Adequate fueling is an essential part of your big day. What should you eat before a marathon? Let’s talk about what you should eat the day before and day of a marathon.

What should I eat before a marathon? Maybe you’ve wondered this.

Between the nerves, the possible travel and new environment, the unknowns (like the weather!), and more, there are many variables that go into having a successful race.

And what you eat before a marathon or half marathon certainly counts!

Let’s talk through what to eat the week of a marathon leading up to the night before a marathon, and how to handle the morning of as well!

What To Eat the Week Before a Marathon

You’ve put in hours running and preparing for your marathon. Now it’s the week before your race.

You’ll want to know what to eat the week before a marathon and week of a marathon to make sure your body is adequately fueled to get through each and every mile.

The main focus this week will be carbohydrates or gluten free high carb foods!

Use this guide to determine the best carbs for runners.

For instance, you don’t want to load up on fiber-rich carbs that fill you up before you eat enough calories.

This can lead to underfueling and not having enough energy stored up for the race.

This can especially be an issue for nutrition for female runners.

How Many Carbs Should you be Eating?

As an endurance athlete, your diet should already be high in carbohydrates—about 45-65% of your total calories.

Performance plates can help you visualize the appropriate ratio of carbohydrates to other nutrients. 

Your body will use glucose as its primary fuel for running.

When you eat carbs, your body breaks it down into glucose—storing it away as glycogen.

Glycogen is then broken down into glucose when your body needs the fuel. 

The carbs you eat in the days leading up to your marathon will serve as that much-needed fuel for your race, preventing you from hitting the wall in a marathon (hopefully -right?!).

While you reduce your training during your marathon taper, your body has a chance to build up those glycogen stores.

Combining your taper with proper carb loading for running increases your glycogen stores above their normal levels—giving you optimal energy for race day.

Carb Loading

A marathon is no easy feat. Not only will carb loading improve your marathon performance, but your run also won’t feel as hard.

Carb loading is done 36-48 hours before your race, in combination with a 3-6 day reduction in training. 

You’ll want to aim for around 10 g/kg body weight of carbs per 24 hours.

While eating extra carbs in the days leading up to the marathon, focus on eating less fat and less high-fiber foods to prevent runner gut and digestive woes. 

Carb loading a couple of days prior to your marathon will help prevent you from hitting the wall—or running out of energy after mile 20 or so. 

Examples of easy-to-digest foods for carb loading:

• White pasta (pasta for runners is a long time favorite!)
• Rice
• Tortillas
• Bread
• Potatoes
• Cereal
• Crackers
• Fruit and juice
• Milk
• Energy bars

Some foods you may want to avoid include: 

• Fatty foods, such as fried foods, ice cream, and cream sauces
• Beans, lentils, and peas
• Whole wheat products
• Berries
• Broccoli
• Bran
• New foods

These are different recommendations from what to eat after a marathon, where you can typically eat anything that sounds good and you like, with the caveat that you are getting fluids, carbs and protein in.

Hydration

Proper hydration for running is also critical for performance and maintaining electrolyte status.

If you’re a salty sweater, you’ll want to be eating more salt in the week leading up to your marathon. This could be more processed foods, or just adding salt at the table.

Just like hydration for the half marathon, you want to have a plan for when and how much you’ll be drinking. You can include both water and sports drinks.

Many sports drinks can also be great for adding additional sodium.

You’ll want to have a hydration pack that you like to help keep you hydrated during running efforts and even on race day.

During the days leading up to the marathon, make sure you’re drinking enough fluids for optimal hydration before your race. 

Of course, water is an obvious choice, but when you’re wanting something flavored, you can try juice, store-bought sports drinks, homemade electrolyte drinks, plant-based milk (almond or coconut milk), or low-fat chocolate milk.

What to Eat the Night Before a Marathon

The night before a marathon, you should aim to have a mixed meal of mostly carbohydrates, paired with lean protein.

Similar to what to eat the night before a long run, these carbs should be easily digestible, and not high in fiber, especially if you have a sensitive stomach.

Also, avoid trying any new foods!

If you are eating out before a marathon, order something you have had before or eat regularly, rather than obsessing about the perfect entree.

Sources of lean protein include: 

• Chicken breast
• Whitefish
• Eggs
• Beef, turkey or bison
• Pork loin
• Tofu
• Greek yogurt
• Low-fat cottage cheese

Round out your meal with a low-fiber vegetable, like carrots, zucchini, cucumbers or green beans. Having cooked vegetables is often more easily digested than raw.

You’ll likely want to avoid alcohol the night before your race—as it may lead to dehydration and a poor night of sleep.

What to Eat the Morning of a Marathon

It’s finally race day and here’s a breakdown of what to eat the morning of a marathon.

Carbs: Just like the night before a marathon, you’ll want to eat a meal of easy-to-digest carbs.

The size of your meal or breakfast may be dependent on how far you’re running.

For example, what to eat before a cross country race or other short race will obviously differ from a longer race.

When you need quick energy spurts, you’ll need quick carbs and can get by on a smaller meal, maybe even 30-45 grams of carbs.

However, how much you eat depends on how far out your race is.

A general rule of thumb is 1 g of carbs/kg of body weight for every hour until your race.

For example, if your race isn’t for 2 hours, you’d consume 2 g carbs/kg. Three hours away, consume 3 g carbs/kg.

So, as you can see, you may want to be up early before your marathon to give yourself time to digest.

This is also true when deciding what to eat the morning of a half marathon.

What if you have no appetite? Nerves may make you feel too jittery to eat.

Or, maybe you didn’t get a chance to train your gut to take in more carbs before a long run.

In that case, take in some simple carbs with running enery gels, sports chews, or even liquid nutrition through a sports drink. 

Some of these principles hold true if you’re not hungry after a workout, too!

Low Fiber Fruit – Another great option is low-fiber fruit. The natural sugar found in fruit, fructose, when combined with glucose may actually improve your run and performance.

Some ideas for a race day breakfast or meals include:

• ½ bagel with peanut butter and jam and a banana
• 2 pieces of toast, a scrambled egg, and a 4 oz glass of juice
• Granola bar, applesauce, and a cup of low-fat milk
• Oatmeal with nut butter and a banana
• Smoothie made with a frozen banana, strawberries, and milk
• Cereal with milk and a 4 oz glass of juice
• Energy bites (try these carrot cake bites)

Again, don’t try anything new!

You don’t want to find out in the middle of your race that your breakfast doesn’t agree with you.

Drinking Coffee Before Running

It’s okay to have coffee before running or tea before your marathon if it’s a part of your normal routine.

In fact, caffeine is an ergogenic aid that may improve your athletic performance.

Keep in mind that now isn’t the time to try that new drink from the coffee shop.

A lot of coffee drinks have a high fat content that in combination with the caffeine may irritate your stomach.

If in doubt, omit it completely, or start with decaf.

This is something you should practice as part of your long run nutrition!

Key Takeaways

• Prioritize foods that are high in carbohydrates, moderate protein, and low in fat during the week leading up to your marathon.
• Carbohydrate loading during your taper period will increase your glycogen storage, leaving you more energy for race day, and thereby improving your performance.
• Make sure your meals before your marathon are high in carbohydrates, low in fiber, moderate in protein, and low in fat.
• A combination of glucose and fructose may further optimize performance.
• You can drink your cup of coffee and maybe even enjoy a boost in energy during your run because of it.
• Don’t try any new foods the week leading up to your marathon.

References:

Burke LM, Jeukendrup AE, Jones AM, Mooses M. Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers. Int J Sport Nutr Exerc Metab. 2019;29(2):117-129. doi:10.1123/ijsnem.2019-0004

Fuchs CJ, Gonzalez JT, van Loon LJC. Fructose co-ingestion to increase carbohydrate availability in athletes. J Physiol. 2019;597(14):3549-3560. doi:10.1113/JP277116

Mata F, Valenzuela PL, Gimenez J, et al. Carbohydrate Availability and Physical Performance: Physiological Overview and Practical Recommendations. Nutrients. 2019;11(5):1084. Published 2019 May 16. doi:10.3390/nu11051084

Guest NS, VanDusseldorp TA, Nelson MT, et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18(1):1. Published 2021 Jan 2. doi:10.1186/s12970-020-00383-4