Vegan Marathon Diet: How to Fuel for Training and Race Day

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A comprehensive guide to fueling before, during and after a half marathon. Plant-based foods that will help you PR in your next race and foods to avoid!

Preparing for a marathon is no easy task. Not only is training important for performance, but so is nutrition.  

Whether you’re new to plant-based eating or a seasoned pro, you may have questions about how to eat the night before and the morning of your race to make sure your body is properly fueled throughout the race. 

What to eat before a half marathon

What to eat for marathon training runs

Marathon training requires a high carb diet. More than 60% of your daily calories should come from carbs when you are logging long miles. That’s because carbohydrates are the main fuel source for exercise.

Be sure to include plenty of carbs in your pre-run meal. Incorporate small amounts of protein as well, since these nutrients provide long lasting energy.

A good rule of thumb is to eat a well-balanced meal 2-3 hours before your training run. For example, eat a bowl of oatmeal with berries and nut butter.

This meal should provide energy for the first 60-minutes of training. During any run lasting longer than 60 minutes, consume 30-60 grams of carbohydrates every hour.

If that seems like more than you can handle at one time, break it down into 15 to 20-minute intervals. Think about refueling in terms of small pit stops on your way to the finish line, just enough to keep you going without taking you out of the race.

Below are some suggestions for vegan fueling during long training runs.

Easy to carry fuel sources

First, think of things that fit in your pack and are easy to eat.

No fueling strategy is perfect for everyone, so it’s best to try out a few different foods and fluids during training to see what works for you. Here are some suggestions:

  • Sports drinks can do double duty, providing fluids and carbohydrates in an easy-to-carry product. 
  • Other supplements, like gels and gummies, are portable, pre-portioned and easy to eat and digest.
  • Some runners tolerate fruit juice or small pieces of fruit, like bananas, while others may find that fructose (fruit sugar) causes gastrointestinal distress.
  • During longer a run, it can be helpful to carry both sweet and savory foods, like candy and pretzels, to keep your tastebuds interested and not overload them with sweet. 
  • Avoid high-fiber foods, like whole wheat bread, since fiber remains undigested in the intestine and can cause stomach issues while running. This is the time when you want to eat white starches!

Let’s dive into each of these options.

Sports drinks

Sports drinks can help replace carbs and electrolytes during a long run. But depending on the length of your run, they may provide too much liquid to rely on sports drinks alone. I recommend pairing a sports drink with some of the options below. And read more about sports drinks and electrolytes here:

Gus and Sports Gels

Sports gus and gels are some of the most portable and runner-friendly sports products. Most brands yield about 100 calories and 22 g of carbohydrate per package, which will supply about 30-45 minutes of energy.

Like anything in the world of sports nutrition, there are some potential pitfalls with taking in too much of this stuff, namely GI distress. PLEASE please please drink at least 6-8 ounces of water with each gu or gel. 

Here are some sports gus and gels recommendations:

GU Energy Gels come in a variety of tasty flavors, such as Salted Watermelon or S’mores. For those who don’t love sucking down a jelly liquid, the wide variety of flavors can definitely help! 

Honey Stinger Organic Gel is one of the only organic and gluten-free options. Made with just seven ingredients, including honey, this 100-calorie gel is great for those who are picky about ingredients lists.  

Huma PLUS gel has double the electrolytes (240 mg sodium, 50 to 75 mg potassium, 15 mg magnesium) compared to the brand’s regular version, which is great for heavy sweaters. Huma uses all-natural ingredients so your electrolytes are coming from coconut water and sea salt. 

Gummies and chews

These colorful bears, worms, blocks, and other familiar shapes are MY favorite sports nutrition product. They’re small, and lightweight and provide excellent and immediate carbohydrate and electrolyte replenishment.

Most supply about 20-30 grams of carbohydrates, which will give you energy for 30-45 minutes. As with the gels, it’s imperative that you eat gummies with some sort of fluid. 

Here are some recommendations:

CLIF BLOKS– These gummies are so easy to carry and come in tasty flavors, like Salted Watermelon, Gingerale and Margarita. Each one is 100 calories, has 24 grams of carbs and some even have extra sodium or caffeine.

GU Energy Chews are also easy to carry in your pack and have a similar nutrient and flavor profile.

Natural foods to eat during a run

By now you know that all carbs are sugar and all runners need sugar for energy. But I would be remiss if I didn’t mention that sugar has a really bad reputation as being the cause of weight gain, inflammation and other more serious ailments.

That said, foods with added sugar can be beneficial to runners. Why? Well, all the good-for-you nutrients that are in foods with natural sugar, like fiber and protein, are difficult for your stomach to digest while running.

That’s why many runners opt for foods that are primarily made up of sugar, like jelly beans, so they can easily digest them during a run. I’m not saying that you should sit in your office and eat jelly beans and hope it will help tomorrow morning’s run. Everything in moderation!

These natural foods are rich in sugar and low in fiber. That means they are easy to digest while running, so they will quickly deliver sugar to working muscles. The only caveat is that they are missing electrolytes, so add a dash of salt to these options:

  • Dates and other dried fruits, like raisins
  • A small glass of 100% fruit juice 
  • Applesauce 
  • Maple syrup or honey packet
  • Mashed sweet potatoes
  • Fruit, like a banana
  • Pretzels
  • Crunchy Chickpeas
  • White crackers, like saltine
  • Unsweetened cereal, like Corn Flakes or Cheerios
  • Homemade sports drink
  • White bread with jam
  • Gummie bears of jelly beans

What to eat the night before a marathon

After you’ve mastered your training runs, it’s time to start thinking about race day nutrition. Since carbs are the primary source of fuel for athletes, many runners may try carb-loading leading up to the event. [Learn more about carb loading and how to do it correctly.]

If you’re carb-loading, you will increase your carb intake to 80% of total calories for the 2-3 days leading up to the event.  The goal is to build up your glycogen, otherwise known as the stored version of carbohydrates in your body, so that your energy levels last longer throughout the race.

That said, if you don’t carb-load before a race, that’s perfectly okay! In that case, eat a pre-race dinner meal that consists of carbs, protein, and fat. Build a plate that is 70-80% carbohydrates with 20-30% protein and a dash of fat.

For a vegan marathoner, this may be a plate that is mostly rice and veggies with some tofu and drizzle of oil. Here are some other suggestions:

Foods to avoid the night before

There are certain foods you definitely want to avoid the night before a race. Never try anything new or unfamiliar because you do not know if that food will cause indigestion, GI issues, and even sleep disturbances. Choose foods that are familiar to you. 

Some foods you want to avoid the night before the race are:

  • Fried Foods, like french fries, can lead to indigestion
  • Caffeine-containing foods or drinks, such as coffee, tea, or chocolate, can alter sleep patterns 
  • Spicy foods, like salsa or sriracha, can cause stomach issues
  • High fiber foods, such as beans and cruciferous vegetables, can cause gas and bloat [How To Beat The Bloat On A Plant-Based Diet 

The night before the race you want to feel fueled, relaxed, and get a good night’s rest, so stick to those foods you know and love. 

What to eat on marathon morning

On the morning of the race, the goal is to eat enough to have energy for the start of the race. 

The best type of pre-race meal/snack is one that contains a good amount of carbohydrates to raise blood glucose and add some additional carbs to your glycogen stores.

You also want to make sure your pre-race meal fuels your hunger, provides fluids to prevent dehydration, and doesn’t cause GI distress.

For the pre-event meal, a runner should consume 1-4 grams of carbohydrate per kilogram of body weight (or per 2.2 pounds body weight) about 1-4 hours before the event. 

Here’s a quick reference tool for you to build a healthy pre-race meal:

Time before raceGrams of carbs/kgExample: 150 pound (68 kg) runner
4 hours before4g/ kg272 grams
3 hours before3g/ kg204 grams
2 hours before2g/ kg136 grams
1 hour before1g/ kg68 grams
healthy breakfast foods to eat before half marathon


If you plan on eating 4 hours before the race, choose a meal that is higher in carbs and contains some protein. Since it is 4 hours before the race, you can have a larger meal because you have more time to digest. Here’s an example:

  • 1-2 cups of granola + 1 large banana +1 cup of non-dairy milk + 1 tablespoon of nut butter + 1 teaspoon honey or maple syrup

If you’re eating 2-3 hours before the race, have a slightly smaller meal that has some carbs and protein to keep you full and provide sustained energy. Here’s an example: 

  • 1 cup oatmeal made with ½ cup milk +1 cup berries + 1 tablespoon nut butter

If you’re eating within 1 hour before the race, opt for simple carbs that can be digested quickly. Here is an example: 

  •  banana and a swig of sports drink.
  • a few handfuls of low fiber cereal and coconut water

Foods to avoid before the race

Similar to the night before the race, you should avoid unfamiliar foods the morning of your race. You’ll also want to stay away from fried foods, high fiber foods, and spicy foods. 

Also, if you’re not normally a caffeine drinker, do NOT include it the morning of your race without experimenting first. Read more about the benefits of caffeine for runners here. 

Specifically, it is best to stay away from foods such as:

  • Croissants, due to high butter (fat) content 
  • Vegan Sausage 
  • Doughnuts
  • Sugary muffins, such as a crumb cake muffin 

The bottom line

Nutrition is a crucial part of fueling the marathon, especially for vegan runners. The good news is that most plant-based foods provide easy to digest carbs that are great for runners.

Make sure you include fuel during your run to keep energy levels high. Try out different forms of fuel to find the one that works for you.

Practice race day nutrition ahead of time to find the perfect pre-race breakfast that works for you.


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I’m Natalie Rizzo, an NYC-based Registered Dietitian.

My mission is to help everyday athletes fuel their fitness with plants.

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