Some people think he's crazy, he's certainly ambitious. East Belfast fundraiser Andrew Park is stepping into his well-worn trainers on Monday to run his second marathon within two weeks.
Father-of-two Andrew (38) has been a long-time supporter of the Northern Ireland Cancer Fund for Children, running the Belfast marathon in aid of the charity last year.
Keen to carry on generating money for the organisation, Andrew decided he needed to set the bar higher this year. After giving it some thought he and his partner Lisa came up with the idea of the "double marathon".
Not content with just increasing the physical challenge, he also set himself the ambitious feat of tripling his fundraising target.
Andrew has already ticked the first box, having completed the London marathon in a respectable four hours and 33 minutes, raising just under £1,500 in the process.
Andrew explained that although the race was challenging the crowds kept him going. He said that inspiration also came from the other runners taking part for various charities.
"You read the stuff they had written on the back of their shirts, that they were running for their mummy or their daddy, that was inspirational too," Andrew said.
"For us to struggle for 26 miles it is only temporary our pain, it goes away. I'm not dismissing what I achieved, but the people I was running for, kids with cancer, they have to constantly live with that battle every single day, they deserve the plaudits. That's what drives me on and keeps me going."
Understandably, Andrew is feeling a little nervous ahead of the Belfast start and is hoping he has the physical strength to complete the run.
"When I did Belfast last year it took me about a month to even contemplate sticking my trainers on. I did go for a run about a week later. I got about a mile down the road and my legs just said, 'Absolutely no way are you doing this to me.' So I'll definitely start Belfast, but whether I can finish it is another matter," he explained.
"I have made people aware that have given me the funds that Belfast might be a feat too far. They're all happy enough, they think doing London was good enough," he added.
One thing that isn't causing Andrew any concern is what other people think.
"People have said I'm mad, even semi-professional runners have said I'm absolutely mad to contemplate doing another marathon within two weeks. They would usually take a month recovering before they would even think about it," he explained.
"But if somebody tells me I can't do something, I'm very likely to go and try to prove them wrong."