Having low energy can make a workout feel like a slog—and feeling sluggish while exercising doesn't make fitness very appealing. Getting the energy boost you need to crush your workouts and come back stronger, comes down to what you eat.  Protein is often the first thing that comes to mind—b ut experts say that’s far from the whole picture, and might not be the most important part of workout nutrition. Whether you’re an early morning gym-goer or an evening runner, what you eat both before and after exercise can make or break your workout and fitness gains. Here’s expert guidance on what to eat to maximize your workouts and recovery. What should you eat before a workout? For those who work out in the early morning hours, the idea of eating first may sound unappealing. But you might want to rethink exercising on an empty stomach. “Eating prior to exercise can really help fuel that workout,” says Stella Volpe, registered dietitian, head of the nutrition and exercise department at Virginia Tech, and president of the American College of Sports Medicine.  You don’t have to eat a full meal—a small snack should do the job, she says. Volpe admits that she struggles to eat before her morning workouts, which is why she sips on hot chocolate or snacks on energy chews on her way to the gym—and there’s good reason why Volpe opts for sugary fuel. “Carbohydrates are going to be your body’s main source of energy whether you’re running, walking, or even strength training,” says registered dietitian Amy Goblirsch, who specializes in working with runners. “Make sure that what you’re eating beforehand contains carbohydrates to support the activity.” Goblirsch emphasizes that working out on an empty stomach can not only hinder your performance, it can also impact how your body bounces back after the workout. “You’re putting your body under more stress, which can lead to poor performance, it can even impact the recovery time, there can be an increase in muscle breakdown—things that you don’t want to have happen,” she tells Fortune.  Eating before a workout won’t interfere with weight-loss goals, Goblirsch adds: “Underfueling is going to cause more damage than overfueling, but so many people are scared of overfueling versus under.” Fueling your workouts will likely help you perform better and push yourself more, she explains, leading to a better workout overall. If you’re tight on time, you’ll want to pick easily digestible, simple, low-fiber sources of carbs to eat 15 to 30 minutes before a workout. Goblirsch and Volpe recommend snacks like: Two to three graham crackers A banana Applesauce pouches An English muffin with peanut butter and jelly A piece of toast Half or a whole granola bar Sports drinks with sugar “We don’t want too much fiber because we don’t want gastric upset,” Volpe says. If you have more time before your workout or exercise later in the day, Volpe says a sandwich with either peanut butter and jelly or cheese would be ideal, about two hours before your workout. For workouts over 90 minutes, Goblirsch advises getting in a more substantial amount of carbs with a bit of protein, which could look like a bagel with peanut butter.  Goblirsch adds that if you’re doing a shorter, low-intensity workout—like a 20-minute yoga session—you might be fine not eating anything beforehand. But you should listen to your hunger—you’re likely going to feel better eating something beforehand, regardless of the intensity, she says. What should you eat after a workout? While protein is vital after a workout, experts say it’s just as important not to skip the carbs. “I think people often tend to forget how important carbohydrates are,” Volpe says.  Your body stores carbohydrates in the form of glycogen, Volpe explains, which is your main source of energy during exercise. When you finish a workout, your glycogen stores are depleted, meaning it’s essential to eat carbohydrates to replenish them. And they’re important whether you engage in cardio or lift weights, Goblirsch adds, because your body utilizes carbs for energy for all activities.  Without enough carbohydrates, Volpe explains, you’ll likely feel more tired, weaker, and struggle to perform at your best during a workout. Thus, eating carbohydrates after a workout “allows your body to be ready for that next bout of activity,” Volpe says.  Protein is also crucial because it will help you repair and build muscle. She recommends a post-workout meal that’s 60% carbohydrates, 20% protein, and 20% fat, which could be a bowl of rice with a protein source like chicken, tofu, or fish, plus vegetables, and a fat source like olive oil. For breakfast, she suggests oatmeal with fruit, protein powder, and peanut butter. Eating soon after your workout will optimize your recovery time, making you feel better for the rest of your day while preparing your body for your next workout, Goblirsch says. “The sooner you can have your post-workout fuel, the sooner your body is going to be able to start that recovery process,” she adds. “Think about it like you’re giving the body the tools to rebuild.” Volpe says the ideal window is within two hours post-exercise, when your muscles are most primed to replenish their glycogen stores and rebuild muscle. Delaying your post-workout meal even further, however, only delays that muscle recovery, Goblirsch says. If you’re short on time, Goblirsch recommends quick snacks that will give you the optimal ratio of carbs to protein, including: Chocolate milk A protein shake with a peanut butter and jelly sandwich Yogurt with fruit and granola Adjust what you eat based on your workout routine It’s important to cater to your individual needs. For example, people training for endurance events like marathons or triathlons are going to require a higher carbohydrate intake to keep up with a more intense workout routine, Volpe explains. “If you really personalize it to how you’re training, that can actually do a person a lot better,” she says. Goblirsch says that principle also extends to what you eat before a workout. If you tend to be hungrier before you start your workout, you might want to eat a little bit more. “Be aware of your body and don’t be afraid to do what’s best for your body, even if it’s different from what other people in the gym are doing when it comes to fueling,” she says. More on fitness: What’s your VO2 max? The most important health metric you’re probably not aware of shows how fit you really are Creatine supplements for boosting muscles might be a waste of money, new study finds 7 micro habits one woman in early menopause used to lose 50 pounds Do energy drinks come with health risks? An expert’s warning This story was originally featured on Fortune.com ...read more read less