Get your timing right to prevent stomach cramps and other discomforts.

athlete running after eating

It’s widely understood that you shouldn’t finish a meal and head straight out the door for a run.

Most, if not all runners can agree that running immediately after eating a meal is a bad idea. You feel sluggish, too full, and lack energy despite just eating. This is because your body sends more blood flow to the digestive organs, and not to your muscles.

So how long should you wait to run after eating? It depends on what you eat, the portion size, and what your digestion is like. But 30 minutes to 1 hour after a snack and 2-4 hours for a small or large meal works best for most runners.

The remainder of this blog post will explain what happens if you run too soon after eating, why you should wait, what to eat before a run, and more.

What happens if you run too soon after eating?

Everyone is different, but in general, running too soon after eating can cause numerous issues. For example, you might encounter:

  • Stomach cramps
  • A side stitch
  • Digestive issues
  • An unexpected trip to the bathroom

Your body needs time to digest the food properly. This is especially true if you plan on eating a large meal before training. Instead, we suggest eating a snack or smaller meal 1-2 hours before running to allow your body enough time to digest the food. If you plan on eating a larger meal, you might want to wait 3-4 hours before running.

athlete jumping a hurdle on a trail run

Why wait to run after eating?

You know that feeling after you’ve eaten a large meal and all you want to do is sleep? That’s your body digesting the food. During digestion, blood flow is directed to the stomach and the intestines to help break down your food.

If you were to run while digesting a large meal, you’ll not only feel sluggish but running too soon might negatively impact your digestion, leading to stomach cramps and all kinds of discomfort. 

As mentioned previously, if you plan on eating before a run, limit it to a snack or smaller meal 1-2 hours before training.

What to eat before a run

Whether or not you eat before your run is up to you — but many runners choose to run fasted (without eating). This is especially popular for those who prefer to run in the morning. However, if you plan on going long, it’s a good idea to eat something beforehand.

For example, let’s say you’re getting ready for your Sunday long run — while you’re plotting your route and trying to find your left running shoe, you might choose to eat a small bowl of oats or some Greek yoghurt and fruit. A light snack also works well. Eating something, even if it’s small, will provide you with a little more energy when you need it most.

Other snacks/small meal ideas for 30 minutes to 2 hours before a run might include:

  • A small bowl of oats 
  • Bananas or other fruit
  • Greek yoghurt 
  • Bagel
  • A small handful of dates or almonds 

You might also want to avoid foods too high in sugar, as these can cause a sugar crash, and high fibre foods, as these can cause cramping and gastrointestinal discomfort.

What to eat while running 

For runs longer than 90 minutes, you’ll want to eat a meal that contains plenty of complex carbohydrates beforehand. If you’re running a long run on Sunday, your evening meal the night before could be some kind of pasta dish, for example.

You can also eat while running — great for those longer-distance events. Some people prefer energy bars, others like the convenience of gels. Our advice? Find what works best for you — no two runners are the same, so test, learn, and find your ideal nutrition strategy.

You can also use the Styrkr fuel tool to help decide how much you should be eating for a goal event.

energy gels for running

What to eat after a run 

There are two types of runners: the one who comes in from a run and eats the entire contents of the kitchen cupboards, and the other who finds it difficult to stomach any food after running.

Despite this, it’s important to refuel your body, replenish lost glycogen stores, replace lost electrolytes and minerals, and begin the muscle repair and growth process.

The more intense your session, e.g. whether an interval workout or 90 minute long run, the more important it is to get fuel on board as soon as possible.

As a general rule of thumb, aim to get some form of carbohydrates and protein. A lot of runners choose a recovery/energy bar, a protein shake, or a dual mix carb:protein blend. If possible, try and refuel within 30 minutes, but at the very least, within 1-2 hours of training.

Related: What to eat after a run to optimise recovery

eating after a run

What about hydration?

We can’t talk about what to eat before a run without highlighting the importance of hydration. It’s the one thing a lot of runners consistently get wrong. 

Dehydration, and not being adequately hydrated before running will impact performance. Your body temperature increases, your aerobic performance declines and your perceived exertion will likely be higher than usual.

athlete hydrating on a run

If you’re a morning runner, you’re at an even greater risk of dehydration
. And while you may spring out of bed to log those early morning miles, you should try and get at least a few sips of water down first. 1-2 glasses of water in the morning before running is a good goal to aim for if you’re up 30 minutes to 1 hour earlier than you head out the door.

And if you’re not a morning runner, drink plenty before your run and throughout the day. Aim for a minimum of 1.5 to 2 litres of water/day, and don’t forget to hydrate after running, too. If you’re running longer than 90 minutes or it’s a particularly hot day, you can also take on fluids during your run. 

Related: Why is hydration important in sport?

To summarise

Wait 30 minutes to 1 hour after eating a snack or a small meal and between 2 and 4 hours after eating a larger meal before running.

Your body needs time to digest your meal — run before this happens, and you’ll feel sluggish, uncomfortable, and you certainly won’t break any personal bests.

Over time, like many other seasoned runners, you’ll find out what works best for you, whether that’s a light snack before your run, a small meal a few hours before, or a large breakfast in the morning followed by a run in the afternoon.


Can I run 1 hour after eating?

Yes, if you had a small snack or meal, you might feel comfortable running 1 hour after eating. But it varies from person to person — find what works best for you.

What happens if I run after eating?

Running immediately after eating will leave you feeling sluggish, full, and uncomfortable. Wait at least 30 minutes after a snack, and up to 4 hours, depending on the meal size.

Can you run 90 minutes after eating?

Yes, if you had a small snack or meal, you might feel okay to run. If not, wait a little longer until your food has been digested.

Styrkr Fuel Tool