How to Prepare for an Ultra-Trail Run?

In the world of running, ultra-trail racing is without a doubt the most spectacular format. The concept of running for hours—day and night—along trails winding through rugged mountain terrain is both fascinating and intimidating. Both mind and body are put to the test in these races, which range from 31 miles to hundreds of miles.

But ultra-trail running is about more than pure performance; it’s an adventure that goes beyond competition, pushing athletes to explore their own limits. Ultra-trail preparation is a long-term process, not simply a question of accumulating mileage. Patience and gradual progression are key to building endurance safely while preserving the joy of running.

To guide aspiring ultra-trail runners, four-time UTMB champion and ultra-trail specialist François d’Haene has shared a few training tips.

What is an Ultra-Trail Race?

Generally, the term refers to any trail run lasting more than 31 miles, which exceeds the standard marathon distance of 26 miles and 385 yards. Even when an event is twice or three times as long, it is still called an ultra-trail run.

The name also applies to races with a broad range of elevation profiles. So how you train for an ultra-trail event is highly dependent on the specific run you are targeting. Consider all factors: elevation profile, terrain type, environment, navigation, and weather.

Ultra-trail events are nothing like running on pavement for a couple of hours. They are extraordinarily grueling, requiring continuous effort over dozens of hours, along with the ability to manage fatigue, running intensity, and nutrition, as well as all the gear needed to brave the elements and navigate changing terrain. A 60-mile run will look very different depending on whether it takes place in mountain terrain, on a beach, or in the desert.

Whatever terrain you are moving through, ultra-trail running is above all an adventure and endurance challenge, where the goal is not just to get somewhere fast, but to get there at all. Training to become an ultra-runner means being willing to work gradually, getting to know yourself, and constantly adapting.

Gradual Progress: A Critical Step

You can’t become an ultra-trail runner overnight. Going from 20 to 60 miles too quickly is almost guaranteed to cause injury or a DNF. Gradual progress is essential. Every step is an opportunity to learn how to manage pace, food intake, emotions, and gear.

This gradual build-up allows you to gain experience so you’re ready when the big day comes, whether you’re running an official race or setting off on a self-supported adventure. Organized races offer some advantages: structure, a target date, the pace of a pack, and simplified logistics for aid and refueling.

Start with shorter events (12–20 miles), then marathon distances (25–31 miles), followed by a “short” ultra (37–50 miles), and if you’re still motivated, tackle the legendary 62-mile-plus events.

Listen to Your Body and Show it Respect

Ultra-trail running is extremely demanding, requiring a healthy lifestyle and near-daily training. Preparing to run over 60 miles in a day takes months and requires as much recovery afterward. “Be careful not to fall into the trap of overtraining or preparing with too much intensity,” warns François d’Haene. It’s all about balance. To find it, listening to your body is crucial:

• Alternate discipline and enjoyment: Let yourself eat what you want once in a while, without obsessing over performance.
• Allow yourself to rest: Know when to ease up if fatigue is taking over.
• Enjoy other sports: Activities like backcountry skiing, biking, or short-format mountain running help stay motivated and develop complementary skills.

As race day draws closer, it's important to find a balance between volume, intensity, and recovery. Of course, you’ll need to get out on long runs, but with restraint. About 6 to 8 weeks out, training runs should increasingly mimic real race conditions: navigating technical terrain, gaining significant elevation, and managing food intake and hydration. The idea isn’t to replicate all ultra conditions but to simulate certain key aspects of the race: try running at night, test out a fully-loaded pack, or run for hours with few breaks.

“The more you can test certain factors ahead of time, then integrate them into training, the more ready you’ll be on the big day.”

You can also get out on long runs over two or three consecutive days. This helps train for cumulative fatigue, an essential skill in ultra-trail running. Two 5-hour runs over consecutive days are more effective than a single 10-hour run because your body learns to keep going when tired. In addition to building endurance, your training should prepare your body for specific terrain challenge:

• Uphills: Work on power, with or without poles.
• Downhills: Strengthen quadriceps and condition joints to absorb impacts.
• Repeated elevation gain: Run loops multiple times to simulate cumulative effort.

This targeted approach develops muscular stamina, essential for long mountain days.

Tapering Before the Event

In the 2–3 weeks before a race, gradually reduce volume. This tapering phase allows your body to recover while maintaining some intensity to stay sharp:

• Reduce volume: Cut by 30% three weeks out, then 50% in the final week.
• Maintain some intensity: Short, dynamic runs keep muscles fresh.
• Run race-day simulations: Try out your full kit, go for short hikes with poles, and test your nutrition plan.

“The important thing is to show up fresh and relaxed on race day. The event will stress your body enough, so there’s no need to add extra strain.”

Nutrition and Hydration: Fuel for Ultra-Trail Running

During 20-, 30-, or 40-hour events, nutrition and hydration are critical. You need to continuously fuel your body so it can go the distance. As you prepare and train, it’s important to maintain a healthy, consistent diet and to avoid overly restrictive eating. Your body needs some indulgence to thrive!

Training is also a great time to test things out and see what’s working. Long days out are an opportunity to figure out how to eat and drink on the move, to observe how your body reacts, to learn how to address any nutritional deficiencies, and to understand what works for your body.

“You absolutely must test your food and hydration plan ahead of time, because race day is no time for improvisation.”

During the race, strive to find a happy medium: eat regularly and don’t wait to be hungry, instead have a snack every 20 to 30 minutes. Energy gels, chews, and bars are useful, but not always enough in the long run. Your body and mind also need variety; pack salty snacks to replace lost sodium, solid foods to break up the monotony, and morale-boosting treats for the darker moments. The key is to stay flexible and adapt to how you feel.

Hydration also demands constant attention. Taking small sips, alternating water with electrolytes, and adjusting intake to heat and effort are simple habits that help ward off dehydration, cramps, and waves of fatigue. Again, don’t go crazy trying to control everything. The race is already putting your body through enough stress, so don’t make it any harder for yourself. The best strategy is often the simplest, driven by instinct.

Gear: Comfort, Safety, Reliability

With ultra-trail running, the tiniest detail can turn into a major problem over the course of 10+ hours. Having a shoe that’s too stiff, a pack that’s too heavy, or the wrong jacket can turn your race into a nightmare. Prioritize comfort over style. “Your gear should be a trusted ally, not a source of doubt. If your shoes feel uncomfortable during training, they will be unbearable after twenty hours of running.”

• Shoes: Favor comfort and protection over minimal weight. Test extensively before a race.
• Running pack: Must be snug, stable, and able to carry essentials (water, jacket, food, headlamp). Test fully loaded in realistic conditions.
• Clothing: Consider changes in weather, choose reliable, breathable jackets over ultra-lightweight options. Socks prevent blisters and chafing.
• Accessories: Use poles to save your legs on climbs, carry a powerful and comfortable headlamp for the nighttime, and pack easy-to-use flasks or reservoirs. Test all gear before race day.

Managing Your Headspace

Over time, fatigue and stress may chip away at your motivation. This is where mental strength comes in. It’s crucial to prepare for the tough times. They will inevitably come, and knowing how to accept them will help overcome them. To do this, visualize the course, imagine the harder sections, and prepare mental routines to help you stick it out. Try to avoid counting the number of remaining miles between you and the finish line, instead setting intermediate goals, such as the distance between aid stations or between mountain passes. Often, it’s your mind, more than your legs, that carries you across the finish line.

Recovery: Let Your Body Do Its Thing

If you want to come back stronger for your next adventure, this last step is crucial: recovery. Ultra-running puts your body through a tremendous amount of stress. So it needs time to recover, both physically and emotionally, from this superhuman effort. The best advice is simply to let your body rest naturally:

• Sleep, eat well, and take slow walks.
• Don’t immediately focus on training or the next race.
• Engage in gentler activities.

Ultra-running isn’t like other running disciplines— you can’t run a bunch of high-intensity ultra races in a single year (unless you're Courtney Dauwalter). Many runners choose to schedule one or two major annual goals, usually in the summer season. That means winter is a time to focus on strength work (skiing, biking, hiking, etc.), while spring brings a gradual return to running, ramping up to bigger training blocks as race days approach. Following this seasonal rhythm helps you feel rested and motivated when it matters most.