(L-R) LaShawn Merritt of the U.S., silver medal, Wayde van Niekerk of South Africa, gold medal, and Kirani James of Grenada, bronze medal, pose on the podium after the men's 400 metres final during the 15th IAAF World Championships at the National Stadium in Beijing, China, August 27, 2015. REUTERS/Damir Sagolj