| Last updated
Ollie was told he may only have five years left to live and, at times, struggled to even walk upstairs.
But none of this stopped him taking on a rigorous task of intense exercise and strict dieting to transform into a super-ripped bodybuilder.
In the 12 weeks Ollie lost 10kg and built up his muscles.
Ollie is originally from Cornwall but moved to Belfast for his job as a personal trainer - however the 22-year-old's life was turned upside down when he was diagnosed with a malignant brain tumour.
The youngster told Cornwall Live: "It was a bit of a shock to say the least.
"There's only so much crying you can do. I was 100 per cent from the get go that I would turn a negative to a positive. Life does not stop. I don't feel sorry for myself because everyone has problems they have to deal with.
"As a personal trainer I know how hard it is for people to lose weight and the excuses people come up with - the lack of motivation, the lack of time, the lack of willpower.
"I wanted to use my illness to inspire people as well as get myself in the best shape of my life."
The personal trainer is unsure of what the future holds for him as he said certain treatments are 'so risky'.
"I've been given five years but this is real life so it can go one of two ways. My condition could worsen in the next year or it could stay stable for 20 years. You just don't know," he said.
"The likes of chemotherapy and radiotherapy aren't really options because it's just so risky and I'm just so young."
But he hopes that if others see his story they'll be compelled to take on their own challenges.
He said: "The 12-week transformation was the hardest process of my life. To be honest, there wasn't a day I didn't think about giving up. Without a doubt it broke me.
"Trying to find the energy just to train and trying to find the energy just to work is horrendous.
"But despite my health being the problem, it was my health that was my motivation in the first place. I had to constantly keep reminding myself of this when I wanted to give up.
"It wasn't just to get a six-pack. That wasn't the purpose. The purpose was to get to the end so that I could inspire other people with my story."
Chosen for YouChosen for You
Most Read StoriesMost Read