Les 10 erreurs qui ruinent votre ravitaillement en course : les principes scientifiques pour optimiser votre stratégie nutritionnelle

In an endurance race, performance depends not only on physical condition, training level, or the equipment used. The ability to maintain an appropriate energy intake throughout the effort is a determining factor, particularly when the duration exceeds 90 minutes.

During prolonged exercise, several factors progressively limit performance: depletion of muscle and liver glycogen stores, dehydration, disruption of electrolyte balance, central fatigue, and the onset of gastrointestinal problems.

Yet many endurance athletes compromise their performance not because of insufficient training, but because of a poorly managed fueling strategy: insufficient carbohydrate intake, poor digestive tolerance, lack of planning, or inappropriate use of energy products.

Competition nutrition must therefore leave nothing to chance. It must be individualized, tested during training, and adapted to the physiological demands of the effort.

Here are the 10 most common mistakes that can limit your performance on race day.

1. Starting to eat too late: the “emergency fueling” mistake

One of the most common mistakes is waiting for the first signs of fatigue before consuming carbohydrates.

When the feeling of low energy appears, the metabolic situation has already deteriorated: blood glucose may have fallen, glycogen stores are heavily depleted, and the ability to maintain intensity decreases.

During prolonged exercise, the brain relies heavily on circulating glucose. Reduced carbohydrate availability increases perceived exertion and may lead to an unintentional decrease in intensity.

Recommended strategy

Start carbohydrate intake from the early stages of exercise, generally after 20 to 30 minutes depending on the intensity and expected duration.

The goal is not to correct an energy deficit, but to prevent it from occurring.

2. Underestimating your carbohydrate needs

Carbohydrates are the main energy substrate during moderate- to high-intensity efforts.

Current recommendations have evolved considerably: modern strategies are no longer limited to avoiding “hitting the wall,” but aim to maximize energy availability during exercise.

The consensus recommendations state:

• 30 to 60 g of carbohydrates/hour for efforts lasting 1 to 2.5 hours;
• 60 to 90 g/h for prolonged efforts;
• up to 120 g/h in athletes specifically trained to tolerate high intakes.

This increase is possible thanks to the use of different intestinal transporters:

• le glucose utilise principalement le transporteur SGLT1 ;
• le fructose utilise GLUT5.

L'association glucose-fructose permet ainsi d'augmenter l'oxydation exogène des glucides et de dépasser les limites d'absorption d'un seul type de sucre.

Erreur fréquente

Consommer un seul gel toutes les heures lors d'un ultra alors que l'organisme nécessite parfois deux à trois fois plus d'énergie.

3. Négliger l'entraînement digestif ("gut training")

Le système digestif n'est pas un facteur fixe : il s'adapte aux contraintes imposées.

De nombreux sportifs limitent leurs apports pendant l'entraînement par peur des troubles digestifs, puis tentent d'augmenter fortement leur consommation le jour de la compétition.

Cette approche est contre-productive.

L'entraînement digestif permet notamment :

• d'améliorer la vidange gastrique ;
• d'augmenter la capacité d'absorption intestinale ;
• d'améliorer la tolérance à des apports glucidiques élevés.

Application pratique

Tester progressivement ses apports lors des sorties longues :

• augmenter la quantité de glucides par heure ;
• varier les textures ;
• reproduire les conditions de course.

4. Choisir un produit énergétique sans tenir compte de sa composition

Tous les gels énergétiques ne répondent pas aux mêmes besoins.

Le choix doit dépendre :

• de la durée de l'effort ;
• de l'intensité ;
• de la tolérance digestive ;
• de la nécessité ou non d'un apport en caféine.

Quelques différences :

Gel principalement à base de glucose/maltodextrine

Avantage :

• assimilation rapide ;
• bonne disponibilité énergétique.

Gel glucose-fructose

Avantage :

• capacité d'absorption supérieure ;
• intéressant sur les efforts longs.

Gel avec caféine

Avantage :

• amélioration possible de la vigilance ;
• réduction de la perception de l'effort.

Mais la caféine doit être testée car la réponse individuelle varie fortement.

5. Boire uniquement de l'eau pendant les efforts prolongés

L'eau est indispensable, mais elle ne remplace pas les électrolytes perdus dans la sueur.

Le sodium joue plusieurs rôles :

• maintien du volume plasmatique ;
• équilibre hydrique ;
• transmission nerveuse ;
• contraction musculaire.

Une consommation excessive d'eau pauvre en sodium lors d'efforts prolongés peut contribuer au développement d'une hyponatrémie associée à l'exercice.

La bonne stratégie

Adapter son apport hydrique selon :

• son taux de transpiration ;
• la température ;
• la durée de course ;
• la concentration en sodium de sa sueur.

6. Consommer trop de fibres, de lipides ou de protéines avant et pendant l'effort

Pendant un effort intense, le débit sanguin digestif diminue afin de privilégier les muscles et la thermorégulation.

Certains aliments deviennent alors plus difficiles à digérer :

• aliments riches en fibres ;
• repas très gras ;
• quantités importantes de protéines.

Cela augmente le risque de :

• ballonnements ;
• reflux ;
• douleurs abdominales ;
• diarrhées.

Before the race

Prioritize:

• easily digestible carbohydrates;
• low fiber content;
• low fat content.

7. Not adapting your strategy to environmental conditions

The same nutrition strategy does not work in all conditions.

Heat causes:

• increased cutaneous blood flow;
• increased sweating;
• accelerated dehydration;
• decreased digestive tolerance.

In the mountains, altitude can also alter the perception of effort and energy needs.

Fueling must therefore evolve according to:

• temperature;
• humidity;
• altitude;
• expected duration.

8. Copying an elite athlete’s strategy

A professional athlete’s nutrition strategy is often based on:

• a high training volume;
• specific digestive adaptation;
• a different body mass;
• years of experimentation.

An amateur runner does not necessarily have the same needs or tolerance.

The best strategy is the one that suits your physiology.

9. Not quantifying your intake

A common mistake is to rely solely on how you feel.

However, two gels can provide very different amounts depending on their composition.

To make progress, it is useful to know:

• grams of carbohydrates consumed per hour;
• amount of fluid consumed;
• amount of sodium provided;
• digestive tolerance.

This approach allows you to gradually refine your strategy.

10. Neglecting recovery immediately after the race

Fueling does not stop when you cross the finish line.

After prolonged exercise, the goal is to:

Restore glycogen

The first hours following exercise are a favorable period for muscle glycogen resynthesis.

Promote muscle repair

A protein intake containing sufficient essential amino acids promotes muscle protein synthesis.

General recommendations are around:

• 20 to 40 g of protein after exercise, depending on body size and training load.

Conclusion

Effective fueling is not simply a succession of gels and sports drinks. It is a true physiological strategy designed to maintain energy availability, limit dehydration, preserve digestive comfort, and optimize recovery.

The best performances are often achieved through attention to detail: starting your intake early enough, reaching an appropriate amount of carbohydrates per hour, training your digestive system, and tailoring your strategy to your constraints.

As with training, race nutrition should be prepared several weeks before the goal. On race day, you should no longer experiment: apply a strategy that has already been validated.