U.S. wins women's 4X400-meter relay at world athletics

U.S. wins women's 4X400-meter relay at world athletics

OSAKA, Japan - Members of the U.S. team, (From L to R) Dee Dee Trotter, Mary Wineberg, Sanya Richards and Allyson Felix, celebrate after winning the women's 4X400-meter relay final at the World Athletics Championship at Nagai Stadium in Osaka on Sept. 2.

U.S. win both women's and men's 4x400-meter relays

U.S. win both women's and men's 4x400-meter relays

OSAKA, Japan - Members of U.S. men's and women's relay teams -- (From L to R) Jeremy Wariner, Allyson Felix, Darold Williamson, Mary Wineberg, Angelo Taylor, Dee Dee Trotter, LaShawn Merritt and Sanya Richards -- celebrate after winning the gold medals in the men's 4x400-meter relay and women's 4x400-meter relay at the World Athletics Championships at Nagai Stadium in Osaka on Sept. 2. (Pool photo by Kyodo News)

Richards-Ross wins gold in Olympic women's 400 meters

Richards-Ross wins gold in Olympic women's 400 meters

LONDON, Britain - Sanya Richards-Ross of the United States smiles after finishing first in the women's 400 meters final at the Olympic Stadium at the 2012 London Olympics on Aug. 5, 2012. Richards-Ross won the gold medal with a time of 49.55 seconds.

Richards-Ross wins gold in Olympic women's 400 meters

Richards-Ross wins gold in Olympic women's 400 meters

LONDON, Britain - Sanya Richards-Ross of the United States waves the national flag after winning the gold medal in the women's 400 meters finals at the 2012 London Olympics at Olympic Stadium on Aug. 5, 2012. Richards-Ross finished with a time of 49.55 seconds.

Richards-Ross wins gold in Olympic women's 400 meters

Richards-Ross wins gold in Olympic women's 400 meters

LONDON, Britain - Sanya Richards-Ross of the United States (R) wins the women's 400 meters final race at the 2012 London Olympics at Olympic Stadium on Aug. 5, 2012. Richards-Ross finished with a time of 49.55 seconds.

U.S. win both women's and men's 4x400-meter relays

U.S. win both women's and men's 4x400-meter relays

OSAKA, Japan - Members of U.S. men's and women's relay teams -- (From L to R) Jeremy Wariner, Allyson Felix, Darold Williamson, Mary Wineberg, Angelo Taylor, Dee Dee Trotter, LaShawn Merritt and Sanya Richards -- celebrate after winning the gold medals in the men's 4x400-meter relay and women's 4x400-meter relay at the World Athletics Championships at Nagai Stadium in Osaka on Sept. 2. (Pool photo by Kyodo News)

U.S. wins women's 4X400-meter relay at world athletics

U.S. wins women's 4X400-meter relay at world athletics

OSAKA, Japan - Members of the U.S. team, (From L to R) Dee Dee Trotter, Mary Wineberg, Sanya Richards and Allyson Felix, celebrate after winning the women's 4X400-meter relay final at the World Athletics Championship at Nagai Stadium in Osaka on Sept. 2. (Kyodo)