The highest marathon in history
In May 2027, a group of intrepid runners will take part in a once-in-a-lifetime challenge: to complete the highest marathon ever attempted.
The 42.2km course will start at 4,810m (above the summit of Mt Blanc) and every step will remain above 4,395 metres throughout - surpassing the world record set in 2026, which is based on the lowest point reached in the marathon.
Every participant who crosses the finish line will become a world record holder - part of a select group of runners who achieve something truly extraordinary, in one of the most extreme environments on Earth.
Questions, questions, questions…
Taking part in the World’s Highest Marathon is a serious undertaking, and it’s natural to have questions before committing to a challenge of this scale.
Our Frequently Asked Questions section covers the key details - from training and altitude preparation to logistics, safety, and what to expect throughout the expedition.
The expedition
This is far more than a marathon - it is a journey across the remote Bolivian Altiplano, to a part of the world few people will ever experience.
The World’s Highest Marathon 2027 begins in La Paz, the highest capital city on Earth, before travelling through Lake Titicaca, the vast Uyuni Salt Flats, and into the high Andes. Along the way, participants will trek above 6,000 metres, allowing their bodies time to adapt before race day.
The marathon itself will start at 4,810 metres, where oxygen levels are just 58% of those at sea level. With every step remaining above 4,395 metres, the course will set a new world record for the highest marathon ever run.
Cold temperatures, exposed terrain, and the scale of the Altiplano make this a demanding environment. Throughout the journey, participants are supported by experienced high-altitude specialists, medics, and support teams.
Organised by BecomingX and Adventure Alternative, the 2027 expedition builds on a legacy of delivering world-first challenges in extreme environments.
Not our first rodeo
This will be the second World’s Highest Marathon. The first took place in Chile in February 2026, where brutal 100kph winds and temperatures dropping to –30°C with windchill meant that only 5 of the 16 strong team even made it to the start line.
The 2027 expedition builds on everything we learned. It has been carefully designed to push the altitude floor even higher than 2026 - setting a new world record and opening the door for a new group of adventurers to take on one of the toughest challenges on Earth.
