Trail nutrition and fueling: a complete guide to optimizing your performance

Starting a trail race without nutritional preparation is like setting out on a hike without a map: you risk running out of energy quickly. A good diet for a long trail race boosts your endurance, prevents energy slumps, and helps you finish your race in great shape. Here is how to manage your trail nutrition before, during, and after the race to optimize your performance.

Eating well for a trail race

Trail nutrition is built around three principles: replenish your stores in advance, stay well hydrated, and adapt your food intake to the intensity of the effort. Before the race, your muscles need to store enough glycogen to last throughout the race. This nutritional preparation directly influences how you feel during the race and your ability to recover.

How should you eat before a trail race?

The The days before a trail race are crucial for fueling up. Three days before the start, gradually increase your consumption of slow-release carbohydrates—brown rice, pasta, sweet potatoes—to maximize your glycogen stores. This tailored nutrition plan forms the basis of your performance.

1. Ideal breakfast on race day: a bowl of oatmeal with a banana, honey, and a few nuts provides gradual energy. Have this meal 2 to 3 hours before the start.
2. Drink enough: drink 500 ml of water with a pinch of salt when you wake up to compensate for overnight dehydration.
3. No innovations: race day is not the time to try new products. Stick to foods you know well.
4. Sugar intake: aim for 8 to 10 g of carbohydrates per kilogram of body weight during the 48 hours preceding the race.

Your nutritional preparation should not be limited to sugars. Include lean proteins and colorful vegetables to reduce inflammation and strengthen your muscles before this trail race. This balanced diet will promote better recovery.

Carbohydrates during a trail race

During exercise, your body consumes between 50 and 120 g of carbohydrates per hour, depending on your pace. Spread this carbohydrate intake every 20 to 30 minutes, along with mineral-rich isotonic hydration, to maintain good energy levels and avoid dips in performance.

1. Plan ahead: don't start fueling when you feel tired; start from the first few kilometers.
2. Vary your options: alternate energy gels, bars, and fruit purées so you don't get bored.
3. Test during training: try out your nutrition strategy over several long runs to fine-tune the quantities.

Energy gels provide quickly available sugars, ideal before steep climbs. Energy bars, being more substantial, are perfect on flatter sections. Fruit purées are easy to digest and invaluable when the pace is intense.

Each format corresponds to a specific situation related to the terrain or your physical condition. During a trail run, fatigue changes your cravings: choose flavors you enjoy so you can continue to fuel properly even after hours of exertion. Discover natural solutions for your trail nutrition.

Effective recovery after a trail run

The 30 to 60 minutes after finishing are the ideal time to recover properly: this is the metabolic window. Combine 20g of protein with 1g of carbohydrates per kilogram of body weight: a protein shake with a banana or an amino-acid-rich recovery drink accelerates muscle rebuilding and replenishes your glycogen stores.

In the evening, put together a balanced meal with lean proteins (fish, eggs), whole grains, and a variety of vegetables. These antioxidant-rich foods help your body eliminate waste produced during exercise. Also remember to stay well hydrated with water and mineral-rich drinks during the 24 to 48 hours following the race for optimal recovery.

Fuel smart on the trail

Compared with traditional snacks, energy fruit purées offer a delicious alternative. Their smooth texture goes down easily, even when your stomach begins to show signs of fatigue after hours of running. Their natural formula helps stabilize blood sugar levels, providing steady energy without sudden fluctuations.

Compotes and purées during a trail race

A 65 g serving of compote in a soft flask is best consumed over an hour, taking small sips every fifteen minutes. This gradual approach helps maintain a good blood glucose level, protects the digestive system, and provides a welcome energy boost before a climb or technical section.

Preparing your own recipes allows you to customize flavors and optimize nutritional intake. For example, a savory purée made with sweet potato, soy milk, turmeric, and spirulina provides approximately 195 kcal and 22.6 g of complex carbohydrates per 200 g, an excellent option for varying the overwhelmingly sweet flavors during a trail race.

1. Savory sweet potato purée: Blend 1 kg of cooked sweet potatoes, 500 ml of plant-based milk, and 200 ml of soy cream with turmeric, ginger, spirulina, and salt. Add water to achieve the desired texture.
2. Sweet chestnut recipe: Combining 150 g of chestnuts, 50 g of sweet potato, 100 g of unsweetened apple compote, 50 g of oat cream, and 80 g of honey (320 kcal, 65 g of carbohydrates).
3. Nutritional benefits: Spirulina provides iron and B vitamins, oat cream contains blood-sugar-regulating beta-glucans, while colorful vegetables provide antioxidants such as beta-carotene.

During your ultramarathon trail race, alternate these energy compotes with gels, an energy bar, and a very lightly sweetened hydration drink rich in electrolytes to meet all your energy, hydration, and sodium needs.

Alternating compotes, gels, and bars

Establish a nutrition rhythm over 60-minute cycles: compote at the 45-minute mark, a gel during a climb at 1:30, an energy bar on a flat section at 2:15, then return to compote. This rotation keeps flavors interesting and provides 50 to 90 g of carbohydrates per hour, accompanied by 150 to 250 ml of electrolyte drink to optimize hydration and digestion.

1. Carbohydrate calculation: A 65 g bottle of apricot compote provides 35 g in total. Adjust your portions accordingly.
2. Weather adaptation: In hot weather, favor liquid textures and increase electrolytes.
3. Strategic timing: Eat before climbs, when digestion is more difficult, and moderate your intake on descents.
4. Managing monotony: Introduce a salty flavor every 3 hours to break the routine and replenish sodium losses.

Remember to rinse your mouth with a sip of water after each sugary intake. This aids digestion, protects your teeth, and makes the next intake more enjoyable.

Hydrating and fueling during a trail

When running a trail for more than two hours, drinking only water is no longer enough. Sweating causes a significant loss of minerals (sodium, potassium, magnesium) and disrupts electrolyte balance. To prevent cramps and fatigue, choosing a suitable isotonic drink becomes essential.

Hypotonic, isotonic, or hypertonic

There are three types of sports drinks:

1. Hypotonic drink: Perfect for short efforts (<1h), it hydrates quickly with few carbohydrates.
2. Isotonic drink: Ideal for endurance, it provides water, electrolytes and carbohydrates in balanced proportions.
3. Hypertonic drink: Reserved for recovery after exercise, as it is high in sugar and absorbed slowly.

Quantify your losses and adjust your sodium intake

To properly fuel your body during a trail:

1. Weigh yourself before/after training: 1 kg lost = 1 liter of water to replace
2. Drink 150–250 ml every 15–30 minutes to maintain hydration
3. Those who sweat heavily should aim for 300–600 mg of sodium/hour

Tip: Prefer frequent small sips rather than large quantities for better absorption. In hot weather, increase your intake of mineral salts (electrolytes).

Discover how to choose the best hydration drink for your needs.

Fueling for races from 25 to 100km

Distance and elevation gain directly determine your energy needs and fueling strategy. A hilly 25km race requires less preparation than a 100km ultra-trail race with 6,000m of elevation gain. By adapting your nutrition plan to each distance, you will avoid both unnecessary overconsumption and calorie deficiencies.

Nutrition plans for 25 km, 50 km, and 100 km

For a 50 km trail race, aim for 50 to 80g of carbohydrates per hour and drink 400 to 700ml of water or isotonic drink, depending on the temperature. Alternate salted fruit purées, energy gels, and small sips every 20–30 minutes to provide your muscles with a steady supply. In case of heavy sweating, consume 300 to 600mg of sodium per hour to maintain electrolyte balance and prevent cramps at the end of the race.

1. 25–35km trail: 30 to 60g of carbohydrates/hour and 300–500ml of water. Alternate energy gels and pieces of energy bar. Test this protocol during training to adjust the flavors and digestive tolerance.
2. 50km trail: Increase to 50–80g of carbohydrates/hour. Use aid stations for solid foods and rinse your mouth after each gel to reduce acidity.
3. Ultra 80–100km: Prioritize liquid textures (60–90g of carbohydrates/hour). Vary the flavors to avoid taste fatigue. 

Start fueling within the first 45 minutes, without waiting until fatigue sets in. Take half a gel before a difficult climb to benefit from the blood sugar peak at the critical moment. This strategy often makes the difference between a controlled finish and a final collapse.

Organizing aid stations during an ultra-trail race

Plan your refueling according to the course and your needs. Two 500ml flasks provide about 3 hours of autonomy—refill them at aid stations with your isotonic drink powder if only water is available. This organization is crucial for nutrition during a 100km trail race, ensuring a steady intake without overloading.

Keep fruit purées and energy gels in accessible pockets so you can eat without interrupting your run. On technical sections, wait for a flat stretch before consuming an energy bar. After a trail race, start recovery with 20g of protein and carbohydrates within 30–60 minutes after the race, even if you have no appetite.

Choose natural and effective products

The 100% natural fruit purées with brown rice syrup help limit digestive issues. Additive-free, they remain easy to digest during prolonged efforts, with rapid absorption (5 minutes), ideal before a difficult section.

Mulebar drinks comply with European standards for electrolytes and vitamins. Their range offers formulas tested by athletes. Compare the compositions with Maurten, Ta, Naak, and others using our trail nutrition guide to choose effective, natural trail nutrition. Consult the comparison guide to choose your trail drink wisely.

Frequently asked questions

How should you manage hydration during an ultra-trail race lasting more than 12 hours?

For For optimal hydration during your ultra-trail race, alternate between electrolyte-enriched water and a carbohydrate-containing isotonic drink. Drink small amounts (150–250ml) every 15 to 30 minutes. A useful guideline: weigh yourself before and after exercise. Each kilogram lost represents approximately 1 liter of fluid to replace. At night, maintain this rhythm despite the drop in temperature, and make sure to consume 300 to 600 mg of sodium per hour to prevent cramps.

Should you prioritize industrial products or homemade preparations for trail running?

Both approaches have their advantages. Homemade foods (savory fruit purées, mashed foods) allow personalized combinations at a lower cost. High-quality industrial products offer consistent composition, long shelf life, and convenient packaging. Our advice: test homemade preparations during training, and use professional solutions during the race for their practicality and contribution to good hydration.

Which foods should you prioritize in the 48 hours following an ultra-trail race to speed up recovery?

Recovery begins as soon as you finish: within the following hour, consume 20g of protein and 1g of carbohydrates/kg through an isotonic drink or fruit. In the days that follow, prioritize balanced meals with:

1. Lean proteins to rebuild muscles
2. Whole carbohydrates (quinoa, sweet potato) to replenish glycogen stores
3. Colorful vegetables rich in antioxidants

Remember to hydrate with water and electrolytes, and allow yourself periods of restorative sleep.