Zinc and magnesium are two of the most essential nutrients for an athlete and many studies have shown also to be some of the most deficient. Many high end strength and conditioning coaches require their clients to have zinc and mag levels at the very top of lab range. I personally have been megadosing both to get my levels up. With meals I have been taking seperate zinc and mag products and before bed ive been using a ZMA product. Its hard to tell any effects in terms of recovery BUT I had issues with some tendons that miraculously cleared up 5 weeks after starting my protocol and the ZMA without a doubt helps me sleep great.
I just started, and feel that I sleep better. A friend of mine that told me about ZMA, and he said that u recover better after a hard workout because of the deep and good night sleep.