Those guys are on a little ride known as the Tour de France, and they are smoking.

haha, seriously tho smoking will really mess you up. I've been a smoker for the past 5 years, but in the last year or so I've gotten it down to like one a day...literally. Since I'm doing a century tomorrow, I haven't had one in a few days. Oxygen uptake is crucial to cycling. Eddy Merckx had the highest recorded oxygen uptake of any athlete ever, and he was a cyclist.