Taking marathon running to another level. History awaits.

Infographic showing various heights: Burj Khalifa at 828m, Empire State Building at 443m, Eiffel Tower at 330m, sea level at 0m, the depth of the world's deepest marathon at Garpenberg Mine, -1120m, along with depths of seas and other features.

The Challenge

In October 2025, 50 intrepid runners will take on an extraordinary challenge: to run the deepest marathon ever run. Covering 42.2km within the Garpenberg Zinc Mine in Sweden, they will descend to a staggering depth of 1,120 metres below sea level. No one has attempted a marathon at this depth before. Participants will endure temperatures of up to 30°C, in total silence and will be running in complete darkness with only their head torches for light.

This pioneering event is being hosted by Boliden, owners of Garpenberg Mine. As one of the world’s safest mining companies, Boliden has ensured that safety remains paramount. Runners will be equipped with personal protective equipment and have access to rescue chambers, adhering to stringent protocols designed to protect them in this unique subterranean environment.

Organised by learning and development specialists BecomingX, co-founded by adventurers Bear Grylls and Paul Gurney, alongside the International Council for Mining and Metals, this historic endeavour captures the spirit of exploration and human resilience, and proves that limits can always be redefined. From the depths of the earth, these trailblazers will push beyond physical and mental boundaries to make history in one of the most extreme environments imaginable.

BecomingX is proud to partner with ICMM and Boliden to organise the World’s Deepest Marathon - an event that embodies our message that we all have the potential to achieve extraordinary things. This will be a true test of mental and physical resilience. Running a marathon is tough, but doing it 1,120 metres below sea level, in total silence and darkness, will push participants to their limits. This is about more than breaking records - it’s about proving what’s possible when we dare to push beyond our perceived boundaries and into the unknown.

Bear Grylls OBE
BecomingX co-founder

A Marathon Like no other

Few marathons require helmets. None demand 3D route mapping. And no marathon in history has ever been run this deep below the earth’s surface. Set up by learning and development company BecomingX, in collaboration with the International Council on Mining and Metals (ICMM) and our industry leading hosts Boliden, the World’s Deepest Marathon aims to showcase human potential, demonstrating that we all have the capacity to achieve extraordinary things.  It is also an opportunity to showcase modern mining: a critical, safe, and socially conscious industry where cutting-edge operations have made it possible to run a full marathon 1,120 below sea level (1,312m underground).

The ParticipanTs

Forty-five determined individuals are preparing to make history as they take on The World’s Deepest Marathon. Among them are CEOs of mining companies, professional services executives, environmental experts, tech entrepreneurs, charity workers and many more – many running their first marathon. Spanning ages from their 20s to 60s and representing over 15 countries, this diverse group is united by a shared spirit of resilience and adventure. More than just a record-breaking race, the event is a powerful testament to human courage, determination and the limitless potential of those willing to step far outside their comfort zone.

THE organisers

The World’s Deepest Marathon is organised by BecomingX in collaboration with our hosts Boliden and industry champions ICMM. Together we aim to showcase human potential and the power of the mining industry to create a brighter, cleaner future for all.


Bold text reading 'BOLIDEN' in blue.

For a century, Boliden has been exploring, extracting and processing base metals and precious metals. Our production is based on experience, innovation and modern technology, developed in collaboration with Nordic technology and engineering companies. Today, we are an industry leader in terms of sustainable metal production from deposits to recycling used metals.


ICMM logo with geometric design and text

ICMM’s goal is to make responsible mining the global standard - creating safer workplaces, reducing environmental impact, and strengthening social outcomes. By driving higher industry standards, we will deliver high-impact improvements while fostering transparency, accountability, and trust in mining’s role in society.


Logo with text 'BecomingX'

BecomingX is a learning and development company set up to help people to realise their potential. To become the high performers. The game changers. The outliers. We know what it really takes to succeed and we equip people with the attitudes and skills to excel, no matter what their starting point.

Garpenberg - The world’s most productive Zinc mine

Boliden are hosting the World’s Deepest Marathon in Garpenberg, Sweden. In Hedemora municipality, Garpenberg is one of the world's most modern mines, extracting 3.5 million tonnes of complex ores containing zinc, lead, silver, copper and gold. Around 1 per cent of the world´s zinc concentrates are produced here. Mining has been conducted here since 350 years B.C. Today, mining is carried out with industry-leading and largely automated technology. Garpenberg is operationally reliable, eco-friendly and cost effective.

By caring for people, the environment and society, and by using their extensive experience, high-level skills and leading technology, Boliden aims to provide the metals essential to improve society for generations to come.

Fundraising

The World’s Deepest Marathon aims to raise $1m for our two selected charities, BecomingX Foundation and Wild at Heart. Most participants are aiming to raise $30,000 each. 

Group of people in red t-shirts attending a BecomingX Foundation life skills education session, holding notebooks and seated in a thatched-roof room.

BECOMINGX FOUNDATION

BecomingX Foundation aims to create a world where everyone can realise their potential, no matter what their starting point in life. 

Several puppies inside a metal crate outdoors, being carried by two people.

WILD AT HEART FOUNDATION

Wild at Heart Foundation fund and support animal welfare projects all over the world. They aim to compassionately reduce the world's stray dog population through sterilisation, education and welfare programmes.

FREQUENTLY ASKED QUESTIONS

  • The World’s Deepest Marathon 2025 is now full! However, there are a few places available for corporate sponsors if you are interested - please see question below!

    It’s not impossible we will get some cancellations, so if you are desperate to join, and think you can raise $30,000 in charity sponsorship, then drop us an email at wdm@becomingx.com.

  • Yes! We have a number of corporate sponsorship opportunities available, ranging from just $5,000 to over $100,000 to help cover costs (with money above this going to our charity partners). Two of our sponsorship packages include the final places for participants. Please contact wdm@becomingx.com and we can send you the details and customise an opportunity.

  • Yes! Please sign up to BecomingX’s contact list (below) and we’ll keep you updated with any events we are organising. You can also go to www.becomingx.com to see what we are up to!

  • Please get in touch with us at wdm@becomingx.com where we can provide you with press releases, imagery and can discuss potential interviews and quotes.

Our Sponsors

Sign up to stay in touch