How Long Should You Wait After Eating to Exercise? (4 Timing Keys)

Maybe you grew up hearing not to swim for 2 hours after eating and now you’re wondering when can I exercise after eating??

Is there a set time frame?

Was that 2 hour rule ever accurate? (hint, no)

Most importantly, I want to make sure you don’t use it as an excuse to continue doing Fasted Cardio. Ladies, we know that empty stomach long or intense exercise wrecks our hormones and is detrimental to performance.

So it’s time to start planning ahead and thinking through the timing of your meals and snacks to better enjoy your workouts.

How Long Should You Wait To Exercise After Eating?

It depends.

Which is basically the answer for most fitness related questions.

But let’s break that down a little bit more to help you decide when to go and when to slow your roll.

The biggest reason for WAITING to exercise is that once we start going the blood is diverted from our small intestine (the digestive track) to our working muscles. This is necessary to ensure that our heart, lungs, legs and brain all receive enough oxygenated blood to work optimally.

Without thinking through the timing we could end up with runner’s diarrhea, side stitches or nausea after running.

None of which are terribly pleasant. Your body stops efficiently digesting which means the food is either sitting in the stomach creating pressure or suddenly really ready to run through you.

To fuel your workout and avoid stomach problems, exercise 1 to 2 hours after a small meal and 30 to 60 minutes after a snack.

But that’s not the whole story, there are in fact four factors that will help answer this question for you for all kinds of running and exercising situations. But before that, there’s another question I get asked really often.

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What Happens If You Don’t Eat Before Exercising?

Just as eating right before you work out can be an issue, so can not eating at all before exercising.

To explain this further, I’ve written a detailed article on Fasted Cardio to help you fully understand the drawbacks of this and when it’s ok.

In general, Registered Dietitian Heather Featherstone has said she does not recommend anyone do workouts in a fasted state. You’re cutting short your full ability by not fueling the body and for many you are actually going to be burning muscle for fuel.

We definitely understand that it can be hard to eat first thing in the morning, but it’s worth it. Check out the article above for more ideas on how to teach your digestive system to better handle food.

Now, let’s talk through some key tips to help you time your nutrition so that you can have a well-fueled workout without any stomach issues.

A Quick Guide to Exercise after Eating

For morning workouts, it’s often easy to grab a bowl of cereal before the workout and then focus on a slightly larger balanced meal of protein, carbs, and fat for recovery after the workout.

For lunch time workouts, think about simple carbs before the run and then again eating lunch with protein after.

For evening workouts, consider a small meal that’s going to cut the hunger and ensure you don’t end up dizzy on the run! This is a common issue for my husband. But even grabbing a granola bar before the run helped him tremendously.

Is it Better to Exercise Before or After Eating?

A good rule of thumb is if it’s been 3-4 hours since you last ate and then workout will be intense or last more than 45 minutes, you should absolutely eat.

Even if it’s half a small sandwich or a smoothie, that nutrition is going to help ensure your muscles have enough energy to perform the workout and get the most benefit from the workout.

We also know that the lack of fuel can SLOW DOWN YOUR RECOVERY TIME.

That’s right, it will break down more muscle and thus you may feel like your next workout is harder, you might have to cut the next one short or you may simply be starting to lose muscle because the body gets inflamed.

So at a minimum, go into your workouts with a snack.

Factors to Consider When Deciding How Long to Wait After Eating to Exercise

There are four factors that determine how long you should wait after eating to exercise. These are:

Size and Type of the Meal
Time of Day and Gut Health
Intensity of the Workout
Your Personal Experiences

Let’s consider each of these in more detail:

1. Size of the Meal

Yup, the size and type of meal are going to be a major factor.

high fiber and/or high fat meals often need more time to digest and thus 1-2 hours from eating to exercise
a large meal of protein sitting in your belly as you start jumping around is absolutely going to lead to issues and again look for a 2 hour window
yogurt and other dairy products are often recommended, but big trigger foods for many people to have stomach upset
low fiber meals are perfect snacks when you need quick fuel to get started right away – think crackers, toast
100-200 calorie snacks (a banana or bagel with 1 tbsp nut butter) are usually fine within 30 minutes of running

Checkout the best pre-workout snack ideas >>

What happens if you exercise immediately after eating?

Usually not much besides some uncomfortable sensations that could include hanging your head over a trash can if it was a big enough meal and the workout was hard.

In swimming, the hour window was thinking about this idea of muscle cramps.

If blood was still working on digestion, then your muscles would be more likely to cramp and well…you drown in that scenario.

This doesn’t seem actually be an issue for anyone playing in the pool or ocean, as we noted the body wants to push the blood in to your muscles because they are asking for the most attention.

There is very little to say that exercising right after eating is going to cause muscle cramps, though it could cause a side stitch while running.

2. Time of Day and Gut Health

The timing of your meals could play a big role in how much you can consume.

Breakfast you might sneak in a carbohydrate filled bowl of oatmeal easily because your stomach isn’t full or currently digesting previous foods.
Due to stress and maybe less than stellar food choices during the day, digestion may be more sluggish by evening. Thus more issues with eating certain foods prior to your sweat session.
Speed eating! How many rush through lunch or you rush through a meal trying to get in that workout…that too will lead to more stomach issues while working out.

One thing that helps many is to improve overall gut health by taking a high quality probiotic >>

A general guideline is to avoid an overly full stomach, but honor your hunger.

how long to wait after eating to exercise

3. Intensity of the Workout

Now we’re getting in to the real meat of the situation. (I cannot pass up a good pun.)

How hard is the workout you’re about to do? And how new or experienced are you with the workout?

Long time runners are often able to eat more or sooner before easy runs because they’ve adapted
Anyone doing HIIT runs or hard intervals is going to find their stomach working overtime with the wrong meal
Weight lifters might find they are less prone to stomach issues because of the lack of bouncing and jostling

If you’ve been in a consistent exercise routine for years, then your body may be more adapted.

BUT these high intensity style moves simply cause the entire digestive system to move a lot more, which does lead to reflux or vomiting at the gym…which I prefer to avoid.

4. Previous Experiences

The final factor might simply be the most important which is your experience of what happens when you workout after eating.

Try keeping a food log or making notes around your workouts to see what has side effects.

How much did you eat?
How long before the workout?
What kinds of foods did you eat? Spicy? Fried? Fatty? Lots of veggies?

If you have kept a log and cannot find a culprit, it just feels like everything is making you feel unwell then it’s time to work with a Registered Dietitian like Lydia Nader.

Especially sports dietitians, have helped so many people work through these same things and to come out the other side feeling stronger and happier with their workouts.

What Should I Eat Before Exercising?

How you eat before a workout depends on how your body breaks down the food you eat and how long and hard you work out. So, the right food can help fuel your workout, improve your performance, and speed up your recovery.

I’ve discussed all the important factors such as timing, intensity, gut health, size, and type of meal, as well as your previous experience in this article above, so always refer back to that. But here are the components that go into a balanced meal before exercising:

Carbohydrates

Complex carbohydrates, such as whole grains, beans, and vegetables, supply energy to fuel your workouts. However, they may take longer to digest, making them a better option several hours before exercise.

Protein

Protein is essential for muscle development and recovery. Protein can be found in lean meats, fish, dairy, beans, and other foods.

Healthy Fats

A balanced diet must include healthy fats, such as those found in nuts, seeds, and fish. As with complex carbohydrates, they take longer to digest and are a better choice for a meal several hours prior to exercise.

If you’re looking for some great, tried-and-tested ideas by a running coach, this guide I’ve written on pre-workout snacks is perfect for you! It includes 19 snack ideas that you can try, along with tips and information that will answer all your questions!

What Foods Should I Avoid Before Exercising?

Pre-workout snacks should be chosen with digestion time in mind; high-fiber, high-protein, and high-fat foods all take longer to break down. If you want to keep your energy levels stable, limiting sugary foods is a good idea.

And, as I mentioned above, you can also modify your pre-workout diet in accordance with what you know about your digestive system and how it reacts to various foods.

If you have a history of acid reflux or heartburn during exercise, you should steer clear of anything that could trigger those symptoms.

Some foods that can cause such issues include spicy foods, fatty foods, chocolate, caffeine, and even citrus fruits. Again, I recommend keeping a food journal to figure out what works and does not work for you and your body.

This process can feel like a bit of trial and error, but it’s well worth it and will save you a ton of trouble down the line, especially when you get into marathons and other types of races.

What Foods Should I Have After Running?

To help you answer this question, I’ve written a full guide which includes 29 post-run meal ideas that I’m sure you’re absolutely going to love.

This guide is also perfect if you’re looking to figure out what to have after a marathon, because that is definitely something every runner looking into running a marathon should learn.

All right, now that I’ve covered everything you need to know on how long to wait for eating to exercise, here are a few other resources I know you’re going to love!

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