Eunice Jepkoech Sum of Kenya celebrates as she wins the women's 800 metres final while Alysia Johnson Montano of the U.S. falls as Mariya Savinova and Ekaterina Poistogova of Russia (L) finish during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 18, 2013. REUTERS/Phil Noble (RUSSIA - Tags: SPORT ATHLETICS)