How long to wait after eating to run

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

Typically, the larger a meal or snack you eat, the longer you should wait before running. 

If your meal was high in protein or fat, it’s best to give your body more time to digest before running.

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 15 minutes to 1 hour after a snack and 2-3 hours for a meal works best for most runners.

The remainder of this blog post explains how long to wait after eating to run (from a large meal to a small snack), along with recommendations from a sports dietitian.

What you will learn:

• What happens if you run too soon after eating 

• Why you should wait after eating before running 

• What to eat before a run for optimal performance 

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 experience:

• Stomach cramps

• A side stitch

• Digestive issues

• An unexpected trip to the bathroom

Your body needs time to digest the food properly, and the larger the meal, the longer it takes to digest.

2-3 hours is recommended as a baseline to digest properly before running.

If you had a snack or a smaller meal, anywhere from 15 minutes to 1 hour is recommended.

Why wait to run after eating?

After eating, blood flow is directed to the stomach and intestines to help break down and digest food.

If you were to run after eating, less blood, which also means less oxygen, is available to send to the muscles and working organs. It negatively impacts digestion, and is why you will often feel sluggish if you’ve ever tried to run after eating.

If you plan on eating before a run, choose a snack or a 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.

However, many runners like to run fasted (without food) — especially morning runners.

If you have as little as 15 to 30 minutes before running, a small carbohydrate snack could improve running performance. So it’s a good idea to eat before if your goals are performance-oriented. 

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. 

Jena Brown, endurance dietitian and owner of Victorem Performance Nutrition in Brenham, Texas, has provided various pre workout snack and meal ideas below.

0-30 minutes before running

“Stick to simple carbs in small amounts — something your gut knows and tolerates well. For most athletes, 30 grams of carbs or less with minimal fat or protein works best,” says Brown.

STYRKR examples:

·       Half a BAR50 Energy Bar

·       Half a BAR+ Recovery Bar

·       1 GEL30

·       Half a serving of MIX60 Dual-Carb Energy Drink Mix

·       1 serving MIX+ Duel-Carb & Electrolyte Mix

2-3 hours before running 

“You can eat more, but still keep it mostly carbs and lighter on fat and fibre. Three or more hours is your best window for a more complete meal. You can include moderate protein and fat as tolerated, with carbs still taking the lead,” says Brown.

Brown also provides a useful table with a macronutrient breakdown and example meals for an endurance athlete.

Example meals using STYRKR products for a 140 lb athlete:

She also explains how pre-run fueling is individual. Practice with timing, textures, and other products, like whole foods, drink mixes or pre-made sports products for functional fueling to support health and training.

What to eat while running 

I’ve already explained what to eat before run. But what about during your run?

For runs longer than 75-90 minutes, you should be eating during your run.

If you’re new to running, this may sound strange. But you need to keep your glycogen levels topped up for energy. It will also help you avoid “hitting the wall” or “bonking.”

As a general rule of thumb, aim for a minimum of 30-60g of carbohydrates per hour [1]. Most runners can tolerate 90g and sometimes more, but build up your tolerance to this to prevent gut upset.

You have lots of foods available, like energy gels, bars, chews, bananas, sweets, and carbohydrate sports drinks.

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.

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.

It’s essential to refuel your body, replenish glycogen stores, replace lost electrolytes and minerals, and begin the muscle repair and growth process.

The more intense your session, e.g., an interval workout or a 90-minute long run, the more necessary it is to get fuel on board as soon as possible. And I’m not just talking about protein shakes!

Instead, 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. Try and get both carbs and protein.

And if possible, 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

What about hydration?

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

Dehydration and not being adequately hydrated before running negatively impact performance.

Your body temperature increases, your aerobic performance declines, and your perceived exertion will likely be higher than usual.

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 to get at least a few sips of water down first. 

1-2 glasses of water in the morning before running is a good goal 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 during 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. Add electrolytes like SLT07 to replace electrolytes like sodium lost in sweat, which can cause muscle cramps.

Not having the right amount of electrolytes can also cause dehydration/impact performance.

Related: Why is hydration important in sport?

Key Takeaways

• How long to wait after eating depends on what you eat, the portion size, and what your digestion is like

• High fibre foods and foods high in protein and fats take longer to digest, so more time is needed for proper digestion

• For a small snack (15-30g of carbs), anywhere from 15-30 minutes is needed before running

• For a larger meal, anywhere between 1-3 hours

• Prioritise carbohydrates before running, but the longer you have, the more balanced a meal you can eat

Read our blog post on how long to wait after eating to workout for more advice, with tips for cyclists, runners, and other athletes.

FAQs

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 15-30 minutes after a small snack, and 2-3 hours for a meal, depending on the 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.

References: 

1) Rodriguez, N.R., Di Marco, N.M. and Langley, S., 2009. American College of Sports Medicine position stand. Nutrition and athletic performance. Medicine and science in sports and exercise, 41(3), pp.709-731.