ZMA is a supplement promoted to aid recovery. One of the claims of the product is it boosts anabolic hormone production. I know many people in the Jiu Jitsu community that have taken it to help recover from their training. A very common strength training supplement too. I was one of them for several months. However, I wanted to do my own research to see if it really boosted testosterone.
Let me start by saying, you can't out train a bad diet, no matter how much Jiu Jitsu or strength training you do. I used to think, and in my experience many still believe that if you train hard, nutrition is not really that important, "you'll just burn it off.” Now, if you're simply thinking of weight management then maybe there is some truth in that belief. Although even, just using the calories in and calories out approach is flawed. Not all calories are equal, what’s also important is the nutrition you get from those calories. If you eat crap, you’ll feel crap. For example...
How much nutritional benefit do you think your body gets from 33 calories of kale (roughly one serving) Vs 33 calories of refined sugar??
Your nutrition matters and while each person has individual needs, I think 95% of people practicing jiu jitsu just first need to focus on some key principles to feel and perform great, everything else is a just a bonus, focus first on strong basics, just like your Jiu Jitsu training. You’re putting a lot of physical demand on your body and with just some small changes, you can make a huge difference to how you feel and perform.