Keep-fit enthusiast Eddie Naisby celebrated his birthday with an early-morning run followed by an exhilarating dip in the sea – which was pretty remarkable considering that it was his 90th birthday!

But the sprightly pensioner, believed to be Wales’ oldest competitive runner, puts most people who are less than half his age to shame in many other ways, as once a week he does voluntary work dry-stone walling for the National Trust in the Conwy Valley.

Eddie, a former geology teacher originally from Liverpool, moved to North Wales with his wife Audrey over 40 years ago to run a smallholding at Clocaenog, near Ruthin.

He had been a keen cyclist but didn’t start running until he was 55.

“I ran to the village to post a letter and realized how unfit I was, so I thought I’d do something about it,” he said. “When I did my first 10k race I thought I was a hero.”

By then he had caught the running “bug”, and over the past 40 years he has completed hundreds of endurance races including 21 marathons in London, Manchester, Rotterdam, Amsterdam, Paris, Lisbon, Athens, Dublin, New York, Vancouver and Snowdonia. His best time, recorded in Manchester, was 3 hours 24 minutes.

Two or three times a week he runs about 10 kilometres and every weekend he has a two-hour run, most of his training being in the hilly forest around Clocaenog.

Like most runners, Eddie, a member of Prestatyn Running Club, has had his fair share of injuries and illnesses. Only a few weeks ago he tripped in the woods, injuring his knee so badly on a rock that he had to crawl home.

“I was on crutches for a while but I got over it and last week I did a 10-mile race in Liverpool,” he said.

Twenty years ago, to mark his 70th birthday, he trekked up Mount Kilimanjaro and was the oldest member of the group to reach the 19,000-feet high summit.

To what does he attribute his amazing stamina and fitness?

“Determination plays a part in it but I have been very lucky with my health and I’ll keep going as long as my knees hold out. I’m looking forward to the next 10 years,” he said.

He is also a firm believer in the benefits of his home-produced honey, peanut butter and chocolate.

Half-marathons are Eddie’s favourite events, and he is already planning to do this year’s races in Liverpool and around Lake Vyrnwy, as well as the annual off-road Race the Train event in Tywyn which he does every year.

“Running keeps my legs strong and I do the dry-stone walling to maintain my upper-body strength,” he said.

For 20 years Eddie taught music at Howell’s School, Denbigh – he plays the flute, saxophone and clarinet – and is still a member of Mold Town Concert Band. He also plays in a local quintet.

Why that unusual 90th birthday celebration?

“It’s not unusual for me to go for a run before breakfast, and I said I wanted to go to Red Wharf Bay, Anglesey, because I have fond memories of being there when I was young,” he explained. “And I have always enjoyed swimming in the sea, so I did three of my favourite things on my birthday.”