The 4 Worst Foods to Eat After a Workout, According to Dietitians

Whether it's a banana with some peanut butter or a quick protein ball, you may have your pre-workout snack down pat. But what you eat after a workout is just as important as what you consume before. After all, your muscles need important nutrients, like protein and carbs, to grow bigger and stronger.

If you want to make the most of your workout and stay energized for training sessions to come, you'll want to fuel your body with nutritious foods. Unfortunately, that means you may have to skip some of your usual post-workout indulgences (at least for the most part). Avoid these foods after a grueling workout to replenish your body properly and keep your digestive system happy.

If you're an early morning runner, it's tempting to pick up a donut or two on the way home. But unfortunately, high-sugar, high-fat foods are one of the worst foods to eat, especially after a grueling a.m. training session, according to Jim White, RD.

After a workout, your main priority is refueling for your next training session. You definitely want to get some high-quality carbohydrates in your muscles to replenish depleted glycogen stores, according to the American Council on Exercise (ACE). But foods high in fat — yep, that includes donuts — can actually slow digestion, impairing your body's ability to transform carbs into glycogen.

Instead, opt for some fast-digesting carbohydrate sources that are lower in fat, White suggests. If you have a sweet tooth post-workout, swap your morning donut with some oatmeal and a banana (or whatever fruit you prefer). Overnight oats are another good option if your mornings are busy, and you don't have enough time to prepare a meal after your workout.

While you may love the occasional post-workout burger, passing on the side of fries is probably a good idea (though it's totally OK to enjoy them every now and again, too). Generally, deep-fried foods are hard on the digestive system and may even cause stomach pain in some cases.

Because they take a lot of energy to digest, fried foods can also make you feel lethargic, rather than energized from your workout, explains Bonnie Taub-Dix, MA, RDN, CDN, registered dietitian, creator of BetterThanDieting.com and author of ‌Read It Before You Eat It: Taking You from Label to Table.‌

"Foods that are more difficult to break down can make you feel sluggish and keep you from feeling replenished and satiated relatively quickly," Taub-Dix says.

Greasy foods can also cause symptoms of gastroesophageal reflux, according to the National Institute of Diabetes and Digestive and Kidney Diseases. If you're already prone to reflux, indulging in some French fries post-workout can exacerbate symptoms.

Instead of French fries, try a baked potato topped with Greek yogurt or cottage cheese, Taub-Dix recommends. A baked potato will give you some easy-to-digest, glycogen-replenishing carbs, while the yogurt and cottage cheese will pack some protein, helping you curb hunger and feel satisfied.

Your post-workout ritual may include an ice-cold soda or beer, but it's not the best way to re-hydrate after a tough sweat session. Adequate hydration is necessary after exercise, but beverages are high in sugar and, in the case of alcohol, can dehydrate your body even more, White explains.

"Soda offers straight sugar with no other nutritional benefit," White says. "This is a no-no post-workout drink."

Alcohol can also impair your muscles' ability to repair and regenerate after a workout, according to the ACE. Moreover, it can slow your body's storage of glycogen, which may affect your energy levels during your next workout.

Although you can definitely enjoy a celebratory beer or soda after a race once in a while, it's best not to make these drinks a habit. If you would like to re-hydrate with something more flavorful, try coconut water, White suggests. Coconut water hydrates your body and provides electrolytes while giving you a hint of sweetness.

Sure, protein is necessary after a workout, but highly processed protein bars can be loaded with unwanted ingredients, according to Taub-Dix.

In addition to the added sugar you'll find in most bars, many processed protein bars also contain sugar alcohols and artificial sweeteners, which can cause an upset stomach, Taub-Dix says. Artificial sugars can, in some cases, also have a laxative effect, causing bloating, gas and diarrhea, per the Mayo Clinic. Look out for acesulfame potassium, aspartame and sucralose on labels.

If you love the convenience of a protein bar, look for an option that's formulated with higher-quality, whole ingredients, including whole grains, nuts and seeds and dried fruit, Taub-Dix suggests. Select a protein bar that's high in protein but also low in added sugar.