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  • Writer's pictureStephanie Ashby

What to Eat Before a Run

Updated: May 6, 2023

Images: Pixabay

When you’re training, exercising, or planning a run, you’ll need extra energy. So what you eat is important. You will likely want to eat the right things, so you perform well, make it to the finish line, and feel good about doing so -- without an upset stomach! It might also be important that you maximise the number of calories you burn when you run.

With all this in mind, here’s what you need to know about what to eat before a run.

How You Make Energy

If you’re going to run or exercise, you’ll need energy. And you get energy from the food you eat, namely carbohydrates. Carbohydrates are the main energy source of the human diet.

When you eat food that contains carbohydrates, those carbs are broken down into glucose, fructose and galactose, which are sugars that your body uses to make energy. Any unused glucose is converted into glycogen and stored in your muscles and liver. When you exercise, your body converts the stored glycogen back to glucose and burns it for fuel. Carbohydrates are the main nutrients that fuel moderate to high-intensity exercise.

So, if you’re running 5km, do you need to eat more carbohydrates?

The answer is, not really.

With shorter workouts, you will already have all the energy you need from the food you ate the day before, so you won’t need to eat anything extra. This is because your body will get the energy it needs from the glycogen stored in your muscles and liver. As you exercise, your body will draw on this energy to keep your engine running.

However, you can only store a relatively small amount of carbohydrates, so if you’re going to be exercising harder and for longer, you will need to keep your carbohydrates topped up.

For longer runs and more intense workouts, for example if you’re planning some intense hill repeats or pushing the pace, you might want to take on some simple carbs beforehand.

For runs longer than 90 minutes, you’ll definitely want to pre-fuel. Your glycogen stores just won’t get you through.

What Should You Eat Before a Run?

To help you decide what to eat, you need to understand the difference between simple and complex carbs.

Complex Carbs

Complex carbs are usually fibre rich, contain nutrients, and take longer to digest than simple carbs. As a result, they provide you with a steady supply of energy. The healthiest complex carbs are those that have not been processed or refined, such as whole grains, legumes, vegetables and fruits.

Simple Carbs

Simple carbs are easier to digest than complex carbs. However, they cause a rapid rise in blood sugar levels, which is good when you want to boost your energy levels fast, but not so good when you notice how later on, you feel sluggish.

Examples of simple carbs include white bread, refined pasta, white rice, breakfast cereals, fruit juices, sugary drinks, and processed or refined grains with added sugars.

Simple carbs aren’t all bad news: fruit and vegetables contain simple carbohydrates, and milk products contain lactose, which is a type of simple carbohydrate.

Tip: It’s good to know that when compared to refined pasta, whole-grain pasta is lower in calories and carbs and higher in fibre and most micronutrients.

So now we can answer that all-important question: what should you eat before you run?

Try the following healthy carbs:

  • Unrefined whole grains, such as whole-grain bread with visible grains or seeds

  • Brown rice

  • Wild rice

  • Whole (or hulled) barley, a versatile cereal grain

  • Bulgur wheat, a whole grain commonly known as cracked wheat

  • Buckwheat, which is a gluten-free whole grain packed with nutrients

  • Quinoa, a South American grain that has been hailed as a superfood

  • Whole oats, such as rolled oats

  • Whole wheat, such as couscous

  • Beans and legumes, like lentils, kidney beans and chickpeas

  • Nuts

  • Starchy vegetables, including potatoes, sweet potatoes and corn

  • Popcorn that you cook at home - not prepackaged or commercially prepared!

  • Non-starchy vegetables

When To Eat

As a general rule, it’s best to eat a light meal about two hours before a run, or a small snack 30 minutes to an hour before running. However, everyone’s digestive system is different, so you will need to experiment to see what works for you.

Ask people you run with for tips on what they eat and when. Runners love to talk about food!

Here are some suggestions for high carb snacks that are easy to digest, so they’re less likely to make you uncomfortable when you run or end up in urgent need of the loo.

  • A wholemeal bagel with peanut butter

  • A banana and an energy bar

  • Cereal and milk

  • Oatmeal with berries

  • Whole wheat bread sandwich or wholemeal toast

  • Energy bars; avoid diet products as they often cut the carbs

  • Porridge

  • Greek yoghurt and granola

  • Granola bars

  • Chilli bean wraps

  • Buckwheat noodles

  • Cinnamon buckwheat pancakes with cherries

What Happens If You Don’t eat Enough Carbs and You Run Out of Energy?

If you don’t have enough fuel for a workout, your body will need to get energy from somewhere else. As a last resort, your body uses protein as a fuel source. This isn’t good. Over time, muscle protein stores will begin to decrease along with lean body mass, which can be detrimental to performance.

Now you know, carbohydrates are an essential energy source for the body. If you choose complex carbohydrates, you will raise your blood glucose levels for longer and enjoy a more lasting elevation in energy. However, what you eat depends on how fast you need energy, and you might choose simple carbs when you want food your body can digest quickly for an energy boost. But for lighter, low-intensity training, you won’t need to eat any extra carbs at all and should opt instead for a protein-based snack. This will help you feel full-up and support ongoing muscle tissue growth and repair.

How are your energy levels? Join us for a walk or run! We're a friendly running group in Coventry and we run from 5km upwards. We also offer a 0 to 5km beginners running program to get you started on your running journey.



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