My boss owns a BJJ school and gave us a can of this stuff. Although it's pricey, I was impressed with it. I'm not sure what on the label does it, but I busted a hard leg workout and drank one after. About 45 minutes later I felt like I could do it all over again. And the stuff only has 25mg of caffeine, mostly to aid absorption of the ingredients.

It's apparently popular with CrossFit people.

The singer in my band is a BJJ competitor, drinks energy drinks often, and even he reported a similar experience on Kill Cliff.

It's too expensive to have around every day, but I'm definitely going to pick up some to stash it for days when I need not to be wrecked the rest of the day by a hellacious workout (like Fridays when I have a band show that night).