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As any half or full marathoner knows, the time to practice fueling for race day is before and during your long runs. This helps you find which foods work for you and how to fuel enough to avoid feeling sluggish and slow or bonking. It can also help you figure out how to avoid eating too much or too close to take-off, leading to cramping, uncomfortable fullness, and other gastrointestinal problems that can derail a run.
So what should you eat before a long run for optimal performance? And when should you eat before you head out? In this guide, we answer all your questions about what to eat before a long run, including why it’s so important to do so and how to get it right, well ahead of race day.
slices of toast with nut butter + 1 banana?
Susan Paul, exercise physiologist and former program director for the Orlando Track Shack Foundation says eating before a long run provides two very important functions. “One, it gives you some blood sugar, which is much needed after a night of sleeping and fasting. Think of it as filling up the gas tank of your car—it’s not completely empty, but you want to top it off,” she explains.
Another important function of eating prior to a long run is that it keeps you comfortable. Paul explains that digestion can be challenging during runs because the body diverts blood flow away from internal organs and shunts it to the large muscles of the body in order to supply them with oxygen-enriched blood to meet the demands of running. The result is that areas like the gastrointestinal tract receive less blood flow during exercise.
Food present in the stomach, however, recruits blood flow for digestion, and with additional blood flow present, the stomach and GI system will be able to retain blood flow when the shunting process from running happens, keeping the GI system in better working order, Paul says. “When no food is on board, blood flow is immediately diverted away. The GI system shuts down, making eating on the run very difficult,” she adds.
“The amount of blood flow that is diverted away from internal organs is usually correlated to the intensity of the exercise. In addition, the longer the run, the more time these organs receive less blood flow, which can contribute to GI issues on long mileage days,” Paul says.
Health - Injuries?
It’s not as simple as grabbing a bagel and lacing up. Paul recommends eating about one to two hours before the run. “Low-fat and low-fiber foods are the best choices for most runners, but experimenting with different foods is important so you can figure out what works best for you. The goal is that by race day, you will have your personal nutritional plan all figured out,” she says.
How to Fuel a Marathon With a Sensitive Stomach breakfast mdash;about a 3:1 ratio of carb to protein works best.&rdquo.
Starla Garcia, RD, dietitian and Olympic trials runner based in Houston, Texas recommends fueling with 50 to 90 grams of carbohydrates for runs longer than 60 minutes. “Runners can adjust for this as well by calculating 1 to 4 grams of carbohydrates per kilogram of bodyweight,” she says.
For example, Garcia says a 140-pound runner who has a two-hour or longer run on the schedule will need roughly 63 to 254 grams of carbs before the run.
Start with the lower end of the calorie and carb range (if you’re not used to fueling prior to running) and gradually increase it as needed. “Better to go minimal first than to overload the system,” Paul says. “Think small meals that contain primarily easily digestible carbohydrates with some protein—about a 3:1 ratio of carb to protein works best.”
What foods should you eat before a long run?
Garcia says if you’re short on time, consider a simple carbohydrate-based option like an energy gel Now that you know how to fuel, you can’t forget hydrated How much should you hydrate before a run.
Every Running Hydration Question, Answered snack that meets their carb needs (as a reminder, that’s 1 to 4 grams of carbs per kilogram bodyweight). Prioritize a full breakfast and/or lunch if your run is much later.
As for what exactly to eat, Garcia suggests avoiding foods like cruciferous vegetables, high-fat foods, or fried-food options to avoid GI distress, and stick with those simple carbs and a little protein instead.
Some examples of what to eat before a long run, as recommended by Garcia:
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- 1 packet of Belvita crackers and banana + 1 serving of sports drink
- 2 slices of toast with nut butter + 1 banana
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- 2 and sports drink combination to get yourself
What foods should you eat before a long run?
Now that you know how to fuel, you can’t forget hydration. Garcia says to drink between 8 to 12 ounces of fluids at least 30 to 60 minutes prior to running. Because we all know that chugging water before you head out the door isn’t going to end well, make sure to sip slowly. “Drinking too much water can cause sloshing or cramping to occur,” she says.
Garcia adds that consuming some electrolytes in your fluids for longer training sessions are a good choice to help improve gut absorption and heat tolerance. The addition of sodium electrolyte can even be beneficial in colder months, as runners may not sweat as much but the addition can encourage drinking more.
“Runners can also consume electrolytes prior to exercise to help avoid dehydration and prevent starting a run dehydrated,” Garcia adds.
When and what should you eat during a long run?
Optimize Your Prerace Nutrition With These Tips fuel you should take in per hour while running is about 30 grams of carbs, Garcia says. The maximum is about 90 grams or in some cases, 120 grams of carbs per hour. But these numbers can vary depending on your body, intensity, timing, how you feel, and more. “Depending on the type of fuel option a runner choses, the recommended time to implement or add fuel will vary,” Garcia adds.
It’s smart to ingest your fuel in increments to help you achieve 30 grams (or more) per hour. That means ingesting a little fuel at a time, say every 15 to 25 minutes or so, after the first half hour.
“Typically for marathons, most runners can tolerate a gel every 30 minutes,” Garcia says. “I would recommend moving to [taking in fuel] every 20 minutes [if you can tolerate it] to get closer to the 90 grams per hour.”
Jennifer Acker reports on a wide range of health and wellness topics for Runner’s World and Bicycling. She’s passionate about delivering journalism that enriches the lives of readers. Jennifer is a lifelong runner—with several half marathons, and a few marathons under her belt, certified yoga instructor, and having grown up in the Pocono Mountains, always has a mountain bike and pair of skis ready for the perfect fall or winter day.
Dr. Namrita Brooke is a full-time endurance sport coach and sport nutritionist advising active individuals and amateurs to professional athletes. She is also an adjunct professor in the Department of Movement Sciences and Health at University of West Florida. Professionally, she also serves on the Board of Editors of the Sports Nutrition Care Manual and remains involved in nutrition and exercise-related research, student mentorship, and coach development. Namrita's personal athletic experience ranges from ultra-endurance mountain biking to off-road triathlon, cross-country mountain bike racing, gravel cycling, duathlon, cyclocross, running, and trail running. Her research background includes hydration and sports drink research, and the interaction of nutrition, physical activity, and the brain.
