Now, he's training for a marathon.

Mr McCallum and his Inland Petroleum colleague Britt Willetts are taking part in the Gold Coast Marathon in July. Despite neither of them having done a marathon before, they'll be doing the whole 42.2 kilometres.

It was Christmas night when Mr McCallum's sister-in-law asked him if he wanted to go for a run the next day. They ended up starting off Boxing Day with a 12 kilometre run.

"I had a pair of ASICS that were about five years old and should have been thrown in the bin about three years before that. They did a lot of damage to my right foot and I couldn't walk properly for a week," Mr McCallum said.

But while he was recovering, he realised despite all the "pain and misery", he had actually loved the challenge of the run. He bought himself a new pair of shoes and when his sister-in-law asked if he wanted to do the Gold Coast marathon, Mr McCallum put his name on the waiting list.

Ms Willetts has been a long-term runner, but when she saw Mr McCallum's impressive Boxing Day feat, she decided to sign up for the marathon as well.

To train for the 42.2 kilometres, Mr McCallum downloaded an 18-week training program - scoffing when it said it wasn't for beginners.

He said the first four weeks "were hell" but then he started getting used to it, and starting enjoying the challenge.

And it's benefiting not only his physical health, but his mental health too.

"There's lots of different ways to relieve stress and mental anxiety in this world and I think in the past, in my twenties, I've gone down the not-so-right way of doing it. When you're young instead of going and exercising you might go and have six beers... Whereas these days I've found a new lease on life. It's a whole new way to deal with stress rather than going and burying your head in Netflix and forgetting about the world," Mr McCallum said.

"There's obviously a science behind it, releasing endorphins and all that stuff. But it's just the challenge that I love about it. It's amazing what the human body can do. If you had told me in January that I'd run 25ks I would have said that's not even remotely possible but I think with running, working out, anything like that, it's all about discipline and consistency. If you're willing to be disciplined and consistent, then you see really good results."

Mr McCallum is raising money for Black Dog Institute as part of the marathon. Ms Willetts has also picked a charity close to her heart, the Australasian Leukaemia and Lymphoma Group.

When Ms Willetts was in her twenties her dad was diagnosed with lymphoma.

"It was quite a significant time in my life and you never forget that," she said.

"You always hear about breast cancer, ovarian cancer, prostate cancer. And leukaemia is talked about but lymphoma's not talked about as regularly. So I think it's about raising a bit of awareness of lymphoma too."

Ms Willetts said she had always been "obsessed with running".

She said running was a form of therapy for her where she was able to go and be in her own space and think.

"We're blessed to run. That's how I see it. It can be something so difficult but it's really rewarding," she said.

Ms Willetts' mindset is to focus on her own goals and achievements, rather than focusing on others.

"What restricts people in a lot of areas of their lives I think is comparing themselves to other people or where they are or what they're doing. I've been guilty of it and I'm sure a lot of people are guilty of it and if we can just all be better at not comparing ourselves to other people in any facet of life, I think we'd all be better off," she said.

"I think you can be motivated by just trying to stay in your own lane and do what's best for you."

Ms Willetts and Mr McCallum have been encouraging not only each other with their runs and recovery, but other Inland Petroleum teammates. They're hoping to motivate others to join them at next year's marathon.

And while he hasn't completed his first marathon yet, Mr McCallum is already looking at doing an ultramarathon in the future.

For anyone in need of some motivation, Mr McCallum said the first step was just to get out of bed.

"Just get out of bed, out your shoes on, tie your shoelaces and get out the door. The hardest part is forcing yourself to get out of bed and get out the door. But when you're lying in bed going 'oh I don't quite feel like this, what if I can't do it?'. Forget about the end goal, forget about worrying about things in the future. All you need to do is just get up, get out of bed, put your shoes on, walk out the front door and keep moving," he said.

"Who cares what happens after that? Whether you get 20 metres down the road, 100m, 5ks, 10ks, whatever. Just shoes on, out the door, anything that happens beyond that is still better than lying in bed."