Centenarian Fauja Singh crosses the finish line in a 100 meter race for centenarians in Toronto, Thursday Oct. 13, 2011. One-hundred-year-old Singh, originally from India now living in London, England, is competing in Toronto's Waterfront Marathon on Sunday.,Image: 727559934, License: Rights-managed, Restrictions: This content is intended for editorial use only. For other uses, additional clearances may be required. STAND ALONE, Model Release: no, Pictured: Fauja Singh, Credit line: Chris Young / AP / Profimedia

February 21, 2013 - Hong Kong, Hong Kong SAR, China - Fauja Singh, British Citizen and the oldest Marathon runner in the world at 101.Press Conference..Mr Singh is going to retire following the Hong Kong Marathon on Sunday 24th Feb 2013.,Image: 444802968, License: Rights-managed, Restrictions: , Model Release: no, Credit line: Jayne Russell / Zuma Press / Profimedia

Image: 7711116, License: Rights-managed, Restrictions: , Model Release: no, Credit line: ersoy emin / Alamy / Profimedia