John Cook, a former coach with the Nike Oregon Project, did an interview with Runners World. It's a pretty interesting read.
"If you take the testing objectively, and you never fail a drug test, as far as the average person is concerned, if you’re negative, you’re negative, and that means you’re a good guy. But that’s not what’s happening...
"...The average fan remains ignorant in terms of it wanting to be that way and wanting it be “Chariots of Fire.” Some of the people I talk to when I’m on the treadmill or lifting weights don’t even know the athletes make money. And they think if [athletes] test negative, they’re as clean as white snow."
"...getting a Therapeutic Use Exemption for an inhaler can be very easily done. If I take you and run your ass up and down the stairs five or six or seven times, then take you into the doctor, you’re going to be asthmatic and fail the test, and you’re going to be allowed to take an inhaler."
"...The chemists will always win. It makes no difference what kind of program you design."