The Ultimate Guide to Marathon Training and Race Day Nutrition

You’ve got to fuel up to finish strong. Even if you’re already familiar with this principle, do you know exactly what or how much you should eat before a marathon?

Food choices matter—especially for runners and other athletes. What you choose to eat (or avoid eating) prior to a race can ensure you don’t bonk, or hit the wall, during your race. It can also minimize fatigue and speed your recovery afterward. 

Carbo-loading, for example, is a popular tried-and-true strategy. But when do you start your marathon fueling, and for how long? Are some carbs better than others? How much should you eat? These are all excellent questions—and what you learn could make or break your race performance.  

Treat your body and yourself like the elite athletes do: by paying careful attention to your nutrition before, during, and after a marathon. You got this.

What to Eat During the Days Before a Marathon

It’s no surprise that endurance running can really take a toll on your body. A marathon will deplete your fluids and electrolytes, use up all your stored energy (glycogen), and break down muscle. 

You may have even noticed this during training on your long runs. Inevitably, about an hour into a long-distance run, you may notice you’re beginning to feel tired and starting to slow down. Consider this a red flag that you’re close to hitting the wall—also known as glycogen depletion. You can combat this early-onset marathon fatigue by making sure you fuel your body properly in the lead-up to and during the big day. 

Running a marathon takes training—something that should begin months before the race. How you fuel your body should be included in this training. It’s the perfect time to practice your nutrition strategy, and experiment with how different foods affect your running performance. This includes giving varying amounts of food and when you consume it a try. For example, some runners require 3 hours after eating to be able to run comfortably, while others need just 1 hour. While you’re at it, give your race-day breakfast a trial run during training as well. Come race day, you don’t want any surprises. 

Ultimately, you will want to have consumed enough carbohydrates and protein to ensure your glycogen stores are topped off and ready for the race. This is where carbohydrate loading comes in. By upping the percentage of high-quality, complex carbs in your diet leading up to the race, you can improve your performance, and feel less fatigued during the run. 

During training, more than half of your calories should be coming from carbs. In the taper week prior to a marathon, boost your carb intake to 65-75 percent of your daily intake. Excellent food choices for carb-loading include sweet potatoes, brown rice, bagels, pasta, whole grains, and quinoa. 

The Evening Before

When you have less than 24 hours before the marathon, you’ll want to choose your food wisely. 

Hydration is always important, but the evening before the marathon is when it starts to become critical. Make sure to add electrolytes, such as with sports drinks. 

For food, continue to focus on carbs, but don’t try to overload. This can contribute to your body’s stores of glycogen, without making you so uncomfortable you feel bloated. Dinner suggestions may include slow-burning complex carbohydrates, such as brown rice, whole-wheat pasta, and quinoa. Add protein to further slow digestion, then give your body time to rest. Avoid eating too late at night. Your body needs time to digest and store the energy you’ve just consumed.

The Morning Meal

Get up and have breakfast early enough so your body will have time to begin to digest what you eat. So, you’ll want to eat breakfast 3-4 hours prior to the start of the race, if possible. Depending on the time of your run, you may also want to supplement this with a combo carb-protein snack 1-2 hours before it’s go-time. 

Breakfast should include cereals, grains, or bread to fully stock your energy supply. For example, your morning food choices might include oatmeal and a banana, a bagel with peanut butter, toast with honey, or eggs and rice. You might also make a smoothie with yogurt and a banana. Choose easy-to-digest carbs to help avoid digestive issues, such as cramps or diarrhea, during your run. 

Of course, make sure you’re continuing to hydrate: There’s no need to chug, but you should drink 8 ounces of water every hour or so. When it comes to water and electrolytes, remember that room-temperature fluids are absorbed more quickly by your body than water that is either hot or cold. 

During the Marathon

Mid-race carb intake is important and all about refueling. When your vehicle is running low, you know you won’t make it to your destination without gassing up. The same is true of your body. You can burn through 1,000 calories an hour during a marathon, so you’ll want to replenish your energy stores (ideally, before you bonk.)

Refueling during a marathon gives your muscles the nutrients they need to elevate your endurance, speed, as well as ease your level of exertion. According to the American College of Sports Medicine, that means consuming 240-360 calories in carbs per hour. Try electrolyte-boosting sports drinks, gels, fruit snacks (bananas, raisins, dried fruit), nuts, and energy bars. It will take your body a moment to access the carbs from mid-race snacks, but you should feel the fatigue lift.

Be sure to balance the high-carbohydrate foods and fluids you’re eating mid-race with what your stomach can handle. This is why practicing your nutritional strategy during training is so important: you’ll end up with a better understanding of the amount of carbs you can consume without becoming nauseous or overly gassy in the middle of a run. 

How much to consume will vary for everyone and can depend on the intensity of the run for you, as well as your weight, muscle mass, gender, and more. 

Post-Marathon Meal (and Celebration)

Congratulations, you just ran a marathon! Now, it’s time to recover. Within an hour of your run, you’ll want to focus on carbs, protein, electrolytes, and hydration. This will restock your glycogen levels and help repair and recover your muscles. It can take a full 24 hours before your body is able to replenish the glycogen that was used up during the race.

For your recovery meals, choose foods that are high in carbs and protein, such eggs, toast, bananas, peanut butter, pasta, and protein shakes. Make sure to include a healthy balance of slow- and fast-digesting carbs, such as whole grains along with fruit or fruit juice. 

Drinking ample fluids should continue, including electrolytes, which can help stave off post-marathon muscle cramping. 

What Not to Eat

No hot takes here—all the usual suspects are among the foods runners should avoid leading up to race day. This includes alcohol (increased risk of dehydration), excess dairy, as well as fried and fatty foods (digestive issues), processed meats (nitrates), and sugary soda (sugar crash). 

There are exceptions, however. While high-fiber foods are generally considered healthy, runners in training for a marathon may want to avoid these during their taper week to avoid GI distress, such as gas and cramping, during the run. Caffeine prior to a marathon, likewise, can stimulate the bowels and may force an unwanted bathroom break during the race. In the end, every single body is different, so it’s best to have a clear understanding of the effects different foods have on your body. 

Common Marathon Nutrition Mistakes

If you’re training for a marathon, here are a few nutritional mistakes to avoid:

More Marathon Eating Tips

Here are some final tips when it comes to properly fueling your body for a marathon:

Calories: Aim for about 1,000 more calories than usual when you’re training for a marathon. If your norm is 2,000 calories/day, make it 3,000. Of course, you’ll want to stick with your carb-loading plan and ensure more than half of those calories are from carbs. 

Mealtimes: Don’t skip meals. Try to keep to a regular eating schedule. Also, eat a healthy mix of carbohydrates, protein, healthy fats, and fruits and veggies. Don’t eat an entire meal made up solely of carbs, for example. 

Caffeine: If you’re used to doing so, having a cup of coffee or tea an hour or so before your marathon can provide a nice little boost. However, as with the “don’t try new things on marathon day” advice, don’t imbibe if you don’t normally.