[melolife]

This is the last thing I'd be worried about. It's coffee, not some kind of anabolic steroid/cocaine mixture.

I know a lot of people who spend way too much time trying to optimize supplements and other tiny details instead of throwing down and getting on with your life.

Edit: after reading other comments yours makes more sense, but I'd still be more worried about what's actually in a pre-work out beverage than over-exertion.