I remember a HS friend's Dad telling me before a marathon in his late 30's he probably smoked 2-3 cigs that morning before his warm up. I am not sure what his time was, but the guy at the time was in his late 50s (over a decade ago) had decent muscle tone and still ran somewhat regularly when he told me this. He eventually quit cigs but did admit he always wondered what his running prowess could have been in his prime had he not smoked. Is this a dirty secret of more runners? No, I am not talking about the once in a while bong hit or the occasional toker, I am talking about people who are generally active yet have a regular, daily nicotine habit. It defies logic to me, but I am betting it's more common that we realize.