Food is fuel for the body, so if you’re going to be exercising, it’s important to dial in your nutrition and fuel your body with the right foods at the right times.
There’s a lot of talk about the “right foods” to eat—nutritious, minimally-processed foods particularly high in carbohydrates and protein—but what about the “right times”?
How long should you wait to work out after eating?
Striking the right balance between waiting long enough after eating to work out so that you’re not overfull and not waiting too long that you’re starving or have low energy can be tricky.
It’s no surprise that one of the most common questions people ask when it comes to scheduling their workouts is, “How long should I wait to exercise after eating?”
In this article, we’ll discuss factors that affect how long after eating to work out and discuss best practices for working out after eating to help ensure you have the energy you need to smash your workouts while sidestepping any digestive issues.
We will cover:
- Why the Timing Of Eating Before Working Out Matters
- Factors that Affect How Long You Should Wait After Eating to Work Out
- How Long Should You Wait To Work Out After Eating?
Let’s jump in!
Why the Timing Of Eating Before Working Out Matters
Whenever you do any sort of physical activity, whether walking around the house, lifting weights in the gym, going for a run or otherwise, your muscles need energy (ATP) to contract and sustain your movement.
This energy is supplied from the food you eat, as the nutrients contained in your diet—carbohydrates, fats, and protein—are digested and metabolized by the cells to produce ATP.
Unfortunately, for most people, it’s not as simple as just eating at liberty and then immediately hitting the gym for a spin class or loading up a barbell for a bunch of near-maximal squats.
Exercising on a full stomach can be painfully uncomfortable and can cause cramping, bloating, side stitches, and indigestion, and can weigh you down and make it difficult to move around quickly.
It also takes time for the pre-workout snack you eat to actually be digested and metabolized, so if the purpose of your pre-workout fueling is to provide energy for your activity, you need to leave ample time for the digestion process.
This is an especially important consideration given the fact that exercise slows digestion.
After you eat, blood rushes to the stomach and digestive tract to begin the digestion and absorption process.
However, when you exercise, blood is shunted from the digestive tract so that it can perfuse the working muscles with the oxygen and nutrients they need to contract and facilitate movement.
As blood is diverted away from the GI tract, digestion nearly ceases, so whatever partially digested food is in your stomach and intestines basically sits around until your workout is over.
Digestion will resume when exercise has stopped, and blood flow resumes to your digestive organs. Consequently, in most cases, exercising immediately after eating is uncomfortable and inadvisable.
On the other hand, waiting too long after you eat so that you end up exercising on an empty stomach can be problematic as well.
One of the challenges of exercising on an empty stomach—particularly first thing in the morning after the overnight fast—is that your blood sugar levels are low, and your muscle and liver glycogen stores are somewhat depleted.
Because the preferred fuel for the muscles during intense exercise is carbohydrates when your blood sugar and glycogen levels are low, you can feel sluggish, weak, and low energy.
Additionally, some people may feel dizzy, lightheaded, or have a headache when exercising on an empty stomach.
In this way, waiting too long to exercise after eating can compromise your performance.
We will now look at some of the deciding factors to help answer the question: how long should you wait to work out after eating?
Factors that Affect How Long You Should Wait After Eating to Work Out
The recommendations for how long to wait after eating to work out depend on several factors, including the following:
#1: Workout Type and Intensity
The ideal pre-workout fueling strategy is affected by the type of exercise and the intensity of your workout.
For instance, if you’re going to be doing a low-intensity form of exercise, such as yoga, walking, or gentle swimming, you can probably enjoy more liberty in terms of how soon after eating you work out, as well as what you choose to eat and how much you can eat.
Generally, the easier your workout, the less affected you’ll be either way in terms of what you do or don’t eat beforehand.
You’ll be less bothered by a full stomach when you exercise if you aren’t running and jumping around or forcefully exerting yourself trying to lift weights.
Moreover, when you perform low-intensity exercise, some amount of digestion continues to take place rather than ceasing completely.
Although the muscles are demanding more oxygen and nutrients than they do at rest, the increase is not so appreciable that all blood is shunted from the GI tract, as it might be with high-intensity exercise.
As a result, you will be able to continue digesting food to some extent, preventing nausea, bloating, and indigestion experienced during vigorous exercise when food just sits and sloshes around the stomach the whole workout.
Similarly, if you’re doing low-intensity exercise on an empty stomach and your energy is poor, it may still compromise your performance and detract from feeling your best, but to a lesser degree than it would for a vigorous, energy-demanding workout like a HIIT workout, plyometrics, or hill sprints.
This is due to the fact that the lower the intensity of your workout, the greater the relative percentage of energy your muscles will get from oxidizing fat.
Plus, you’ll just need fewer calories (energy) for a low-intensity workout.
Therefore, the necessity for adequate pre-workout carbohydrate intake to top off your glycogen stores is far less important during easy exercise than it is before vigorous exercises, wherein the body relies much more heavily on metabolizing carbohydrates for energy.
With vigorous exercise, you have to wait significantly longer after eating to work out and harder to give your stomach time to digest and metabolize the food.
#2: Workout Duration
The longer your plan to work out, the more fuel your body will need.
If you are doing an endurance-based workout or something longer than 45 minutes or so, you will want to ensure you have a nutritious meal or snack within a reasonable timeframe to prevent hunger pangs, sluggishness, and low energy.
#3: How Long It’s Been Since You’ve Eaten
Another important factor to consider is when you are working out and having a pre-workout meal or snack within the greater context of everything else you’ve eaten that day.
For example, if you work out first thing in the morning, you will not have eaten anything since the night before, so your pre-workout snack will be the only thing you will have eaten in hours.
On the other hand, if you work out in the evening, you’ve presumably eaten at least breakfast and lunch, if not additional snacks, so you have a day of nutrients within your body.
In this latter scenario, a smaller pre-workout snack or just lunch may be all you need to have ample energy for your workout.
#4: What You Ate
Your food choices can also affect how long you should wait after eating to exercise.
Foods that contain fiber and fat, and to a lesser degree protein, take longer to digest and empty from the stomach.
Therefore, if you’re going to be working out right after eating, it’s best to stick with simple carbohydrates like sports drinks, fresh or dried fruit, or rice cakes or crackers.
#5: How Much You Ate
The more you eat from both a volume and a calorie standpoint, the longer you will want to wait to exercise.
Both scenarios slow gastric emptying, and it’s particularly uncomfortable to work out on a stomach filled with bulky foods like Brussels sprouts and mashed potatoes.
Studies show that the average stomach empties at a rate of approximately 1-4 kcal/min, so the more calories you eat at one time, the longer it will take your stomach to process the food.
#6: Your Digestive System
Lastly, the sensitivity of your digestive tract also plays a role. Some people do not seem bothered by exercising on a full stomach, whereas others need to wait a long time before moving around after eating.
How Long Should You Wait To Work Out After Eating?
Clearly, guidelines for how long after eating to work out are difficult to establish because there are numerous factors at play, and you have to find the balance of having enough fuel and nutrition to feel strong and energized for your workout without feeling saddled with a stomach full of undigested food.
Although the length of time you should wait after eating is clearly somewhat individualized, here are some guidelines for: how long should you wait to work out after eating?
For low-intensity exercise (yoga, walking, hiking, Pilates, gentle swimming, and low-intensity cardio)
- Wait 2-3 hours after a large meal to work out
- Wait 1-2 hours after a small meal to work out
- Wait 30-60 minutes after a snack to work out
For vigorous exercise (running, HIIT, strength training, cycling, fast swimming, intense cardio, etc.)
- Wait 3-4 hours after a large meal to work out
- Wait 2-3 hours after a small meal to work out
- Wait 1-2 hours after a snack to work out
- Wait 30 minutes after a quick bite or sports beverage to work out
So, the next time you ask yourself, how long should I wait to exercise after eating, take a peak at our recommendation list for guidance. Also, experiment with different foods and timing windows to see what works best for you. It might be that your body operates in line with the recommendations, or you might be an outlier.
Looking for some snack ideas to whip up before your next workout? Check out our Best Snacks For Runners Guide.