How long should you wait after eating to work out?

And how to find what works best for you.

What you eat and how long you should wait before working out depends on how much time you have available.

For example, if you have 30 minutes before a morning run or weights session, you shouldn’t have a full meal. Instead, choose a small, easy-to-digest carbohydrate option with minimal fat and protein.

If you have time for a full meal, wait up to 2-3 hours before working out.

These are just guidelines — how you respond to food before a workout varies from person to person.

I spoke to Jena Brown, RD, CSSD, a sports dietitian for endurance athletes and owner of Victorem Performance Nutrition in Brenham, Texas, for guidance on what to eat before a workout. (And how long you should wait after eating to workout.)

This article explains everything you need to know to help you get the most out of your pre-workout nutrition. 

What you will learn:

• How long to wait after eating to workout to increase performance

• What happens if you exercise too soon after eating 

• What to eat and how much to eat before a workout to fuel performance

• Side effects of eating the wrong foods or too much food before a workout

How long after eating to work out

You should work out 2-3 hours after eating a full meal.

That’s the short answer.

Brown explains that nutrient timing depends on body weight, the type and quantity of food, and individual tolerance. Generally, the larger the meal or snack — especially if it is high in protein or fat — the longer it takes to digest. Therefore, more time is needed before a workout.

According to the International Society of Sports Nutrition, nutrient timing is essential for optimal fueling for performance and training adaptations. There are recommended guidelines for carbohydrates before a workout, but targets for protein and fat are less defined. Protein and fat tolerance vary for each athlete, and needs vary on many other things, such as age, activity intensity, and more.

See the table below for guidelines on how many carbs, proteins, and fats to eat before a workout provided by Brown.

Is it better to work out on an empty stomach or a full stomach?

A lot of this is personal preference.

Ideally, you don’t want to train on an empty or a full stomach. Instead, you’d have enough energy for your workout without being hungry or too full.

Many morning gym-goers prefer to train in a fasted state, for example.

If that’s you, that’s okay.

But if you wake up hungry, fatigued, and lacking energy, it’s a good idea to get some food in your system before working out.

On the other hand, I recommend eating before exercising if you’re going for a long run or ride, for example.

You want to ensure your glycogen stores are topped up before long bouts of exercise to avoid hitting the wall — this is when you run out of energy and struggle to continue. 

If you are doing aerobic exercise for over 75 minutes and can eat while working out, topping up the fuel tank before heading out the door is a good idea.

Play around with your nutrition and find what works best for you.

Try meal planning to fuel performance

To perform your best, whether a weekly long run, sportive, or morning gym session, time your nutrition around your workout.

If you are working out in the morning and have minimal time to eat, choose an easy-to-digest carbohydrate option like a granola bar or sports drink.

On the other hand, if doing a long ride in the afternoon, eat a full meal 2-3 hours before. Aim to get 0.9-1.4 grams per pound body weight, 20g of protein, and 20g or less fat.

Play around with it and find what works best for you.

When done correctly, meal planning around your workouts will improve performance.

And hey, if you prefer working out fasted, that’s cool, too.

What happens if you exercise after eating?

If you exercise too soon after eating, you may experience side effects like bloating, nausea, stomach upset, and sluggishness.

This is because blood flow is redirected to digestion rather than sending blood to the muscles to support performance. 

Side effects of exercise after eating 

Often, the conversation on eating before a workout is centred on getting enough fuel.

But eating too soon before your workout may cause various side effects. Take these into consideration when timing your pre-workout nutrition.

Brown says eating too much, or the wrong types of food before a workout can cause:

• Bloating

• Burping

• Gas and stomach cramps 

• Vomiting

• Diarrhea 

You can train your gut to tolerate more food volume before a workout. However, Brown recommends working with a sports dietitian to create a personalised plan for improved performance while minimising unwanted side effects, like a last-minute trip to the bathroom.

What to eat before a workout 

“If you have a short timeline before a workout — less than 2 hours, for example — choose a high-carbohydrate, low-fat snack,” says Brown. Fresh fruit, a granola bar, or a sports drink are quick energy sources that digest quickly.

She also recommends avoiding foods that are too high in fat, fibre, and protein. These slow down digestion.

The more time you have before a workout, the more balanced a pre-workout meal or snack can be. Practising a pre-race meal based on proper timing and body weight is recommended to train the gut leading up to race day. For example, if you’re training for a marathon, this should be a part of your training.

FAQs

Can I work out 30 minutes after a meal?

Yes! However, choose a small snack high in carbs and low in fat and protein so it does not affect digestion too much.

Can I work out 1 hour after eating?

Yes, you can exercise 1 hour after eating. You can have a small meal or snack to fuel your performance. Aim for 0.5g of carbs per pound of body weight (so if you’re 150 lbs, that’s 75g).

Is 2 hours enough to digest food before a workout?

Yes, 2 hours is enough to digest food before a workout. Most people can digest a medium-large meal in 2 hours. But experiment with your pre-workout nutrition to find what works best for you.

Key takeaways

• If eating a full meal, wait 2-3 hours before working out

• You can eat closer to a workout, as soon as 15-30 minutes, but limit protein and fat intake and aim to get 15-30g of carbs instead

• The longer you have before a workout, the more balanced a meal you can eat

• Time your meals and snacks to fuel your performance 

• If you eat too soon before exercising, you may experience stomach upset, bloating, or even diarrhoea 

• Try granola bars, sports drinks, and or fresh fruit before a workout if you’re pressed for time