The sky turns black before a heavy rain shower as Germany's Hannes Aigner competes in the heats of the K-1 men's canoe slalom at Lee Valley Whitewater Center, at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Kirsty Wigglesworth)

Judges watch Russian gymnast Anastasia Grishina perform on the beam during the Artistic Gymnastics women's qualification at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Gregory Bull)

Cho Jun-ho, of South Korea celebrates winning the bronze medal in the men's 66 kg judo competition at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Paul Sancya)

Great Britain's Freddie Evans is sprayed with water between rounds against Algeria's Ilyas Abbadi, during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Ivan Sekretarev)

Colombia's Rusmeris Villar Barbosa reacts during the women's 53-kg, group A, weightlifting competition at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Ng Han Guan)

Poland's Aleksandra J Klejnowska-Krzywanskareacts during the women's 53-kg, group A, weightlifting competition at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Hassan Ammar)

United States' Lebron James looks up the court during the first half of a preliminary men's basketball game against France at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Charles Krupa)

Marianne Vos, left, of The Netherlands, outsprints Britain's Elizabeth Armitstead to win the gold medal in the Women's Road Cycling race at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Christophe Ena)

U.S. gymnast Gabrielle Douglas performs on the uneven bars during the Artistic Gymnastics women's qualification at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Gregory Bull)

A car drives along the Olympic lane near the Olympic Park at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Jae C. Hong)

Italian gymnast Vanessa Ferrari performs on the floor during the Artistic Gymnastic women's qualifications at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Julie Jacobson)

Chinese gymnast Huang Qiushuang performs on the beam during the Artistic Gymnastics women's qualification at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Gregory Bull)

Gymnast Do Thi Ngan Thuong from Vietnam performs on the balance beam during the Artistic Gymnastics women's qualification at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Gregory Bull)

Russia's Nikolay Kovalev reacts after defeating Germany's Nicolas Limbach during the quarterfinals of the men's fencing individual sabre at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Andrew Medichini)

Italy's Diego Occhiuzzi reacts after defeating Italy's Aldo Montano during the men's individual sabre round of 16 fencing at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Dmitry Lovetsky)

Tarlan Karimov of Azerbaijan (in blue) competes against Musa Mogushkov of Russia during the men's -66kg judo competition at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Paul Sancya)

Malin Petersen, of Sweden, and her horse Sofarsogood, exit the ring after competing in the equestrian eventing dressage phase at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/David Goldman)

China's Li Xuanxu, top, and Britain's Rebecca Adlington compete in a women's 400-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Sunday, July 29, 2012. (AP Photo/David J. Phillip)

South Africa's Cameron van der Burgh reacts after winning gold and setting a new world record in the men's 100-meter breaststroke swimming final at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. Van der Burgh set a new world record with a time of 58.46. (AP Photo/Mark Duncan)

India's Bombayla Devi Laishram grabs an arrow from her quiver during the women's archery team competition at the 2012 Summer Olympics, Sunday, July 29, 2012, in London. (AP Photo/Marcio Jose Sanchez)