The world's oldest marathon runner on Friday was preparing for his last competitive run, the Hong Kong Standard Chartered Marathon, on Sunday.

Fauja Singh, the 101-year-old Indian-born British runner was training with his friends on Friday for the annual marathon, in which he will run a 10-kilometre leg.

He said that he would retire from competitive running after crossing the finishing line.

Last year it took him 94 minutes to complete the 10-kilometre race.

"I am looking forward to it and I am hoping other elders would join me," Singh said.

When Singh turned 100, he became the oldest full marathon runner after he finished the Toronto Waterfront Marathon.

However, he was not granted a Guinness World Record as he was not able to show his birth certificate, according to his coach.

However - the Guinness World Record does not seem to be what Singh cares about - raising funds to help people in need is one of the incentives for him to race.

According to marathon organizers, Singh raised $25,800 US dollars last year.

Singh said he had mixed feeling of happiness and sadness about retiring.

"I am feeling a bit of happiness and a bit of sadness mixed together. I am happy that I am retiring at the top of the game but I am sad that the time has come for me to not be part of it," said Singh.

Singh was not a professional racer when he was young but a farmer in Punjab, India.

He started running when he was 89 after he lost his wife and his fifth son. That was the way for him to find a new focus and start a new live, he said.

He decided to end his running career in Hong Kong because of the publicity he received when he ran there in 2012.

The Hong Kong Standard Chartered Marathon features a full 42 kilometre marathon, a half marathon, a 10 kilometre leg, a half marathon wheelchair race and a 3 kilometre wheelchair race.