Knowing how to fuel your body for physical activity can be tricky business. Plus, add figuring out what to eat after the gym to the mix, and you've got a whole other layer of complexity. While pre- and post-workout nutrition can be confusing, it doesn't have to be. The main thing to understand is that the food you put in your body before, during and after a workout significantly impacts your performance, recovery and overall health. And when it comes to sports nutrition, carbohydrates (or carbs, for short) are the king macronutrient (sorry, protein!)—both before and after training sessions. Keep reading to find out which carbs deliver a quick energy source before hitting the gym, if you should replenish carbs during exercise, the best carbs to eat post-workout and whether or not meal timing matters.
What are carbs?
Carbohydrates are one of the three primary macronutrients (the other two are protein and fats). Unfortunately, this macronutrient often gets a bad rap as the culprit causing weight gain. However, when people talk about carbs and weight gain, they're usually referring to refined, simple carbs found in processed foods such as high-added-sugar cereals, white bread, pastries and the like. These foods typically have less fiber and nutrients than less-refined counterparts. When you eat carbs, your digestive system breaks them down into glucose, a type of sugar that's the primary source of energy for the cells in our body. While simple carbs are quicker to digest and easier to absorb than complex ones, they tend to spike your blood sugar levels faster and higher. Repeated spikes in your blood sugar over time can increase your risk for chronic illnesses, such as heart disease, kidney problems, diabetes and nerve damage.
Conversely, complex carbs are your body's ideal fuel source for physical performance. Complex carbs are found in several whole foods, including fruits, vegetables, whole grains, legumes, nuts and seeds. Because the foods that complex carbs are found in also contain fiber, your body digests complex carbs more slowly, reducing the rate at which they're released into your bloodstream. This prevents your blood sugar from spiking by providing a slow-release, sustainable energy source over a longer period of time.
Related: What Are Net Carbs?
The best carbs to eat before a workout—and when
Though complex carbs are the best possible fuel source for any physical activity, you may be wondering: Which complex carbs should I eat before my workout? Or, how long should I wait to exercise after eating a meal? Well, the answers depend on various factors, including the intensity and duration of your workout, your schedule and biometrics such as your height, weight and sex. However, as a general guideline, complex carbs should be consumed two to three hours before exercising, regardless if you're strength training, doing cardio or playing sports. Examples of complex carb-rich foods to load up on ahead of your workout include rolled oats, buckwheat, whole-wheat bread, lentils, beans, whole-wheat pasta, blueberries, raspberries, apples, potatoes and yams.
Mandy Enright, M.S., RDN, RYT, a registered dietitian and the author of 30-Minute Weight Loss Cookbook: 100 Quick and Easy Recipes for Sustainable Weight Loss, tells EatingWell, "Complex carbs are best to have earlier in the day, at least a few hours before your workout. Pre-workout you usually want a source of simple carbs as that will help give some immediate energy right before a workout. Avoid having a complex or high-fiber carbohydrate within an hour beforehand as the food tends to sit in your stomach and not digest as fast."
As a guideline, the National Academy of Sports Medicine (NASM) recommends that a 150-pound athlete consume about 68 grams, or 4 to 5 servings, of complex carbs at least one hour before exercise. During intense or prolonged workouts, NASM suggests you consume 30 to 60 grams of carbs every hour.
What about simple carbs?
Though complex carbs provide a slow-releasing, steady fuel source, simple carbs can still come in handy and deliver a quick energy burst pre-workout. But, again, it depends on the type of exercise you're doing. Since simple carbs are digested much faster than complex carbs and are readily absorbed by your blood cells, they can be ingested 30 to 60 minutes before a workout to provide a quick, efficient energy source. Examples of faster-absorbing carbs to have as a pre-workout snack include fruit smoothies, bananas or other fruits, crackers, rice cakes and dried fruit. When choosing more simple carbs, the American Academy of Nutrition and Dietetics advises opting for natural sources, such as fruit and milk, since these foods are nutrient-dense and don't contain added sugars that are found in many prepackaged simple carb foods like candy bars and energy drinks.
The best carbs to eat post-workout
After you've completed your workout, it's time to kickstart the recovery process by replenishing carbs, electrolytes and fluids lost during the activity. Carbs are essential for replenishing glycogen (a form of carbohydrate stored in your muscles) after exercise. According to NASM, a 150-pound person requires another 68 to 102 grams of carbs post-workout to promote recovery. "After a workout, you typically want a protein and carb combination. The best carb sources are ones you can readily absorb so you can replenish the energy you just utilized," says Enright.
Include 20 to 30 grams of protein with your carbs within one hour of finishing your workout to enhance muscle protein synthesis and recovery. If your workout was cardio-intensive, focus more on carbs and less on protein. If your exercise was a strength training session, pay more attention to protein and less on carbs. Examples of healthy post-workout snacks that deliver carbs and protein include whole-wheat toast and avocado with tofu, Greek yogurt with berries and granola, brown rice with black beans and steamed broccoli, quinoa with asparagus and edamame or a smoothie bowl loaded with fruits, greens and veggies along with a scoop of protein powder if you so choose.
The bottom line
Carbohydrates are the optimal energy source for fueling any physical activity. Eat complex carbs from whole food sources at least two to three hours before training. Then, consume simple carbs from whole food sources within 30 to 60 minutes before a workout. If your training session goes beyond one hour, consider taking in more simple carbs during the workout for a quick energy burst. Have a snack containing complex carbs to replenish depleted glycogen stores in your muscles within one hour after your workout. In addition, ensure you include 20 to 30 grams of protein in your post-workout snack to promote muscle recovery.