How Many Carbs Should a Runner Eat a Day?

October 24, 2025 •

4 min read

According to sports nutrition experts, the exact carbohydrate needs for a runner vary widely depending on their training intensity, body weight, and exercise duration. An appropriate diet ensures muscles are properly fueled with glycogen, the body's preferred energy source, for optimal performance and recovery.

Quick Summary

This guide outlines a runner's daily carbohydrate needs based on training volume, from light activity to intense sessions. It explains the timing and type of carbs to consume, focusing on fueling strategies for before, during, and after runs. Practical examples and a comparison of carb sources are included to help optimize performance.

Key Points

Adjust for Intensity: Your daily carbohydrate intake should be dynamic, based on your training volume and intensity, ranging from 3-5 g/kg/bw on rest days to 8-12 g/kg/bw for ultra-endurance.
Timing is Key: Consume easily digestible simple carbs for quick energy before and during runs, and focus on complex carbs and protein for muscle recovery post-run.
Practice Makes Perfect: Experiment with your fueling plan during training, not on race day, to ensure your gut can handle your race-day nutrition strategy.
Don't Fear Carbs: Restricting carbohydrates, especially for distance runners, can lead to depleted glycogen stores, poor performance, and inhibited recovery.
Prioritize Quality: Choose nutrient-dense carbohydrate sources like whole grains, fruits, and starchy vegetables to get the most nutritional value from your intake.
Hydrate to Fuel: Adequate hydration is crucial for storing and utilizing glycogen, so drinking enough water is just as important as eating enough carbs.

Calculating Your Daily Carbohydrate Needs

The question of how many carbs should a runner eat a day is not one-size-fits-all. Instead, the answer is dynamic, shifting with your training volume and intensity. Nutrition guidelines from sports dietitians provide a tiered approach based on your activity level, measured in grams of carbohydrates per kilogram of body weight (g/kg/bw).

For an average runner, daily requirements can range from 3 to 12 grams of carbohydrates per kilogram of body weight. To get started, first convert your body weight from pounds to kilograms by dividing by 2.2. A 150-pound (68 kg) runner doing moderate training, for example, would aim for 340-476 grams of carbohydrates per day. The key is adjusting this intake according to your training load.

Daily Carbohydrate Intake by Training Volume

Light, low-intensity exercise (rest days or up to 60 mins): 3–5 g/kg/bw. The focus shifts to rebuilding muscle and restoring glycogen, so complex carbohydrates and fiber are beneficial. For a 68 kg runner, this means roughly 204–340 grams.
Moderate exercise (approx. 1 hour/day): 5–7 g/kg/bw. This level requires a balanced approach to sustain daily energy and support recovery. A 68 kg runner would target 340–476 grams.
Moderate- to high-intensity exercise (1 to 3 hours/day): 6–10 g/kg/bw. As mileage and effort increase, so does the need for readily available energy. A 68 kg runner could need 408–680 grams.
Extreme endurance (4 to 5+ hours/day): 8–12 g/kg/bw. Ultra-endurance athletes require a very high carbohydrate intake to prevent glycogen depletion and maintain performance over prolonged periods. A 68 kg runner could need up to 816 grams or more.

The Importance of Carbohydrate Timing

Properly timing your carbohydrate intake is just as important as the total amount. Runners should be strategic about when they consume different types of carbs to maximize their benefits.

Before a run: A pre-run meal or snack is crucial, especially for early morning sessions. The goal is to top up liver glycogen stores that deplete overnight. Timing depends on the size of the meal:

2–3 hours before: A full meal with a good balance of complex carbs and lean protein is ideal.
30–60 minutes before: A small, easily digestible source of simple carbohydrates is best for a quick energy boost, like a banana or a handful of pretzels.

During a run: For sessions lasting over 60–90 minutes, taking in carbohydrates is essential to maintain blood sugar and spare glycogen stores. Recommendations range from 30 to 90 grams per hour, with higher intakes needed for longer and more intense efforts. Popular options include energy gels, chews, and sports drinks.

After a run: The 30–60 minute window immediately after a run is critical for muscle glycogen replenishment and repair. Aim for a carbohydrate-protein mix, often in a 3:1 ratio. Chocolate milk is a classic example that fits this profile perfectly.

Comparison of Simple vs. Complex Carbohydrates

Not all carbohydrates are created equal, and knowing when to use each type is vital for a runner's performance. The table below summarizes the key differences.


Feature	Complex Carbohydrates	Simple Carbohydrates
Digestion Speed	Slow digestion for sustained energy.	Fast digestion for quick energy.
Nutrient Density	High in fiber, vitamins, and minerals.	Minimal fiber and nutrients.
Best for...	Daily fueling, post-run recovery.	Pre-run snacks, during-run fueling.
Examples	Oats, sweet potatoes, whole grains, lentils, quinoa.	Bananas, sports gels, white bread, honey, dried fruit.
GI Distress Risk	Higher fiber content can cause GI issues if consumed too close to a run.	Lower risk of GI issues due to quick digestion.

Practical Tips for Fueling Your Runs

Practice your fueling strategy: Do not wait until race day to experiment with your carb intake. Test different foods and quantities during your training runs to see what works best for your body.
Hydrate adequately: Carbohydrates are stored in the muscles and liver with water. Proper hydration is essential for efficient glycogen storage and utilization.
Consider carb loading for major events: For races longer than 90 minutes, consider carbohydrate loading in the 24-48 hours prior. This involves increasing your carb intake (10-12 g/kg/bw) while reducing exercise intensity.
Don't skip rest day carbs: Even on days you aren't running, your body needs carbohydrates to replenish glycogen and aid in recovery. Focus on whole-food sources.

Conclusion

Determining how many carbs a runner should eat per day depends on a personalized approach tailored to their training load, body weight, and individual tolerance. By understanding the tiered recommendations for daily intake, strategic timing for different types of carbohydrates, and smart fueling strategies before, during, and after runs, athletes can optimize their energy levels and enhance performance. For distance and endurance runners, embracing a carb-centric diet is key to avoiding glycogen depletion and achieving peak physical condition. With a little practice and attention to your body's signals, you can confidently fuel your running goals.

Sources

Frequently Asked Questions

Glycogen is the stored form of glucose in your muscles and liver and is the body's primary fuel source for endurance exercise. Maintaining adequate glycogen stores through proper carbohydrate intake is crucial for a runner's performance and to prevent 'hitting the wall'.

Yes, especially if it's a long or intense run. Your liver glycogen stores can become depleted overnight. A small, easily digestible carbohydrate snack 30-60 minutes before can provide a quick energy boost.

There is no single best source, but a variety of whole-food complex carbs like oats, sweet potatoes, and whole grains are best for daily fueling. For quick energy before and during a run, simple carbs like bananas, sports gels, or white bread are effective.

For runs over 90 minutes, runners should aim for 30 to 60 grams of simple carbohydrates per hour. For ultra-endurance events, some athletes may consume 60 to 90 grams per hour.

First, convert your body weight from pounds to kilograms (divide by 2.2). Then, multiply your weight in kg by the recommended grams per kg based on your training intensity. For example, a 150lb (68kg) runner in moderate training needs 340-476g per day (68 x 5-7g).

Experts often recommend a 3:1 or 4:1 carbohydrate-to-protein ratio within the 30-60 minute window after a run to maximize muscle glycogen replenishment and repair.

No, carb loading is generally only recommended for endurance events lasting over 90 minutes. Casual runners can typically meet their needs with a higher daily intake of carbohydrates without needing a formal loading period.