In the case of the Rupp, Farah, and Ritz training group, I'm as confident that I can be that they are all clean. Why? Setting aside their extraordinary potential as exhibited when they were in high school (Rupp and Ritz in particular), there's this: this is not just any training group--this is NIKE'S training group. It is inconceivable to me that Phil Knight and the Nike hierarchy would permit their hallmark long distance athletes, who train on the Nike campus, who are there everyday, to bring shame upon the Nike brand.
... Isn't Nike notorious for sweat shops?