Running 100 km a day across France: Duncan Perrillat’s audacious challenge

Some challenges command instant respect. Duncan Perrillat’s is one of them. A top-level French marathoner, he is about to embark on an extraordinary project: running a lap of France through the country’s markets. 3,400 km in 30 days. That’s 115 km a day. Every day. For a month. With a world ultra-endurance record in his sights. It is an ambitious challenge that suits him, combining extreme physical performance with a search for meaning. Just days before the start, we had the chance to speak with him.

A project that had been taking shape for years

Duncan is a familiar figure in French athletics. A top-level marathoner, he ran a personal best of 2:09:05 in Seville at the start of 2025. But beyond the performances, he is a distinctive character: authentic, passionate, and in love with running and long distances. Though he is a road specialist, he is not afraid to venture off the beaten track, particularly onto the trails. In 2023, for example, he won the Trail du Saint-Jacques by UTMB (126 km / 5,250 m elevation gain).
Duncan is a curious athlete, and the Neuilly-Plaisance Sports club member enjoys mixing things up. But this new project goes beyond sport. It comes from somewhere deeper. Much deeper.

“ I lived in the United States for four years, and I missed France enormously. When I came back, I wanted to rediscover it, to really travel through it, not just see it from a plane or a car. I wanted to feel it.”

It started as a holiday idea with his brother, a run-bike tour that stayed on the shelf. Then the project kept growing in the back of his mind until it finally began to take shape after his performance at the Seville Marathon in February: “ I’ve had this project in the back of my mind for several years. I told myself that if I ran under 2:10, I’d take on the adventure. The time is right.”

An endurance-focused build-up

Running more than 100 km a day may sound insane, but if anyone is capable of pulling it off, it is Duncan Perrillat. He is used to heavy training loads, with marathon build-ups that have reached 240 km per week. For this challenge, however, he has moved away from high mileage and hard sessions to focus on aerobic conditioning. As he puts it: “ I prepared with less volume than I would for a standard marathon, but with much more endurance work. Long runs, cycling, hiking… The aim is to teach the body to keep going, not to perform.”

His friend and coach, Faustin Guigon, did not draw up a detailed training plan. “ He told me I was a bit crazy. More than anything, he supported me as a friend. No one really knows how to prepare for something like this. It’s an ultra-trail… of ultra-trails.”

It is an extraordinary challenge, matched by an equally improbable record: that of Tomio Takahashi, a Japanese runner who covered 1,965 km in 30 days, an average of 65.5 km per day. The feat remains unbeaten, despite several attempts that were not ratified by Guinness World Records. Duncan is aiming higher. Much higher, with his target of 3,400 km in 30 days.

I prepared with less volume than I would for a standard marathon, but with much more endurance work. Long runs, cycling, hiking… The aim is to teach the body to keep going, not to perform. Running with the handbrake on so I don’t go too fast and can manage around 10 hours of running. Every day.“
Duncan Perrillat

Crossing France’s markets in tribute to his family and country

Duncan will not be alone out on the road. A team will accompany him by bike and car, providing logistical support and, above all, moral support. He will also be filmed throughout the adventure. A documentary is in the works, with each episode shared on the athlete’s Instagram account, combining a sporting odyssey with a journey through France’s heritage.

“ I’m going to cross markets all over France. It’s also a tribute to my grandfather, who was a butcher in Annecy and sold his meat at markets. He passed away a few years ago. This project is also a way of paying tribute to him.”

That is where the challenge moves beyond sport. It becomes an act of remembrance, a celebration of French heritage and cultural transmission. It is no coincidence that Duncan is so keen to discover the regions, their produce and their cultures. Between two runs, he will encounter the France of local traditions, the France of its people.

Managing pace and fuelling

Running 115 km a day is not about running fast. It is the very definition of resilience and endurance. Duncan knows it: “ I’ll run by feel, but I’ll cap myself at 15 km/h. The target will be closer to 12 km/h. Ten hours of running a day, with breaks to eat, meet people and take it all in.”

Food, naturally, will play a central role. Unlike conventional races, where gels are essential for taking on carbohydrates during the effort, Duncan wants to take the time to eat properly, using quality ingredients. Proper meals, tasty, balanced and local. Every day. “ We’re going to make our way around local markets in France. Yes, it will cost us a little time, but that’s fine. I’d rather have proper meals at lunchtime and in the evening, with snacks throughout the day. I need to be ready to go again the next day, every day. That changes everything. No compromises on food or sleep.”

The support of those closest to him

But beyond the physical challenge, there is the mental side. And that is probably what Duncan fears most: “ I remember having a major moment of doubt on Saint-Jacques. Over 30 days, I know there will be some very tough days, moments when I’ll want to quit. Doubt is scary. It’s part of the adventure.”

Fortunately, he will never truly be alone. Family, friends, fellow athletes… A whole circle of people close to him will be there to help him keep going. “ Having people around you, even 50% of the time, takes 50% of the mental load away.”

A sporting project, but above all a human one, with his sponsor’s support

A challenge of this scale is bound to attract the attention of running and marathon fans. Covering 3,400 km in a month is both inspiring and intimidating. For Duncan, who is used to long distances, performance will not be the priority on this adventure.

“ The record would be cool, but it isn’t the only goal. What drives me is curiosity: seeing how far the body can go. And above all, experiencing something real and shared. There’s a sense of discovery and simple pleasure to it. Even though it will also be a daily job, hard graft.”

On the road, Duncan will be able to rely on an essential ally: his shoes. Supported by Hoka since 2022, he will mainly wear the Rocket X 2, his favourite model, but he is also planning a few alternatives to give his legs a break when needed.

“ I love running in the Rocket X 2, even for high mileage. They save my muscles well and the cushioning is great. I think they’ll be my main shoe. But I’ll also bring a more comfortable pair, perhaps the Skyward X, for more protection from the impact of all those kilometres. And if I end up on trails, I’ll probably bring the Tecton X3. ”

The record would be cool, but it isn’t the only goal. What drives me is curiosity: seeing how far the body can go. And above all, experiencing something real and shared. There’s a sense of discovery and simple pleasure to it. Even though it will also be a daily job, hard graft. Over 30 days, I know there will be some very tough days, moments when I’ll want to quit. Doubt is scary. It’s part of the adventure. Having people around you, even 50% of the time, takes 50% of the mental load away.
Duncan Perrillat

What comes next?

What do you do after running around your country? Duncan has a vague idea, but would rather not think too much about it just yet. “ I’m going to take this challenge one day at a time. A thousand things are going to happen. Afterwards, I think I’ll want to celebrate”. For the rest of 2025, he is considering returning to the classic distance in search of a new personal best: “ I think I’ll start another marathon build-up in the autumn. Maybe Chicago, maybe Rennes. Two cities that mean a lot to me.”

Dare to do it, without fooling yourself

This project is also a philosophy of life. A quiet, deliberate boldness. Duncan knows he is unconventional, and makes no attempt to hide it. He embraces it: “ I don’t care what people think. If you stop at every criticism, you never live. I want to enjoy my life and my projects”. And if he had to sum up his challenge in two words, he does not hesitate: “ boldness and creativity ”.

Behind the dizzying numbers is the story of a man who runs to explore, reconnect and pass something on. An extraordinary challenge at the crossroads of sport, family heritage and a love of place. This run around France is as much a physical feat as an inner journey. Duncan Perrillat is forging his own path, at his own pace.

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