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-metre 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,” a happy Nagaoka declared.

She also 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-metre swim in a 50-metre pool in the women’s freestyle category.

Born in 1914, she lives alone in the South of Japan and at age 104, is Japan’s oldest swimmer. This is the third time that she’s competing at the FINA Masters World Championships.

Nagaoka started Masters swimming in Japan only at the age of 84. At 88, she made her first appearance at the Masters Worlds in 2002 in Christchurch (New Zealand), winning the bronze in the 50m backstroke. She was back for more in 2004 in Riccione (Italy) where she won three silver medals (50m, 100m and 200m backstroke).

(With inputs from PTI)