Tokyo: A 100-year-old Japanese woman has become the world’s first centenarian to complete a 1,500-metre freestyle swim.

Mieko Nagaoka, from Yamaguchi Prefecture, took just under an hour and 16 minutes to finish the race in a 25-meter pool.

She was the sole competitor in the 100 – 104-year-old category at a short course pool in Ehime, western Japan on Saturday.

Her time is expected to be recognised by Guinness World Records after she submits an application to the international swimming federation, Japan Times reported.

Nagaoka began swimming at the age of 80 as part of rehabilitation for her hurt knee. At that time, she could barely swim.

“I want to swim until I turn 105 if I can live that long,” Nagaoka said.

Nagaoka, who published a book last year entitled “I’m 100 years old and the world’s best active swimmer”.

Last year, Nagaoka had completed a 1,500-meter swim in a 50-meter pool in the women’s freestyle category.

Nagaoka is one of the growing number of elderly Japanese who are enjoying longer and healthier lives as the country ages.