What to Eat Before a Half Marathon (So You Don’t Hit the Wall at Mile 9)

Want to avoid the dreaded wall at mile 9 and not hit the porta-potty a million times during your race?

Your nutrition during race week and on race day can be the deciding factor in your performance. 

It can mean the difference between multiple porta-potty stops or running a race free of GI issues, between hitting the wall and having an absolutely miserable racing experience or completely avoiding the wall and running a strong race. 

Being strategic about proper fueling is essential for achieving your best race day experience and performance.

In this guide, we’ll cover how to eat before a half marathon so you can fuel well, run strong and nail your racing goals!

Your First Step: Nail Your Day-to-Day Nutrition

One of the biggest nutrition mistakes runners make when preparing for a half marathon is only focusing on their nutrition during race week. 

Just as you train for months to build endurance and strength for race day, your day-to-day nutrition should be a priority throughout your entire training journey, not just the week of a race. Your day-to-day nutrition is your nutrition foundation and you want to have a strong foundation.

Establishing proper fueling early on in your training will help you optimize your performance, enhance your recovery and ensure you’re well-fueled for race day. Then, as race week approaches, having a nutrition plan and the right strategies in place is key!

Proper fueling on a day-to-day basis means eating enough calories, getting in the right balance of macronutrients (carbs, fat, protein), eating plenty of micronutrients (vitamins and minerals) and hydrating intentionally to get the most out of your training and to enjoy your life outside of training!

Calories provide the body with energy, they’re not bad! Many runners are afraid of calories when in reality, they need sufficient calories to be healthy, support their hormone health, avoid underfueling and to run and race well. 

Signs that you’re underfueling:

• Low energy
• Stuck in the restrict/binge cycle (you know when you restrict your eating all day and then completely overeat/binge at night?)
• Hitting the wall during long runs and races
• You’re in a plateau with your training (your endurance & speed is not improving)
• Thinking about food 24/7
• Feeling hungry all the time
• Poor exercise recovery
• Irregular/loss of period in female athletes
• Frequent illness and injury

A runner’s calorie, macronutrient, micronutrient, and hydration needs are unique to their individual body, medical history, training demands and goals. So your nutrition needs are likely different from your family members and even your running friends!

Tip: as your mileage and training duration & intensity increase, so do your daily calorie and carbohydrate needs. It’s important to intentionally adjust your intake to prevent underfueling and avoid the negative symptoms and consequences that come with it.

For more tips on hydration for runners, check out my post on Runner’s Hydration: 4-Simple Steps!

What to Eat The Week Before a Half Marathon 

Eating well-balanced meals and plenty of carbohydrates is a great focus for race week!

Let’s split race week up into 2 parts: the days before you carb load and carb loading the 1-2 days leading up to your race. 

During the first half of your week, at all your meals, fill up your plate with 50% grains/starches, 25% protein, 25% fruits/veggies and a source of healthy fats. Here’s an example: a quinoa bowl with quinoa, chicken/tofu, roasted veggies and avocado for healthy fats. 

Then I recommend carb loading for the 1-2 days leading up to your race. So if your race is on Sunday, you’ll want to carb load on Friday and Saturday. 

Carb loading is beneficial for races where you’ll be running over 90 minutes, so for most of us, that’s our half marathons, marathons and beyond. Carb loading can help you avoid hitting the wall and help you shave minutes off your finish time (along with fueling well during the race).

Write out your carb loading plan well before race day and practice at least 1 day of it the day before a long run. Then make adjustments as needed before you carb load for real for your half marathon!

Check out The Best Foods for Carb Loading for Your Race.

What to Eat the Night Before a Half Marathon

Dinner the night before a half marathon isn’t something to just wing. This is something you’re going to want to figure out during your training. 

Trial out some dinner options the night before your long runs to see what sits well in your stomach and helps you feel energized and run strong during your long run the next day. Once you pinpoint a dinner that works, this can become your dinner the night before your race.

Make your dinner carb-rich which will help you optimize your glycogen stores. Some examples are pasta dishes, rice dishes or a potato-based dish with some protein. 

Eat until you’re comfortably full. There is no reason to stuff yourself to the brim, which can backfire and result in some GI issues the following day. 

Foods to avoid before half marathon races are really high fiber foods like chickpea pasta, high fat foods like fried foods, spicy foods and any foods that you are intolerant to.

I had a 1:1 nutrition client that I was working with who decided to eat high-fiber chickpea pasta the night before a long run and it caused her to stop to use the bathroom multiple times during her run the next day. Thank goodness she didn’t eat this before a race and she realized during her training that this did not work!

The following weekend, she changed to lower fiber, white pasta the night before her long run and guess what? No GI issues! This is an example that shows what we eat the night before can affect how we feel on our run the next day.

Bottom line: dinner should be practiced and identified during your training, it should be carb-rich, simple and on the bland side! 

What to Eat for Breakfast Before a Half Marathon

Just like dinner the night before, you don’t want to just wing it with your breakfast on race day. 

Breakfast is another thing that you want to practice during your training. Before your long training runs, trial and identify what foods and amounts work the best for you.

Something to also practice is the timing you need for proper digestion before your run. Running with a full stomach will only lead to GI issues during the race so giving yourself enough time to digest is vital!

Make your breakfast carb-rich! Some examples are waffles, bagel, bananas and carb-rich sports drinks.

Aim for a bare minimum is 1 g/kg of body weight of carb at your breakfast. Ideally you’d want to further optimize to >1 g/kg of carb if possible. Then give yourself 1-2 hours to digest. The more you eat, the longer your body may need to digest.

The closer you get to exercise, you’ll want to pull back on fiber, protein and fat because these slow digestion and if too much is consumed too close to exercise, it can lead to GI issues.

Bottom line: breakfast should be practiced and identified during your training, it should be carb-rich, provide at least 1 g/kg of carb and give yourself 1-2 hours to digest!

What to Eat During a Half Marathon

Myth: you don’t need to fuel and hydrate during half marathons.

Science: fueling during half marathons is a smart way to support your body, muscles and race day goals.

The goal is to fuel well during your race so you can run strong and avoid hitting the wall, hydrate well and take in electrolytes so you can maintain fluid balance and support your performance (PS as little as 2% dehydration can result in performance declines).

There are 3 parts to build into your race day nutrition plan:

1. Carbs: food and sports nutrition products that provide simple carbs
2. Fluids: you’ll need to figure out if you want to carry fluids with you vs take cups from the race course
3. Sodium: an electrolyte we lose the most of in our sweat which we can get from higher sodium gels, salt capsules/chews and sodium-rich sports drinks 

Avoid the mistake of trying new fuel and sports drinks on race day. General rule of thumb: nothing new on race day!! 

During your training, figure out what foods/sports products you’ll use for fuel on race day, how much and how often you’ll take in fuel throughout the race to meet your fueling needs and how you will keep up with your hydration and sodium needs. 

You will want to be proactive with fuel and hydration during your race. Start within the first 30 minutes and continue at regular intervals throughout the race. Waiting until you become really thirsty to drink or waiting until you feel low in energy to start fueling is too late.

Check out The Best Energy Gels For Running: a Dietitian Review.

Takeaways

The way you fuel your body during race week and on race day can significantly impact your overall performance and race experience.

First work on nailing your day-to-day nutrition: your calorie intake, macronutrient intake, micronutrient intake and your hydration. 

Then, dial in your nutrition before and during running. This includes your nutrition race week, carb loading 1-2 days before your race, dinner the night before, breakfast the morning of and fueling and hydrating during the race. 

During training, practice at least 1 day of your carb loading plan, practice your dinner the night before, breakfast the morning of, timing of that breakfast and your during race fueling and hydration plan. 

That way, you can head into race day with a plan that you feel confident and comfortable with! This can help you avoid any surprises on race day and it can set you up for a strong race that you’ve been training months for! 

I help runners train smarter with personalized run, strength and fueling support. Learn how I work 1:1 with athletes and active people here!