Sanya Richards-Ross (C) of the U.S. runs to win the gold medal in the women's 400m final during the London 2012 Olympic Games at the Olympic Stadium August 5, 2012. From left, the runners are: Britain's Christine Ohuruogu, who won the silver; Botswana's Amantle Montsho, who finished in fourth place; Ross; Russia's Antonina Krivoshapka, who finished in sixth place and DeeDee Trotter of the U.S., who won the bronze. REUTERS/Lucy Nicholson (BRITAIN - Tags: SPORT ATHLETICS OLYMPICS)