Hugh McLaughlin pushed himself to the limits by completing 29 marathons in 29 days.
Belfast was the final stretch and he passed the finish line at Ormeau Park in just over four hours and 20 minutes on Monday, raising thousands of pounds for charity.
"I feel really good, really excited, because 28 were done on the treadmill so it was a little bitmonotonous, soul destroying standing on the treadmill for 26.2 miles but I am really excited to be here today with all these people," explained Hugh.
"At mile 11 or 12 a lady came to me, she said she had liver cancer and breast cancer and she had just meet a guy with brain cancer, she took my hand as I was on the treadmill and she looked at my eyes and she said 'you are an inspiration'.
"I just thought, I've never seen so much inspiration in that woman's eyes and it was from that day when I was at my lowest with the pain and the injuries that I knew I was going to finish."
Hugh, whose father beat bladder cancer, ate 3,000 calories every day to help him complete the 760 miles - the equivalent of running from Belfast to Paris.
He admitted he felt "a wee bit tired" after his challenge.
Hugh added: "I'm really pleased to get round in the time I did! I feel great, I mean I feel this has been an amazing journey, the runners out there have been fantastic patting me on the back, showing me support and stuff it has just been unreal, unreal."
The marathon man now has his sights set on a swimming challenge.
But in the meantime, like the almost 18,000 other runners who raced the Belfast marathon, he's getting some well earned rest.