This working out on weed shit comes up all the time. I have this to say...

There are some minor psychological effects like, thinking your endurance goes up, some people even say it regulates your breathing (mmm.... ok>?).

But riddle me this, havent any of you been punched in the fucking face while high????? I am pretty much sober after that (same goes for sex, with myself and others). Also, with trainers around that would call you a dipshit and being inside a no smoking facility with hundreds of thousands of dollars on the line, I think the boxer would probably just wait till after. Do you know what kind of insane fucking cardio they have to output? They tweak their diets to the most minute little detail, I think they would consider breathing tar into that equation.

I heard Tito Ortiz smokes sometimes, but probably not before a fight in his fucking dressing room.