I think "clean athletics" is a farce at this point. Tests always lag behind, and the financial incentive to get ahead through some it's-technically-not-cheating-because-the-sporting-body-who-makes-the-rules-don't-know-of-its-existence treatment or drug is just too great. People were taking blood transfusions to artificially increase their red blood cells count, but it was only until the 00s that you were able to test people.