What are the best carb loading foods for runners?

December 15, 2025 •

4 min read

For endurance events lasting over 90 minutes, carbohydrate loading can boost muscle glycogen stores by as much as 30% or more, significantly enhancing performance and delaying fatigue. Choosing the right foods is crucial for maximizing this effect while minimizing digestive upset, which can be a race-day disaster.

Quick Summary

A proper carb loading strategy involves selecting easily digestible, carbohydrate-dense foods to maximize muscle glycogen stores in the days leading up to an endurance event. Focus on low-fiber, lower-fat options like pasta, rice, and potatoes, while incorporating some simple sugars to reach your daily carb target effectively.

Key Points

Prioritize Easily Digested Carbs: Focus on refined grains like white rice and pasta over their whole-grain counterparts to reduce fiber and prevent stomach upset.
Increase Liquid Carbohydrates: Use sports drinks, juice, or liquid carbs to help meet your high daily carb target without the bulk of solid food.
Reduce Fat and Fiber: Cut back on high-fat and high-fiber foods in the 2-3 days before your race to prevent bloating and sluggishness.
Start Early: Begin your carb-loading phase 48-72 hours before your race, not just with a single large meal the night before, for optimal glycogen storage.
Hydrate Adequately: Remember to increase your fluid intake alongside your carb consumption, as your body stores extra water with the glycogen.
Practice in Training: Always test your carb-loading strategy during your long training runs to identify foods and timing that work best for you.

The Science Behind Carb Loading

Carbohydrate loading is a nutritional strategy used by endurance athletes to maximize the storage of glycogen in their muscles and liver. Glycogen is the body's primary fuel source during prolonged, high-intensity exercise. By strategically increasing carbohydrate intake while tapering training volume in the days before a race, runners can start with a full fuel tank, delaying the onset of fatigue, or 'hitting the wall'. This approach is most beneficial for races lasting 90 minutes or longer, such as marathons and half-marathons. For shorter races like 5Ks, standard high-carb meals in the days prior are sufficient, and a full carb-load is generally unnecessary.

Simple vs. Complex Carbohydrates for Runners

Not all carbs are created equal, especially when it comes to carb loading. Understanding the role of different types can help you plan your meals effectively.

Complex Carbohydrates: These are the backbone of your carb-loading diet. Found in foods like pasta, rice, and potatoes, complex carbs consist of long chains of sugar molecules that provide a steady, sustained release of energy. They are ideal for the primary meals during your 2-3 day carb-loading phase. To minimize stomach upset, many runners switch from whole-grain to lower-fiber refined versions (like white rice and white pasta) in the final 48 hours.
Simple Carbohydrates: Composed of one or two sugar molecules, simple carbs are digested quickly and offer a rapid energy boost. They are great for topping off glycogen stores in the final hours before a race, during the race itself via gels or chews, or for increasing overall carb intake without the bulk of complex carbs. Examples include ripe bananas, fruit juices, and honey.

The Best Carb Loading Foods for Runners

To fill your glycogen stores efficiently and without causing digestive distress, focus on these easily digestible, carb-dense options. The key is to reduce fiber and fat intake slightly to prevent bloating and discomfort.

Grains and Starches

White Pasta and Rice: The classic choice for a reason. Their refined nature makes them easily digestible, and they are excellent sources of complex carbohydrates.
Potatoes and Sweet Potatoes (peeled): A versatile and nutrient-rich option. Peeling them reduces fiber, which can be beneficial for sensitive stomachs. Plain mashed or baked potatoes are excellent choices.
Bagels and White Bread: These are dense in carbohydrates and low in fiber, making them easy to digest. A bagel with jam or honey is a classic pre-race snack.
Low-Fiber Cereal: Simple corn or rice-based cereals are great for breakfast or as a snack. Pair with low-fat milk or juice.

Fruits and Sweets

Bananas: A runner's favorite for a reason. They provide easily digestible simple carbs and potassium.
Dried Fruits: Highly carbohydrate-dense and portable. Dates, raisins, and dried apricots are excellent choices to add quick carbs.
Fruit Juice: A simple way to boost your carb intake without adding bulk. Options like orange or apple juice are effective.
Honey and Jam: Quick sources of simple sugar to add to toast, bagels, or oatmeal.

Liquid Carbohydrates

Sports Drinks: Designed to provide easily absorbable carbohydrates and electrolytes, sports drinks can help you meet your high carb target without feeling excessively full.
Chocolate Milk (low-fat): A great option for recovery, offering a perfect carbohydrate-to-protein ratio, but also useful during the loading phase.

Comparison Table: Carb Loading Foods


Food Type	Best for Carb Loading	To Limit or Avoid	Why?
Grains	White rice, white pasta, plain bagels, low-fiber cereal	Whole-grain bread, brown rice, high-fiber cereals	Higher fiber content can cause GI distress when consumed in large quantities.
Starches	Peeled potatoes, sweet potatoes	Potato skins, other high-fiber root vegetables	High fiber and complex structure can slow digestion and cause bloating.
Fruits	Ripe bananas, applesauce, fruit juice, dried fruits	High-fiber fruits with skin like apples, pears	Fiber content can be problematic for some sensitive stomachs when consuming large volumes.
Dairy	Low-fat milk, low-fat yogurt	High-fat cheese, whole milk dairy	High-fat products are slower to digest and can lead to GI issues before a race.
Snacks	Pretzels, rice cakes, fig bars, honey	Chips, pastries, high-fat energy bars	High fat content can slow carbohydrate absorption.
Protein	Lean protein sources like chicken breast or fish	Fatty meats, excessive amounts of beans or legumes	High-fat and high-fiber protein sources can fill you up and displace carbs.

Practical Tips for Successful Carb Loading

Plan Your Timing

Begin your carb-loading phase 2-3 days before your race, not just the night before. This gives your body time to adequately fill its glycogen stores. As you increase carbohydrate intake (to 8-12 grams per kg of body weight daily for some athletes), slightly decrease your fat and protein intake to manage overall calories and avoid feeling overly full or sluggish.

Prioritize Liquids

For many runners, consuming enough solid food to meet high carb targets is challenging. Liquid calories from sports drinks, juices, and low-fat milk can be an easy and effective way to supplement your intake without the bulk. Remember to also increase your overall fluid intake, as each gram of stored glycogen holds 3 grams of water, making proper hydration essential.

Practice in Training

Never try a new carb-loading strategy on race day. Practice during a few of your long training runs to see what foods and timing work best for your digestive system. This familiarity builds confidence and helps prevent unwanted surprises on race day.

Conclusion

Choosing the best carb loading foods for runners is a critical step in preparing for an endurance event. By prioritizing easily digestible, high-carbohydrate options like white pasta, rice, potatoes, and bananas while reducing fat and fiber, you can maximize your glycogen stores and improve your performance. Successful carb loading is less about eating massive quantities and more about making smart, targeted dietary adjustments in the days leading up to your race. By following these guidelines and practicing your fueling strategy during training, you'll be ready to perform at your peak on race day.

Outbound Link

For more information on general runner's nutrition and proper fueling, you can explore the Mayo Clinic Health System's guide.

Frequently Asked Questions

For the night before a marathon, focus on a familiar, carb-heavy meal that is low in fiber and fat. Classic options include white pasta with a simple tomato sauce, white rice with lean chicken or fish, or a plain baked potato. Eat dinner on the earlier side to allow for adequate digestion.

During the 2-3 day carb-loading phase, you should focus on complex carbohydrates like pasta, rice, and potatoes for sustained energy storage. However, for a quick top-up in the final hours before a race, simple carbs like a banana or sports gel are more effective for a rapid energy boost.

Effective carb loading typically takes 2-3 days (48-72 hours) before an endurance event. This timeframe allows your muscles to maximize glycogen stores. Starting earlier is not necessary and might lead to excessive fat or fiber intake.

Avoid high-fat foods (creamy sauces, fried foods), high-fiber foods (beans, whole grains, raw vegetables), and excessive protein. These can slow digestion, cause bloating, and displace the high volume of carbs needed.

No, carb loading is generally not necessary for a 5K race. Your normal daily high-carb diet provides sufficient energy stores. For shorter events, focusing on a balanced pre-race meal and proper hydration is more important than a dedicated loading protocol.

Recommendations are typically between 8 and 12 grams of carbohydrates per kilogram of body weight per day, depending on the duration and intensity of the event. It's crucial to find a balance by reducing fat and protein, not just by adding more total calories.

Energy gels and sports drinks are excellent tools for increasing your carb intake, especially if you struggle with the bulk of solid food. They provide easily absorbed, simple sugars and can be used as part of your loading strategy, particularly closer to race day.