Michael Phelps of the U.S. swims to a fourth place finish in the men's 400m individual medley final during the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/David Gray
Michael Phelps of the U.S. adjusts his swim cap before his men's 200m butterfly heat at the London 2012 Olympic Games at the Aquatics Centre July 30, 2012. REUTERS/Toby Melville
Michael Phelps of the U.S. looks up after his men's 200m butterfly heat at the London 2012 Olympic Games at the Aquatics Centre July 30, 2012. REUTERS/Tim Wimborne
Michael Phelps of the U.S. reacts after taking third place in his men's 200m butterfly heat at the London 2012 Olympic Games at the Aquatics Centre July 30, 2012. REUTERS/Toby Melville
Michael Phelps of the U.S. competes in his men's 200m butterfly heat at the London 2012 Olympic Games at the Aquatics Centre July 30, 2012. REUTERS/David Gray
Silver medallists Nathan Adrian, Cullen Jones, Ryan Lochte and Michael Phelps (in grey, L-R) of the U.S. shake hands with gold medallists Amary Leveaux, Fabien Gilot, Clement Lefert and Yannick Agnel (in white, L-R) of France in the men's 4x100m freestyle relay victory ceremony during the London 2012 Olympic Games at the Aquatics Centre July 29, 2012. REUTERS/David Gray
Nathan Adrian, Michael Phelps, Cullen Jones and Ryan Lochte (L-R) of the U.S. pose with their silver medals in the men's 4x100m freestyle relay victory ceremony during the London 2012 Olympic Games at the Aquatics Centre July 29, 2012. REUTERS/David Gray
Michael Phelps of the U.S. bangs the starting block as he watches the men's 4x100m freestyle relay final during the London 2012 Olympic Games at the Aquatics Centre July 29, 2012. REUTERS/Jorge Silva
Michael Phelps of the U.S. reacts after a fourth place finish in the men's 400m individual medley final during the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/David Gray
Michael Phelps of the U.S. swims to a fourth place finish in the men's 400m individual medley final during the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/David Gray
Michael Phelps of the U.S. swims during the men's 400m individual medley heats at the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/Tim Wimborne
Michael Phelps of the U.S. checks his time after his men's 400m individual medley heats at the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/Tim Wimborne
Michael Phelps of the U.S.swims in his men's 200m butterfly heat at the London 2012 Olympic Games at the Aquatics Centre July 30, 2012. REUTERS/Michael Dalder
Michael Phelps of the U.S. starts his men's 400m individual medley heats at the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/Al Bello/Pool
Michael Phelps of the U.S. swims during the men's 400m individual medley heats at the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/Tim Wimborne
Michael Phelps of the U.S. competes in the men's 400m individual medley heats at the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/David Gray
Michael Phelps of the U.S. reacts after taking first place in heat 4 of the men's 400m individual medley at the London 2012 Olympic Games at the Aquatics Centre July 28, 2012. REUTERS/Michael Dalder