Jamaica's Asafa Powell (L) competes in the men's 100m heats at the athletics event of the London 2012 Olympic Games on August 4, 2012 in London. AFP PHOTO / FRANCK FIFE
Jamaica's Asafa Powell, Barbados' Ramon Gittens and The Netherlands' Churandy Martina compete in the men's 100m heats at the athletics event of the London 2012 Olympic Games on August 4, 2012 in London. AFP PHOTO / JEWEL SAMAD
Britain's Dwain Chambers (R) compete in the men's 100m heats at the athletics event of the London 2012 Olympic Games on August 4, 2012 in London. AFP PHOTO / JEWEL SAMAD