Phil Marshall completed the Montane Spine Race in around six-and-a-half days, following the Pennine Way non-stop through snow, ice, rain and high winds.
The epic challenge was in aid of The Pulmonary Hypertension Association UK which is searching for a cure for the rare and terminal illness his wife Sarah has.
Phil, 35, said he is proud after getting through hallucinations, freezing temperatures, sleeping in public toilets and more to finish the ultramarathon.
“It was the toughest thing I have ever done, it was so relentlessly hard to keep going but having the support of Sarah and everyone at home motivated me to finish,” he said.
The race, described as the most brutal in Britain, takes participants on some of the toughest terrain in the country through the Peak District, Yorkshire Dales and the Cheviots.
Phil battled through driving rain, snow drifts and gale force winds on very little food or sleep, grabbing an hour of rest wherever he could.
At one point the race was stopped for six hours because it was too dangerous, while he was at the top of the tallest mountain on the route, so him and eight others had to cram into an abandoned building until it was safe to continue.
With much of the path covered in snow, Phil said he often found it difficult to follow the route or see where he was going.
He accidentally walked into a frozen pond and had to struggle to the edge to get out, leaving his gloves frozen solid.
Phil had to use a torch on his dog’s collar as two broke, and his GPS system also failed at points, making it really hard to go in the right direction.
Phil said he even started hallucinating as a result of a lack of sleep, with tempting mirages of sofas and armchairs appearing by the path.
The weary runner fell straight over when pausing to lean against a lamppost, which was a figment of his imagination.
But after 155 hours of non-stop running, having started in Edale on Sunday, January 14, Phil reached the finish line in Kirk Yetholm at the Scottish border on Saturday.
“I felt an enormous amount of relief and satisfaction at the finish line, all I wanted to do was find a comfortable seat and get my shoes off,” he said.
“Having sat down, I just fell asleep straight away.”
The gruelling challenge was all for his wife Sarah, whose life has been turned upside down after being diagnosed with pulmonary hypertension four years ago, aged 33.
She went from being a fit and active primary school teacher in Fritwell to relying on oxygen and a mobility scooter, unable to go too far from home in case a lung transplant is ready.
Sarah said she was also up most nights following Phil’s progress and is so proud of him for completing the challenge.
“It was more epic than I thought it was going to be, it was hard hearing someone you love calling in tears due to his blisters or fatigue, it was really horrible,” she said.
“But I’m so proud of him and the money he’s raised will make such a difference to PHA UK to fund research into a cure.”
Phil took up running partly to cope with the stress of living with a terminally-ill wife and has quickly gone from short races to marathons and now to the toughest challenges he can find, and this was the hardest yet.
The initial target for Phil’s adventure was £5,000, so for it to be nearly doubled is very pleasing for the couple.
“Anything we can do to raise awareness is fantastic and to have smashed our target is amazing,” he said.
To donate and find out more, visit justgiving.com/fundraising/phil-marshall15.