United States' Michael Phelps gets out of the water after swimming butterfly in the men's 4 X 100-meter medley relay at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012.  (AP Photo/Jae C. Hong)

Photo by: Jae C. Hong

United States' Michael Phelps gets out of the water after swimming butterfly in the men's 4 X 100-meter medley relay at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/Jae C. Hong)