Mr Mahoney is taking on Bravehearts' 777 Marathon challenge, which seeks to raise awareness and funds for Bravehearts, a charity for the prevention of child sexual abuse and exploitation.

The seven marathons this year will take place in seven Queensland locations, including Mount Isa.

The Mount Isa marathon is on at 7am, Wednesday, June 30 at Lake Moondarra with locals invited to take part in distances of 7km or 14km or 21km or 42km.

Mr Mahoney said he runs for the love of the kids.

"I see my grandkids here... they're loved and they're cared for and fed and looked after and you think, 'God, how horrible is it that so many kids in a country like ours don't have that security and safety'," he said.

After a back injury in his early 40s prompted Mr Mahoney to start running, he has run 247 marathons and said having a purpose is what drives him to continue.

"To run for something outside of yourself changes everything," he said.

"You will make more effort, you will push harder."

Bravehearts' 777 event was cancelled last year due to COVID-19, but Bravehearts representative Kayleen Johnston said that in 2021 "we are not going to let the pandemic slow us down".

This year the event has been modified to have the seven marathons held throughout Queensland instead of nationally, with runners who are unable to travel, like Peter, encouraged to join virtually.

Ms Johnston said that anyone across Australia can join the event, which offers runners distance options of seven kilometers, 14km, 21km and 42km.

"You don't need to be a professional athlete, you just need determination and a passion for protecting Aussie kids," she said.

Participation this year marks the third 777 marathon challenge for Mr Mahoney, who has raised about $5000 this year for Bravehearts.

Funds raised go to counselling and support services, and sexual assault prevention programs in schools.

Mr Mahoney, from Mount Helen in Ballarat, Victoria, said it was an important conversation to have locally and that Ballarat was still healing from institutional historical cases of abuse.

"Ballarat has a sad history connected to child sexual abuse, it just keeps rearing it's ugly head," he said.

"No one really wants to scratch that surface ... It's something that we've got to keep pushing out there, because people don't want to hear about it."

Mr Mahoney trains all year for the 777 marathons and wears the Bravehearts merchandise whenever he runs to raise awareness.

"What I get out of it now is that buzz of someone coming up and saying 'why are you doing seven marathons?'," he said.

"Then I can explain to them all about it, and you hope they go back to their partners, their workplaces and say, 'hey I ran into this silly old bugger running seven marathons'.

"Getting the conversation going - that's what it's all about."

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