Exercising After Eating: Timing, Side Effects, and More (2024)

You don’t need to wait until food is fully digested before exercising, but it’s a good idea to give it some time to settle, such as 1–2 hours after a moderate-sized meal, and 30 minutes after a snack.

It’s often recommended to eat before exercising to top off your energy stores.

However, some people may experience side effects when eating too close to exercising.

These can usually be avoided by allowing sufficient time for digestion, though this time period varies by the type of exercise.

This article explores how long you should wait to exercise after eating.

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When consuming a meal, food enters your stomach and is slowly processed and released into your small intestine in small amounts.

It generally takes 2–4 hours for food to completely move from your stomach to your small intestine (1).

While it’s usually unnecessary to wait until food is fully digested before exercising, it’s best to give it some time to settle in your stomach.

For most people, 1–2 hours is sufficient after a moderate-sized meal, while waiting at least 30 minutes after a snack is fine.

At that point, food has digested enough to avoid stomach upset. That said, as the intensity of the exercise increases, so does the risk of side effects.

summary

While it generally takes 2–4 hours to fully digest a meal, waiting 1–2 hours after a moderate-sized meal and 30 minutes after having a snack should be sufficient before exercising to avoid side effects.

When it comes to eating before exercise, meal size and composition play a significant role.

The larger the meal you eat, the longer it will take to digest, increasing the amount of time you should wait before exercising.

In addition, the composition of the meal affects digestion time.

Meals that are higher in fat, protein, and fiber tend to be digested slower than those containing a larger proportion of simple carbs and more processed proteins, such as those found in some protein shakes and supplements.

High protein foods include intact animal proteins such as beef, pork, chicken, and fish.

Thus, it’s best to avoid eating large meals that are high in fat, protein, and fiber shortly before exercising to avoid any potential negative side effects.

Summary

Meal size and food composition affect the rate of digestion, so it’s best to avoid large meals that are high in fat, protein, and fiber shortly before exercising.

While the side effects that may result from eating close to a workout are highly individual, the most common ones are digestive symptoms and performance issues.

May cause digestive symptoms

Eating too close to working out may cause some digestive discomforts. The most common ones include (2, 3):

• bloating
• nausea
• cramping
• reflux
• vomiting
• diarrhea
• sluggishness

Data suggests that endurance athletes like runners and cyclists are at the highest risk of experiencing these side effects due to the nature of their sport (2).

Lower intensity sports such as golf, walking, and archery are much less likely to trigger digestive symptoms.

Furthermore, most of these side effects can be avoided by allowing some time for digestion before training.

Usually, 1–2 hours is sufficient after a moderate-sized meal, while waiting at least 30 minutes after a snack is fine.

May affect your performance

While fueling up for an intense training session is important, eating too close to a workout may harm your performance.

Athletes and recreational gym-goers often experience a feeling of sluggishness when exercising right after a meal.

A small study in 10 male basketball players found that several of them experienced nausea, belching, and stomach bloating when a protein and carb meal was consumed before training, compared with eating a high carb meal without protein (4).

These symptoms may hinder performance when participating in your sport or exercise of choice.

Summary

Some people may experience various side effects when exercising shortly after eating. These include bloating, nausea, cramping, reflux, vomiting, diarrhea, sluggishness, and potentially hindered performance.

The amount of time required to avoid digestive side effects varies by individual and the sport.

While data on the specific amount of time you should wait is limited, here are some general recommendations:

Some endurance sports, such as running, cycling, and cross-country skiing, lasting over an hour may require eating while exercising to maintain energy stores.

In this case, it’s best to stick to fast-digesting carbs like energy gels or chews to prevent any digestive side effects.

You may find that you can comfortably train shortly after eating, or on the contrary, you may require waiting several hours to avoid side effects.

Therefore, you should experiment to determine your ideal digestion period before exercising.

Summary

The length of time you should wait before exercising varies by sport and individual. Thus, you may have to experiment to find your ideal digestion period. Commonly, it ranges from 30 minutes to 3 hours.

To optimize your energy stores, it’s generally recommended to eat something before exercising.

That said, some may experience negative side effects when eating too close to a workout.

For most people, waiting 1–2 hours to exercise after a meal and at least 30 minutes after a snack is sufficient to avoid side effects.

Those practicing endurance sports may want to wait longer and need to incorporate fast-digesting carbs during workouts lasting longer than 1 hour.

Lastly, avoiding large meals containing a high proportion of fat, protein, and fiber will further help lower the risk of negative side effects.