So, you’ve signed up for a half marathon and now you’re wondering what to eat before the big race. Probably, you’ve heard that a combination of carbohydrates, protein, and enough hydration is all you need. That’s correct. 

But not just any type of these classes will do the job. For instance, high-fiber protein can cause digestive issues and discomfort during your run.

In this guide, we provided tailored recommendations on what to eat the day before running a half marathon. Whether this is your first 13.1 miler or your fiftieth, these pre-race eating strategies will help you cross the finish line feeling strong.

Carbohydrates for Half-Marathon Runners

Carbohydrates act as the primary fuel source for your muscles during a half marathon. Stored in your liver and muscles as glycogen, they readily convert to glucose, powering your relentless stride. 

However, glycogen reserves are limited, depleting after approximately 90 minutes of prolonged exertion. This manifests as fatigue and a dreaded performance decline, known as “hitting the wall.”

So, you must ensure you take adequate pre-race carbs to take you through the 13.1 miles. The recommended daily intake in the three days preceding your race ranges between 7 to 10 grams per kilogram of body weight.

Here are some examples of carbohydrate pre-race fueling for half marathon runners:

1. Bananas (Quick Digesting Option)

They are readily available pre-race or mid-race food that provide a quick jolt of energy without gastrointestinal distress. Their potassium content additionally serves as a valuable muscle cramp deterrent. 

2. Energy Gels (Quick Digesting Option)

Convenient and portable, energy gels offer a concentrated dose of readily absorbed carbohydrates for an immediate energy boost. But remember to pair them with water to avoid dehydration.

3. Oatmeal with Berries for Sustained Energy

This breakfast or pre-race snack masterfully combines complex and simple carbohydrates, ensuring stable blood sugar levels and enduring energy. 

Oatmeal’s fiber content promotes healthy digestion and prevents constipation, while the antioxidant power of berries fights running-induced inflammation.

4. Whole-grain Toast with Nut Butter for Lasting Fuel

This balanced trio of carbohydrates, protein, and healthy fats delivers sustained satisfaction and prolonged energy. 

Whole-grain bread offers B vitamins for optimal energy metabolism and nerve function, while nut butter aids muscle repair, strengthens the immune system, and reduces inflammation. Its healthy fats further contribute to cardiovascular health.

Protein for Endurance


Protein helps runners build and repair muscles, tendons, ligaments, and bones. It also bolsters your immune system, hormone production, and enzyme function. In addition, it aids in feeling full, reducing overeating and weight gain.

Your protein needs vary based on body weight, training intensity, and race pace. Generally, you should consume 1.2 to 1.6 grams per kilogram of body weight daily. However, increased protein may be necessary for intense training, injury recovery, or if you’re on a vegetarian or vegan diet.

Protein options for half marathon preparation include:

1. Lean Protein Like Turkey or Chicken

They offer high-quality protein for muscle repair and immune support, are low in fat and calories, as a result, aid weight maintenance. You can grill, bake, or roast them as you wish.

2. Greek Yogurt with Granola and Fruit

This is ideal for breakfast or a snack as it combines protein, carbohydrates, and calcium for nourishment and energy. 

Greek yogurt is higher in protein and lower in sugar, prolonging fullness and stabilizing blood sugar. On the other hand, granola provides carbohydrates, fiber, and fats for energy and digestion. Fruit adds vitamins, minerals, and antioxidants for cell protection and immune enhancement.

3. Protein Smoothies with Greens and Fruits

They offer a liquid mix of protein, carbohydrates, and micronutrients for hydration and glycogen replenishment. They are suitable for breakfast or a snack, easy to digest, and help avoid digestive issues. 

You can use any protein powder like whey, soy, pea, or hemp, and mix it with greens and fruits like spinach, kale, banana, pineapple, and berries for flavor and nutrition.

Hydration Strategies for a Half Marathon

Hydration is crucial for runners, as it helps regulate your body temperature, blood pressure, heart rate, and fluid balance. On the other hand, dehydration can impair your performance, cause headaches, cramps, nausea, and fatigue, and increase your risk of heat stroke and injury.

The amount of fluid you need depends on your body weight, sweat rate, weather conditions, and race pace. A general guideline is to drink 500 milliliters of fluid two hours before your race, and another 250 milliliters 15 minutes to it. 

During your race, you should drink according to your thirst and the availability of water stations.

Here are some examples of hydration tips specific to a half marathon:

1. Electrolyte-rich Drinks for Endurance Athletes

Electrolytes, including sodium, potassium, calcium, magnesium, and chloride, are vital for fluid balance, muscle function, nerve transmission, and maintaining pH levels. 

Sweating depletes electrolytes, impacting performance and health. To counter this, especially in hot, humid conditions or for heavy sweaters, consume electrolyte-rich drinks before, during, and after the race.

2. Coconut Water for natural hydration

Coconut water, a natural choice, effectively hydrates and restores electrolytes. Rich in potassium, magnesium, calcium, and phosphorus, it supports muscle and bone health. Its antioxidants reduce inflammation and oxidative stress from running.

Low in calories and sugar, it helps avoid weight gain and blood sugar spikes. Suitable before, during, or after the race, coconut water can replace or supplement water and sports drinks.

Pre-Race Snacks for Quick Energy

Snacking helps you replenish glycogen stores and provide quick energy for a half marathon. It also helps stave off hunger and cravings, preventing distractions during the race. However, avoid excessive snacking or doing so too close to the race, as it may lead to stomach upset and cramps.

The best snacks for pre-race nutrition are those that are high in carbohydrates, moderate in protein, and low in fat and fiber. 

They are easy to digest and absorb and familiar to your stomach. Aim to consume your last snack about one to two hours before your race, and limit it to about 200 to 300 calories.

Here are some examples of practical snack ideas suitable for the day before a half marathon:

1. Nuts and Dried Fruits

These are simple and convenient snacks that can provide you with a mix of carbohydrates, protein, and healthy fats that will keep you satisfied and energized. 

They also contain vitamins, minerals, and antioxidants, which can help protect your cells from damage and enhance your immune system. Almonds, walnuts, cashews, raisins, dates, apricots, and figs are excellent choices.

2. Energy Bars

These are a convenient and tasty snack that provides a balance of carbohydrates and proteins to keep you fueled and satisfied. 

Energy bars are easy to carry and consume and are found in various flavors and brands. But be careful to choose those low in sugar, fat, and additives, and high in natural ingredients, fiber, and protein.

3. Low-fat Chocolate Milk

Low-fat chocolate milk is also a good source of carbohydrates and protein, which can help restore your glycogen levels, repair your muscles, and support your immune system. 

It also contains calcium, which can help strengthen your bones and prevent stress fractures. You can drink low-fat chocolate milk as a snack the day before your race or after your last training session.

Avoiding Discomfort with Light and Digestible Meals

One of the most common mistakes that runners make while preparing for their half marathon is eating too much or too heavy meals close to race time. This can cause gastrointestinal distress, such as bloating, gas, nausea, diarrhea, and cramps, which can ruin your race and your health. 

Generally, in choosing what not to eat the day before a half marathon, you must avoid foods high in fat, fiber, protein, and spices. Instead, opt for light and digestible meals that are high in carbohydrates and low in fat and fiber. 

Salads, with ingredients like lettuce, spinach, kale, cabbage, carrots, tomatoes, cucumbers, peppers, olives, cheese, nuts, seeds, and dressing, provide a refreshing and nutrient-rich option. Additionally, whole-grain wraps, filled with turkey, chicken, ham, cheese, hummus, avocado, lettuce, tomato, cucumber, and salsa are a good option.

Moreover, ensure you eat your last meal about three to four hours before your race, and limit it to about 500 to 700 calories. You should also avoid foods that are unfamiliar, spicy, greasy, or dairy-based, as they can cause stomach upset and intolerance. Lastly, remember that alcohol, caffeine, and carbonated drinks can dehydrate you and interfere with your sleep quality.

Final Half Marathon Fueling Tips

Use these final half marathon nutrition tips to customize your eating schedule leading up to race day:

Fueling properly for your half marathon is a strategic process, requiring planning and practice. With the right fuel, you’ll cross the finish line feeling energized and accomplished after tackling 13.1 miles!