Rory Coleman (top right) and the 54 other runners who took on the challenge of the world's deepest marathon [BecomingX/Chrome Productions]Gareth Bailey - BBC Sport WalesTue, December 2, 2025 at 4:42 AM UTC·4 min readWhen you have run more than 1,000 marathons in your lifetime, you would be forgiven for struggling to find a new running challenge.
You could do the Marathon des Sables across the Sahara Desert, but when you have done that 18 times, drastic measures tend to kick in.
AdvertisementAdvertisementAdvertisementEventually Rory Coleman from Cardiff did find a new challenge, as he set his mind on achieving his 10th Guinness World Record.
The challenge? Running a marathon 1,118.56 metres below sea level, alongside 54 other people in the Garpenberg zinc mine in central Sweden.
"I'm the British guy that's done the Marathon des Sables the most times," said Coleman.
"The race is part of my daily life, I even met my wife at the races.
It was at the Morroco desert ultramarathon that he met a partner of Bear Grylls with an ambition to run the world's deepest marathon.
"When they started talking to the people in Boliden in Sweden, they sort of said 'Wouldn't it be fun if we got a lot of people down there, and we did a group world record as well'," added Coleman.
AdvertisementAdvertisementAdvertisement"And so the plan was set in motion to create the race.
"He contacted me and said 'Would you coach the participants?'
"I took a millisecond to say yes!"
Overcoming a health scare
Not only did the deepest marathon add to Coleman's impressive running resume, it also marked the 250th marathon he had completed since being diagnosed with Guillain-Barre syndrome.
"[It] is a really rare condition, it affects about 600 people in the UK a year," explained Coleman
"I didn't know that it existed or that I had it, I'd been in the desert, had a tummy upset and two weeks later I was paralysed from the neck down in University Hospital Wales with them trying to work out what on earth was wrong with me.
AdvertisementAdvertisementAdvertisement"You get a stomach upset and your body's autoimmune system reacts against that and shreds the lining of your nervous system."
Coleman spent five months in hospital slowly learned to walk again, something he describes as "a really unusual thing to go and do".
"Taking those first four steps were probably harder than any marathon I'd ever done," he added.
"I remember fist pumping the physiotherapist at the end of the rails, three weeks later I did a park run, annoyingly I finished last, but again everybody was fist pumping me.
"Then I did the Cardiff Half and was back running marathons two months later, then the following year I went and did the Marathon des Sables again, that was my driver really for when I was ill.
AdvertisementAdvertisementAdvertisement"The underground marathon was really special because it was my 250th since I was ill, so it added a little bit of a special kick to it as well."
Runner overcomes his biggest challenge
Runner Rory completes 1,000th marathon
What next for Coleman after conquering his latest challenge?
"I've done some interesting things," Coleman told BBC Sport Wales.
"I've done all of the Premier League grounds, I started in Southampton finished in Newcastle, that was good, I ran to Lisbon in Portugal for Euro 2004 and I did a lot of treadmill world records in 1998.
"I looked for things where I would stand out from other people and where I could make my mark as a runner.
AdvertisementAdvertisementAdvertisement"You have to play to your strengths, I'm not particularly quick, my marathon PB is three hours and 24 minutes so I've had to find somewhere where I could shine.
"Being able to run a marathon every day for 40 days, that's my kind of thing."
Coleman says for him running is all about mental resilience.
"I've set off 1229 times to run a marathon and I've never not finished, I've always somehow got to the finish line, sometimes really well, sometimes a struggle.
"My thing is about completing, not necessarily competing, but completing. I think that's helped me through the dark times of life as well."
AdvertisementAdvertisementAdvertisementColeman is hopeful that his son can continue the family's running journey.
"I'm running Marathon des Sables again with my son in April. He said he'd only ever do it once but he very quickly signed up, so maybe he's going to follow in my footsteps a bit.
"I want to keep doing this as long as I possible can, I'm 64 next year, and as long as I can go and do the big multiway races and finish and still enjoy it, I want to do this for as long as possible.
"I'm sure there's going to be a deeper underground marathon and hopefully I'll be invited to go do that.
"Running really is part of life now and I can't remember it not being part of it."
