Phelps Calls It A Career

Phelps Calls It A Career
United States' Michael Phelps watches teammate Nathan Adrian swim in the men's 4 X 100-meter medley relay as he gets out of the water at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/Jae C. Hong)

After four Olympic Games and 22 medals, American Swimmer Michael Phelps is calling it a career. ABC's Alex Stone says that's not much of a surprise.