Exceptions to the rule don't make the rule obsolete. How many smokers do you know that could reliably run any distance further than 800m? I don't know any, but I do know plenty of people that quit smoking because it was inhibiting their exercise. Being a human that grew up in an area that normalized tobacco consumption and played sports, I've tried cigarettes. It absolutely affects performance in a very negative way. He completed the marathon in spite of his smoking, and would have performed better even if he stopped for a couple weeks beforehand and immediately resumed smoking after.