United States' Carmelita Jeter reacts as she crosses the finish line to win the women's 4x100-meter relay at the 2012 Summer Olympics, London, Friday, Aug. 10, 2012. The United States relay team set a new world record with a time of 40.82 seconds. (AP Photo/Anja Niedringhaus)

Photo by: Anja Niedringhaus

United States' Carmelita Jeter reacts as she crosses the finish line to win the women's 4x100-meter relay at the 2012 Summer Olympics, London, Friday, Aug. 10, 2012. The United States relay team set a new world record with a time of 40.82 seconds. (AP Photo/Anja Niedringhaus)