How do you fuel a long run? A comprehensive guide for endurance runners

October 17, 2025 •

4 min read

According to sports dietitians, many runners mistakenly blame fitness gaps for poor performance when the real issue is a flawed fueling strategy. Understanding how do you fuel a long run effectively is crucial for preventing fatigue, avoiding the infamous 'wall,' and optimizing your performance, not just on race day, but throughout your entire training cycle.

Quick Summary

This guide outlines a comprehensive nutritional strategy for long-distance running, detailing pre-run meals, mid-run fueling options, and essential post-run recovery foods. It covers hydration needs, practical examples of food choices, and common mistakes to help runners improve performance and endurance.

Key Points

Pre-Run Carb-Loading: Maximize your muscle glycogen stores by increasing carbohydrate intake 24-48 hours before long runs or races, focusing on complex carbs and staying hydrated.
Strategic Pre-Race Meal: Eat a balanced, carb-heavy meal 2-4 hours before your run, and a smaller, easy-to-digest snack 45-60 minutes prior, avoiding high fiber and fat to prevent stomach issues.
Consistent Mid-Run Fueling: Consume 30-60 grams of fast-acting carbohydrates per hour for runs over 60-90 minutes, starting within the first hour to maintain energy levels.
Optimal Recovery Window: Refuel within 30-60 minutes post-run with a 3:1 or 4:1 ratio of carbohydrates to protein to replenish glycogen and repair muscles efficiently.
Prioritize Hydration and Electrolytes: Stay consistently hydrated throughout the day and before your run. During longer or hotter runs, replace electrolytes lost in sweat with a sports drink, chews, or salt tablets.
Practice Makes Perfect: Always test your fueling and hydration strategy during training runs. Never try new foods or products on race day to avoid unexpected gastrointestinal distress.

Master Your Pre-Run Nutrition

Properly preparing your body for a long run begins hours, and sometimes days, before you lace up your shoes. The primary goal is to top off your glycogen stores—the stored form of carbohydrates that your muscles and liver use for energy. For runs longer than 90 minutes, or for a race, a strategic approach is essential.

The days before (Carb-loading)

For endurance events like a half-marathon or longer, a period of carbohydrate loading can help maximize glycogen stores. This involves increasing your carbohydrate intake 24 to 48 hours before your long run while slightly reducing your training volume. Focus on high-quality, complex carbs such as whole-grain breads, pasta, rice, and starchy vegetables.

The night before

Your pre-run dinner should be balanced, with a significant portion of carbohydrates, some lean protein, and a moderate amount of healthy fats. Examples include pasta with a simple tomato sauce and lean protein, or a rice and vegetable stir-fry with tofu or chicken. To prevent stomach issues, avoid excessively high-fiber foods and overly fatty meals.

The morning of

The timing and composition of your morning meal are critical. The longer the run, the more carbs and time for digestion you'll need.

2-4 hours before: A full meal is ideal for longer digestion time. A good option is oatmeal with fruit and nuts, or a bagel with peanut butter and jelly.
45-60 minutes before: Opt for a smaller, easily digestible snack consisting primarily of simple carbs. Examples include a banana, a piece of white toast with honey, or an energy bar.

Fuelling Mid-Run: Staying Energized

Once your run extends beyond 60-90 minutes, your body's readily available glycogen stores begin to deplete, leading to fatigue. This is when you must introduce a steady stream of carbohydrates to maintain energy levels and prevent hitting the wall.

Carb intake: Aim for 30-60 grams of carbohydrates per hour for runs lasting up to 2.5-3 hours. For ultra-endurance efforts beyond this, some athletes can train their gut to handle up to 60-90 grams per hour by utilizing multiple carbohydrate sources, like glucose and fructose.
Timing: Start fueling within the first 30-45 minutes of the run and continue with regular, small doses every 15-20 minutes. Consistency is key to a steady energy supply.

Mid-run fuel options

There is no one-size-fits-all solution for mid-run fueling; practice is essential during training to find what your stomach tolerates best.

Energy Gels: Convenient and fast-acting, gels offer a concentrated dose of carbohydrates. Many come with added electrolytes or caffeine.
Energy Chews or Blocks: A solid alternative to gels, these are easy to chew and digest.
Sports Drinks: Provide both carbohydrates and electrolytes, serving a dual purpose. Look for a 6-8% carbohydrate solution to avoid stomach upset.
Real Food: For some runners, options like bananas, dried fruit (raisins or dates), or small pretzel bags work well.

Comparison of Mid-Run Fuel Sources


Feature	Energy Gels	Sports Drinks	Real Food (e.g., Banana)
Carbohydrates	Concentrated, fast-digesting	Provides carbs + hydration	Natural, easy to digest (for most)
Electrolytes	Often included	Included, important for hydration	Primarily potassium (in bananas)
Convenience	Highly portable, easy to carry	Combines fluid and fuel	Requires carrying and potentially more chewing
Ease of Digestion	Very easy for most	Easy, but higher concentrations can cause issues	Can be slower to digest due to fiber
Cost	Generally more expensive per serving	Varies, can be cost-effective in bulk	Economical, whole-food source

Post-Run Recovery: Rebuilding and Refueling

Your work isn't done when you cross the finish line. The 30-60 minute window immediately after your run is a critical period for recovery. This is when your muscles are most receptive to restocking depleted glycogen stores and beginning the repair process.

Carbohydrates: Refuel with a carbohydrate-rich snack to replenish muscle glycogen. The recommended amount is about 1 gram of carbohydrate per pound of body weight within the first 2 hours.
Protein: Pair your carbs with high-quality protein to repair muscle damage. A 3:1 or 4:1 carb-to-protein ratio is a good target. Aim for about 20-25g of protein in your recovery snack or meal.
Hydration: Continue to rehydrate with fluids and electrolytes to replace sweat losses. Drink 16-24 ounces of fluid for every pound lost during the run.

Sample recovery meals and snacks

Smoothie: Blend frozen fruit, Greek yogurt, and protein powder.
Chocolate Milk: Offers an optimal carb-to-protein ratio and helps with rehydration.
Sandwich: Turkey and avocado on whole-grain bread.
Oatmeal: Topped with nuts, fruit, and yogurt.

Don't Forget Hydration and Electrolytes

Beyond just eating, maintaining proper hydration is non-negotiable for a successful long run. Dehydration can lead to fatigue, reduced performance, and heat-related illness.

Pre-run: Drink 17-20 ounces of fluid 2-3 hours before your run.
During run: Aim for 5-10 ounces of water or a sports drink every 15-20 minutes.
Electrolytes: Sodium and other electrolytes are lost in sweat and are crucial for fluid balance and muscle function. For runs over 90 minutes or in hot conditions, supplementing with electrolytes via a sports drink, chews, or salt tablets is vital.

Conclusion

Effectively fueling a long run is a skill that, like running itself, requires practice and personalization. By focusing on a strategic, carbohydrate-centered diet before, during, and after your runs, and paying close attention to your hydration and electrolyte needs, you can dramatically improve your performance and recovery. Test different foods and products during your training to discover what works best for your body, ensuring you never face the starting line unprepared. Your nutrition is a powerful training tool—use it wisely to go the distance feeling strong and energized. For more detailed nutritional plans, consulting with a sports dietitian can help tailor a strategy to your specific needs and goals.

Frequently Asked Questions

The night before a long run, you should eat a balanced meal rich in complex carbohydrates and moderate in lean protein and healthy fats. Good examples include pasta with lean chicken and tomato sauce, or a rice and veggie stir-fry. Avoid high-fiber and excessively fatty foods to prevent digestive issues during your run.

For a long run, eat a full meal 2-4 hours before starting. An easily digestible, carb-focused meal like oatmeal with fruit is a good choice. If you only have 45-60 minutes, a small, simple carb snack like a banana or toast with honey is sufficient.

For runs lasting over 60-90 minutes, you should start consuming fuel within the first 30-45 minutes and aim for a steady intake every 15-20 minutes thereafter. The goal is to provide a consistent energy supply to your muscles.

Alternative mid-run fuel options include energy chews or blocks, sports drinks, dried fruit (like raisins or dates), small pretzels, or even real foods like mashed potato pouches. Practice with different options during training to see what works best for you.

Electrolytes, particularly sodium, are very important, especially for runs over 90 minutes or in hot, humid conditions. They help regulate fluid balance and prevent cramping caused by sweat loss. Water alone is often not enough; you should supplement with electrolytes through sports drinks or tablets.

Aim for a 3:1 or 4:1 ratio of carbohydrates to protein in your post-run recovery meal or snack. This combination has been shown to enhance glycogen replenishment and muscle repair more effectively than carbohydrates alone.

For runs under 60 minutes, your body typically has sufficient glycogen stores from your regular diet, so you will likely not need to eat or drink anything other than water during the run. Focus on proper pre-run and recovery nutrition instead.