Best ZMA Supplement for Athletes
What is ZMA?
ZMA stands for Zinc Monomethionine Aspartate and is a supplement that is used by many athletes, particularly bodybuilders. If you search ZMA in Google, you will quickly find that much of the results are full of claims and marketing strategies, which is not preferred when attempting to make an informed decision on whether or not ZMA is right for you.
The aim of this article is to explain what ZMA is, how ZMA works, why it could provide benefits, and our general consensus on the effectiveness of ZMA, and our recommendations for ZMA supplements currently on the market.
Zinc in ZMA
ZMA contains zinc, magnesium aspartate, and Vitamin B6. While zinc is essential, it’s actually not that abundant in our bodies. Therefore, small increases or decreases in zinc levels carry the potential to elucidate relatively strong physical responses, or lack thereof.
For example, zinc is required for a healthy immune system. If you lack zinc, you may be more prone to becoming sick due to immune system deficiencies.
What is more applicable to athletic training is zinc’s role in cell division, cell growth, healing, and the breakdown of carbohydrates.
These fundamental roles of zinc are the reason that researchers began studying zinc in the context of sport, and the general consensus now is that it helps improve recovery time by boosting serum levels of naturally occurring anabolic hormones in the body, e.g. testosterone, IGF-1, and growth hormone.
Magnesium in ZMA
Magnesium helps with hundreds of processes that occur in the human body. Magnesium is fairly abundant in bones, so it helps keep your bones strong.
It is also crucial for proper nerve and muscle function, which is directly related to sports performance. It can also assist with regulation of blood glucose levels and protein production, which is also very important for recovery.
One other process that magnesium helps regulate is your sleeping cycle.
Magnesium has often been used for relief of insomnia, mainly due to its ability to decrease cortisol levels. Cortisol is a stress hormone that is quite similar to adrenaline, whereby increases in production will create a short-term boost in energy levels.
It’s thought that the fundamental “purpose” of cortisol is to help in survival situations when the body is in imminent danger, for example, the “fight-or-flight” response. Therefore, reduction in cortisol release will allow for a more relaxed state. Magnesium also has some properties that act as a light muscle relaxant, which can further facilitate a good sleep, and subsequently, good recovery.
Vitamin B6 in ZMA
You may have seen Vitamin B6 on the shelves before, as it’s a fairly common dietary supplement. Vitamin B6 is present in much of the food we eat, but various cooking processes can decrease the Vitamin B6 content (you could think of it as being “burned off”), so many people find it helpful to supplement.
Similar to magnesium, Vitamin B6 does a lot of work for the body and is involved in hundreds of processes. However, much of these processes have to do with maintenance of proteins metabolism, as well as metabolism of carbs and fat. It’s also good for the mind, as it helps with the production of neurotransmitters, which are required for the delivery of information from one nerve cell to another.
Training Benefits of ZMA
In addition to general supplementation for a healthy immune system, ZMA holds potential to provide benefits specific to athletes. ZMA as a performance supplement is still relatively new, but has been around long enough for some researchers to study it in this setting. Here are some of their findings.
One of the most popular studies investigating the effects of ZMA on training outcomes was performed by Brilla and Conte in 2000.
This double blind randomized study examined ZMA supplementation in college football players over an 8 week period. The results showed that those football players who supplemented with ZMA had increased levels of zinc and magnesium, and increased production of free testosterone and IGF-1.
Even further, the ZMA athletes showed significantly higher leg strength compared with the placebo, as assessed with a Biodex isokinetic dynamometer. While this was peer-reviewed research, we would consider these results with a grain of salt, as the researcher who published the study also holds the trademark for the original ZMA formula (conflict of interest).
So is there any evidence showing that ZMA hinders training? Not really, but there are some that show a more tempered effect of ZMA on training than studies like Brilla and Conte.
For example, a study performed by Wilborn et al, 2004, recruited a large group of recreationally active males and matched them according to fat free mass. Then, in a double-blinded manner, participants supplemented with either a placebo or with ZMA for 8 weeks. The results showed the ZMA group had higher zinc levels, but not significantly higher magnesium levels. Furthermore, testosterone and IGF-1 levels showed slightly enhanced values in the ZMA group, but the differences were not statistically significant.
There also appeared to be a positive effect of ZMA on fat mass, fat free mass, and body fat percentage, but again, these results were not statistically significant. Therefore, this study showed that ZMA has potential for beneficial training effects, but maybe not to the extent that some other studies suggest.
Overall, in our opinion, ZMA supplementation has the potential to offer some very useful fitness benefits to recreational and competitive athletes alike. Combined with the general immune system benefits and low occurrence of side effects (assuming a modest dose), it’s definitely worth the consideration.
Side Effects of ZMA
Given the information above, it appears that ZMA has some clear potential as a general supplement as well as a training supplement. However, it’s definitely worth noting any reported side effects. In this case, the side effects of ZMA occur when you have taken too much, and are generally the same as taking too much zinc or magnesium.
These side effects may include nausea, upset stomach, and lower absorption of prescription medications. Long-term overuse of zinc (greater than 100mg per day for 10 or more years) has also shown potential to increase the risk of prostate cancer. Taking a smaller dose of ZMA is recommended in order to avoid any of these side effects.
What Dose of ZMA Should You Take?
In order to maintain higher circulating levels of zinc, magnesium, and vitamin B6, it is generally recommended to take ZMA on a daily basis.
According to the National Institute of Health, the recommended daily intake of zinc to reach an adequate level is 11mg. They also state a tolerable upper intake level of 40mg. In terms of magnesium, the recommended daily intake is 400-420mg, with an upper tolerable limit of 350mg (* upper limit for supplementation only!). For vitamin B6, the recommended dietary allowance is 1.3-1.7mg per day, with an upper tolerable limit of 80-100mg per day.
Keep in mind, these values are mostly based on meeting nutrient requirements in normal individuals, not those that are participating in an intense training regime.
Best ZMA Supplements for Training
Optimum Nutrition is arguably one of the most popular brands for athletic training supplements, and their ZMA is a pretty decent deal. They use a reputable zinc-magnesium formula (SNAC System) that has been supported by scientific research.
There are 180 capsules in this pack, and each capsule contains 30mg of zinc, 450mg of magnesium, and 10.5mg of vitamin B6. They recommend taking three capsules daily, and while this does appear to be in a safe range, we would suggest with starting out a lesser dose, maybe one or two capsules daily.
This will stretch your supply a little longer, and will also help avoid any initial side effects. They also recommend stacking with other supplements like creatine or glutamine, but this is more likely a ploy to get you to buy other products. Whether or not you stack with another supplement is up to you and depends largely on your training regime.
Another extremely popular dietary supplement brand, NOW foods offers similar capsules of ZMA, just with a zinc/magnesium blend that is proprietary to NOW Foods.
There are 180 capsules in total, with each capsule containing 30mg of zinc, 450mg of magnesium, and 15mg of vitamin B6, which is pretty standard for a ZMA supplement. The recommended dosage as stated on the label is 3 capsules daily for men, and 2 capsules daily for women. However, just like the Optimum Nutrition ZMA supplements, we would suggest scaling back just a little bit to be safe and stretch the supply.
Primaforce is another good brand for ZMA supplements, as they also incorporate the SNAC zinc/magnesium formula into their capsules. Moreover, their capsules do not contain any yeast, wheat, gluten, corn, soy, milk, sugar, salt, colors, or preservatives, making them a nice option for vegetarians who want to know all of the ingredients in that are in the capsules.
The Primaforce ZMA capsules contain the standard dose found in most supplement capsules: 30mg of zinc, 450mg of magnesium, and 10.5mf of vitamin B6. We also prefer Primaforce’s recommended dosage as well, as they recommend one capsule per day on an empty stomach before bed. They also mention that it’s best to try and avoid taking the ZMA along with other items that contain calcium, as the calcium can block some of the absorption.