A 92-year-old US grandmother has become the oldest woman to finish a marathon, when she crossed the finish line of a San Diego 42km race on May 31, race organisers said.

A smiling Harriette Thompson, aged 92 years and 65 days, was cheered by dozens of onlookers and supporters as she completed the Southern California event in seven hours, 24 minutes and 36 seconds.

She broke the US record for the fastest marathon run by someone in the 90 to 94 age group. The previous record was held by a 90-year-old runner in Portland, Oregon who ran a marathon in 8:53:8

Speaking to her hometown newspaper, the Charlotte Observer, Thompson said she felt “a little stiff” after the race.

“I was really tired at one point. Around mile 21 (34km), I was going up a hill and it was like a mountain,” she told the Observer.

“I was thinking, ‘This is sort of crazy at my age.’ But then I felt better coming down the hill. And my son Brenny kept feeding me all this wonderful carbohydrates that kept me going.”

Fauja Singh running the Mumbai Marathon in 2013. Photo: AFP

The previous oldest woman marathon runner was another American, Gladys “Gladyator” Burrill, who was 92 years and 19 days old when she did the Honolulu event in 2010.

Thompson participated in the marathon to raise money for cancer research, a disease she has herself survived. According to local media reports, she made her marathon debut aged 76 and has only missed two editions of the race since – in 1998 and in 2013, after she’d had most of her upper teeth removed because of oral cancer.

The grandmother to 10 grandkids also completed the race last year with a time of seven hours, seven minutes and 42 seconds.

The oldest male marathon runner is Fauja Singh, who was 101 when he retired from racing in 2013.

Amazingly, Thompson’s average pace of 16 minutes, 20 seconds per mile (1.6km) even surpasses the walking speed of a typical healthy adult! – AFP