For 31 days, from September 3 to October 4, 2025, Kilian Jornet redrew the map of human endurance. The stats are completely wild: 72 of the highest peaks in the western United States climbed using only the strength of his legs, approximately 5,000 km on foot and by bike, and a total elevation gain equivalent to 14 times Everest… Welcome to the heart of the “States of Elevation” challenge, which, beyond the feat itself, is a true masterclass in nutrition.
When Kilian eats during such a challenge, it looks complex, but it makes sense, and I’m going to explain everything.
Here’s a summary of his approach: a fusion of an almost ascetic food philosophy, pragmatic adaptation to the demands of the extreme, and cutting-edge scientific support.
With this article, you will understand how he was able to transform a month-long odyssey into a performance that few human beings would be capable of accomplishing.
The challenge: enduring… enduring for a very, very long time
Taking on an ultra-endurance challenge lasting several weeks requires thinking differently. Nutrition must make it possible to sustain daily efforts lasting more than 18 hours for over a month, with an extreme calorie expenditure (~8,000 to 9,000 kcal/day), while minimizing digestive problems and promoting rapid recovery.
There, that’s settled. So, how did he do it?
The philosophical foundation: whole foods
The cornerstone of Kilian Jornet’s nutrition for this project rests on a simple but radical principle: eating almost exclusively whole, unprocessed foods. In the motorhome that served as his mobile base camp, his vegetarian diet consisted of a simple yet nutrient-dense foundation: sweet potatoes, tofu, eggs, and dates.
This is not a whim, but a deliberate strategy.
By prioritizing low-glycemic-index, nutrient-rich foods, he ensures a slow and sustained release of energy. This prevents blood sugar spikes and sudden energy crashes, the nightmare of endurance athletes.
It is a diet designed to build deep resilience, nourishing the body over time rather than simply “fueling” it for immediate exertion. This philosophy is consistent with strategies he has already shared, particularly on Reddit.
The pragmatism of the extreme: eating on the move
Yet this philosophical foundation has to contend with the reality of the trail: a daily effort equivalent to “a stage of the Tour de France plus a marathon at altitude.” That is where Kilian’s pragmatism comes into play.
Since eating a dish of sweet potatoes or rice while climbing is difficult, he opts for more direct sources of energy that are easy to carry and digest: pure olive oil (nearly 9,000 kcal per liter), sometimes accompanied by sandwiches, biscuits, gummy candies, or even donuts, depending on the occasion.
This is not a departure from his principles, but an intelligent adaptation between his staple diet (at base camp: fresh produce, sourdough bread, etc.) and food consumed while on the move.
These simple, enjoyable carbohydrates serve him during quick breaks or in cases of severe fatigue, but remain secondary to the fat-based strategy. The latter provides him with continuous energy and allows him to save his carbohydrate stores for moments of technical intensity or energy deficit.
His approach could be summed up as follows: whole foods and healthy fats build long-term endurance, while fast-acting carbohydrates and a few treats break the monotony and provide immediately available energy.
Although the basic rules may seem simple, even simplistic, they must adapt to the many constraints of ultra-endurance efforts. Extreme fatigue, weather conditions, technical sections, altitude, time of day, overall physical condition, and so on. The mind itself must also be taken into account.
The invisible engine: metabolic efficiency and gut health
One of the most puzzling characteristics of Kilian Jornet is his ability to perform for hours with minimal food or drink. He can sustain 10-hour “training sessions” without drinking or eating, and this is just one example among many other “oddities.”
This ability is not magic; it is the result of profound metabolic adaptation: he is what is known as a “fat-adapted” athlete. His body is extraordinarily efficient at using its own fat stores as an energy source, even during intense efforts.
Its metabolic efficiency gives it exceptional energy autonomy, freeing it from constant dependence on carbohydrates and reducing the risk of gastrointestinal problems.
But for even an efficient engine to operate for such an extreme duration, the plumbing has to keep up. That is where a more scientific dimension of his strategy comes in: gut health.
For “States of Elevation,” Kilian was supported by a probiotic brand. The goal was to maintain a healthy gut microbiome for three critical reasons:
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Optimize nutrient absorption Ensure that every calorie consumed, whether it comes from a sweet potato or a piece of candy, is used efficiently by the body.
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Reduce inflammation Extreme effort and altitude generate major inflammatory stress. A healthy gut helps modulate this response, promoting better recovery day after day.
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Supporting the immune system : Such a journey weakens the body's defenses. Probiotics help maintain immune resilience against infections.
This focus on gut health is a cutting-edge approach, particularly crucial at high altitude, where digestion is often compromised. Its aim is to make performance sustainable.
A stratA strategy in motion : the art of adaptation
It is impossible to set a nutritional plan in stone during such an adventure. Jornet's system is dynamic.
The first days in Colorado were particularly difficult, marked by dehydration and weight loss of up to 5 kg. And it's not as if he had set off overweight!
He had to make real-time adjustments to meet enormous energy and hydration demands.
How did he adapt in practical terms? By drawing on his vast experience and his ability to listen to his body.
You don't fuel yourself the same way when doing 31 ultras in a row as when running an Ultra-Trail du Mont-Blanc or a Western States. In a 100-mile race, Kilian Jornet's plan is precise to the millimeter: he starts with a fat-rich mix (avocado, coconut oil, nuts) for the first few hours, then gradually switches to almost pure carbohydrates (gels) toward the end of the race, reaching up to 110 g of carbohydrates per hour for maximum intensity.
Don't try this at home; it's extreme and reserved for elite athletes. At 60 g of carbohydrates per hour, you're already taking in a good amount of energy.
For "States of Elevation", Kilian has chosen a strategy that breaks with the conventions of modern endurance sports. Instead of gels and energy powders, he favors a diet very high in fat: he pours pure olive oil directly into his flasks, taking advantage of its exceptional calorie density (around 9,000 kcal per liter) and its ease of transport by bike or while running.
This strategy reduces dependence on cumbersome logistics and helps limit the digestive problems that can easily arise during prolonged expeditions. Olive oil provides sustained energy during long periods of moderate effort. Carbohydrate stores are thus preserved for the most intense moments, such as a technical ascent or a rapid attack.
True to his principle of adaptation, he constantly adjusts the type and quantity of nutrients he consumes according to his body's signals and the demands of the moment, making the most of his metabolic flexibility—this carefully considered mix of fats and sugars that sets his diet apart from that of many other runners.
And after such a challenge? How do you get back to normal?
After the intense effort of States of Elevation, Kilian Jornet returned to a regular, balanced diet focused on unprocessed, fermented, and whole foods, continuing to prioritize an enduring and healthy metabolism.
He emphasizes the importance of listening to the body, staying constantly hydrated, and maintaining fixed meal times (three meals a day) to optimize muscle recovery and prevent chronic fatigue.
An original strategy? A comparison with the science of sports nutrition
Kilian Jornet’s strategy is not a revolution that contradicts the foundations of sports nutrition. Rather, it is a masterful and highly personalized application of them.
His originality does not lie in inventing new principles, but in synthesizing and mastering validated concepts, taking them to an extreme level of effectiveness.
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Fat adaptation: a well-known principle, mastered exceptionally. The concept of the “fat-adapted” athlete is well established in the world of ultra-endurance (Ketogenic diet). Science recommends developing this “fat-burning engine” through fasted training and a diet that favors healthy fats for long efforts at moderate intensity. Kilian Jornet’s strategy fits perfectly within this framework. What is exceptional is his level of adaptation, allowing him to function for hours with minimal intake—a capacity he has developed over many years.
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The “whole foods” foundation : a distinctive approach. Where standard sports nutrition relies heavily on formulated products (gels, powders, bars), Kilian bases his overall strategy on whole, unprocessed foods. This is his main point of difference. While experts recommend complex carbohydrates such as brown rice syrup For sustained energy, he goes further by using sweet potatoes or dates as a basic fuel source. This approach prioritizes nutritional density and long-term digestive health, a crucial aspect for an effort lasting a month.
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The pragmatism of simple carbohydrates: a convergence with science. Despite his “whole foods” philosophy, Kilian does not reject conventional energy sources. His consumption of candy, biscuits, or gels during intense phases or toward the end of a race is perfectly aligned with scientific recommendations advocating rapid carbohydrates for an immediate energy boost and to support high-intensity efforts. He thus demonstrates essential flexibility, distinguishing everyday nutrition from race fueling.
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Gut health: an absolute priority. Jornet's focus on his gut microbiome through probiotics places him at the forefront of sports nutrition. While the general public is only beginning to discover the importance of gut health, performance science has already validated its crucial role in nutrient absorption, inflammation management, and immune support, especially at altitude. This approach is not "original" in the sense of being unscientific, but it is still uncommon and reflects a comprehensive understanding of performance.
Kilian Jornet's originality does not lie in defying science, but in embodying it with extreme discipline and personalization.
He combines a sustainable, healthy approach (whole foods) with the demands of high performance (fast carbohydrates), all optimized through metabolic mastery and cutting-edge scientific support (gut health).
The best of both worlds: How can you take inspiration from Kilian Jornet without being Kilian Jornet?
Kilian's strategy is that of an exceptional athlete, but you can absolutely draw inspiration from it! Whether you're a trail runner, cyclist, or marathon runner, his fundamental principles can be adapted to improve your performance, comfort, and enjoyment.
The idea is simple: combine a healthy basic diet with natural, effective sports nutrition products to meet all your needs before, during, and after exercise.
Pillar 1: Your daily foundation of whole foods
Like him, you would do well to base your everyday diet on whole, natural, minimally processed foods. That's what builds your foundational resilience. Your meals before and after training should prioritize complex carbohydrates (oats, brown rice, sweet potatoes), quality protein, and healthy fats.
Pillar 2: Energy pragmatism during exercise with Mulebar
This is where Kilian's strategy and Mulebar products come together perfectly. During exercise, let's be honest, it is difficult to consume complex foods. Mulebar products, 100% natural, are designed to provide you with easily digestible, effective energy.
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For sustained energy and moderate efforts: The energy bars Mulebar, rich in natural carbohydrates from grains and fruit, provide sustained energy and a soft texture, ideal at the start of an outing or during activities such as hiking or cycling.
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For easy-to-digest energy: As the effort intensifies, digestion becomes more delicate. The energy purées Mulebar are a delicious, semi-liquid alternative that is easier to digest than solid foods. Perfect for trail climbs or intense phases on the bike.
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For an immediate boost: The energy gels Mulebar are designed for ultra-fast absorption (in under 5 minutes), making them ideal just before a challenging section or to counter a drop in energy.
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For hydration and electrolytes: Dehydration is your enemy. hydration drinks Mulebar make up for mineral salt losses, while sports drinks add carbohydrates for a valuable double supply.
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To avoid flavor fatigue: For efforts lasting more than 3–4 hours, feel free to alternate the sweet flavors of Mulebar products with a savory option, such as homemade homemade sweet potato purée). This is a winning strategy for maintaining your appetite.
Pillar 3: Optimized recovery with protein
The period immediately after exercise—the famous “metabolic window”, is crucial. This is when your muscles are like real sponges, ready to repair themselves and replenish their energy stores (glycogen).
The protein bars Mulebar are specifically designed for this phase. With 10g of protein and 17g of carbohydrates per bar, they allow you to begin rebuilding your muscles properly. According to science, aim for a ratio of 3g of carbohydrates to 1g of protein, and keep in mind 20 to 40g of protein after each session, depending on its intensity and how close the next session is.
A concrete example: Your nutrition plan for a long outing (3–4-hour trail ride/cycling session)
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Before your outing (3 to 2 hours before): Have a meal based on whole foods, such as a good porridge or brown rice.
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Just beforehand (1 hour before): A energy bar to replenish your stores.
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During exercise: Sip regularly from an sports drink.
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First hour: Eat an energy bar in several portions.
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Hours 2 and 3: Switch to energy purées, which are easier to digest at this stage.
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If you feel your energy dipping: An energy gel just before a major climb will give you a boost.
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After exercise (within 30–60 min): A protein bar and good rehydration (carbohydrates + electrolytes) to kick-start your recovery perfectly.
By combining a healthy basic diet with Mulebar natural products, you can apply the principles of a champion like Kilian Jornet. Adapt his strategy to your own level to optimize performance, enjoyment, and recovery.
With experience, you too can achieve Kilian’s masterful blend of simplicity and extreme precision. You do not need to be a top-level athlete to learn about yourself and find what works for you.
So, like him during his “States of Elevation” challenge, consume pure foods, with the pragmatism of fast-acting sugars.
Train so that your metabolism, even if it does not fall outside the norm, becomes flexible, supported by rock-solid gut health.
Learn to know yourself, of course, but use that knowledge to adapt: every element of your nutrition has its place and its timing.
