Best Carbs For Runners
Trying to find the best carbs for runners and performance? This post breaks down all different types of carbohydrates, when to have each around your run, and how they can aid (or hurt) performance!

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Carbohydrates are one of the three macronutrients – the food components that give your body energy.
Carbs are the primary energy source for the brain and the body.
There are different types of carbs and different factors to consider when choosing carb foods, especially around a workout.
Best Carbs for Runners: Quick Carbs vs. Slow Carbs
There are two types of carbohydrates – complex carbs and simple carbs.
Both are important in a runner’s diet but they play slightly different roles.
When practicing carb loading for runners, it’s important to distinguish between the two because the best carbs for endurance athletes may vary depending on the athlete and situation.

Complex Carbohydrates
Complex carbs are less broken down from their natural source.
They include foods such as whole grains, such as brown rice, whole wheat bread, quinoa, and oats. Many carbohydrates do contain gluten, however a gluten free diet for athletes doesn’t have to be overly challenging.

Other sources of complex carbs include whole grain pasta, cereal, and crackers as well as legumes like lentils, chickpeas, beans, and peas and starchy vegetables like potatoes, sweet potatoes, and corn.
Complex carbs have more fiber than simple carbs, meaning it takes the body longer to break down and process these foods.
They are often considered a more stable or longer-lasting energy source for that reason.
Quick or Simple Carbohydrates
Simple carbs are more broken down or processed from their natural state, making them easier to digest.
They include foods such as white bread, white pasta, fruit juice, baked cookies, and candy, and alcohol.
These are typically good carbs to eat before a run and during a run. They are the basics of half marathon nutrition and fueling for a marathon.
Simple carbs have less fiber than complex carbs, so they are a faster source of energy for both the brain and muscles.
These are also ideal for what to eat before a cross country race.
This is good before a run! For example, having a banana, energy gel or running chews before a run.
However, while alcohol is a simple carbohydrate, running after drinking alcohol is not advised.

But, if you want a longer lasting energy source, you’ll want a choose a complex carbohydrate or pair your simple carb with a source of protein, fat, or fiber.
If you’re an ultra runner, you probably want a combination of the two!
Here are some of the best foods for ultra running.
Another way to distinguish between quick and slow carbs is by their glycemic index (GI).

The GI is a value that measures how quickly a particular food raises your blood sugar.
In the glycemix index, foods are classified as low, medium or high glycemic foods and are ranked on a scale of 0-100.
Simple carbs have a higher glycemic index because they raise your blood sugar more quickly. This is what you want if you’re choosing an energy source pre-workout.
The lower the glycemic index, the less impact that food may have on your blood sugar and the longer it takes to turn that food into energy. Complex carbs, due to their higher fiber content, usually have a lower GI.
How Many Carbohydrates Should Runners Eat?
Remember, carbs are the primary fuel source for the brain and for the body. When deciding what to eat before a marathon (or any race), carbs should be first and foremost.
Someone who is more active needs more carbs than someone who is less active.
For runners and active individuals, the majority of calories should come from carbohydrates. This translates to about 45-65% of total calories coming from carbs.
We like to recommend the performance plates as visuals, as they can be helpful in determining what to eat the night before a long run.

The exact amount of carbs a runner should eat is very individualized, however.
Especially for women, since sports nutrition for women, varies somewhat compared to nutrition recommendations for men.
The general rule of thumb for carb intake for active individuals is as follows:
Exercise Level | Carb Amounts Per Day |
Light (low intensity) | 3-5g/kg of body weight |
Moderate (~1 hour per day) | 5-7g/kg of body weight |
High (endurance; 1-3 hours per day) | 6-10g/kg of body weight |
Very high (>4-5 hours per day) | 8-12g/kg of body weight |
For example, if a 150 lb. runner is aiming to get 3-5g of carbs per kg of body weight, that would look like: 150lb./2.2 = 68kg X 3-5g = 205g-340g of carbs per day.
To give you an idea of what that looks like in terms of food, here is a list of ~20g carb serving sizes:
- 1 slice of bread
- ½ cup of cereal
- ½ cup of oatmeal
- ½ of a medium bagel
- 1 English muffin
- 2 corn tortillas (6”)
- ¾ cup pretzels
- 3 cups of popcorn, popped
- 1 Nature Valley granola bar
Many of these foods are some of the best foods for carb loading, especially those with less fiber because it’s easier to eat more of them.
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Packaged Options vs. Whole Foods
Carbohydrates come in many different forms.
Packaged options, like granola bars, oatmeal packets, applesauce, cereal, crackers, pretzels, chips, cookies, fruit snacks and energy gels can be great, convenient options.
Here are some of the best energy gels for running!
Many of the best recovery drinks for runners focus mostly on protein but do contain some carbohydrates.
However, you’ll want to add additional carbs, through fruits, grains, dairy, etc.
These can be great for fueling on the go and are often better options for fueling pre or post-workout since they are more easily digested.
Whole food options of carbohydrates include whole grains such as bread, rice, and quinoa; beans, lentils, pasta, potatoes, and fruit.
These are more nutrient-dense options, meaning they usually provide more nutrients, vitamins, minerals and fiber.

While people tend to vilify pasta, pasta for runners is a wonderful, nutrient-dense food!
Complex carbohydrates are great to include daily to provide your body with adequate nutrition, including fiber, vitamins, and minerals.
However, they may not be the best options for fueling before or during a workout as they may cause GI issues and they are not always easily portable.
Avoiding these foods before a run if you have a sensitive stomach can reduce some runners gut unpleasant symptoms.
Fiber and Digestion
Fiber is a type of carb that the body cannot digest. To further the discussion on fiber (since it is present in carbohydrate foods), there are two types of fiber: soluble and insoluble.
- Soluble fiber – Fiber that dissolves in water and helps to lower blood sugar and cholesterol levels. Food sources of soluble fiber include oats, chia seeds, nuts, beans, and apples.
- Insoluble fiber – Fiber that does not dissolve in water and helps food to move through the digestive system. Insoluble fiber helps to promote regular bowel movements and prevent constipation. Food sources of insoluble fiber include whole grains, lentils, nuts, seeds, and fruits with skin such as pears and apples.
Fiber takes longer for the body to process and break down, so it slows digestion and raises blood sugar less quickly than simple carbs and hence, has a lower GI score.
Fiber takes longer for the body to process and break down, so it slows digestion and raises blood sugar less quickly than simple carbs and hence, has a lower GI score.
It is recommended for women to get at least 25g of fiber per day and for men to get at least 38g of fiber per day. Many Americans are not meeting these numbers.
Does Blood Sugar Impact Running?
Exercise, including running, helps to move the sugar (glucose) from the bloodstream into the muscles to be used for fuel.
Therefore, running typically decreases blood sugar levels.
If someone has diabetes or issues with large fluctuations in blood sugar, they may need to track their blood sugar levels before, during, and after exercise to learn how their body responds to different types, amounts, and intensities of exercise.

Many factors can impact blood sugar levels, such as hydration status, stress, sleep, food, exercise, genetics, etc. Physical activity can lower your blood glucose up to 24 hours or more after your workout by making the body more sensitive to insulin.
How Many Carbs Do I Need Before a Run?
Fueling before a run with carbs is ideal to “top off the tank” and provide your muscles with some extra energy. There are multiple factors to consider, such as last time you ate, the time of day of the run, stomach sensitivities, etc.
In general, the closer it is to the run, the less you’ll want to consume and the quicker energy sources of carbs you’ll want to consume.
For example, if it’s 3-4 hours before a run, you can consume a more complete meal that includes carbs, protein, fat, and a fruit or vegetable.
If it’s 30 minutes to an hour before a run, you’ll want something small and mostly carb based such as a piece of toast, a banana, or a bottle of sports drink.
General Rule of Thumb for Carbs Pre-Workout:
Timing Before Exercise (Hours) | Carbohydrates (g/kg body weight) |
1 | 1 |
2 | 2 |
3 | 3 |
4 | 4 |
For example, a 150 lb. runner weighs 68kg (150/2.2) so if they are eating 4 hours pre-run, they can consume 272g of carbs but if they are eating 1 hour pre-run, they’ll want more like 68g of carbs.
Carbohydrates in Sports Drinks
Getting carbs from a fluid or drink option can be ideal for those that have a hard time eating something pre or during a run or want the convenience of having their fluids and fuel all in one.
There are lots of sport drink options such as Gatorade, Powerade, and Propel. They have varying amounts of carbs as well as varying amounts of electrolytes, such as sodium and potassium.
There are also carb powders you can add to a fluid source such as Skratch hydration mixes, UCAN energy powders, and Nuun Endurance, to name a few. They also have varying amounts of carbs as well as varying amounts of electrolytes.

You’ll want to experiment with different types of carbs before and during your training runs.
In addition to amounts of carbs and electrolytes, you’ll also want to consider flavor, texture, and caffeine, amounts as well as portability.
Want your running nutrition questions answered?
Fill out this form to be matched with one of our sports dietitians.
Other Posts You May Like
- Protein shakes for runners
- What to eat after a marathon
- Vitamin C for Runners
- Marathon Taper Nutrition
References:
- Abou Elmagd, M. (2016). Benefits, need and importance of daily exercise. Int. J. Phys. Educ. Sports Health, 3(5), 22-27.
- Sports Nutrition: A Practice Manual for Professionals, 5th ed. (2012)
- Team USA Athlete Services. Accessed from https://www.teamusa.org/Team-USA-Athlete-Services/High-Performance/Nutrition