I think it is fine. I've heard all the negative effects of weed on a cycle, but have never seen any proof or studys on it. I smoke while on and think it has benefits like increased appetite. Also after a grueling leg or back workout, when you're feeling nautious(sp), a few tokes makes that nausea go away. I suppose it may also make you lazy and not want to go to the gym either. I say smoke on off days and only after workouts on training days.