Dopers : Why they do it, and what to do about it.
Micheal Shermer of Skeptic magazine write about what makes athletes dope and what we can do to stop them.
The short answer to why they do it:
“The reason is threefold: (1) the drugs work, (2) the arms race between drug takers and drug testers is consistently won by the dopers, and (3) the athletes believe they have to dope to compete.”