Whether your goal is to finish your first half marathon, improve your personal best, or simply cross the finish line with a smile, a balanced and appropriate diet is essential for optimizing your performance and facilitating recovery throughout your training.

The half marathon is a long-distance race that requires sufficient energy intake and good nutrition management to avoid digestive and muscular problems.

Preparation phase: 9 tips for your diet

During this food preparation phase, it is important to ensure sufficient calorie and nutritional intake. Here are some nutritional tips to follow during the preparation phase:

1. Consume enough calories based on activity level, metabolism, body composition, and training conditions.
   
2. Stay hydrated: performance can drop significantly at the first signs of dehydration.
   
3. Eat a balanced diet in macronutrients:
   • 45–65% carbohydrates
   • 10–35% protein
   • 20–35% fat
     
4. Prioritize carbohydrates for energy: 5-6 g/kg/day (see 10 g/kg/day the day before).
   • Recommended sources: fruit, sweet potatoes, oatmeal, brown rice, whole-grain pasta.
   • Performance during a race depends directly on the availability of carbohydrates: before exercise, carbohydrates help maximize glycogen stores; during exercise, they help preserve these stores by providing quickly accessible energy; afterexercise, they promote recovery and replenishment of stores. 
     
5. Include enough protein for muscle recovery: 1.6 g/kg/day
   • Sources: lean meats, fatty fish, legumes, soybeans, eggs.
   • After endurance exercise, in response to low blood sugar, the body may use muscle amino acids to synthesize glucose. A carbohydrate+whey shake after endurance exercise helps replenish glycogen stores and preserve the athlete's muscle tissue.
     
6. Don't neglect healthy fats for nerve function and endurance: 1–1.5 g/kg/day
   • Monounsaturated sources: vegetable oils, olives, avocados, nuts.
   • Polyunsaturated sources: fatty fish, seeds, vegetable oils.
     
7. Ensure adequate intake of micronutrients through fruits and vegetables.
   • Supplementing with B12, D, and iron may be relevant for vegetarian/vegan diets.
     
8. Adjust meal timing :
   • Before training: a meal low in fat and fiber, rich in carbohydrates.
   • During exercise: for efforts lasting longer than 1 hour, consume 30–60 grams of carbohydrates per hour.
   • After training: meal rich in carbohydrates and protein + hydration
     
9. Test your fueling strategy during specific half-marathon pace training sessions to avoid unpleasant surprises on race day.

Whey and running?

Whey comes from milk serum and is obtained through mechanical filtration. Rich in protein, it is quickly absorbed by the body, making it an excellent choice for supplementation alongside training.

During exercise, muscles suffer micro-injuries that whey, thanks to its amino acids, helps to repair effectively, thereby reducing the risk of injury.

Although it is often associated with muscle building, whey in running ensures sufficient protein intake while controlling total calorie intake.

It thus helps improve the runner's body composition by reducing fat mass and increasing lean muscle mass, which can directly improve half-marathon performance.

As the half marathon approaches: what should you eat?

In the week before the half marathon, the goal is to saturate muscle glycogen stores. To do this, it is advisable to increase your carbohydrate intake: 8-9 grams of carbohydrates per kilogram of body weight per day for the last two days before the race.

In this context,maltodextrin is often consumed during half marathons to supplement carbohydrate intake while avoiding digestive problems. It allows for a steady release of carbohydrates and improved digestive comfort.

What to eat and drink on the day of the half marathon?

Hydration on the big day:

• 2 hours before: drink approximately 250ml of low-mineral water per hour. A slightly sugary drink can help combat pre-race stress.
• During the race: hydrate every 20-25 minutes with 3-4 sips of water (150-200 ml).

Food on the big day:

• For fast runners (less than 1 hour 45 minutes), water and possibly an isotonic drink may be sufficient.
• For runners taking longer than 1 hour and 45 minutes, an energy gel halfway through the race may be beneficial.
• Always test your nutrition strategy during your long training sessions.

What to eat after a half marathon?

In the half hour following exercise, take advantage of the anabolic window to promote recovery. Although a half marathon is less strenuous than a marathon, recovery is still important.

Hydrate regularly to compensate for losses due to perspiration and consume quickly absorbed carbohydrates and proteins to replenish glycogen stores and rebuild muscle tissue. Nutrients consumed during this period will be used more efficiently by your body.

Conclusion

Nutrition plays a fundamental role in preparing for and successfully completing a half marathon. Throughout this article, we have explored how to adapt your diet during the preparation phase, as the race approaches, during the event itself, and during recovery.

A balanced and appropriate diet should be considered an integral part of training, just like running sessions. A well-thought-out meal plan not only optimizes performance but also prevents injuries and improves recovery.

The key point to remember is that you need to maintain sufficient carbohydrate intake to maximize your glycogen stores. Starchy foods such as white rice, pasta, wholemeal bread, or sweet potatoes should form the basis of every meal. It is also a good idea to choose lean proteins such as ham, cottage cheese, or plain yogurt to promote muscle recovery.

As the half marathon approaches, attention should be focused on hydration before the race and digestion. Drinking 500 ml of water per hour and eating a light meal the night before the race will help you arrive at the starting line in the best possible condition.

On race day, your nutrition strategy should be tested in advance during long training runs. An energy drink or easily digestible bar can make all the difference in the second half of the race.

Each runner must adapt these nutritional tips to their own habits, digestive system, and how they feel. Food preparation is as individual as the training itself. 

By following these principles and carefully planning your diet, you will maximize your chances of having a positive experience during your next half marathon, both in terms of performance and enjoyment.