15th IAAF World Athletics Championships Beijing 2015 - Day Seven [Getty Images]

BEIJING, CHINA - AUGUST 28: Gold medalist Allyson Felix of the United States poses on the podium during the medal ceremony for the Women's 400 metres final during day seven of the 15th IAAF World Athletics Championships Beijing 2015 at Beijing National Stadium on August 28, 2015 in Beijing, China. (Photo by Alexander Hassenstein/Getty Images for IAAF)

Getty Images Sport Alexander Hassenstein