How many carbs per day as a runner? A Comprehensive Fueling Guide

November 18, 2025 •

4 min read

According to a paper published in Nutrition Today, carbohydrates are an "indispensable energy source for high-intensity performance". To effectively fuel their runs and recovery, it is crucial for runners to understand how many carbs per day as a runner are needed based on their training intensity and goals.

Quick Summary

A runner's daily carbohydrate needs vary based on training intensity, ranging from 3 g/kg for light activity to 12 g/kg for intense endurance training. Individual factors determine the optimal intake.

Key Points

Training dictates intake: Your daily carb needs depend on your running volume and intensity, ranging from 3 g/kg for light days to 12 g/kg for heavy training.
Timing matters: Eat complex carbs in regular meals for sustained energy and use simple carbs closer to, or during, high-intensity efforts for a quick energy boost.
Fuel during longer runs: For runs over 90 minutes, consume 30–60 grams of simple carbs per hour to prevent fatigue and maintain performance.
Prioritize recovery carbs: Refuel within 30–60 minutes post-run with a high-carb, moderate-protein snack to replenish glycogen stores quickly.
Carb-load for long events: For marathons and similar distances, increase carb intake to 10–12 g/kg daily for 24–48 hours beforehand to maximize glycogen storage.
Choose wisely: Incorporate a variety of complex carbs like whole grains and sweet potatoes for daily fueling, saving simple carbs like gels and fruits for timed boosts.

Calculating Your Daily Carbohydrate Needs

Determining the right amount of daily carbohydrates for a runner is not a one-size-fits-all prescription. The ideal intake depends heavily on the intensity and duration of your training, as well as your body weight. The standard method involves calculating your needs in grams of carbohydrate per kilogram of body weight (g/kg). To start, divide your weight in pounds by 2.2 to find your weight in kilograms.

Daily Intake Based on Intensity

Light, low-intensity training: For runners during an off-season or those performing light activity, a lower intake is sufficient. The recommendation is approximately 3–5 g/kg of body weight per day.
Moderate training (approx. 1 hour/day): As training volume increases, so does the need for fuel. For those logging consistent moderate runs, the daily recommendation is 5–7 g/kg of body weight.
Moderate to high-intensity training (1–3 hours/day): This level of training requires a significantly higher carbohydrate intake to maintain performance and recovery. Aim for 6–10 g/kg of body weight per day.
Extreme endurance training (4–5+ hours/day): For ultra-endurance athletes, the demand for carbohydrates is at its peak. Daily intake can range from 8–12 g/kg of body weight.

The Timing and Types of Carbohydrates

Just as important as the quantity of carbs is the timing and type. Different carbohydrates serve different purposes before, during, and after a run.

Before Your Run

Proper pre-run fueling is essential to top off your muscle glycogen stores. The timing of this meal is critical to prevent gastrointestinal distress. For a longer, more sustained energy release, a meal 2–4 hours before a run should consist of easily digestible, high-quality complex carbs with some protein. A snack closer to the start time (under an hour) should focus on simple carbohydrates for quick energy.

During Your Run

For runs lasting longer than 60–90 minutes, ingesting carbohydrates during the activity is necessary to prevent fatigue and "hitting the wall". A common strategy is to consume 30–60 grams of simple carbohydrates per hour. Sources include sports drinks, energy gels, chews, and easily digestible foods like bananas or dried fruit. For longer endurance events, some athletes can tolerate up to 90 grams per hour by using products with a mix of glucose and fructose. Practicing your fueling strategy during training is key to avoiding stomach issues on race day.

After Your Run: The Importance of Recovery

Replenishing glycogen stores after a run is crucial for muscle repair and recovery. The 30–60 minute window immediately following exercise is when muscles are most receptive to restocking glycogen. The recommendation is to consume 1–1.2 g of carbohydrates per kg of body weight per hour for the first four hours after intense exercise. A snack or meal with a 3:1 or 4:1 ratio of carbohydrates to protein is ideal, such as chocolate milk, a turkey sandwich, or a bowl of oatmeal with fruit.

Carb-Loading for Endurance Events

Carb-loading is a strategy used for events lasting longer than 90 minutes, like marathons, to maximize muscle glycogen stores. A modern approach involves increasing carbohydrate intake to 10–12 g/kg of body weight daily for 24–48 hours before the event, combined with reduced training. It is best to choose low-fiber carbohydrate sources like white pasta, white rice, and bread during this phase to minimize the risk of gastrointestinal issues.

Comparison of Runner's Carbohydrate Needs


Training Intensity	Daily Carb Range (g/kg)	Example Runner (70kg)	Focus
Light/Off-season	3–5 g/kg	210–350 g	General health, balanced diet
Moderate (1 hr/day)	5–7 g/kg	350–490 g	Consistent energy for daily runs
High (1–3 hrs/day)	6–10 g/kg	420–700 g	Fueling heavy training and recovery
Extreme (>4 hrs/day)	8–12 g/kg	560–840 g	Maximizing performance for ultra-endurance

Best Carbohydrate Sources for Runners

Choosing the right sources can optimize your fueling strategy. Incorporate a variety of nutrient-dense options into your daily diet.

Complex Carbohydrates (Sustained Energy)

Oatmeal
Sweet potatoes and other starchy vegetables
Brown rice and quinoa
Whole grain breads and pasta
Legumes (lentils, chickpeas)

Simple Carbohydrates (Quick Energy)

Fruits (bananas, berries)
Dried fruit (raisins, dates)
Sports drinks and energy gels
White bread or rice before a race

Conclusion

Determining how many carbs per day as a runner is not fixed but dynamic, directly proportional to your training intensity and individual physiology. By calculating your g/kg needs and strategically consuming both complex and simple carbohydrates throughout the day—especially before, during, and after runs—you can optimize your performance and recovery. Periodizing your carbohydrate intake to match your training schedule and experimenting with different food sources during practice is essential for developing a personalized and effective fueling strategy. For specific advice, it is always best to consult with a registered sports dietitian.

For additional fueling strategies and tips, a resource like the Mayo Clinic offers guidance on nutrition for runners.

Frequently Asked Questions

First, convert your weight from pounds to kilograms by dividing by 2.2. Then, multiply your weight in kilograms by the recommended carbohydrate range (e.g., 5–7 g/kg for moderate training) to find your total daily carbohydrate goal.

For most runners, a low-carb diet is not recommended as it can lead to fatigue, decreased performance, and muscle breakdown. Carbohydrates are the body's primary fuel for moderate to high-intensity exercise.

3–4 hours before a long run, have a meal with a mix of complex carbs, protein, and some fat, such as pasta with a lean meat sauce. 1–2 hours before, opt for a small, easily digestible carb snack like a banana or toast with a small amount of jam.

For runs lasting over 60–90 minutes, you should begin consuming carbohydrates about 30 minutes in. Aim for 30–60 grams of carbs per hour to maintain energy levels and delay fatigue.

To maximize glycogen replenishment, consume a carbohydrate-rich snack or meal within 30–60 minutes after finishing a run. Combining carbs with protein is even more effective for recovery.

Carb-loading is the practice of increasing carbohydrate intake in the days leading up to an endurance event to maximize glycogen stores. It is typically only necessary for events lasting longer than 90 minutes and not for shorter distances like a 5k or 10k.

During a run, simple carbohydrates from sources like gels, chews, or sports drinks are best because they are digested quickly and provide a fast source of energy. Complex, high-fiber carbs should be avoided during exercise to prevent stomach upset.