Last year's Tokyo Marathon was blessed by good weather, for a change, though marred by controversy after women's winner Tatyana Aryasova failed a doping test following the race. Here's hoping for balmy conditions and an absence of performance-enhancing drugs this time around – if that isn't too much to ask. The top seeded runners in the men's and women's sections are Ethiopian veteran Haile Gebrselassie (who had to pull out of last year's race due to injury) and Kenya's Helena Loshanyang Kirop, respectively, while Japan's Yuki Kawauchi and Yukiko Akaba are fancied to do well. Obviously, it's far too late to register to take part yourself, but it's a fun event for spectators too. The marathon starts at the Tokyo Metropolitan Government building in Shinjuku and loops to Shinagawa and Asakusa before winding up at Tokyo Big Sight in Odaiba (see the course map on the official website for details).