Mike P.T. is right, try dymetadrine xtreme, I've used it for years and years. It is not only a stimulant, but you can actually lift alittle more weight and that's gonna work the muscle harder yet. The effects wear off after a couple hours but while your on it I find I can generally lift about 10-15 lbs more on my max's. Great stuff and it really isn't that expensive either.