Should I eat anything before a race to improve my performance?

December 14, 2025 •

4 min read

For endurance events, your body's glycogen stores are often only sufficient for about 90 minutes of intense activity. Therefore, the answer to "should I eat anything before a race?" is a resounding yes, especially for longer distances. Strategic fueling and proper hydration are critical for maximizing performance and preventing fatigue.

Quick Summary

Eating and hydrating properly before a race is crucial for performance and endurance, particularly in events over 90 minutes. A solid fueling plan provides the necessary glycogen to sustain effort and avoids digestive issues. The timing and type of food are essential for optimal energy levels.

Key Points

Fueling is essential: Eating before a race, especially for endurance events, is necessary to top up glycogen stores and prevent premature fatigue or "bonking".
Timing is crucial: A substantial, high-carb meal should be eaten 2-4 hours before, with smaller, easy-to-digest snacks closer to the start line.
Carb-load for long races: For events over 90 minutes, practice carb-loading by increasing carbohydrate intake in the 1-3 days prior to maximize glycogen storage.
Choose simple, familiar foods: Opt for easy-to-digest carbohydrates like oatmeal, bananas, and white bread, and avoid high-fiber, high-fat, and spicy foods that can cause stomach upset.
Prioritize hydration: Stay consistently hydrated in the days leading up to the race and consider supplementing with electrolytes, especially during longer races or in hot weather, to maintain fluid balance.
Practice, don't experiment: Never try a new food, gel, or drink on race day. Test all fueling and hydration strategies during your training runs to find what works best for you.

The Science of Pre-Race Fueling

Your body relies on carbohydrates, stored as glycogen in your muscles and liver, for the energy needed during intense exercise. Starting a race with depleted glycogen stores is a major handicap, leading to what many athletes call "hitting the wall"—a sudden, overwhelming feeling of fatigue. Eating before a race ensures these stores are topped up, providing the readily available fuel needed to maintain your pace and performance. Proper nutrition also aids in maintaining stable blood sugar levels, preventing dizziness and low energy.

Carb-Loading for Endurance Events

For events lasting longer than 90 minutes, such as a marathon or half-marathon, a pre-race strategy known as carb-loading is recommended. This process involves gradually increasing your carbohydrate intake over the few days leading up to the race while reducing your training volume (tapering). This allows your muscles to maximize their glycogen storage, giving you a significant energy reserve.

During a carb-loading phase, it's not about eating more total calories but shifting the calorie composition to be heavily carbohydrate-based, while reducing fats and protein. This also means you will gain a few pounds of water weight, as each gram of glycogen is stored with several grams of water, a normal and beneficial part of the process.

Timing Your Meals: The Crucial Window

The timing of your last meal is as important as what you eat. A substantial, carbohydrate-rich meal should be consumed 2 to 4 hours before the race to allow for proper digestion and absorption. This provides a final top-up of your glycogen stores. As you get closer to the start, lighter, easily digestible snacks are a better choice, if needed.

A Guide to Pre-Race Fueling Timing


Time Before Race	Type of Food/Drink	Example Foods
3-4 Hours	Substantial meal (high-carb, moderate protein, low fat/fiber)	Oatmeal with banana and a scoop of protein powder, bagel with peanut butter
1-2 Hours	Small, easily digestible snack	Banana, half an energy bar, small handful of pretzels
30-60 Minutes	Quick, simple carbs (optional)	Energy gel, sports drink, a few dates
< 30 Minutes	Hydration with water or electrolytes	Water, electrolyte drink

What to Eat and What to Avoid

The ideal pre-race meal consists of easily digestible carbohydrates, with moderate amounts of protein and low levels of fat and fiber. The goal is to provide fuel without upsetting your stomach or slowing digestion.

Best Pre-Race Fuel Options:

Complex Carbs: Oatmeal, rice, potatoes, pasta, bread, bagels
Simple Carbs: Bananas, fruit juice, energy gels, sports drinks, dried fruit
Easy Proteins: Scrambled egg whites, cottage cheese, deli turkey

Foods to Avoid Before a Race:

High-Fiber Foods: Raw vegetables, whole grains, and beans can cause gastrointestinal distress.
High-Fat Foods: Fried foods, greasy meats, and high-fat dairy take longer to digest and can make you feel sluggish.
Spicy Foods: Can lead to heartburn and stomach irritation during exercise.
Alcohol: Is a diuretic and can cause dehydration.

The Role of Hydration

Proper hydration is a key component of your pre-race strategy. It's not just about drinking right before the event, but staying well-hydrated in the days leading up to it. Aim to drink consistently throughout the day, and check your urine—it should be a pale straw color.

Over-hydrating, particularly with plain water, can also be dangerous, potentially leading to a low blood sodium condition called hyponatremia. For endurance events, adding electrolytes, especially sodium, to your hydration routine can help retain fluid and maintain electrolyte balance. Many sports drinks contain the right mix of carbohydrates and electrolytes to fuel and hydrate simultaneously.

Common Pre-Race Fueling Mistakes to Avoid

Trying something new on race day: Stick to foods and drinks you have practiced with during training. Never experiment with a new gel, drink, or meal on race day to avoid an upset stomach.
Skipping breakfast: For races longer than an hour, your body needs a fuel top-up. Missing breakfast can leave you running on empty.
Overeating: Eating too much, too close to the race start can lead to digestive issues and discomfort. Listen to your body and stick to your practiced timing.
Ignoring hydration: Dehydration, even a small amount, can significantly impact performance and increase fatigue. It is a critical component of any fueling strategy.

Conclusion

Eating before a race is not just a preference but a vital component of a successful performance strategy. By timing your meals correctly, choosing easily digestible and carbohydrate-rich foods, and staying adequately hydrated, you can ensure your body has the energy reserves needed to perform at its best. Practice your fueling strategy during training to find what works for you, so you can arrive at the starting line confident and ready to run strong. Runner's World: Race Day Fueling Strategy

Frequently Asked Questions

A substantial meal of easily digestible carbohydrates with moderate protein is best. Examples include a bagel with a small amount of peanut butter and a banana, or a bowl of oatmeal with fruit.

Yes, a banana is an excellent pre-race snack. It offers simple, easily digestible carbohydrates for quick energy and is low in fiber, minimizing the risk of stomach issues.

Carb-loading is not necessary for shorter distances like a 5K. Focus on a balanced diet and a light snack before the race, as your existing glycogen stores are sufficient for the duration.

Avoid high-fat foods, high-fiber foods, spicy dishes, and excessive alcohol. These can slow digestion, cause stomach cramps, and increase the risk of gastrointestinal issues.

Proper hydration is extremely important. Start hydrating well in the days before the race, not just on race morning. For longer events, electrolytes are crucial to maintain fluid balance and prevent hyponatremia.

If you struggle with solid food, opt for liquid carbohydrates like sports drinks or smoothies. These can provide the necessary fuel more easily and are often gentler on the stomach.

While some short, easy runs might be fine on an empty stomach, it is generally not recommended for races or longer, harder efforts. You risk running out of energy and compromising your performance.

No, you should never try new foods or drinks on race day. Stick to what you've practiced during training to prevent unpredictable digestive reactions.