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Here is Part II of this Marathon Prep series, written by guest blogger Sarah Gold.

What to eat before a long run can be a stressful decision. You need to figure out what foods will provide adequate fuel without upsetting your stomach or the rest of your gastrointestinal tract. As you read last week, training your gut to tolerate food is important, but knowing what foods to choose and which ones to avoid can improve the performance and enjoyment of your training runs. Remember to practice your race-day breakfast on your long training runs leading up to the big day!


What should I eat?

Before a long run, your meal should include carbohydrates that digest easily and are low in fiber. Aim for approximately 2 calories of carbohydrates per pound of body weight (0.5g carbs per lb). A 150lb runner would want approximately 300 calories in carbohydrates. This will add to your glycogen stores and play a role in keeping your blood sugar constant. It will also keep hunger down during your run.


Don’t go crazy counting carbohydrate grams; this is just a guide. Adding a little fat or protein can help with satiety and flavor, but the carbohydrates are the most important factor here. Also, too much protein or fat can sit in the stomach, making for an unpleasant run. Some good pre-run choices include:

o     Toast (or a bagel) with jam & a medium banana

o     Cereal with milk and a banana

o     Oatmeal with berries or raisins

o     Pancakes (1-2) with fruit

o     Granola bar that is low in fiber

o     Fruit smoothie: 1 large banana, ½ cup berries, ½ cuplow-fat milk (or yogurt for extra creaminess), ice cubes.

o     Trail mix with dried fruit, cereal, and pretzels

o     Crackers with hummus and fruit


When should I eat?

While you want to allow 1 to 2 hours after a substantial pre-run breakfast to allow enough time for digestion and absorption, you can likely tolerate a smaller (200 to 300 calorie) snack within an hour pre-run. If you don’t have any trouble with running with food in your stomach, you can shorten this window. However some runners with digestive concerns get up early, eat breakfast, and then go back to bed. Others eat an extra snack before they go to bed, and then eat something smaller in the morning only 30 minutes before a run.


What if I get an upset stomach or GI tract when I eat before a run?

By starting with small amounts of food, most runners can train their GI tract to accept some food. Even a little fuel can improve energy and performance. Some people like sports drinks because they may feel less heavy in the stomach.  If you really struggle, try to eat your breakfast the night before. Before you go to bed, enjoy a carbohydrate-rich snack, such as a bowl of cereal or a bagel . However, I would not recommend running the full marathon without eating the morning of the race, so it’s best to try to train your gut to tolerate food.


Eat wisely and run well!
Nancy and Sarah


For more information:

Food Guide for Marathoners

Food Guide for New Runners

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Nancy Clark RD CSSD

Nancy Clark RD CSSD

Member since: Jul 8, 2007

Hi! I specialize in nutrition for exercise, and help active people figure out how to manage food, weight, exercise, energy and enjoyment of eating. Let me know if you have any questions!

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