What do you eat and drink during an ultra run?

Trail Nutrition


Running beyond the marathon boundary changes everything. As soon as you start an ultra run, your body demands a specific approach. Fitness and mental strength are important, but your digestion is often the deciding factor in reaching the finish line. In many ways, an ultramarathon is an eating and drinking contest where you run in between.

Keeping going for hours on end is only possible if you take food and drink seriously. Without sufficient fuel, you will inevitably hit the wall. Your brain then slows down the muscles due to a glucose deficiency. A good nutrition plan requires insight into your gut under physical stress, proper hydration and Electrolytesbalance and the right equipment to carry everything comfortably.

The physiology of nutrition during ultra-distances


During strenuous exertion, less blood flows to your stomach because your active leg muscles take priority. As a result, your digestive capacity decreases significantly. While your legs consume a lot of energy during climbs on technical trails, your stomach can only absorb a fraction of that energy per hour.

Your body primarily uses two energy sources: glycogen (Carbohydrates stored in your muscles and liver) and body fat. Even the most trained runners have a large fat reserve, but burning it is a slow process that requires a lot of oxygen. Glycogen provides quick energy, but the supply is limited. After about 90 to 120 minutes of intense running, this supply is depleted, leading to a rapid decline in performance.

To prevent this, take small amounts continuously while walking. Carbohydrates too much fast sugar at once can draw fluid into the intestines, resulting in cramps and nausea. Therefore, carefully dose your intake to spare your digestive tract.

8,000 kcal
Average energy consumption during a 100km trail

Aim for an intake of 200 to 300 calories per hour, primarily from easily digestible foods. CarbohydratesThis is equivalent to approximately 60 to 90 grams CarbohydratesA higher intake under physical stress quickly leads to stomach problems, because the intestines simply cannot process the amount during running.

Target calories per hour 200 - 300 kcal
Goal Carbohydrates 60 - 90 g/hour
Primary energy source Carbohydrates & Fats

Hydration and Electrolytesmanagement on the trail


Staying adequately hydrated during an ultra-marathon requires a targeted approach. Your sweat loss depends on temperature, humidity, terrain, and your personal physiology. A fluid loss of just 2% of your body weight already noticeably reduces your performance and increases your heart rate. However, simply drinking large amounts of water is not sufficient.

You lose important minerals with your sweat, particularly Sodium. Do you drink exclusively water without this Electrolytes to replenish, then you risk hyponatremia. This is a deficiency of Sodium in the blood that can lead to headache, confusion, and nausea. Therefore, add Electrolytes ready for your drinking water. Aim for 500 to 800 milligrams Sodium per liter of fluid, tailored to your personal sweat percentage.

Between aid stations, you must be self-sufficient. Comfortable Running vestknow or hydration vests are ideal for this. With these, you wear soft flasks directly on your chest for quick hydration. Additionally, they distribute the weight evenly, which prevents chafing and bouncing during descents.

Pro Trail Tip

Perform a sweat test during a training session. Weigh yourself before and immediately after a one-hour run at race intensity. Every half kilogram of weight loss corresponds to approximately half a liter of fluid loss. This way, you can easily calculate an accurate baseline for your hydration needs.

Also take weather conditions into account. In cold weather, you notice fluid loss less quickly, while your need for Sodium rises particularly sharply in hot weather. Make drinking a regular part of your routine and try to empty a 500 ml bottle every 60 to 90 minutes. This keeps your blood volume stable and supports your muscle function.

Solid food versus liquid food: Combating taste fatigue


In the first hours of an ultrarun, energy gels and Sports drinkand excellent. They provide fast sugars with minimal strain on the stomach. Over time, however, taste fatigue can set in. Resisting sweet, syrupy flavors makes it difficult to keep eating, which can lead to an energy deficit.

Therefore, alternate with savory, solid foods in a timely manner. This slows down digestion slightly, but provides a mental boost and soothes the stomach. Boiled potatoes with salt, pretzels, small sandwiches, or rice balls are excellent alternatives. These provide Carbohydrates and salt without overstimulating your taste buds.

Pro Trail Tip

Distribute your nutrition strategically across your hydration vest. Keep sweet products on one side and savory options on the other. This way, you can quickly grab what you need at that moment while on the go.

Structuring your trail nutrition strategy


Eating and drinking during an ultrarun requires a strict schedule. Waiting until you get hungry is unwise, because exertion suppresses your appetite. As soon as you feel hungry, the energy deficit is often already too great. Therefore, eat at fixed times, for example every 20 to 30 minutes.

Tailor your nutrition to the course. Chewing solid food during a fast descent is difficult and hinders your breathing. It is better to eat solid food during walks or gentle climbs. Your heart rate is lower then, which makes swallowing and digesting easier. Save liquid nutrition and gels for the flatter sections where you maintain a steady pace.

First phase (Hours 1-3) Gels, energy chews, Sports drinkand
Middle phase (Hours 4-8) Savory solid food, salted potatoes, energy bars
Last phase (Hour 9+) Easily digestible liquid Carbohydrates, ginger tea, broth

Bringing your food: Jackets and backpacks


In addition to the right nutrition, how you carry it is also important. Loose items in your pockets will chafe and bounce around while running. A well-fitting trail running vest keeps your nutrition stable and immediately within reach.

Modern Running vestknow They have pockets on the front for soft flasks, bars, and gels. This means you don't have to stop to eat or drink. The stable weight distribution across your upper body prevents back pain and ensures you can move unhindered over technical trails.

Practice makes perfect


Every digestive system reacts differently. What works for one person can lead to stomach problems for another. Therefore, thoroughly test your nutrition plan during training. Use your weekly long runs to accustom your stomach and intestines to carbohydrate intake under load.This way, you discover what works best for you and avoid surprises on match day.

A structured approach to nutrition, hydration, and equipment significantly increases your chances of a successful finish. By treating food and drink as an essential part of your preparation, you get the most out of your training and conquer the kilometers on the trail with confidence.