Japan’s Mieko Nagaoka has become the first 100-year-old to complete a 1,500m freestyle swim in a 25m pool.

Mieko Nagaoka, who only took up swimming at the age of 82, already holds the record in her age category for the same distance in a 50m pool.

The Japanese completed the latest feat in just over one hour and 15 minutes, using backstroke all the way.

Mieko Nagaoka was the only person taking part in her age range – 100 to 104 – at the competition in Matsuyama on April 4.

She already dominates the world record board for her age group, as awarded by the international swimming federation (FINA), holding 24 titles over both short and long distances.

Mieko Nagaoka’s latest achievement is now expected to be recognized by Guinness World Records.

She began swimming as therapy for her knees, but was soon training several times a week. She has since attended swimming competitions around the world, and said her family members also swimmers.

After turning 100 in 2014, Mieko Nagaoka released a book entitled I’m 100 years old and the world’s best active swimmer.

Mieko Nagaoka told Japan’s Kyodo news agency: “I want to swim until I turn 105 if I can live that long.”

Japan has a rapidly rising aging population, and with 59,000 centenarians on official records in 2014.

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