James Mason Triumphs in World's Deepest Underground Marathon
In an extraordinary feat of endurance, James Mason emerged victorious in the world's deepest underground marathon, held 1,120 metres below sea level in the Garpenberg zinc mine in Sweden. The event, which took place in October 2025, saw 55 participants from 18 countries tackle a unique and challenging course entirely underground, with all finishers earning a Guinness World Record.
A Decade-Long Hiatus and an Unusual Challenge
Mason, a passionate runner since childhood in the Yorkshire Dales, had not competed in a major race for over ten years, focusing instead on his family and career. When his company received an invitation to join the marathon, he seized the opportunity, despite learning it was entirely underground. His wife, Stephanie, was supportive, though bemused by the lack of scenic views, replaced by grey rock walls.
The preparation was unconventional. Mason trained by running with a headlamp and helmet in summer heat, drawing curious looks, and later switched to night runs to simulate the darkness of the mine. He noted that the mine's environment was warmer than expected, around 24°C due to geothermal energy and machinery, with tunnels pumped with fresh air to maintain oxygen levels. Health and safety regulations prohibited headphones, requiring runners to complete the marathon in silence.
The Gruelling Race Day Experience
On race day, Mason felt a mix of nerves and excitement. Although not claustrophobic, he found it unnerving to consider the 1,300 metres of solid rock overhead. The operational mine featured vending machines and brightly lit offices, creating an entire underground world. The marathon course involved running 11 laps along a five-metre-wide tunnel stretching over a mile, totaling the standard marathon distance of 26.2 miles.
The conditions were harsh, with 72% humidity and near-total darkness beyond the headlamp's light. Mason described the monotony of the unending grey walls as a significant challenge, with the only relief coming from cheers at the starting point. He initially ran in packs, enjoying a party atmosphere, but later focused on maintaining pace with his colleague, Michael, just behind the frontrunner, Mika.
Victory and Camaraderie in the Depths
As the race progressed, Mason found the last six miles particularly testing, with dust caking his face from the churned-up floors. Noticing Mika and Michael slowing, he pushed ahead at their urging, unsure if he had counted laps correctly. To his amazement, he crossed the finish line first with a time of three hours and 17 minutes, securing the win.
The highlight for Mason was the camaraderie among participants. All runners congratulated the final finisher, then celebrated with a meal and a pint, toasting their record-breaking achievement. Reflecting on the experience, Mason expressed pride in becoming a Guinness World Record holder, a rare accomplishment shared by all who completed the marathon.
This underground marathon not only tested physical limits but also showcased human resilience and solidarity in an unprecedented setting.
