A 105-year-old Japanese man has broken his own record as the world's oldest competitive sprinter but said he is unhappy with his time.

Hidekichi Miyazaki took part in the Kyoto Masters Athletics Autumn Competition yesterday, just one day after turning 105.

Born on 22 September 1910, he was eight when World War One ended and 34 when the Second World War ended in Japan's defeat.

But he did not start running until he was well into his 90s, according to Guinness World Records.

At the Nishikyogoku Athletics Stadium in Kyoto, Mr Miyazaki reset his own record as the oldest man to sprint competitively with a time of 42.22 seconds for 100 metres, though fell short of his personal best.

In the time it takes to watch this, 105-year-old Hidekichi Miyazaki sets a new record as the world's oldest sprinter https://t.co/5ImSp8rhQI
— RTÉ News (@rtenews) September 24, 2015

"I wanted to shave off a few more seconds as I got 36 seconds while training", Mr Miyazaki told reporters after his heat.

His personal record of 34.10 seconds was achieved when he was 103 and remains unbeaten.

Asked what motivates him to keep running, Mr Miyazaki said it was his health.

"The doctors are all surprised. It's all about being in good health," he said, elaborating that he exercised daily, ate in moderation and chewed his food properly.

Mr Miyazaki who is also known as 'Golden Bolt' for his poses imitating Jamaican Olympian Usain Bolt, also said he longs for the opportunity to challenge the fastest man in the world according to the Guinness World Records.

Bolt, who is 29 and 76 years Mr Miyazaki's junior, holds the world record of 9.58 seconds for 100 metres, which was set in 2009 in Berlin.

On Monday, Japan celebrated Respect for the Aged Day and released a report revealing it to have topped the world in the number of people over the age of 65.

Around 60,000 of them are over the age of 100, according to the Statistic Bureau of the Ministry of Internal Affairs and Communications.