In addition, its immune-promoting effects will help to keep you healthy and in the gym so you can keep going and growing.
Are you deficient?
As early as 1981, research confirmed that athletes are often deficient in zinc and magnesium. This may be due to several factors, such as lost zinc in sweat during training, increased use of zinc for recovery and protein synthesis following training, as well as greater loss of zinc in urine. In addition, there are dietary factors to consider. For example, refined sugars and white-flour products (such as white bread) lower blood levels of zinc and magnesium. Foods rich in calcium (as found in dairy products) inhibit absorption of both zinc and magnesium by the small intestines. Copper, as well as foods rich in phytates (phosphorous compounds found in whole-grain breads, cereals, and legumes) also hinder the absorption of zinc by the small intestines. Alcohol, too, decreases the absorption of zinc and magnesium and increases their loss through urine.
Given the fact that you likely are not adequately absorbing the zinc from your whole foods and that you are losing copious amounts of the zinc you do absorb, you should seriously consider taking a ZMA supplement to maximize muscle mass and strength gains.
Author: Jim Stoppani