110-meter hurdles star Liu Xiang reacts during his training session in Shanghai, on Tuesday March 10, 2009. Liu started his first training class Tuesday, following his coming back to China on Monday after a successful foot surgery and three-month rehabilitation in the United States.

Coach Sun Haiping helps 110-meter hurdles star Liu Xiang to stretch during a training session in Shanghai, on Tuesday March 10, 2009. Liu started his first training class Tuesday, following his coming back to China on Monday after a successful foot surgery and three-month rehabilitation in the United States.

110-meter hurdles star Liu Xiang reacts during his training session in Shanghai, on Tuesday March 10, 2009. Liu started his first training class Tuesday, following his coming back to China on Monday after a successful foot surgery and three-month rehabilitation in the United States.

110-meter hurdles star Liu Xiang smiles during his training session in Shanghai, on Tuesday March 10, 2009. Liu started his first training class Tuesday, following his coming back to China on Monday after a successful foot surgery and three-month rehabilitation in the United States.

Photographers take pictures of Liu Xiang during his training session in Shanghai, on Tuesday March 10, 2009. Liu started his first training class Tuesday, following his coming back to China on Monday after a successful foot surgery and three-month rehabilitation in the United States

110-meter hurdles star Liu Xiang (R) talks with his team mates during his training session in Shanghai, on Tuesday March 10, 2009. Liu started his first training class Tuesday, following his coming back to China on Monday after a successful foot surgery and three-month rehabilitation in the United States.