Should You Eat Carbs Before Or After You Work Out? We Asked the Experts

Carbohydrates like pasta, toast, and oatmeal probably top your list of your favorite foods to fuel up with before a long run, bike ride, or cardio dance workout. Or, you might instead prefer to enjoy a turkey sandwich or burrito after a lengthy gym session. 

We can all agree that carbs are delicious. But you may be wondering when, exactly, it's best (and most optimal) to eat them—before or after you train? 

According to experts who specialize in sports nutrition, when you should eat carbs depends on a few factors like how often you train and what type of exercise you are doing. Here’s what to consider before you dive into that bowl of bolognese. 

Carbohydrates: The Fuel Your Body Needs

Carbs get a bad rep, but don’t buy the rumors. They are essential for any athlete’s (or frequent gym goer’s) performance, explains Emilie Burgess, RDN and board-certified sports dietitian (CSSD) at Laura Moretti Nutrition in Boston. 

“Muscle glycogen (the storage form of glucose/carbohydrates in the muscles) is the major source of carbohydrate fuel in the body, followed by our liver glycogen stores, and then blood sugar,” she says. “The glucose or carbohydrates that our body stores or that is within our blood is converted into ATP (energy) within our cells.” 

In other words, carbohydrate stores are helping give you the energy you need to get through your favorite spin class or run. 

Slow vs. Fast-acting Carbs 

Even though all carbs give the body energy, what type of carbohydrates you are eating and when you eat them also matters, Burgess explains. “There are two different types of carbs: fast acting and slow acting. Both are essential to an athlete's performance. But when we think about an athlete's main meals of the day—breakfast, lunch, and dinner—we want to prioritize slow acting carbs here,” she says. “This helps keep you fuller longer throughout the day and keeps energy levels stable.” 

However, you shouldn’t discredit fast-acting carbs. They are important when you need to eat something quickly before your workout. “When we need a quick boost of energy, or a snack prior to working out, quick acting carbs come into play. These types of carbs digest and absorb quickly, causing a rise in blood sugar, and make glucose available to the muscles for performance,” she says. 

Just be careful to check how much added sugar your fast-acting carbs have, adds Melissa Morris, ISSN certified sports nutritionist. “Simple carbohydrates are helpful for providing a quick source of fuel for activity, but they can also have a lot of added sugar. Too much added sugar can increase the risk for cardiovascular disease and add on unwanted extra calories.”  

The Carb Window: When to Eat Carbs Before, And After, Working Out

Burgess recommends eating carbs before and after your workout, but how close you are to go-time should determine whether you should eat a slow or fasting carb-rich snack or light meal. “The closer we get to performance, the more carbohydrate based you want your meal/snack to be. Fats and proteins take a longer time to digest, therefore, if eaten too close to a workout, they can lead to gastrointestinal distress,” she warns. 

• 2-3 hours before workout: If you remember to eat two or three hours before your workout, aim for a meal/snack that is high in carbs and moderate in protein and fat. For example, peanut butter on whole wheat bread or a chopped hard-boiled egg and crackers. 
• One hour to 30 minutes pre-workout: Working out immediately after work or first thing in the morning, but need a light snack or meal before you go? An hour or 30 minutes before, aim for a quick carbohydrate source (around 30-60 grams of carbs) like a handful of pretzels or a gu or gel packet. 
• Post-workout: Aim for a 3:1, or 4:1, ratio of carbohydrates to protein. (Or a ratio of 40 grams of carbs to 10 grams of protein.) Try chocolate milk to refuel and get the protein your muscles need to recover. 

Carbohydrates For Cardio vs. Strength Training 

You’ll need some carbohydrates for energy whether you are doing cardio or strength training. However, you’ll want to add some protein if you are strength training, recommends Josh Axe, ND, CNS, and founder of Ancient Nutrition. “Carbs are important for any extended, high intensity workout. If you’re doing strength training or weight lifting, it’s important to add in protein too. A protein shake, cup of Greek yogurt or some hard-boiled eggs are good options,” he says. 

Should You Avoid Carbohydrates? 

If you’re active, Burgess doesn’t recommend avoiding carbohydrates. “All carbs are equal within your body, and all carbs can fit into an athlete’s lifestyle,” she says. Just watch what type of carbohydrates you are having and when. “You do want to avoid high levels of slow acting carbs within 30-60 minutes of a workout due to the high fiber content, which can upset the stomach. These types of carbs won't give you the same boost of energy quickly compared to quick acting carbs like pretzels or gels,” she warns.