Here are some signs China's Ye Shiwen is using performance enhancing drugs:

She is only a 16-year-old girl, but she is swimming the final 50 meters faster than men's gold medalist Ryan Lochte.

On one lap she tried to stop, but broke the pool wall with her head.

And I think the most sure sign that Ye Shiwen is using performance enhancing drugs is that she is using her penis as a rudder.