While many people his age might be using a wheelchair or walker to get around, Mr Beagle says he's never been fitter.

"I do exercise six days a week. I go to the gym three days a week and run or jog three days a week," Mr Beagle said.

"I don't have any ambition to anything other than be as fit as I can."

The Canberran first got into running in his 30s and 40s, and has never looked back since, having run in marathons and even fun runs against the likes of Robert de Castella.

His next challenge will be The Canberra Times Fun Run on November 10, where he will be running the 10 kilometres.

It will be the first time Mr Beagle will run in the event since 2016, after he underwent brain surgery for trigeminal neuralgia, a chronic pain condition that affects one of the largest nerves in the head.

"I just became very weak, and I couldn't see properly, and I was utterly weak at the time," he said.

After not being able to exercise for a year, Mr Beagle is back at it again and ready to make a return to the fun run.

"I suppose I'm resilient," he said.

"If you're fit, you can handle all sorts of upset. It's essential to maintain fitness."

Mr Beagle's association with running goes back several decades, setting up one of the first jogging clubs in Canberra, which is still running to this day.

While he may not be the eldest competitor at the fun run, Mr Beagle said he would want to see more older people getting out and about and exercising.

He said taking risks was the key. "To be comfortable in old age is to bring yourself to an early and unhappy end, because comfort in old age is a killer," Mr Beagle said.

"A lot of older people don't have to make decisions because it's all in front of them.

"You need to be able to consider your health at the end of your working life."

In order for people of older generations to be fit and healthy, Mr Beagle said moderation was the key.

"Start exercising moderately within your capacity and eat and sleep properly," he said. "So many people cruel themselves because they're impatient and they want a quick fix. As you age, that's not a possibility.

"Start walking and then gradually, if you feel up to it, gently jog for a short time, but at no time do you need to exhaust yourself."

While this year's fun run may not be the fastest Mr Beagle will run the course, after a few years on the sidelines, he's still aiming for a good time.

"I want to do it comfortably in under 100 minutes, but I've done it in under 50 minutes when I was younger," he said.

"I'm interested in what I can do, and if others can benefit from that, saying if that old guy can do it then maybe I can, well that's good as well."