Race Day Nutrition: Kilian Jornet’s Strategies for Ultra Marathons

Last Updated on September 27, 2025 by Amanda Bowden

How Does Kilian Jornet Fuel for Ultra Marathons?

A quick note before we dive in: I do not recommend copying Kilian Jornet’s nutrition strategy exactly. What works for him has been refined over decades of racing at altitude, climbing mountains on minimal sleep, and running further than most of us can imagine. His stomach is probably tougher than ours too! But looking at what Kilian does on race day gives us some fascinating insights into fueling for ultra-endurance events – and maybe even a few practical tips you can test in training.

If you’ve followed ultrarunning for a while, you’ll know Kilian Jornet needs little introduction. He’s won almost everything there is to win: UTMB (four times), Hardrock 100, Western States, and plenty more. In 2025, he lined up once again at Western States – one of the fastest 100-mile races in the world – and fans weren’t just watching his splits, they were wondering: what’s Kilian eating to keep going for 14+ hours?

The answer, as usual, is surprisingly simple. Kilian has said many times that food is just fuel for him. He doesn’t obsess over exact numbers, and he definitely doesn’t log calories during a race. Instead, he eats what he knows his body can handle: mostly carbohydrates, easy on the stomach, and nothing too fancy.

What Kilian Actually Eats During Races

Kilian’s race-day nutrition isn’t a mysterious super-secret formula – it’s basic, familiar foods. Over the years, he’s mentioned eating things like pasta, rice, gnocchi, jam sandwiches, and gels while out on long efforts. These are all high in carbs, easy to digest, and quick to prepare.

In one interview, he described how in the middle of long mountain days he might reach for something as ordinary as bread with jam – the kind of food you’d find in any European kitchen. On the other end of the spectrum, during a 24-hour elevation challenge, he tested more sports-specific options and ended up consuming thousands of calories in the form of drinks and carbohydrate snacks just to keep his energy levels steady.

It’s worth pointing out that Kilian doesn’t eat constantly, either. In his book Above the Clouds, he even describes an experiment where he went several days running without eating at all, just to test what his body could endure (he eventually passed out on day five!). That experiment wasn’t a race, of course, but it shows his curiosity about human limits — and how much he’s willing to learn from trial and error.

So on race day, instead of overcomplicating things with spreadsheets and calculations, Kilian keeps it practical. He eats foods his stomach knows, and he focuses on consistent carb intake rather than precision fueling strategies.

Gels and Recent Race-Day Strategies

That doesn’t mean Kilian avoids sports nutrition products altogether. In fact, he adapts his strategy to the demands of each race. At UTMB, where he’s out for 20+ hours in rugged terrain, he might combine “real food” like sandwiches with gels later in the race when his stomach is more sensitive.

But at Western States in 2025 – a much faster race, where efficiency is everything – reports noted Kilian fueling with Maurten Gel 160, carried in a flask and sipped every 30 minutes or so. That method (frequent, small doses of carbohydrate) is very much in line with what sports scientists now recommend for endurance athletes.

It’s a good reminder that while his overall philosophy is simple, Kilian isn’t stuck in the past. He experiments, evolves, and uses the tools that make sense for the race in front of him. Jam sandwiches might work on a training run in the mountains, but against the world’s best at Western States, gels were the obvious choice.

Hydration and Salt: Keeping It Simple, but Adapting to Conditions

Kilian Jornet has always stood out for his straightforward approach to hydration. He doesn’t chase complicated formulas or rigid hourly targets. Instead, he focuses on drinking steadily and adapting to the conditions — whether he’s running through the cool alpine air at UTMB or the sweltering canyons of Western States.

That said, he’s not afraid to change things up when the race demands it. At Western States 2011, where temperatures regularly soar past 30°C (86°F), Kilian was seen taking salt tablets — something he hasn’t always used in cooler mountain races. It was a simple but smart adjustment, showing how even the best athletes in the world make pragmatic choices when faced with unique challenges.

In general, Kilian tends to rely on water and sports drinks as his hydration base, letting his food and fluids provide most of the electrolytes he needs. He’s spoken about the risks of overloading on salt or fluids, which can backfire by upsetting the stomach or causing issues like hyponatremia. Instead, his approach is grounded in moderation: don’t underdrink, don’t overdrink, and use salt strategically rather than as a blunt-force solution.

The key lesson for ultra runners is that there isn’t one single answer. Kilian’s success shows the value of listening to your body and adapting to the race in front of you. Sometimes that means sticking to the basics, and sometimes — like in the heat of Western States — it means pulling out a salt tab when you need it most.

Fueling on the Run: Gels, Real Food, and Aid Station Feasts

When it comes to race-day fueling, Kilian Jornet’s approach is a little different from the “steady drip” style you often hear about. Many athletes aim to take in carbs every 20–30 minutes like clockwork — but Kilian has said he doesn’t always eat that regularly.

In fact, during training, he often goes long periods without eating at all. This isn’t about dieting or restriction; it’s about teaching his body to become more efficient at burning fat and conserving glycogen. By training in a semi-fasted state, he can prepare his body for the long stretches in races where food might not be appealing, or where aid stations are far apart. It’s an old-school approach that he’s used since his early days in the mountains.

But come race day, things shift. Kilian does use energy gels as a quick, portable source of carbs when he’s pushing hard — especially during climbs or when he feels his energy dipping. He’ll combine this with sports drinks for hydration and steady carbohydrate intake.

Then there are the aid stations. Unlike some elites who breeze through with just a water refill, Kilian has admitted he often eats quite a lot at aid stations, depending on how he feels. In past interviews, he’s mentioned grabbing bread, cheese, fruit, and even soup during races like UTMB. These are not the kinds of foods you’d usually find in a sports nutrition guide, but they work for him — giving both calories and variety when gels alone start to feel sickly.

It’s this flexible approach that really stands out. Kilian doesn’t force food if his stomach is unsettled, but he also doesn’t shy away from eating more heavily when the opportunity presents itself. It’s the opposite of a rigid “X grams of carbs per hour” spreadsheet — and yet, it’s helped him succeed at everything from Western States to Hardrock to UTMB.

For everyday ultra runners, there’s a lesson here: you can mix fast energy (like gels and sports drink) with real foods that you actually enjoy eating. And while training, it may even help to occasionally practice running on less fuel — so your body knows how to handle those inevitable “low points” in a race.

Takeaways for Your Own Ultra Marathon Nutrition

Not many of us can run like Kilian Jornet — but we can borrow ideas from how he fuels on race day. Here are a few lessons worth testing in your own training and races:

• Train low sometimes. Kilian often runs for hours without eating in training. You don’t need to copy this to the extreme, but the idea of occasionally running with less fuel can help teach your body to burn fat more efficiently.
• Keep it simple on race day. Gels and sports drinks are staples for a reason — they’re light, fast, and reliable. Use them when you need quick energy.
• Mix in real food. Bread, fruit, cheese, or even a salty soup — Kilian shows that variety can save your stomach over long ultras. Don’t be afraid to experiment with “normal” foods that sit well with you.
• Listen to your body. Instead of rigidly forcing calories at set intervals, be flexible. Eat when you’re hungry, hold off if your stomach rebels, and use aid stations as opportunities to reset.
• Practice what you race. Kilian has tested his nutrition strategies for years in training and competition. The golden rule for the rest of us: never try something new for the first time on race day.

Conclusion

Kilian Jornet’s race day nutrition isn’t about perfection — it’s about practicality. From gels on the go to hearty snacks at aid stations, his strategy reflects both experience and adaptability. What makes him unique is not just the foods he eats, but the way he listens to his body and adapts in the moment.

For ultra runners looking to learn from the best, the key takeaway is this: have a plan, but don’t be afraid to adjust it. Flexibility, variety, and practice can make the difference between a mid-race meltdown and a strong finish.

So while you might never win UTMB like Kilian, you can fuel smarter, run stronger, and find your own rhythm on race day — and that’s a victory in itself.

If you’d like to know more about Kilian’s diet then check out these posts:

• The Science Behind Kilian Jornet’s Carb-Heavy Diet: Performance and Recovery Benefits
• Kilian Jornet Diet: What Does The Champion Ultra Runner Eat?