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A half marathon has an official distance of 21.097 kilometers. For most recreational runners, race time usually falls between 1 and 2 hours.
During this time, the body mainly relies on two energy systems:
- Oxidative metabolism (aerobic).
- Glycolytic metabolism.
Although the intensity is high, it is usually slightly lower than in a 10 km race, since the effort must be sustained for a longer period. This means the body must properly manage:
- Muscle glycogen.
- Blood glucose levels.
- Hydration.
- Electrolytes.
In this guide, you will discover how to fuel before, during, and after a half marathon to optimize your performance:
Index
Nutritional Checklist for a Half Marathon
?Before the race:
✔ Slightly increase carbohydrate intake 3–4 days before.
✔ Maintain good hydration.
✔ Reduce fiber intake 48 hours before.
✔ Test supplements during previous training sessions.
?➡️During the race:
✔ Take energy gels depending on race duration.
✔ Drink small sips of water or an isotonic drink.
✔ Maintain a consistent hydration rhythm.
?After the race:
✔ Consume carbohydrates and protein.
✔ Rehydrate with electrolytes.
✔ Prioritize muscle recovery.
Nutrition the Week Before a Half Marathon
The days leading up to the race are essential to prepare the body and ensure you reach the start line with sufficient energy reserves and proper hydration.
During this phase, it is recommended to focus on three key aspects:
1. Maintain Proper Hydration
? A runner should aim to consume approximately:
- 30–40 ml of water per kg of body weight per day
For example: A 70 kg runner should drink between 2.1 and 2.8 liters daily.
- Additionally, on training days or in hot conditions, it may be necessary to add 500–700 ml extra.
2. Slightly Increase Carbohydrates
? Between 3 and 4 days before the race, it is recommended to slightly increase carbohydrate intake to optimize muscle glycogen stores.
The general recommendation for moderate endurance events like a half marathon is:
- 5–7 g of carbohydrates per kg of body weight per day
Practical example: A 70 kg runner should consume approximately 350–490 g of carbohydrates daily.
- Some useful foods to achieve this include: rice, polenta, cream of rice, pasta, potatoes, oats, bread…
3. Reduce Foods That May Cause Digestive Discomfort
? During the 2 days before the race, it is advisable to moderate foods high in fiber or difficult to digest.
For example: limit very fibrous vegetables, reduce legumes, and avoid very fatty or spicy foods.
- An intake of around 15–20 g of fiber per day during these days is usually enough to avoid gastrointestinal discomfort.
Race Day: What to Eat Before and During a Half Marathon
The main objective during the race is to maintain energy levels and delay fatigue. When glycogen drops too much, the muscle loses its ability to produce ATP, the energy required for movement.
This can lead to:
- A drop in pace.
- Premature fatigue.
- The feeling of “hitting the wall”.
Therefore, consuming carbohydrates during the race helps to:
maintain blood glucose + delay fatigue + sustain race pace
Pre-Race Breakfast: Your First Fuel Load
☕ Breakfast should not be an experiment. The goal is to replenish liver glycogen (used overnight) without overloading the digestive system.
- Timing: Eat breakfast 2–3 hours before the start.
- Composition: Prioritize easily digestible carbohydrates, moderate protein, and low fiber and fat.
- HSN Example: A bowl of cream of rice with a piece of fruit (ripe banana) or white bread toast with honey.
? The Performance “Plus”: Nitrates
To improve energy efficiency and vasodilation, nitrates play an important role. Research suggests an effective dose of 600 mg. This amount is provided by Evopump from SportSeries.
- When to take it: Between 2 and 3 hours before the race (with breakfast).
- Benefit: Helps your muscles require less oxygen to produce the same energy, allowing you to sustain higher paces for longer.
Last-Minute Fuel
?To avoid starting with half-empty energy stores, choose one of these options according to your preference (even a third extra):
- Option A (60 min before): A complete pre-workout to maximize blood flow and concentration. Our recommendation is Evobomb from SportSeries with caffeine, citrulline malate, beta-alanine, L-tyrosine, and Panax notoginseng.
- Option B (10 min before): A gel just before the start to stabilize blood glucose without stomach heaviness. We suggest Evoenergy Hydrogel with caffeine (100 mg) and 120 mg sodium, or if you prefer without caffeine.
- Option C (60 min before): If you prefer a solid option, this energy cake with honey and guaraná provides 80 mg of natural caffeine and easily chewable carbohydrates (2:1 ratio).
When to Take Gels in a Half Marathon
⚡Don’t wait until you feel hungry or fatigued; in a half marathon, the key is to stay ahead of the “wall”. Here is a visual roadmap for your supplementation:
| Time / Km | Gel Type | Objective |
| Minute 45–50 (Km 9–10) | Without caffeine | Maintain stable glycogen stores. |
| Minute 80–85 (Km 16–17) | With caffeine | Final boost to combat central fatigue. |
Why gels instead of solid food?
At half-marathon intensity, blood flow is directed to your legs, not your stomach. Gels are the perfect ally because:
- Rapid gastric emptying: absorbed with minimal digestive effort.
- Fast-track energy: carbohydrates with immediate availability.
- No distractions: no chewing, no disruption to breathing rhythm.
What to Take After the Race
Recovery begins the moment you cross the finish line. After a half marathon, your body needs the right tools to move from “breakdown” mode to “repair” mode.
For optimal recovery, you need a combination of:
Carbohydrates (Glycogen) + Proteins (Repair) + Electrolytes (Rehydration)
This combination helps to:
- Restore muscle glycogen stores.
- Repair muscle fibers damaged by impact.
- Accelerate the return to training.
Evorecovery: The Refreshing “All-in-One”
?Many runners avoid post-race shakes because they are often heavy. Evorecovery from SportSeries changes the game with its WPI Clear format: a light, crystal-clear texture more similar to juice than a milkshake.
- Optimized energy: includes 4 types of carbohydrates for optimal, ultra-fast glycogen replenishment without heaviness.
- Muscle repair: 14 g of high-quality hydrolyzed protein and amino acids to immediately stop catabolism.
- Electrolyte replenishment: provides Sodium, Potassium, Magnesium, and Calcium. Drinking only water is not enough; you need to replace minerals lost through sweat to avoid cramps and delayed dehydration.
The Solid “Extra”: Energy Bar Flapjack
?If you are someone who needs to chew something to feel fully recovered, the new Energy Bar Flapjack from FoodSeries is the perfect companion for your post-race shake.
- Real energy: with 42.9% gluten-free oat flakes, providing complex carbohydrates that settle the stomach.
- Premium texture: crunchy almonds, blueberries, and real chocolate for a rewarding post-effort treat.
- The perfect combo: take it together with your cold Evorecovery; while the drink hydrates and repairs, the Flapjack provides the satiety that liquids alone cannot offer.
Related Posts
- We explain how to optimize half marathon performance in this link.
- Do you know the Science-Backed Running Supplements? Discover them by clicking here.
