The most demanding trails in France: Challenges for the most enduring

France is full of trails that push the limits of human endurance and willpower. From steep mountains to endless trails, these races are reserved for the most seasoned trail runners. If you are looking for extreme challenges, discover our selection of the most grueling trails in France, including the Chartreuse Terminorum, the Diagonale des Fous, the Infernal Trail des Vosges, the Grand Raid des Pyrénées (GRP), the Ultra-Trail du Mont-Blanc (UTMB), the GR20 and the GR10. Prepare yourself for courses where every stride becomes an exploit.

Chartreuse Terminorum: A challenge inspired by Barkley

The Chartreuse Terminorum is undoubtedly one of the most extreme and mysterious trails in France. Inspired by the legendary American Barkley Marathon, this race takes place in the heart of the Chartreuse massif. It offers a 300 km course with nearly 25,000 meters of elevation gain, all without markings or refreshments. Participants must complete five loops through wild and technical terrain in less than 80 hours. Few runners manage to complete this monumental challenge, which makes the Chartreuse Terminorum a feared event.

Want to know more? Check out our guide to Chartreuse Terminorum to discover one of the most formidable trails.

The Diagonale des Fous: An exceptional ultra trail in Reunion

The Diagonale des Fous , also known as the Grand Raid de La Réunion, is one of the toughest ultra-trails in the world. This 165km course with 10,000 metres of elevation gain crosses the island of La Réunion, passing through volcanic landscapes, spectacular cirques and tropical forests. The terrain is extremely technical and the weather can be unforgiving, with intense heat and torrential rain. Finishing this race is a feat that requires both extraordinary endurance and the ability to handle extreme conditions.

Want to know more about this legendary race? Check out our article on the Diagonale des Fous .

The Infernal Trail of the Vosges: A hellish course

The Infernal Trail des Vosges is aptly named: this race is a real test for the bravest trail runners. The 200 km course with 10,000 meters of elevation gain takes place in the green but very demanding landscapes of the Vosges. The race is known for its steep climbs and technical descents, which put the participants' bodies and minds to the test. The often humid atmosphere and unpredictable weather conditions make this race even more difficult, adding a real additional challenge to the trail runners.

Find out everything about the Infernal Trail des Vosges and its demanding routes.

Grand Raid des Pyrénées (GRP): An adventure in the heart of the mountains

The Grand Raid des Pyrénées (GRP) is an ultra-trail that crosses the breathtaking landscapes of the Pyrenees. With several courses, ranging from 40 km to 220 km, the GRP is an unmissable event for trail runners in search of adventure. The 160 km "Ultra" course with 10,000 meters of positive elevation gain passes through emblematic peaks such as the Pic du Midi, offering exceptional panoramas while being a true test of endurance. The altitude, the changing weather conditions and the technicality of the terrain make the GRP a daunting challenge.

Want to know more? Check out our article dedicated to the Grand Raid des Pyrénées to find out everything about this race.

Ultra-Trail du Mont-Blanc (UTMB): The Holy Grail of Ultra-Trails

The Ultra-Trail du Mont-Blanc (UTMB) is arguably the most famous and prestigious trail in the world. With its 171 km and 10,000 meters of elevation gain, this epic race crosses three countries – France, Switzerland and Italy – around the Mont-Blanc massif. It is a true test of endurance and mental toughness, as runners must face endless climbs and technical descents on sometimes very steep terrain. The UTMB is a legendary race, a dream for many trail runners, but also a formidable challenge.

Ready for one of the biggest challenges of your life? Discover our guide to the Ultra-Trail du Mont-Blanc (UTMB) .

GR20: The trail of all records in Corsica

The GR20 is often considered the most difficult long-distance footpath in Europe. This 180km route with almost 13,000 metres of elevation gain crosses Corsica from north to south, passing steep ridges, deep valleys and crystal clear mountain lakes. Although not an official race, the GR20 is regularly used as a personal challenge for trail runners. Those who venture onto this trail face extremely technical terrain, with climbing sections and very changeable weather conditions.

Want to explore this legendary trail? Check out our article on the GR20 to learn more.

GR10: An extraordinary crossing of the Pyrenees

The GR10 is a long-distance hiking trail that crosses the Pyrenees from the Atlantic to the Mediterranean. With its 850 km and 48,000 meters of cumulative elevation gain, it is one of the longest and most demanding trails in France. This route, which can be completed in several weeks, passes through majestic peaks, isolated valleys and breathtaking landscapes. The GR10 is a long-term endurance challenge, requiring excellent physical and mental preparation to tackle sometimes very technical and demanding stages.

Discover everything about the GR10 and prepare yourself for an extraordinary adventure.

The toughest trails, a challenge for the soul and body

These trails are among the most demanding courses in France. Each race is a unique challenge, requiring as much physical preparation as mental strength. Whether you choose to participate in a legendary race like the UTMB or take on the personal challenge of the GR20, you will live an intense and unforgettable experience. Prepare to push your limits and discover extraordinary landscapes while testing your endurance.