Where's Milandro? - Our source of all things coffee!
From my experience, I drink several large cups of strong "real" coffee every day. and find them stimulating .
If I play in public, I have a pint of beer before- to "set me up to play", but , like Stephen, no more until the gig is over, as I find my concentration goes.
I once experimented on a long , French Motorway drive,with some caffeine "pick me up " pills - I sure didn't fall asleep, but felt agitated, and could not sleep at all that night . Ifelt awful next day, and had disturbed sleep during the following night.
My Verdict is that you don't get anything for nothing,so everything in moderation !.
Incidentally I once knew a guy who smoked spliffs a lot - he tended to play loud, and was often out of time , so was not an asset to any band.
Blowhard2