when you exercise, your body produces adrenaline and endorphins. you know what adrenaline is, and endorphins get you high.

why do you think people get addicted to excercise? endorphins; that is what you and your friend are reffering to.

i read a long time ago that smoking marijuana increases the body's natural production of canabinoids and endorphins, so there MAY be SOME truth in your buddies statement, just not in the way that they think.

love, kp