What to Eat Before a 5k: How To Fuel For Success

Whether you’re a beginner just trying to finish your first 5k or a seasoned runner chasing a PR, there are plenty of free and premium 5k training plans available online these days, so you can find exactly what workouts you should do to prepare to run a 5k.

However, many of these training plans omit a key component of training—your nutrition. Although runners can usually get away with any sort of diet when training for and running 5ks, if you really want to maximize your performance and feel your best when you run, nutrition really matters, especially what to eat before a 5k race.

Even if you typically follow a pretty well-balanced, healthy diet, your food choices in the day or so leading up to the race can potentially make or break the difference between a decent 5k race and a great 5k race.

If you’re hoping to get an extra edge and run your best race, keep reading for our guide to what to eat before a 5k race for information and tips for dialing in your nutrition on race day.

We will look at: 

  • Nutrition for Running 5ks
  • General Nutrition for Runners
  • What to Eat Before a 5k: The Night Before
  • What to Eat Before a 5k: Morning Races
  • What to Eat Before a 5k: Evening Races

Let’s jump in!

Three containers of overnight oats and fruit, an example of what to eat before a 5k.

Nutrition for Running 5ks

Many runners make the mistake of thinking that nutrition plays a very small role in successful 5K running. After all, according to Running Level, the average finish time for the 5k across both sexes and all ages is 23:58, meaning that most runners can finish the distance in 20-30 minutes.

As such, your body most likely has enough stored carbohydrates on board to have any necessary fuel source available during the 5k, even if you have not eaten anything since the night before the race.

For the same reason, unlike long races like half marathons and marathons, most runners do not need to take in fuel during a 5k, which simplifies the race strategy and 5k nutrition plan.

However, the relative ease of 5k fueling practices shouldn’t be assumed to mean that what you eat before a 5k doesn’t matter.

You can certainly find yourself battling side stitches, cramps, diarrhea, gas, bloating, low energy, and other digestive issues and physical consequences that affect your running performance if you eat the wrong foods or right foods at the wrong times before a 5k.

A variety of granola bars.

General Nutrition for Runners

Throughout your training program leading up to your 5k, you’ll want to fuel your body with healthy foods and a balanced diet to ensure your body is getting the nutrients it needs to fuel your workouts, recover from your runs, and maintain optimal health.

Your diet should consist of a variety of whole, natural, unprocessed foods, such as vegetables, fruits, lean proteins, legumes, seeds, nuts, whole grains, eggs, low-fat dairy, and healthy fats. 

Processed foods, such as frozen entrees, canned soups, packaged cakes and cookies, candy, fried snacks, processed meats such as hot dogs and bologna, and foods with hydrogenated oils, artificial colors, artificial sweeteners, and artificial ingredients should be avoided as much as possible.

It’s also advisable to be mindful of your intake of foods high in salt, sugar, or trans fats, and your consumption of alcoholic beverages. 

While many runners are getting into the good habit of scanning the nutrition facts panel on a food package prior to buying or eating the food to ensure it will fit in with their dietary goals, it’s an equally valuable healthy practice to read the ingredients label.

A variety of different whole grains.

Although it may seem like an overused, trite saying these days, the advice to choose products with an ingredients list containing only foods you can easily pronounce and recognize (no long chemical-sounding names) still has merit. 

In general, the shorter the list of ingredients, the better. In that vein, the closer the food product is to its whole, natural form, the better. 

For example, whole apples are better than applesauce and whole oats are healthier than quick oats. This is because the unprocessed, or minimally-processed foods retain more of the natural vitamins, minerals, and fiber, and are less likely to have added sweeteners, oils or fats, salt, stabilizers, flavors, colors, or other unhealthy ingredients.

The recommended daily caloric intake and ideal macronutrient ratio for your diet will vary from runner to runner, depending on numerous factors such as your age, sex, body size, activity level, and body composition goals.

According to the International Society of Sports Nutrition (ISSN), most recreational athletes can meet their nutritional goals through a diet comprised on 45–55% carbohydrates (3–5 g/kg/day), 15–20% protein (0.8–1.2 g/kg/day), and 25–35% fat (0.5–1.5 g/kg/day).

Athletes who are engaging in moderate and high-volume training need greater amounts of carbohydrate and protein (e.g., 2–3 h per day of intense exercise at least 5–6 times per week) typically requires a diet consisting of 5–8 g/kg/day of carbohydrates), but for most 5k runners, this is unlikely to be a necessity. 

What to Eat Before a 5k: The Night Before

Most distance runners are indoctrinated with the benefits of carbo loading before an endurance event, but this doesn’t really pertain to running a 5k, simply because the duration it will take you to run a 5k is not long enough to necessitate needing to overload your muscle glycogen stores. 

Therefore, as much as you might be inclined to dish up a huge plate of pasta or potatoes the night before the race, this will ultimately not improve your 5k performance and may actually detract from it. 

The body stores 3-4 grams of water for every gram of stored glycogen, so a carbohydrate-rich dinner can leave you feeling bloated, sluggish, and even nauseous. 

Instead, eat a well-balanced meal with complex carbohydrates, protein, and healthy fat, relying on foods your body is accustomed to eating. A balanced meal can have lean protein (such as fish, poultry, tofu, eggs, etc.), vegetables, a starchy carbohydrate (sweet potatoes, barley, quinoa, etc.), and healthy fats (avocado, olive oil, etc.). 

A well-balanced meal consisting of fish, rice, vegetables and avocado.

What to Eat Before a 5k: Morning Races

Depending on what time your 5K race is in the morning, what time you typically get up, and how well your body tolerates running after eating, you’ll want to eat a small pre-race meal or snack at least 1-2 hours before the 5k, but ideally 2-3 hours before.

Running too soon after eating can result in cramping, bloating, indigestion, and food sloshing around in your stomach, which can make you feel miserable during your race.

It’s impossible to give one-size-fits-all guidelines for what to eat before a 5K because everyone’s body and digestive system are different. 

The best advice is to stick with foods your body is used to and has responded well to in training. In other words, don’t eat anything out of the ordinary on race day morning, or leading up to the race for that matter.

You should be able to keep to your standard diet, perhaps with a few modifications. If you tend to eat a fiber-rich diet or lots of greasy, heavy, or rich foods, you will want to opt for simple carbohydrates and less fat in your pre-race meal or snack, since fat and fiber can slow digestion and may lead to digestive distress during your race.

Examples of good pre-race breakfasts for a 5k include overnight oats, oatmeal, toast with nut butter, yogurt and granola (if you aren’t sensitive to dairy), bagel, banana with peanut butter, a breakfast bar, whole-grain cereal or muesli, whole-grain waffles, smoothie, or an egg on an English muffin.

A blueberry smoothie.

What to Eat Before a 5k: Evening Races

Not every 5K race will necessarily be scheduled for the morning. When your race is later in the day, you have more time to enhance—or possibly derail—your nutrition

If your 5k race is in the afternoon or evening, eat a healthy, well-balanced breakfast that you’re accustomed to. Your last full meal should be eaten at least 3-4 hours before the race. 

This meal should consist of some complex carbohydrates, protein, and healthy fat, but might be lighter in fat, protein, and fiber than your usual meals to reduce the risk of digestive distress. 

Examples include a turkey breast, chicken, tuna, hummus, tofu, or nut butter sandwich on whole grain bread, quinoa or rice with lean protein and veggies, oatmeal or muesli with seeds and fruit, sweet potato with almond butter, or whole-grain crackers and crudités with hard-boiled eggs.

A turkey sandwich.

If you tend to be a fast metabolizer and don’t have a sensitive digestive tract, you should consider a snack 1-2 hours before the race consisting mostly of simple carbohydrates. 

Examples include a banana with a tablespoon of nut butter, a piece of toast with jam, a low-sugar, natural granola bar or energy bar, or a handful of dried fruits and almonds. 

Depending on your body size, this pre-race snack might fall in the 100-250 calorie range.

Regardless as to the time of day of the race, be sure to hydrate well with water, aiming for pale yellow urine. If you have a sensitive stomach, avoid coffee or caffeine on the morning of the race, unless you’re used to caffeine in training.

Finding what to eat before a 5k often takes a little experimentation. However, use your training runs and workouts to play around with different combinations of foods and nutrient timing to see what feels best.

Now that you know what to eat before a 5k, how about a training plan to get you there? Check out our 5k training resources for whatever your goal may be.

Blocks that spell out healthy diet with a variety of fruits, vegetables, grains and meat surrounding it.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, and contributes to several fitness, health, and running websites and publications. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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