Christina Schwanitz of Germany competes in the women's shot put final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.KAI PFAFFENBACH/Reuters
Michelle Carter of the U.S. competes in the women's shot put final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.KAI PFAFFENBACH/Reuters
Valerie Adams of New Zealand competes in the women's shot put final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.KAI PFAFFENBACH/Reuters
Seito Yamamoto of Japan celebrates after clearing the bar at the men's pole vault final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.DYLAN MARTINEZ/Reuters
Augusto de Oliveira of Brazil celebrates after clearing the bar at the men's pole vault final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.DYLAN MARTINEZ/Reuters
Koji Murofushi of Japan competes in the men's hammer throw final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.FABRIZIO BENSCH/Reuters
Seito Yamamoto of Japan clears the bar in the men's pole vault final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.KAI PFAFFENBACH/Reuters
Sergey Kucheryanu of Russia celebrates after clearing the bar at the men's pole vault final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.MAXIM SHEMETOV/Reuters
Renaud Lavillenie of France competes in the men's pole vault final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.DYLAN MARTINEZ/Reuters
Renaud Lavillenie of France competes in the men's pole vault final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.MAXIM SHEMETOV/Reuters
Xue Changrui of China competes during the men's pole vault final at the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.FABRIZIO BENSCH/Reuters
Brad Walker of the U.S. competes in the men's pole vault final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.DENIS BALIBOUSE/Reuters
LaShawn Merritt of the U.S. leaves the starting block in his men's 400 metres semi-final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.GARY HERSHORN/Reuters
Tony McQuay of the U.S. looks at the scoreboard after the men's 400 metres semi-final heat event of the IAAF World Athletics Championships at the Luzhniki Stadium in Moscow, August 12, 2013.LUCY NICHOLSON/Reuters
Shelly-Ann Fraser-Pryce of Jamaica runs in her women's 100 metres semi-final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.DOMINIC EBENBICHLER/Reuters
David Oliver of the U.S. (L) clears a hurdle in the men's 110 metres hurdles semi-finals during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.DOMINIC EBENBICHLER/Reuters
Carmelita Jeter of the U.S. (C) runs between Murielle Ahoure of Ivory Coast (L) and Ezinne Okparaebo of Norway in their women's 100 metres semi-final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013.DOMINIC EBENBICHLER/Reuters
Canada's Brianne Theisen Eaton competes in the high jump in the heptathlon at the World Athletics Championships in the Luzhniki stadium in Moscow, Russia, Monday, Aug. 12, 2013.Matt Dunham/The Associated Press
Brianne Theisen Eaton, centre, of Canada clears a hurdle in the 100 metres hurdles during the women's heptathlon at the IAAF World Athletics Championships in the Luzhniki stadium in Moscow August 12, 2013.GARY HERSHORN/Reuters
Jamaica's Usain Bolt stands on the podium with his gold medal during the medal ceremony for the men's 100-metres at the World Athletics Championships in the Luzhniki stadium in Moscow, Russia, Monday, Aug. 12, 2013.The Associated Press