Swimming at the London 2012 Olympics (405 images)

USA's Michael Phelps is hugged by a teammate after they won the gold medal for the Men's 4x100 Medley Relay Final at the Aquatics Center during the London 2012 Summer Olympics in Stratford, London on August 4, 2012. Phelps won his record 18th gold and 22nd Olympic Medals to end his Olympic career. UPI/Pat Benic

Michael Phelps (R) celebrates with his teammates Matt Grevers, Brendan Hansen, and Nathan Adrian after they won the Men's 4x100 Medley Relay Final at the Aquatics Center during the London 2012 Summer Olympics in Stratford, London on August 4, 2012. Phelps won his record 18th gold and 22nd Olympic Medals to end his Olympic career. UPI/Pat Benic

The USA team of Matt Grevers, Brendan Hansen, Michael Phelps and Nathan Adrian show their gold medals for the Men's 4x100 Medley Relay Final at the Aquatics Center during the London 2012 Summer Olympics in Stratford, London on August 4, 2012. Phelps won his record 18th gold and 22nd Olympic Medals to end his Olympic career. UPI/Pat Benic

China's Sun Yang smiles as he shows his gold medal during the award ceremony for the Men's 15000M Freestyle Final at the Aquatics Center during the London 2012 Summer Olympics in Stratford, London on August 4, 2012. Sun's time of 14:31.02 was a world record. UPI/Pat Benic