BEIJING, CHINA - MAY 21: Justin Gatlin of United States celebrates after he won the Men's 100 Metres at National Stadium, also known as Bird's Nest, during 2013 IAAF World Challenge Beijing on May 21, 2013 in Beijing, China. Beijing won the bid to host the 2015 IAAF World Championships in Athletics in 2010, and accordingly it will organize the world challenge games in 2013 and 2014 respectively. (Photo by Feng Li/Getty Images)
BEIJING, CHINA - MAY 21: Justin Gatlin of United States celebrates after he won the Men's 100 Metres at National Stadium, also known as Bird's Nest, during 2013 IAAF World Challenge Beijing on May 21, 2013 in Beijing, China. Beijing won the bid to host the 2015 IAAF World Championships in Athletics in 2010, and accordingly it will organize the world challenge games in 2013 and 2014 respectively. (Photo by Feng Li/Getty Images)