last summer before my highschool soccer season i smoked once a day, everyday. and i ran 2 miles every other day which helped. Im still a really good runner and shit. during the season i cant remember a single time where i was like "man, i wish i didnt smoke that much."
Personally i think if you smoke dank bud like 2-7 times a week your breathing will berely be afected. i say dank because if u rip 2 garvity bong hits you inhale less smoke than someone smokin a few fattys every day.

contrary to what most ppl on this site think. "moderation is best and too much of anything can be a bad thing"

BUT I LOVE MARY JANE AND SHE LOVES ME! lol
PEACE