By Marnie Kunz, NASM-certified trainer, USATF- RRCA-certified run coach

Knowing what to eat before a long run can make or break your performance. Eating the right foods can help power you through the long miles without weighing you down from digestion issues. As a running coach, I often get asked what to eat before long runs and races, so I am compiling my top tips here and offering science-backed guidelines to help you fuel your runs. Whether you’re marathon training or preparing to run a half marathon, these tips will help you eat the best foods to stay energized for long training runs.

What to Eat Before a Long Run: The Science of Eating and Running

When running long distances, your body uses carbs for energy. Carbs are converted to glycogen, which powers your muscles on the run. This is why eating carbs is essential before long runs and races. You’ve probably heard of “carb loading” for marathons and long races, which means stocking up on carbs for long-run energy. During your long runs, your body will deplete its glycogen stores, which is why it’s important to also have fuel on the run.

Foods to Avoid

Before running, it's best to stay away from high-fiber foods as these can make you have GI issues, need to use the restroom, and disrupt your workout. Also, some foods like dairy products can cause bloating and digestion issues for runners, especially those who are lactose-intolerant.

Best Carbs for Runners

If you’re wondering what to eat before a long run, this list includes the best carbohydrates for runners. Not all carbs are created equal, as some are easier to digest and use than others. Try some of these easily digestible carbs to help you power through your long runs:

Bananas

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Bananas are an excellent source of quickly digested carbs that can provide fast energy for your long runs. Bananas are one of my go-to foods for a quick energy boost before long morning runs. They are easy on the stomach and have the added benefit of potassium and magnesium, which are electrolytes your body needs to run well. Try slicing a banana and putting it on toast with peanut butter, grabbing a plain banana, or putting banana slices on top of your oatmeal or in your smoothie to boost energy and electrolytes.

Toast

Toast is one of my favorite light meals before a long run. It is easy to digest and won’t make you feel nauseous if you’re nervous before a race. You can add peanut butter and bananas to your toast for a nutritious boost. Opt for freshly baked bread for the easiest-to-digest toast before long runs.

Bagels

If you're a bagel person, bagels are a great carb-rich option for long run fuel. Whole-grain bagels offer complex carbs that can help endurance athletes power through many miles.

Sweet potatoes

Sweet potatoes are another great carb source for long runs. These carb-rich veggies are easy to digest and have lots of potassium, which helps prevent muscle cramps. Add sweet potatoes to your dinner the night before a long run by dicing and placing sweet potatoes in a quinoa or rice bowl, or have a baked sweet potato with some lean protein for a nutritious meal.

Oats

Oats are rich in carbs and fiber, and you can add bananas, berries, chia seeds, or nuts for even more nutrients. Oatmeal is a filling pre-long run breakfast. Just give yourself an hour or two to digest your oats before running, as the high fiber may make you have to use the restroom.

Smoothies

Smoothies are another way to get a boost of carbs before long runs. You can personalize your smoothie with the fruits of your choice and add some Greek yogurt or protein powder for a boost of protein. I like to add chia seeds as well for healthy fats.

Sample Meals

Here are some sample meals to help you decide what to eat before a long run. If you’re doing your long run in the morning, a carb-rich dinner and an easily digestible breakfast will help you stay energized. For afternoon and evening long runs, you’ll want to have plenty of carbs for breakfast and a carb-rich, bland meal at least 1 to 2 hours before your long run.

Breakfast

Toast with almond butter and banana slices.
Oatmeal with almonds, berries, and bananas.
Avocado toast on whole wheat bread. (Optional - add an egg on top).

Lunch

Quinoa bowl with sweet potatoes, mushrooms, and lean protein (tofu, chicken, or beans).
Peanut butter, honey, and banana sandwich on fresh bread.
Tacos with diced sweet potatoes, avocado, tomatoes, cilantro, and protein (beans, chicken, or beef).

Dinner

Baked salmon and baked sweet potato with a side of mixed vegetables.
Quinoa bowl with diced sweet potatoes, vegetables, and lean protein (lentils, chicken, tofu, beans, beef, or seafood).
Whole wheat pizza with roasted vegetables.
Protein pasta with fresh vegetables.

These are just some ideas for healthy pre-long-run meals that are rich in carbs. You can personalize the options by adding the protein and vegetables of your choice.

When to Eat Before a Long Run

Knowing what to eat before a long run is only half the battle - figuring out when to eat is important too. Your body will need time to digest so you don’t get an upset stomach on the run. Everyone’s digestion times are different, but here are some general guidelines to help you figure out when to eat before your long run:

Eat a moderate to large meal at least 3 hours before your long run. If you eat a big meal, it’s best to wait at least 3 hours to allow your body to digest your food before running.
You can eat a small meal (up to 400 calories) up to 2 or more hours before your long run. A sandwich, light breakfast, or small dinner should be fine if you eat it at least 2 hours before you run.
Eat a snack between 1 hour to 30 minutes before running. If you need a snack, give yourself at least 30 minutes to digest it before running. A banana is a great pre-run snack that’s easy to digest.
Have running fuel before and during long runs of over 1 hour. This includes running gels and fuels that you take 45 minutes before running and periodically during your long runs.

Related Post: When and What to Eat Before Running

Fuel on the Run

In addition to eating carb-rich, digestible foods before long runs, you’ll also need to take some running fuel during any runs over an hour. Aim to take 30 to 60 grams of carbs for each hour you’re running beyond the first hour. The exact amount of carbs you need during your run depends on your body weight, according to experts. Check the guidelines of your particular running fuel to see how often you should take it and how much you need.

Running Strong

Figuring out what to eat before a long run can take some trial and error as you experiment with different foods to see what is easiest for your body to digest. Remember to take fuel during your long run to replenish your glycogen stores.

If you need more training help and want a personalized plan, head to our Training Center for virtual training options to crush your running goals. Happy running to you! 😊

Marnie Kunz is a NASM-certified trainer and USATF- and RRCA-certified running coach, a dog lover, an Akita mom, and the founder of Runstreet. She specializes in helping runners get faster and stronger and helping beginners elevate their fitness levels. She is based in Brooklyn, New York.

What to Eat Before a Long Run: Tips from a Coach