Gold medalist Anna Meares of Australia (C), silver medalist Victoria Pendleton of Britain (L) and bronze medalist Guo Shuang of China attend victory of women's sprint contest of cycling track event, at London 2012 Olympic Games in London, Britain, on August 7, 2012. (Xinhua/Li Ga)

Special Report: London Olympics 2012

Anna Meares of Australia (L) and Victoria Pendleton of Britain compete in women's sprint contest of cycling track event, at London 2012 Olympic Games in London, Britain, on August 7, 2012. Anna Meares of Australia won gold medal. (Xinhua/Li Ga)

Guo Shuang (L) of China competes in women's sprint contest of cycling track event, at London 2012 Olympic Games in London, Britain, on August 7, 2012. Guo Shuang of China won bronze medal. (Xinhua/Li Ga)

Anna Meares of Australia (L) and Victoria Pendleton of Britain compete in women's sprint contest of cycling track event, at London 2012 Olympic Games in London, Britain, on August 7, 2012. Anna Meares of Australia won gold medal. (Xinhua/Wang Jianhua)

Anna Meares of Australia takes part in women's sprint contest of cycling track event, at London 2012 Olympic Games in London, Britain, on August 7, 2012. Anna Meares of Australia won gold medal. (Xinhua/Wang Jianhua)

Anna Meares of Australia kisses her medal after women's sprint contest of cycling track event, at London 2012 Olympic Games in London, Britain, on August 7, 2012. Anna Meares of Australia won gold medal. (Xinhua/Li Ga)

Bronze medalist Guo Shuang of China attends victory of women's sprint contest of cycling track event, at London 2012 Olympic Games in London, Britain, on August 7, 2012. (Xinhua/Li Ga)