Come on.

In another sport, Armstrong doped; I didn't follow the shit, but that seems to be what happened or at least what people seem to think.

He won a lot because he probably lived his sport and had some of the best medical advice at his disposal.
These doctors most likely got hired by teams who have sponsors and those like winners very much.

It isn't that far-fetched an idea to me that professional athletes just have to perform in the eyes of these people allowing them to compete on the level they strive for. It wouldn't be absurd to think that long-term health ethically's considered secondarily when opposed to short-term performance financially.

All of this is transferable.

While the idea of competitive sports is a noble one, there seems to be an advantage to know how what is changed in the athlete's body to whatever else and how which test would be able to prove this or not.

Then there's greed.