it wont have an effect oon your metabolism as mari. alters your nervous system in the brain, not the part that creates hormones, in which controls metabolism....the only way it will effect your weight is if you give into those crazie munchies!!

as far as working out while stoned, i wouldnt recommend it because mari. changes the speed in your heart beat...it slows down, then as you get higher, it jumps up and goes too fast. when you are stoned, you don't feel things as you normally would and you could end up hurting yourself.