What to Eat Before a Marathon, the Go-to Guide for Runners

What to eat to perform your best on marathon day.

“Running 26.2 miles is not for the faint of heart – or the under-fueled athlete. Pasta the night before and a bowl of oatmeal on race morning may not be enough,” says Jena Brown, RD, CSSD, sports dietitian and owner of Victorem Performance Nutrition in Brenham, Texas.

Marathon nutrition preparation should begin weeks before marathon day.

You’re likely familiar with Benjamin Franklin’s quote, “By failing to prepare, you are preparing to fail.” And while he wasn't a marathon runner, his words ring true. You need to prepare your nutrition plan ahead of time.

To set you up for success, I asked two sports dietitians for advice on what to eat before a marathon. 

What you will learn:

• What to eat the days before a marathon

• What to eat the night before

• What to Eat for Breakfast on Marathon Day

• How to improve recovery by prioritising nutrition after a marathon

What to eat during the days before a marathon

“Marathon nutrition preparation should begin weeks before the big day,” says Brown.

Fueling for a marathon is not just about eating carbohydrates the day before. It’s also testing what foods your body responds best to during training. For example, if you’ve never used energy gels, you wouldn’t use these for the first time in a marathon. This is how you spend more time in the bathroom than running.

Nutrition preparation also includes knowing what foods to avoid. Some runners like pizza before a marathon. But if you try this before a long run and it causes stomach upset, you know NOT to do it the day before your marathon.

You want to learn these lessons when it matters least. Not when running 26.2 miles.

Brown says, “You should eat more carbohydrates the closer you get to race day. Carbohydrates are the primary energy source during exercise, especially long and intense durations, like the marathon.”

Grace Kelley, Sports dietitian and owner of Nourished Endurance, tells STYRKR that “Focusing on carbohydrate-rich foods helps maximise glycogen stores before the marathon. This is why carb loading in the days leading up to the race can be so beneficial.”

The sections below explain what to eat the day before and on the day of your marathon.

What to eat the night before a marathon

“Eat a carb-heavy meal with moderate protein, fat, and fibre the night before a marathon. Avoid trying new or spicy foods that could cause gastrointestinal distress before or during the race. Pasta with marinara sauce or a large baked potato with grated cheese are great options. These foods are high in carbs and rich in electrolytes – essential for marathon fueling and hydration,” says Brown.

As a general rule of thumb, aim for a meal with 60 to 90 grams of carbohydrates and 20 to 30 grams of protein.

Don’t forget to drink plenty of fluid, either. She says this ensures the body can store the added carbohydrates you eat in your muscles – otherwise, you’ve eaten a load of carbs for no reason. So bottoms up! But avoid the alcohol.

What to eat for breakfast before a marathon

Kelley recommends 3 grams of carbohydrates for every kilogram of body weight when training or racing over 2.5 hours.

This means that a 150-lb (68-kg) athlete should consume about 200 grams of carbohydrates in the morning before a marathon.

And while this may sound like a lot of carbs to eat early in the morning before running, you don’t need to complicate it. She recommends foods like a bagel with peanut butter and banana, a cup of orange juice, a bottle of a carb-rich sports drink, and a gel to get you to 200 grams of carbohydrates. 

While carbohydrates are our main energy source, she says a small amount of protein and fat, like nut butter, can help with flavour and satisfaction without causing GI distress.

You should eat the same foods before the marathon as you do before a long run. This is the perfect time to test breakfast options that help fuel your body without causing GI upset.

Also, runners should have most of their carbs about 1.5-2 hours before the race. Kelley suggests you can also take an energy gel about 20 minutes before running to top up your glycogen stores.

Best food for marathon runners during race

Although this article is about what to eat before a marathon, I’ve included a little on what to eat during the marathon.

The ACSM recommends 60 grams of carbohydrates per hour. Another study in the Journal of Sports Medicine advises a higher intake of 90 grams per hour for events lasting longer than 2-3 hours.

Ideally, you will have practised eating while running on your weekly long runs. Some runners may tolerate 90g, while others may experience GI upset. Don’t leave your race nutrition to chance. 

Eating during the marathon provides your body more energy and the muscles the nutrients it needs to maintain your pace. It also means there’s less chance of you hitting the wall – when you run out of energy and cannot continue.

So what should you eat during a marathon?

Most runners prefer easy-to-digest carbohydrates like energy gels, bars, chews, and sweets.

Again, experiment with it and find what works best for you. The above food suggestions are a great place to start!

What to eat after a marathon 

Before the celebrations begin (and they should, because you’ve earned it!), focus on refuelling.

Eat a meal within 1-2 hours after running. If you feel like you can’t stomach anything just yet, that’s okay.

Ideally, eat a meal with plenty of carbohydrates and protein. Your body is likely in the red – it needs fuel to repair and recover. Drink plenty of water and, even better, rehydrate with electrolytes. This will help with the cramping and improve recovery by helping you rehydrate. It also contributes to muscle repair.

Foods to avoid day before a marathon

“Avoid trying new or spicy foods that could lead to gastrointestinal distress before or during the race,” says Brown.

Other foods to avoid include: 

• Fatty foods

• Foods high in fibre 

• Dairy products 

• Fried foods 

• Protein bars

• Alcohol 

The above food items are more likely to cause stomach upset and discomfort. Some may contribute to cramping, bloating, and dehydration.

Again, you should practice what to eat and what not to eat during your weekly long runs. So experiment, find what works best for you, and fuel yourself to either complete your first marathon or achieve a personal best on race day.

Key takeaways

• Marathon nutrition preparation should begin weeks before marathon day

• Increase carbohydrate intake the week before to maximise glycogen stores

• Eat a carb-heavy meal with moderate protein, fat, and fibre the night before, like pasta or a large baked potato with sides

• Avoid trying new foods leading up to marathon day (and especially the day of and the day before)

• Eat a breakfast with plenty of carbs, like a bagel with peanut butter and a banana, a cup of orange juice, a bottle of a carb-rich sports drink, and a gel before running

• Aim for 60-90g of carbohydrates during the marathon

• After running, re-fuel and take electrolytes to improve muscle repair and recovery

FAQs

Should I run a marathon on an empty stomach?

No! You should prioritise eating more carbohydrates the days before a marathon. Eat a breakfast 1.5-2 hours before running, including foods like a bagel, banana, and a sports drink. 

What food is the best to eat before a marathon?

Eat plenty of carbohydrates like pasta with marinara sauce or a large baked potato the evening before. In the morning, eat foods like a bagel, overnight oats, or toast with nut butter, for example.

How many gels for a 3 hour marathon?

You would need 6-9 gels for a 3 hour marathon (if this was your primary source of fuel).