BEIJING, CHINA - AUGUST 30:  Francena McCorory of the United States, Sanya Richards-Ross of the United States, Natasha Hastings of the United States and Allyson Felix of the United States pose prior to the Women's 4x400 Relay Final during day nine of the 15th IAAF World Athletics Championships Beijing 2015 at Beijing National Stadium on August 30, 2015 in Beijing, China.  (Photo by Patrick Smith/Getty Images)