A complete guide to fueling a trail half marathon

By JuanPa, creator of TrainingForever · With the experience of Marc Bañuls, coach with more than 15 years of experience

Rapid response: In a half marathon trail nutrition is planned in three moments. Before: meals rich in carbohydrates and a breakfast already tried between 1 and 4 hours before. During: in efforts of 1 to 2.5 hours about 30–60 g of carbohydrates per hour are recommended and drink according to thirst and heat, often between 0.4 and 0.8 L per hour (ACSM: Thomas et al., 2016; Sawka et al., 2007). Then: carbohydrates and protein to recover.

Introduction to Nutrition in a Half Trail Marathon

The half marathon trail is a discipline that combines the endurance of running with the adventure of trail running, offering a unique challenge that requires meticulous preparation, especially with regard to nutrition. Proper nutritional planning not only improves performance, but can also be crucial in preventing injuries and ensuring effective recovery. In this section, we will explore the importance of nutrition in trail racing and key differences between trail racing and asphalt racing.

Importance of nutrition in trail racing

Nutrition plays a key role in the performance of any racer, but its importance is magnified in the context of a half-trail marathon. Trail racing presents unique challenges, such as irregular terrain, altitude changes and variable climatic conditions, which require an adapted nutritional approach.

1. Performance optimization: A balanced and well-planned diet helps maximize glycogen reserves, which are crucial for maintaining energy throughout the race. Complex carbohydrates, lean proteins, and healthy fats should be key components of a trail runner's diet.
2. Injury prevention and fatigue: Proper nutrition helps maintain muscle and bone integrity, which is vital to withstand the repetitive impact and physical demands of trail running. In addition, adequate hydration and electrolyte consumption are essential to prevent cramping and dehydration.
3. Efficient recovery: Intake of nutrients after the race is crucial for muscle recovery and replacement of energy reserves. Consuming a combination of carbohydrates and proteins within 30 minutes after the race can speed up recovery.

Differences between trail and asphalt racing

Although both trail running and asphalt racing share the essence of running, they present significant differences that affect the nutritional strategy.

1. Ground and physical effort: Trail racing often involves irregular terrain, steep slopes and natural obstacles, which requires greater physical effort and hence increased energy demand. This contrasts with asphalt races, which are often more predictable and less demanding in terms of terrain variability.
2. Duration and pace: Half-trail marathons can last longer than their asphalt equivalents due to the difficulty of the terrain. This means that runners need to plan their nutritional intake for a longer period, ensuring that they maintain stable energy levels throughout the race.
3. Environmental conditions: Trail racing often takes place in natural environments, where weather conditions can vary dramatically. This can influence hydration needs and the choice of foods and supplements. For example, running at high altitudes can increase the need for oxygen and therefore for fast absorption carbohydrates.
4. Supply strategy: In trail running, victualling points may be more spaced than in asphalt races, which requires runners to be more self-sufficient in terms of nutrition and hydration. This involves carrying energy gels, bars or even solid foods that are easy to consume in motion.

Pre-race nutritional planning

Nutritional planning prior to half a trail marathon is essential to maximize performance and ensure that the body is adequately prepared to meet the challenges of the terrain. Below is a structured approach to optimizing nutrition in the days leading up to the race.

What to eat the week before

The week before a half marathon trail is crucial to properly load the glycogen reserves, which are the main source of energy during the race. Here are some guidelines to ensure your body is well stocked:

1. Gradual increase in carbohydrates: Progressively increases the intake of complex carbohydrates, such as brown rice, pasta, quinoa and oatmeal. These foods help fill muscle glycogen stores. For moderate-high-volume training, ACSM suggests about 6–10 g of carbohydrates per kg of weight per day (Thomas et al., 2016).
2. Quality proteins: Maintain adequate protein intake to support muscle repair and growth. Sources such as chicken, fish, eggs and legumes are ideal.
3. Healthy fats: Do not neglect healthy fats, which are essential for cell function and vitamin absorption. Include avocados, nuts and olive oil in your diet.
4. Constant hydration: Make sure to maintain good hydration throughout the week. Drink water regularly and consider including isotonic drinks to balance electrolytes, especially if you train in warm climates.
5. Avoid new foods: Do not experiment with new foods or supplements the week before the race to avoid possible digestive problems.

Dinner before race day

Dinner before race day is one of the most important meals, as it provides the energy needed for the next day. Here are some recommendations to optimize this meal:

• Complex carbohydrates: Opt for a dinner rich in complex carbohydrates, such as brown pasta or rice. This will help maximize glycogen stores.
• lean proteins: Includes a portion of lean proteins, such as chicken or tofu, to help in muscle repair.
• Cooked vegetables: Add cooked vegetables, which are easier to digest and provide essential vitamins and minerals.
• Avoiding heavy food: Avoid fatty or very seasoned foods that can cause stomach discomfort.
• Hydration: Accompany dinner with water or an isotonic drink to ensure good hydration.

Breakfast on race day

Breakfast on race day should be light but energetic, providing the necessary fuel without causing digestive discomfort. Here's how to structure it:

• Easy-to-digest carbohydrates: Opt for foods like whole toast with honey or oatmeal with fruits. These provide quick energy and are easy to digest.
• Light proteins: Includes a small amount of protein, such as a cooked egg or yogurt, to maintain the nutritional balance.
• Avoid fiber-rich foods: Although fiber is important in the daily diet, on race day it is better to limit it to avoid digestive problems.
• Hydration: Drink enough water, but avoid consuming large amounts just before the race so you don't feel heavy.
• Consumption time: Try breakfast at least two hours before the start of the race to allow proper digestion.

Properly planning nutrition in the days leading up to a half trail marathon is essential to ensure that your body is in the best condition to perform to the maximum. Following these guidelines, you will be able to optimize your energy reserves and minimize the risk of digestive problems during the race.

Nutrition during half a trail marathon

Nutrition during half a trail marathon is a critical component to ensure optimal performance and avoid exhaustion. Unlike asphalt racing, trailing presents unique challenges, such as uneven terrain and elevation changes, which can significantly increase energy demands. Next, we will explore best practices to maintain adequate nutrition during the race, including food and supplement options, hydration strategies and how to avoid the dreaded "wall."

Food options and supplements

During a half marathon trail, it is essential to maintain a constant supply of energy for the muscles. This can be achieved through a combination of fast-absorbing carbohydrates and some strategic supplements. Here are some recommended options:

• Energy gels: They are a concentrated source of carbohydrates that are absorbed quickly. It is recommended to consume one gel every 30-45 minutes during the race. Opts gels containing electrolytes to assist in the replacement of mineral salts.
• Energy bars: They offer a mixture of carbohydrates and proteins. They are useful for longer races, but make sure they are easy to chew and digest while running.
• Dried fruit: Options such as raisins or dates are natural and provide fast sugars. They are light and easy to carry, although it is important to test them in previous workouts to ensure that they do not cause digestive problems.
• Electrolyte supplements: These can come in the form of effervescent tablets or powders to mix with water. They help prevent cramps and maintain water balance.

Adequate hydration

Hydration is a crucial aspect that should not be underestimated during a half trail marathon. The loss of fluids through sweat can be significant, especially in warm or humid climates. Here are some guidelines for maintaining proper hydration:

• Plan your liquid intakes: Drink small sips of water regularly instead of large amounts at once. This helps maintain a constant level of hydration without overloading the stomach.
• Use isotonic beverages: These drinks not only replenish liquids, but also electrolytes lost through sweat. They are especially useful in long stretches or in extreme heat conditions.
• Know your rate of sweating: During your workouts, weigh your body before and after running to estimate the amount of fluid you lose. This will help you better plan your fluid intake during the race.
• Attention to signs of dehydrationSymptoms such as dizziness, dry mouth or cramps are signs that you need to increase your fluid intake.

Strategies to avoid the "wall"

The "wall" is a phenomenon feared by many runners, characterized by a sudden loss of energy and motivation. It often occurs when glycogen stores run out. To avoid this, consider the following strategies:

• Carbohydrate Load: Make sure that your glycogen stores are filled before the race by a carbohydrate-rich diet on the days before the event.
• Regular carb consumption during the race: As mentioned above, consuming energy gels or dried fruits at regular intervals can help maintain blood glucose levels.
• Keep a steady pace: Avoid starting too fast. A steady pace will help you conserve energy and prevent premature exhaustion.
• Listen to your body: Pay attention to signs of fatigue and adjust your pace or intake of food and fluids as needed.

Post-care recovery

Completing a half-thon trail is an impressive feat that requires not only physical and mental preparation, but also a well-planned recovery strategy. Post-care recovery is crucial for repairing muscle damage, restoring energy levels, and rehydrating the body. Below, we will explore the essentials of recovery, including foods for muscle recovery, effective rehydration, and recommended supplements.

Food for muscle recovery

After half a trail marathon, your muscles have worked hard and need specific nutrients to recover. The right combination of carbohydrates and proteins is essential for repairing muscle tissue and replenishing glycogen stores.

1. Carbohydrates: Eating fast-absorbing carbohydrates within the first 30 minutes after the race helps to replenish muscle glycogen. Opt for options such as fruits, smoothies or energy bars. An example of post-race food could be a banana milk and oat milk shake.
2. Proteins: Proteins are essential for muscle repair. It is recommended to consume between 15-25 grams of high quality protein in post-race food. Sources such as chicken, fish, eggs or legumes are excellent options. A turkey sandwich with integral bread can be a practical and effective option.
3. Healthy fats: Although not the immediate priority, healthy fats such as those found in nuts, avocado and olive oil can help reduce inflammation and provide sustained energy.

Effective rehydration

Rehydration is a critical component of post-race recovery. During a half-thon trail, you are likely to have lost a significant amount of fluids and electrolytes through sweat.

• Water: Start rehydrating immediately after crossing the finish line. Drinking water is essential, but it is not enough alone to replace lost electrolytes.
• Electrolytes: Electrolytes such as sodium, potassium and magnesium are crucial for muscle function and the prevention of cramps. Consider drinking sports drinks or rehydration solutions containing these electrolytes. Alternatively, you can opt for electrolyte-rich foods, such as bananas, oranges and salted nuts.
• Monitoring of hydration: An easy way to check your hydration level is to observe the color of your urine. A light color indicates good hydration, while a dark color suggests that you need to drink more fluids.

Recommended supplements

Supplements can play a complementary role in post-race recovery, especially if you have difficulty getting all the necessary nutrients through the diet.

1. Protein powder: Protein shakes can be a convenient way to ensure adequate protein intake, especially if you don't have immediate access to a full meal.
2. BCAA (branched chain amino acids): BCAA can help reduce muscle fatigue and accelerate recovery. Taking a BCAA supplement before and after the race can be beneficial.
3. Magnesium: Magnesium is essential for muscle function and can help reduce cramps and fatigue. Consider a magnesium supplement if you experience frequent cramps.
4. Antioxidants: Antioxidants such as vitamin C and E can help reduce oxidative stress caused by intense exercise. However, it is important not to overdo it, as excessive supplementation can interfere with adaptation to training.

In short, post-care recovery is an integral process that requires attention to nutrition, hydration and, in some cases, supplementation. By following these guidelines, you can optimize your recovery, reduce the risk of injury, and better prepare for your future adventures in trail running.

Good practices

Managing nutrition for a half trail marathon is a crucial aspect that can make the difference between a successful race and a challenging experience. Below, we present a series of good practices that will help you optimize your performance and well-being during the race.

Listen to your body

One of the most important skills a broker can develop is the ability to listen to your body. This means paying attention to the signals it sends you during training and racing. These signs may include hunger, thirst, fatigue, or digestive discomfort. Ignoring these signals can lead to reduced performance or even health problems.

Recognize the signs of hunger and thirst

It is essential to learn how to differentiate between real hunger and emotional hunger or boredom. During a half trail marathon, you are likely to experience hunger due to energy spending. Plan your intakes to match your energy needs, thus avoiding excessive or insufficient food consumption.

Thirst is another important sign. Dehydration can seriously affect your performance and health. Learn to recognize the first signs of dehydration, such as dry mouth or decreased urine production, and respond appropriately.

Customizing the nutrition plan

There is no one-size-fits-all approach to nutrition in trail racing. Each runner has different needs based on its metabolism, food preferences, and tolerance to certain foods and supplements. Customizing your nutrition plan is essential to maximize your performance and minimize the risks of digestive problems.

Individual considerations

1. Metabolism: Some people burn calories faster than others. Adjust your calorie intake based on your baseline metabolic rate and activity level.
2. Food preferences: Choose foods that you enjoy and that are easy to digest for you. Avoid foods that are heavy or difficult to eat during exercise.
3. Tolerance to Supplements: Not all runners tolerate energy gels or isotonic beverages well. Try different options during your workouts to find what works best for you.

Previous tests in trainings

One of the golden rules in sports nutrition is never to try anything new on race day. Training is the ideal time to experiment with different nutritional strategies and discover what works best for you.

Simulation of race conditions

1. Long training: Use your longer workouts to simulate the conditions of the race. This includes eating food and liquids at the same intervals you plan to follow during the half marathon.
2. Variety of food and supplements: Try different combinations of foods and supplements to see how your body responds. This will allow you to adjust your choices before race day.
3. Climatic conditions: If possible, train in climatic conditions similar to those expected for race day. This will help you adjust your hydration and nutrition strategy based on temperature and humidity.

In short, good nutrition management practices for a half trail marathon focus on listening to your body, customizing your nutrition plan, and conducting previous tests during workouts. Following these guidelines, you will be better prepared to face the challenges of the race and enjoy a more satisfying and successful experience.

Common errors

Preparation for a half marathon trail involves not only physical training, but also proper nutrition planning. However, it is easy to make mistakes that can affect your performance. Below, we explore some of the most common mistakes and how to avoid them to ensure an optimal race experience.

Try new foods on race day

One of the most frequent and potentially harmful errors is experimenting with new foods or supplements on race day. Although it may seem tempting to try that new energy gel or isotonic drink that promises superior performance, doing so without having previously tested it in workouts can lead to unexpected digestive problems.

The digestive system can be sensitive to abrupt changes, especially under the stress of a race. Foods that have not been tested can cause stomach upset, nausea, or even diarrhea, which can ruin your race. Keep your nutrition plan simple and based on what you already know works for you.

Ignoring hydration

Hydration is a critical component of trail racing performance, and underestimating it can have serious consequences. During a half marathon trail, the body loses fluids through sweat, and if not properly replenished, it can lead to dehydration, which affects both physical and mental performance.

Importance of adequate hydration

Dehydration can cause premature fatigue, muscle cramps, and decreased concentration capacity. In addition, under heat or altitude conditions, the risk of dehydration increases significantly. It is crucial to have a hydration plan that includes water and electrolytes to maintain the right balance.

Underestimating the importance of carbohydrates

Carbohydrates are the main source of energy during endurance activities such as a half-trail marathon. Underestimating its importance can lead to a lack of energy and the dreaded feeling of "knocking on the wall."

Role of carbohydrates in performance

During prolonged exercise, carbohydrates stored in the muscles and liver as glycogen are depleted. If they are not properly replenished, the body will begin to use fats and proteins as a source of energy, which is less efficient and can lead to a decrease in performance.

Strategies for an adequate carbohydrate load

1. Prior planning: It gradually increases carbohydrate intake in the days leading up to the race. This may include pasta, rice, whole bread and fruits.
2. During the race: Eat easily digested carbohydrates every 45-60 minutes. This can be in the form of gels, energy bars or dried fruits.

Nutrition plan for a half trail marathon

Orientation: It's a coach's work pattern, not a medical prescription. Attach it to each athlete and consult a healthcare professional if there is severe or persistent pain.

«In trail, victualling is not always where it works for you. Therefore I plan with the athlete where he eats and drinks according to the profile: in the long climbs it is easier to swallow than in the descents." — Marc Bañuls, coach with more than 15 years of experience

Frequently Asked Questions

How many gels to take in a half trail marathon?

Depends on the duration and grams of each gel. As a reference, ACSM suggests 30–60 g of carbohydrates per hour in 1 to 2.5 hour effort.

How much water to drink in a 21km trail?

Depending on thirst, heat, and your sweating rate, ACSM often mentions 0.4–0.8 L per hour. Avoid losing more than 2 % of weight.

What's for breakfast before a half-trail marathon?

Something rich in carbohydrates and already tried, between 1 and 4 hours before, low in fiber and fat if you have digestive discomfort.

How much water should I drink during the race?

Hydration is a crucial component for performance and safety during a half trail marathon. The amount of water you should consume can vary depending on several factors, such as temperature, humidity, your sweating rate, and the intensity of your effort. However, a general rule is to try to consume between 400 and 800 ml of water per hour of race.

In addition, it is essential to pay attention to the signs of your body. Thirst is a good indicator that you need to drink, but don't wait to feel thirsty to moisturize. Keep a steady fluid intake rate throughout the race to avoid dehydration.

An effective strategy is to use a hydration backpack or bottle belt, which will allow you to drink small amounts of water on a regular basis. You can also consider the use of isotonic beverages that, in addition to hydrating, will provide essential electrolytes that are lost through sweat.

Is it necessary to consume energy gels?

Energy gels are a concentrated source of carbohydrates and can be a useful tool to maintain your energy levels during a half trail marathon. However, their use is not mandatory and depends on your personal preferences and how your body tolerates them.

Gels are designed to be consumed every 30-45 minutes during the race, providing a quick supply of energy that can be crucial in times of fatigue. If you decide to use them, it's important that you try them during your workouts to make sure they don't cause you digestive problems.

Remember that, if you consume gels, you must accompany them with water to facilitate their digestion and absorption. Avoid consuming them with isotonic beverages, as this may result in excessive intake of sugars and electrolytes.

What to do if I have digestive problems during the race?

Digestive problems are a common concern for trail runners, especially when faced with the combination of intense physical exertion and the intake of food or energy supplements. If you experience stomach upset during the race, here are some strategies you can consider:

1. Slow down: Declining the intensity of your race can help relieve discomfort. A slower pace allows blood flow to be redirected to the digestive system, facilitating digestion.
2. Evaluate food and liquid intake: Check what you've recently consumed. If you have ingested too many carbohydrates or fluids in a short time, consider taking a break in your intake to allow your stomach to settle.
3. Opt for soft foods: If you need to eat something, choose easy-to-digest foods, such as bananas or crackers. These can provide energy without overloading your digestive system.
4. Practice breathing techniques: Deep, controlled breathing can help reduce stress and tension in the abdomen, which may relieve discomfort.
5. Consult a professional: If digestive problems are recurrent, it may be helpful to talk to a sports nutritionist to adjust your nutrition strategy.

Read also

• Ultra trail nutrition
• Train your digestive system
• Sodium and sweat
• Recovery after a trail

Sources

1. Thomas DT, Erdman KA, Burke LM. Nutrition and athletic performance (ACSM/AND/DC position). Med Sci Sports Exerc. 2016;48(3):543-68.
2. American College of Sports Medicine; Sawka MN, et al. Exercise and fluid replacement (position stand). Med Sci Sports Exerc. 2007;39(2):377-90.
3. Jeukendrup A. A step towardss personalized sports nutrition: carbohydrate intake during exercise. Sports Med. 2014;44(Suppl. 1):S25-33.