What that means, in simple English, is that if a bunch of Chinese unknowns suddenly start winning medals in the swimming competitions, they were probably doped and stopped taking the stuff 2 weeks ago so it wouldn't show in urine tests. There are reasons why Chinese swimmers, particularly the females, look just like the East German women's swim team did in the 1980's, and it's not because they train 24-7! The NOVA special on the devastating results of doping those East German athletes in the 1980's should be enough to make anyone pee their pants. One woman was so altered by the constant overdoses of steroids and testosterone that she had a sex change operation and became a "he."
Here's the full story about the Chinese and doping: Spectre Of Doping Haunts China On Eve Of Games, Jul 21, 2008, by Craig Lord, SwinNews.com.
Of course, doping is not limited to the Chinese, but it is interesting that as of the date of this story, no members of the Chinese swim team had yet been named! Were they waiting to see who would pass their internal urine tests prior to naming the team???