Gallery: The toughest Hong Kong Marathon yet

Marathon participants run down a street in Causeway Bay.

The Standard Chartered Hong Kong Marathon held on February 28 was one of the hardest races ever. The warm weather and 90 per cent humidity coupled with a tricky new route, put 55 runners in hospital. Three of them are in critical condition and remain in hospital.

Kenyan Kiogara Mwobi won the race for the second time, taking home US$18,000, and even he admitted it was the "toughest race in his life." Mwobi finished the 42.2 kilometers about five minutes slower than his winning time in 2009.

The main race started off from Nathan Road in Tsim Sha Tsui at 7:15 am. Runners passed through some of Hong Kong's iconic infrastructure, including the West Kowloon Expressway, Stonecutters Bridge, Tsing Ma Bridge, Ting Kau Bridge and Western Harbour Tunnel, before finishing at Victoria Park.

Even though 60,000 people had originally signed up for the run, 7,000 of them decided not to go through with it in the end.

The city was shrouded in thick fog all day, as a warm and humid maritime airstream passed through.

Kenyan Kiogara Mwobi won the men's main race in 2 hourse, 20 minutes and 12 seconds.

Indonesia's Triyaningsih, 10km winner of the Southeast Asian Games last year, won the women's full marathon at 2 hours, 47 minutes and 35 seconds.

On location medics had their hands full with runners collapsing from heat-stroke and dehydration as well as ankle injuries.