Jamaica's Usain Bolt crosses the finish line to win gold in the men's 100-meter final during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Sunday, Aug. 5, 2012. (AP Photo/David J. Phillip )

Jamaica's Usain Bolt, foreground left, goes to cross the finish line ahead of Jamaica's Yohan Blake, third from right, United States' Tyson Gay, second from right, and Trinidad's Richard Thompson in the men's 100-meters final during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Sunday, Aug. 5, 2012. (AP Photo/Matt Dunham)

United States' Sanya Richards-Ross celebrates her win in the women's 400-meter final during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Sunday, Aug. 5, 2012.(AP Photo/Anja Niedringhaus)

USA's Sanya Richards-Ross reacts after winning the women's 400-meter during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Sunday, Aug. 5, 2012. (AP Photo/Markus Schreiber)

South Africa's Oscar Pistorius runs in one of the men's 400-meter semifinal races during the athletics competition in the Olympic Stadium at the 2012 Summer Olympics, London, Sunday, Aug. 5, 2012. (AP Photo/Lee Jin-man)

Britain's Andy Murray celebrates after defeating Switzerland's Roger Federer to win the men's singles gold medal match at the All England Lawn Tennis Club at Wimbledon, in London, at the 2012 Summer Olympics, Sunday, Aug. 5, 2012. (AP Photo/Victor R. Caivano)

Britain's Andy Murray celebrates after defeating Switzerland's Roger Federer to win the men's singles gold medal match at the All England Lawn Tennis Club at Wimbledon, in London, at the 2012 Summer Olympics, Sunday, Aug. 5, 2012. (AP Photo/Victor R. Caivano)

Iran's Ebrahim Barkhordari loads his gun during qualifiers for the men's 50-meter pistol event, at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. (AP Photo/Rebecca Blackwell)

James-Andrew Davis of Great Britain competes against Valerio Aspromonte of Italy, right, during the men's foil team fencing competition at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. Italy beat Great Britain to advance. (AP Photo/Dmitry Lovetsky)

Venus Williams, right, and Serena Williams of the United States celebrate their victory against Andrea Hlavackova and Lucie Hradecka of the Czech Republic during the gold medal women's doubles match at the All England Lawn Tennis Club in Wimbledon, London at the 2012 Summer Olympics, Sunday, Aug. 5, 2012. (AP Photo/Elise Amendola)

Serena Williams, left, and Venus Williams of the United States laugh together on the podium after receiving their gold medals in women's doubles at the All England Lawn Tennis Club in Wimbledon, London at the 2012 Summer Olympics, Sunday, Aug. 5, 2012. (AP Photo/Elise Amendola)

Trinidad and Tobago's Nijsane Nicholas Phillip unzips his jersey during a track cycling men's sprint event, at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. (AP Photo/Matt Rourke)

In this photo made using a fisheye lens, Jaime Azcarraga, of Mexico, rides his horse Gangster, in the equestrian show jumping team competition at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. (AP Photo/David Goldman)

Marc Houtzager, of the Netherlands, rides his horse Tamino in the equestrian show jumping team competition at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. (AP Photo/David Goldman)

Gymnast Krisztian Berki of Hungary performs during the artistic gymnastics men's pommel horse final at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. Berki won the gold medal. (AP Photo/Julie Jacobson)

Ben Ainslie of Great Britain celebrates his gold medal during the Finn dinghy class medal race at the London 2012 Summer Olympics, Sunday, Aug. 5, 2012, in Weymouth and Portland, England. (AP Photo/Francois Mori)

Jennifer Abel of Canada dives during women's 3-meter springboard diving finals at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Sunday, Aug. 5, 2012. Abel took sixth in the event. (AP Photo/Mark J. Terrill)

Gold medalist Wu Minxia from China competes during the women's 3-meter springboard diving final at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Sunday, Aug. 5, 2012. (AP Photo/Michael Sohn)

Siarhei Karneyeu of Belarus, reacts after his fight against Teymur Mammadov of Azerbaijan, during a heavyweight 91-kg quarterfinal boxing match at the 2012 Summer Olympics, Sunday, Aug. 5, 2012, in London. (AP Photo/Ivan Sekretarev)