l-arginine alpha ketoglutarate is a precursor for Nitric Oxide in the body. Nitric Oxide supplementation won a Nobel prize in 1998. It can "speed up" fast twitch muscle fibers, and make slow twitch fibers "act" like fast twitch fibers. I have been using this supplement for quite a while, and ALWAYS get good results. It is also a product that you do not have to cycle off of.