John Day has been a stalwart of the parkrun at Cleveland, near Brisbane, since it began in 2013.

And on March 16 he proved age is no barrier as he crossed the line for the 500th time.

"I don't see why 80- and 90-year-olds can't enjoy parkrun too," he said in a video shared by the parkrun Australia Facebook page.

"And I'm sure there's a lot of people who could - I'd love to see more older people, I'd love to see more younger people too."

Parkrun is a free 5km walk or run every Saturday morning at 485 locations across Australia.

It was started in the UK in 2004 before growing to 22 countries and millions of participants.

Mr Day said the first event he went to "gelled" with him and he had hardly missed one since, often joined by his wife Daphne.

"It's wonderful for your morale to keep happy, of course, as you get older and if you do parkrun you tend to do a bit of practice every week," he said.

Fitness is one reason he keeps going back but Mr Day said he enjoyed the community was just as important.

"There's always somebody waving or calling you by name and it's just a lovely, friendly experience every Saturday morning and something I really look forward to," he said.

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