成人快手

Cycling is one of the most physically demanding of professional sports. It is also one of the most tainted.

In the last decade, a host of top riders have been exposed as drugs cheats, including David Millar.

Millar held the Tour de France's yellow jersey and was a world champion before he was exposed.

Banned for two years, he then came back, committed, not just to racing, but to cleaning up cycling.

But is there room for integrity in a world where winning is everything?