alcohol, weed, tobacco, etc etc. its all negative as far as i'm concerned.
Arnold back in the day would need an oxygen tank after a workout. when i have a tough workout I am huffing and puffing. you need your lungs to be working at full force. smoking weed or cigarettes makes it harder to breathe, hence it will hurt your workouts and recovery pure and simple. i think it is a MAJOR negative and why we don't discuss recreational drug use on this board!
and please people dont insult my intelligence and say weed isn't as bad as cigarettes. puhleeze. i dated a girl who smoked weed and she had a cough like a 70 year old man and was coughing up yellow crap all the time.