Yes, knowm... if you smoked shit loads during a work out you would suufer from loss of stamina... but saying that. I work out every day, and I smoke while I'm doing it. Sometimes I'll have a joint hanging from my lips when doing the bench press. I suppose it's okay unless you are doing cardio.
Car pollution is more likely to cause lung cancer than smoking cigarettes, but who gives a fuck? Everything causes cancer these days.