Let me back up slightly to explain how I found myself with just four others from our team of 24 on top of the highest volcano on Earth, having just battled 100kph winds and -30°C windchill.
I set up my company, BecomingX, with the singular goal of helping people realise their potential. We work with professionals in global organisations, as well as young people and those from disadvantaged communities - helping them build skills, confidence and belief in what they’re capable of. Part of how we do this is through extraordinary demonstrations of human potential.
Having successfully organised the World’s Deepest Marathon - 1,119 metres below sea level in a Swedish mine - our next ambition was to go high. Specifically, 998 metres higher than the existing world record, which had been set on Kilimanjaro in 2022.
Sponsored by Ford, Wheaton Precious Metals, Montane and La Sportiva (with additional support from Vango and The Altitude Centre), we assembled a remarkable team. Elite climbers and athletes including former Royal Marine and high-altitude expert Aldo Kane, world record-holding endurance cyclist Mark Beaumont, and legendary mountaineer Sibusiso Vilane stood alongside experienced runners and amateurs alike - many of whom had never experienced extreme altitude before.
In total the team was made up of: ten runners. Six in the support team. Seven in the Chrome Productions film crew. One photographer. Seven guides.
From left: Andrea Cornejo (Chile), Mark Beaumont (UK), Paul Gurney (UK). Credit: BecomingX/Andrew Goss
Training for a Mountain Marathon
It’s hard to properly prepare for altitude, without actually spending time at altitude. Some of the UK-based team worked with The Altitude Centre, firstly to understand their physiology and response to altitude (some very cool tests in their London lab), but secondly to undertake a programme of hypoxic training to help adapt the body to altitude.
Fitness is of course key. Most of the team were either highly experienced mountaineers or marathon runners. However, only four of us had ever been at this altitude, and also run the marathon distance. Of course, none of us… no-one ever (!), had ever run an organised marathon from this altitude, so it was going to be a learning experience all round.
Credit: BecomingX/Andrew Goss
Kitting up for the World's Highest Marathon
I had 184kg of team and personal luggage at Heathrow Airport - not including the 400kg of filming equipment.
Packing for extreme altitude is complex, which is why partnering with Montane made such a difference. On Ojos, you can experience -25°C and +25°C in the same 24-hour period. You can go from ice at the summit, to soft sand and shorts and T-shirt at base camp.
This means thinking through a lot of scenarios. Take footwear – all of us had at least four types of footwear: heavy mountaineering boots, hiking boots, trail running shoes, and sandals for base camp. Add crampons to the list, and that’s at least half of a 120L base camp bag.
Layering was critical. Our acclimatisation days saw constant transitions between Montane Malli base layers, Dart XT tops, and the Kamen XT Hooded Down Jacket. The ultra-light Montane Featherlite windproof jacket was a personal standout. Winds on Ojos are relentless, and having a layer that could cut through that exposure without adding weight made a real difference.
We carried multiple bags too - heavyweight duffels for logistics, the Trailblazer 32L on the slopes, and the Gecko VP 20+ for the marathon itself.
We even began the marathon wearing helmets, as the first 30 metres involved a roped descent from the summit.
This was not a conventional marathon kit list and it took months of preparation to ensure we had the right kit.
Credit: BecomingX/Andrew Goss
Getting to the Start Line
Half the challenge of the World’s Highest Marathon was simply reaching the start line.
It took nearly two weeks of acclimatisation to prepare our bodies. Even then, summit day required 11 hours and 30 minutes of phenomenal effort in the face of incredibly tough conditions.
From base camp, we drove two hours to Refugio Tejos, a shipping container perched at 5,825m - already far higher than Everest Base Camp. We set out at 10.30pm in our convoy of top end Ford 4X4s (which were utterly extraordinary in this terrain), and started our climb just before 1am.
t those temperatures and altitudes, everyone looks identical. Faces covered, goggles on, no skin exposed. With most of the team donning their gold Montane down jackets right from the start, it was hard to distinguish who was who in the darkness.
As the hours passed, the wind intensified. What began as difficult very quickly became absolutely brutal. People began turning back. Exhaustion, altitude, and cold began taking their toll. By sunrise, the wind had reached 100kph. It was impossible to stand upright at times. Just five of us remained.
After 11 hours and 30 minutes, we reached the summit.
Oddly, this was quite literally just the start line.
Approaching the caldera at 6,750m: Credit BecomingX/Mark Beaumont
Running the Highest Marathon in History
Firstly, don’t assume much running happened. Despite the pedigree on that start line, we were pretty broken. The conditions had been brutal, and whilst they had been downgraded, they were still ‘challenging’. Without any support team or film crew, all we could do was shout ‘go’ and synchronise watches. There was a bigger issue though, which was that with just two guides, no support team on the mountain, and just a skeleton crew at our first checkpoint, for safety reasons we had to go down in two groups.
It took about 3 hours to get to the first checkpoint where we waited for over 2 hours for the last in the group to arrive, and get out of summit gear into running gear (yes, a marathon that involves a full change of clothes). We got out of the down jackets and mountain boots, and into windbreakers and trail shoes. With just one of our five Ford 4X4s available to provide back up support, we had a similar challenge in that we had to move as a group to get safely down to the tarmac road, ~20kms that would mostly be done at night and at sub-zero temperatures.
Whilst we did manage some running when we still had the light over the Atacama desert, as soon as night fell, the pace dropped – a serious fall up here, with just one support vehicle (ably managed by seven summitter and adventure legend Gavin Bate), and the challenge was likely to be over.
We made it to the road by about 1.30am where we were ‘on our own’ – with our film crew back on the road and picking up the action from about 3am. After stopping for about the 10th time to replace my GoPro batteries (one challenge for a Guinness record is that you need to film everything) and helping one of the team really struggling, we realised Aldo, being the former commando that he is, was suddenly way ahead of us. Not with the mentality of ‘winning’, rather that he was just so tired, he just wanted to finish and get to bed after we had already been on our feet for over 24 hours.
In the 20 minutes or so we had been supporting others and sorting our kit, Aldo’s military ‘yomping’ had put him a good 3km ahead of us. Being the great team players that we are, Mark Beaumont and I didn’t want to risk him ‘winning’, so we decided to run him down. So there we were running at a healthy 11kph at about 4,700m chasing down our sniper friend at 3am. Adventure at its best.
From left: Sibusiso Vilane (South Africa), Mark Beaumont (UK), Paul Gurney (UK). Credit: BecomingX/Andrew Goss
Crossing the Line
In truth, after what we had gone through together that day, there was no way any one individual would ‘win’ this. It was a team effort from start to finish.
So it was only fitting that myself, Aldo and Mark finished together.
At 5.01am, after descending from the highest volcano on Earth, and covering what our watches tell us was actually about 54km (due to the summit descent and real world route constraints), we crossed the finish line on the shores of Laguna Verde, and into the waiting arms of our fully assembled support team and film crew.
Sibu Vilane and ultra-runner Sara Storey came in 90 minutes later, meaning all five of us completed the distance.
Sixteen hours and thirty-four minutes after starting.
Over 28 hours on our feet.
But the real achievement wasn’t the record itself.
It was what it represented.
BecomingX team, Ojos del Salado, February 9th 2026: Credit BecomingX/Andrew Goss
What the World's Highest Marathon Really Means
Standing there at the end, watching the sun rise over Ojos for a second day, I reflected on how improbable it had all been. Not just the summit or the marathon. But the journey that had brought each of us there.
Extreme altitude strips everything back to fundamentals. There is no comfort. No control. No certainty. Just your preparation, your mindset, and your willingness to continue when all logic tells you to turn around.
At BecomingX, we teach people how to build discipline and resilience for all aspects of life. These are not things you are born with. They are learned - through teaching, through experience, through adversity, and through stepping repeatedly into the unknown.
In environments like Ojos, the margin between continuing and turning back can be determined by small details - the right layer pulled on at the right moment, the ability to regulate temperature, the confidence that your kit will do its job when conditions deteriorate. Those details matter more than you realise when you are standing at nearly 7,000 metres in a raging gale.
The World’s Highest Marathon wasn’t about running. It was about showing people what is possible with the right ambition, preparation and team. We all have the potential to achieve extraordinary things – you just need to know how and be prepared to step into the arena.
And that, ultimately, is what human potential looks like.
