Reading through the comments makes me wonder about testing in professional sports and cycling especially.
If you assume people will cheat, pretty good assumption, in my opinion. Given 400+/- elite cyclist is the world and probably another few thousand who think they have a chance, some of them will be willing to cheat to get ahead.
So if you assume there are cheaters, finding people cheating means your doing something right, yet people say how dirty your sport is.
Seems like your option is to have joke testing (US based professional sports) or have people say how bad your sport is and how they are all cheaters. MLB has 5% to 7% of players test positive for steroids in 2003, do you think all those guys have stopped or just switched to HGH, not tested for in MLB still. What is the solution?