Michael Phelps of the US goes through some stretching exercises prior to a training session at the FINA 2011 Swimming World Championships in Shanghai, China, Thursday, July 21, 2011. (AP Photo/Mark Baker)
Michael Phelps of the US goes through some stretching exercises prior to a training session at the FINA 2011 Swimming World Championships in Shanghai, China, Thursday, July 21, 2011. (AP Photo/Mark Baker)
