Why can't East African runners be both genetically superior and the use of Epo widespread among elite runners in the 90's. I think that Geb, Bekele, Tergat, Komen, ect would have been the best in the world with or without Epo, but it is hard to explain the correlation with the dramatic drop in WR's and the availability of Epo, then the subsequent slowing down of times with better testing. Do you really think that if there is an undetectable (at the time) drug that improves your time 20 seconds that its use won't be widespread. Or that everyone uses it except for the very best? This isn't to try to explain why the US was so noncompetitive in running during that time, I think that drug use had little to nothing do do with it (even high school performances were terrible then). However, to argue that the top runners were not using Epo during that time seems like ignoring the evidence.