His aching feet are chafing in his trainers and virtually his entire body is in pain, but Adam Conlon will not stop running until he gets home.
When I speak to Adam, he is nearing Chester and tells me he is on the homeward stretch.
Liverpool or Wrexham might seem likely end-points, but in fact Adam lives in Belfast and started his run in Bath - some 180 miles away.
In all, he is running nearly 200 miles, over seven and a half marathons, in just six days.
He is among the hundreds taking part in a campaign raising funds and awareness for wounded servicemen and women.
The Walking Home for Christmas campaign is an annual initiative organised by Walking with the Wounded, which encourages people to collect money for homeless and vulnerable veterans with physical, mental or social injuries.
Adam spent over seven years in the army, including two tours of Afghanistan and said, "people always looked after me in the military, there was a great sense of camaraderie.
"I saw Prince Harry do the trek to the North Pole with Walking with the Wounded and thought this would be a great chance to do something crazy to raise money for people who need it", he says.
Surely such a mammoth run requires months of training?
Before taking on the challenge, Adam says he had not made any special preparations, "but I tend to keep myself fit and healthy".
Five days into his run, Adam has smashed his initial fundraising target of £100, with the total now standing at over £2,700.
He says it has been the support and messages from loved ones that kept him going.
"On the third morning, I could barely walk at all, to the point I thought I might have to quit. If not then, at a later stage.
"But I got calls from my family and friends and that pushed me on," he adds.
Adam aims to get on the road by around half past seven, before sunrise and finishes at around four or five o'clock, after running 50-60km.
As well as the sheer physical exertion of covering such a distance, eating has been difficult. "For the first couple of days, I lost my appetite. Then I realised my body's like a machine, I need to feed it, so I've been eating energy bars and gels and trying to eat normal foods when I can. Thankfully, my appetite's come back".
So, as he gets closer to the ferry that will take him on the final leg of his journey back to Belfast and home - would he do it again?
"Every so often I like to do something that scares me. It can be good to take on something you think you might not be able to finish, you can surprise yourself with what you can do. But no, let's just say I'll be getting the plane back from bath in future".
For more details and to help with Adam's fundraising, click the link below.