Ah, the joy...
Of having a predisposition to Atrial Fibrilation.
It makes it impossible for me to have any stimulnts of just about any sort. I can't drink anything with caffeine in, take speed or anything like that. Mind you, the flip side of this is that if I drink a lot the night before I play, my body doesn't really like having that amount of alcohol by-products in it and so it tends to mess my heart up.
Basically, the easiest thing for me to do is not smoke when I am playing (but start when we are done for the day) and avoid alcohol and dehydration the night before. Otherwise I get a heart rate of 200 bpm and a pulse rate of 70 bpm.
Still, it doesn't stop me running a mile and a half a day, although my girlfriend's birthday party last night (and the Carlsberg that it required) will do!
Wookie