Drinking an isotonic drink during a trail run is an excellent practice if you want to limit fatigue and boost your performance. As the miles accumulate, proper hydration becomes essential to preserve your endurance and support your muscles over time.
That said, this drink must be consumed in a specific way depending on the stage of the race and the intensity of the effort to maximize its effects on your body.
In this article, you will discover the benefits of isotonic drinks for trail running, a list of ingredients to prepare it yourself, as well as the quantity to consume depending on the distance covered.
Why consume an isotonic drink during a trail run?
During a trail run, the body is subjected to significant stress. To cope with this, consuming an isotonic drink is highly recommended.
Compensate for fluid and electrolyte losses
Prolonged effort leads to significant fluid and electrolyte losses. In other words, you lose water and minerals that are nevertheless essential for maintaining fluid balance and the muscles' ability to contract.
Without an adequate intake of water and electrolytes, the runner is exposed to cramps, a drop in performance, or intense muscle fatigue. Consuming an isotonic drink helps to compensate for these losses and prolong performance.
Optimize endurance and delay fatigue
Isotonic drinks contain sugar which will provide a rapid boost to the body when it is subjected to a significant energy loss during exercise.
This not only allows for a quick replenishment of energy reserves but also helps to maintain a stable energy level over time.
Maintain stable blood sugar during exercise
During a race, the body produces energy by rapidly drawing on its glycogen reserves. If these reserves are depleted too quickly, blood sugar drops. This situation generally causes fatigue, a decrease in concentration, or even a reduction in performance.
Thanks to their simple and complex carbohydrate content, isotonic drinks release energy gradually. They thus help maintain stable blood sugar levels during a trail run.
Aid in the elimination of metabolic waste products
During a trail run, your body produces various metabolic waste products such as lactate (lactic acid), carbon dioxide, urea, and ammonia. By consuming an isotonic drink, you hydrate yourself and at the same time facilitate their elimination.
This elimination, mainly carried out by the kidneys, limits the accumulation of toxins in the body and reduces the risks of nausea, headaches, and the sensation of heavy legs that generally occur during exercise.
Ideal composition of an isotonic drink for a trail run
To understand the effectiveness of an isotonic drink in trail running, it is important to look at its list of ingredients.
Simple and complex carbohydrates for energy
An effective isotonic drink combines simple and complex carbohydrates for optimal energy intake during exercise.
Complex carbohydrates, also known as slow sugars, provide a continuous supply of sugar and allow the body to maintain a stable energy level.
Simple carbohydrates or fast sugars, such as sucrose and dextrose, are rapidly absorbed and act as an energy booster with each sip. This mixture thus produces a drink that effectively supports the athlete throughout their race.
Key electrolytes: sodium, potassium, magnesium
Electrolytes are essential elements in an isotonic drink. They help compensate for losses due to perspiration and maintain fluid and muscular balance, especially during prolonged efforts. This list of minerals includes:
- Sodium (300 to 500 mg/L) : Sodium promotes water retention in cells and limits the risk of dehydration. It also plays a key role in nerve transmission and muscle contraction;
- Potassium (150 to 250 mg/L): Its role is to support muscle function and prevent the onset of cramps;
- Magnesium (20 to 50 mg/L) : Present at a ratio of 20 to 50 mg/L, magnesium reduces neuromuscular fatigue and participates in cellular energy production;
- Chloride (200 to 400 mg/L): As for chloride, it helps maintain acid-base balance and complements the action of sodium for effective hydration.
Natural ingredients: honey, lemon, green tea, mint
To enrich an isotonic drink and provide additional benefits, certain natural and organic ingredients can be added.
Honey provides a natural dose of rapidly assimilable carbohydrates, while lemon and other fruits provide essential vitamins and minerals.
There is also green tea and mint which contribute respectively to antioxidant intake, and freshness during exercise.
How much isotonic drink to consume depending on the trail distance?
The quantity of isotonic drink to consume varies depending on the distance and intensity of the efforts made. Managing this intake well will allow you to boost your performance and optimize your nutrition during the race.
Short trail (10 to 20 km): light and targeted hydration
Even over a reduced distance (10 to 20 km), a short trail remains an intense exercise. To avoid energy failure, you can carry an isotonic drink in a water bottle or flask.
This way, you can adjust the dose according to the duration of the effort and your nutritional needs. The recommended average is 500 ml to 1.5 liters of drink. Prefer a light sugar ratio to avoid any digestive discomfort if the race lasts less than 1h30.
Medium trail (20 to 80 km): active hydration strategy
For a medium trail, nutritional and energy needs are more significant. It is recommended to plan for approximately 500 ml to 1 liter of drink per hour of effort, in order to maintain an optimal ratio between water, electrolytes, and energy carbohydrates.
Use a 1.5 to 2-liter container, such as a camelback, as well as a flask or a flexible cup for aid stations. Adjust the consumed dose according to your pace and weather conditions.
Ultra-trail (80 km and +): structured protocol with aid stations
In the case of an ultra-trail, nutrition and hydration become strategic elements. It will therefore be necessary to precisely plan the quantity of drink per hour (between 600 and 800 milliliters) and adjust it according to temperature, altitude, or intensity of effort.
To limit the risks of nausea or extreme fatigue, it is recommended to provide several different energy drinks:
- A neutral-tasting drink like water,
- A slightly salty version,
- A version based on fruits,
- Broths.
These options allow for varying the intake of vitamins, electrolytes, and energy carbohydrates.
Homemade recipe for a natural honey isotonic drink
If you want to avoid buying isotonic drinks, which are often expensive on the market, it is possible to create your own preparation from a list of natural and organic ingredients.
Isotonic drink recipe for a short trail run
For a short trail run, here is a recipe to prepare and adapt to your tastes and preferences:
List of ingredients
- Between 30 and 70 g of sugar (sucrose), adjusted according to temperature and effort intensity, to provide rapidly assimilable carbohydrates,
- A cup of green tea, flavored with lemon or vanilla, for a supply of antioxidants and beneficial minerals,
- A pinch of salt, essential to compensate for electrolyte losses and support muscle contraction,
- Cold or lukewarm water to complete the drink and ensure good hydration.
Preparation
Here are the steps to follow for preparation:
- Dissolve the sugar in the flavored green tea.
- Add a pinch of salt to maintain electrolyte balance.
- Top up with water to achieve the desired quantity and let it cool in the refrigerator.
You can replace the tea and sugar with 50 cl of fruit juice and top up with 50 cl of water, for a fruitier and more natural version.
Isotonic drink for a long trail run (more than 2 hours)
For a long trail run, you will need to adapt your drink and nutrition to continuously provide the energy, electrolytes, and vitamins necessary for endurance and performance.
List of ingredients
- 30 to 40 g of maltodextrin: provides complex carbohydrates for gradual energy release and compensates for glycogen losses during prolonged efforts;
- 30 to 70 g of sugar (sucrose) depending on temperature: provides an immediate energy boost to support effort intensity and maintain stable blood sugar;
- 1 liter of water or tea: forms the basis of the drink;
- 1 pinch of salt: provides essential electrolytes for muscle maintenance and fluid balance;
- Optional: 50 cl of fruit juice: for a milder and organic version, providing vitamins, minerals, and a pleasant taste, while contributing to overall energy intake.
Preparation
- Pour the maltodextrin into the water or tea and mix.
- Add the sugar or syrup and the pinch of salt.
- For a fruity version, replace the sugar with 50 cl of fruit juice and top up with 50 cl of water.
- Keep refrigerated and consume within 24 hours.
How to properly use your isotonic drink during a trail run?
The effectiveness of an isotonic drink in trail running relies not only on its composition but also on how it is consumed. Depending on the moment of the race, your energy needs, electrolytes, and hydration are not the same.
Before the race: light fluid load
It is advisable to drink between 300 and 500 ml of isotonic drink (divided into small quantities of 100 to 150 ml every 30 minutes) in the two hours preceding the start. This light fluid load helps replenish water and electrolyte reserves.
During effort: fractional absorption, avoid sudden intake
During the race, the important thing is to drink regularly, in small sips every 10 to 15 minutes, rather than consuming large quantities all at once.
This fractional intake prevents digestive problems and helps maintain a constant energy supply. The goal is to stay in an optimal hydration zone throughout the effort.
After effort: rehydration and optimized recovery
The period immediately following arrival is important for recovery. An isotonic drink consumed within hours of exercise (the metabolic window) helps to replenish glycogen stores, compensate for mineral losses, and facilitate the elimination of metabolic waste.
Should you always use an isotonic drink when trail running?
The use of an isotonic drink during trail running depends primarily on the duration and intensity of the effort. For short or low-intensity outings, water alone is generally sufficient to maintain good hydration.
However, when the effort exceeds one hour, especially in hot conditions or at a sustained pace, the benefit of an isotonic drink becomes clear.
Common mistakes to avoid with an isotonic drink when trail running
However, there are some common mistakes to avoid if you want to prepare or consume an isotonic drink during exercise:
- Using too much fructose: this can cause digestive problems or a laxative effect during exercise;
- Adding too much salt: this can have the opposite effect to what is intended and increase dehydration;
- Avoid overloading the drink with glucose: An excess of sugar in your drink can lead to a blood sugar spike, followed by reactive hypoglycemia. Above all, it risks causing gastric upset if your digestive system is not well prepared for such a concentration.
Your questions about isotonic drinks for trail running
Why are drinks called isotonic?
Drinks are called isotonic because they contain the same concentration of dissolved substances (sugar, sodium, potassium, etc.) as blood. This promotes faster absorption during exercise.
Is it possible to prepare an isotonic drink the day before?
Yes, but it must be kept refrigerated and consumed within 24 hours to maintain its properties.
How to prepare an isotonic drink?
Simply mix water, carbohydrates (sugar, honey, maltodextrin), and a pinch of salt, possibly supplemented with fruit juice.
What is the composition of an isotonic drink?
It contains water, simple and complex carbohydrates, electrolytes (sodium, potassium, magnesium, chloride), and sometimes natural ingredients.
What is the recipe for an energizing isotonic drink for running?
For a simple recipe, mix 500 ml of water with 250 ml of fruit juice (orange or lemon). Then add 20 to 40 g of sugar or maltodextrin, and a pinch of salt to compensate for electrolyte losses.
Conclusion
Drinking an isotonic beverage during a trail run helps to support endurance, compensate for water and electrolyte losses, and limit muscle fatigue.
Whether you are on a short course or an ultra-trail, properly adapt the composition, quantity, and consumption rhythm of your drink to get the most out of your effort.
By integrating these practices, you will optimize your performance while preserving your comfort and recovery.
Bibliography
Hydration and performance with isotonic beverage
Bechke, E. E., Zaplatosch, M. E., Choi, J.-Y., & Adams, W. M. (2022). Utility of an isotonic beverage on hydration status and cardiovascular alterations. Nutrients, 14(6), 1286. https://doi.org/10.3390/nu14061286
Hydration strategies and physiological indicators
Pałka, T., Koteja, P. M., Tota, Ł., Rydzik, Ł., Kopańska, M., Kaczorowska, I., Javdaneh, N., Mikulakova, W., Wolski, H., & Ambroży, T. (2023). The influence of various hydration strategies (isotonic, water, and no hydration) on hematological indices, plasma volume, and lactate concentration in young men during prolonged cycling in elevated ambient temperatures. Biology, 12(5), 687 https://doi.org/10.3390/biology12050687
Maltodextrin-based sports drink and performance
Lisnawati, N., Amin, N., & Lestari, Y. N. (2023). Sport drink containing maltodextrin to improve physical performance of soccer athletes. AIP Conference Proceedings, 2586, 060012. https://doi.org/10.1063/5.0107861
Intestinal absorption of ingested fluids
Leiper, J. B. (2015). Fate of ingested fluids: Factors affecting gastric emptying and intestinal absorption. Nutrition Reviews, 73(Suppl_2), 57–66. https://doi.org/10.1093/nutrit/nuv004
Comparison of coconut water and carbohydrate-electrolyte beverage
Kalman, D. S., Feldman, S., Krieger, D. R., & Bloomer, R. J. (2012). Comparison of coconut water and a carbohydrate-electrolyte sport drink on measures of hydration and physical performance in exercise-trained men. Journal of the International Society of Sports Nutrition, 9(1), 1. https://doi.org/10.1186/1550-2783-9-1
Electrolyte supplements and post-exercise recovery
Choi, D. H. (2021). Effects of electrolyte supplements on body water regulation and recovery after exhaustive exercise. Electronics, 11(19), 9093. https://doi.org/10.3390/electronics11199093
Composition of beverages for hydration and performance
Pérez-Castillo, Í. M. (2023). Compositional aspects of beverages designed to promote hydration and performance. Nutrients, 16(1), 17. https://doi.org/10.3390/nu16010017
