Sports and Nutrition: Fueling Your Performance

  • Young men's version of this guide

girl holding soccer ball

Just as a car runs best with a full tank of gas, your body needs the right kind of fuel from food in order to perform at its best. A balance of carbohydrates, proteins, fats, minerals, vitamins, and water will give your body what it needs for peak performance.

What should I eat to fuel my exercise?

Before exercise: The food you eat before you exercise greatly affects the quality of your athletic performance as well as how you feel during and after exercise. These tips will help you plan your pre-exercise meals to prevent low blood sugar, to keep you from feeling hungry during your workout, and to fuel your muscles for training and competition.

  • Eat a larger meal that contains carbohydrates, protein, and fat if you have 4+ hours before you begin your exercise. Smaller “mini” meals that are high in carbohydrates and moderate in protein are better if you have 2-3 hours before your workout begins. Carbohydrates are important to be having at all meals and snacks because they give you energy. Whole grain carbohydrates will give you long-lasting energy power and are best eaten further out from a workout. Whole grain pasta, bagels, baked potatoes, brown rice, and fresh fruit are all good sources of complex carbohydrates. Refined carbohydrates (such as white bread, white rice, white crackers) will give you quick energy, and are best eaten 30 min-1 hour prior to exercise.
  • Avoid high-bulk (high-fiber) foods such as broccoli, baked beans, or high-fiber cereal right before exercise. These foods may cause stomach pains during exercise due to their passing more slowly through your digestive system. However, high-fiber foods are loaded with good nutrition, so be sure to include them at other times of the day.
  • Sugars and sweets (especially soda and candy) don’t provide lasting energy, and therefore aren’t recommended to fuel your exercise.
  • Limit foods that are high in dietary fat such as fast food, ice cream, nuts, and cheese for your pre-exercise meal. These foods take much longer to digest and may make you feel sluggish and tired if you eat too much of them right before working out.
  • Don’t try new foods before a competition. You may have trouble digesting a food you have never eaten before. Choose foods that are familiar to you or try something new on a training day.

30 min- 1 Hour Before Exercise

  • Eat: Fresh fruits (such as melon or grapes) or dried fruit, crackers, granola, cereal bars, pretzels, applesauce
  • Drink: Water, sports drink such as Gatorade (if working out for longer than 90 minutes)

2-3 Hours Before Exercise

  • Eat: Granola bar and yogurt, ½ bagel or 1 English muffin with peanut butter and/or jelly, cereal and milk, or oatmeal and berries
  • Drink: Water

4+ Hours Before Exercise

  • Eat: a meal that incorporates carbohydrates (grains with fruit/vegetables), protein, and healthy fats such as:
    • turkey and cheese sandwich on wheat bread with lettuce and tomato, a piece of fruit, and a cup of pretzels
    • grilled chicken with brown rice or sweet potato and veggies
    • bowl of cereal with milk, scrambled eggs, and a piece of fruit
    • egg and cheese on a whole wheat bagel or English muffin with a piece of fruit
  • Drink: Water

During exercise: Depending on the length of your workout, you may or may not need to eat something during exercise. If you find that you are getting hungry and/or your workout is lasting more than an hour and a half, try having something easy to digest that will provide you with fast acting energy such as fruit, an energy bar, or pretzels. There are products such as sports gels and chews formulated for endurance athletes; talk to a registered dietitian about whether these are appropriate for your level of activity.

After exercise: It’s very important to refuel your body after a hard workout. Because your body needs to replace glycogen stores in your muscle within the first few hours after exercise, it’s important to eat carbohydrates and some protein soon after your workout.

Follow these tips when planning your post-exercise meal:

  • Sometimes exercise can cause people to feel less hungry even though they need to eat afterward. Try having a snack that contains carbohydrates and protein (such as a yogurt, half a sandwich, or chocolate milk) within 30-45 minutes after a workout. This will help your body recover quickly.
  • You should eat a larger meal that’s higher in carbohydrates and contains protein within the next 2-3 hours to replace muscle glycogen stores and repair muscle tissues. This will help you recover faster and be ready for the next time you exercise.

How can I make sure to eat enough calories?

Calories fuel your body for exercise and replace energy that is used up during sports performance. Cutting calories keeps you from performing your best. As exercise and athletic training demands energy above and beyond your body’s day-to-day needs, it is essential to meet these needs in order to compete at full strength and recover quickly after a workout. Skipping meals will hurt your performance. Eating regular meals and healthy snacks is the best way to fuel your body for athletic events.

Because different foods have different nutrients, you should eat a variety of foods to get all the nutrients you need to stay in peak condition. For example, oranges provide vitamin C and carbohydrates, but not iron or protein. A piece of grilled chicken provides iron and protein, but not vitamin C or carbohydrates. Remember, a balance of carbohydrates, proteins, fats, minerals, vitamins, and water is best for peak performance.

Carbohydrates or “carbs” (found in pasta, bread, cereal, rice, grains, potatoes, fruit, vegetables, milk, yogurt, etc.) are especially important for athletes because they supply the body with glucose for energy. Extra glucose is stored in the muscles and liver as glycogen, your energy reserve. During short bursts of exercise such as sprinting, basketball, gymnastics, or soccer, your body relies on glycogen to keep your blood sugar levels stable and thus maintain your energy. If you don’t have enough glycogen, you may feel very tired or have difficulty sustaining the activity – effects that will, undoubtedly, impact your performance! During longer exercise, your body primarily uses your glycogen stores, but depending on how long the activity lasts, your body will also utilize fats stored in your body to fuel performance.

Fat is an important source of energy used to fuel longer exercise and endurance activities, such as hiking, cycling, and long-distance running or swimming. Eating a diet that is too low in dietary fat may decrease athletic performance and cause other health problems, such as deficiencies of certain vitamins, which require fat to be absorbed. Heart-healthy sources of fat include avocados, salmon, nuts and nut butters, and olive oils.

Protein is needed for your body to build and repair muscles. Small amounts of protein may also be used for energy. Protein can be found in lean meats like chicken and turkey, beans, tofu, eggs, and dairy products such as Greek yogurt, cheese, and milk.

Vitamins and minerals are not sources of energy, but they have many important functions in the body. For example, vitamin D and calcium are needed for strong bones, and iron is needed for blood cells to carry oxygen throughout your body. Certain minerals, like potassium, calcium, and sodium are called electrolytes. They are important during exercise because they have an effect on the amount of water in your body and on how your muscles work. Athletes should eat a balanced diet with a variety of foods to make sure they get enough vitamins and minerals. It is fine to take a regular multivitamin, but supplements with high doses of vitamins and minerals do not improve performance and may actually be harmful. Talk with your health care provider or dietitian if you need to add more specific supplements, like iron, calcium/vitamin D, or B vitamins into your diet.

Water is essential to keep you hydrated. Dehydration (when your body doesn’t have enough fluids to work efficiently) can cause muscle cramps, and dizziness or lightheadedness. When you are physically active, dehydration is not only dangerous, but can also keep you from performing your best. In order to stay hydrated, keep a water bottle with you and drink throughout the day.

What is carbohydrate loading?

Carbohydrate loading is a technique used to increase the amount of glycogen in muscles. It involves eating extra carbohydrates during the week before a competition, while at the same time cutting back on your training. Carbohydrate loading is intended for marathon runners and other competitive endurance athletes and isn’t necessary for most sports.

Should I eat extra protein or use protein supplements?

Although some extra protein is needed to build muscle, most people get plenty of protein from food. Getting extra protein from supplements won’t have any added benefit. Eating enough calories (especially from carbohydrates!) is actually more important for building muscle than having extra protein. Without enough calories, your body can’t build new muscle.

Should I eat energy bars?

It depends. There are many different energy bars you can buy. Some are high in carbohydrates and/or protein, but some may also be high in sugar. They don’t contain any magic ingredients that will help your athletic performance, but are convenient and useful when on-the-go and may help you fit a snack into a busy schedule. Foods that have some carbohydrate and protein in them such as yogurt, cheese and crackers, or peanut butter and fruit are typically just as good (if not better) and may cost less than energy bars.

What fluids should I drink and how much do I need?

Athletes need more fluids than non-athletes because of additional sweat loss from exercise. Do not wait until you are thirsty to start drinking water, because thirst means that you are starting to dehydrate. Remember to drink even more in hot and humid weather.

Before exercise: The goal of drinking fluids before exercise is to be well hydrated before you are physically active. Different people need different amounts of water before they exercise depending on a wide variety of factors, including their weight/height, how much they sweat before exercising, how much they’ve eaten, and the weather outside. In general, teens should drink 16-20 oz (2-2.5 cups) of fluid at least 2-3 hours before physical activity; they should then drink 8-10 oz (1-1.5 cups) of water 10-20 minutes before the activity.

During exercise: Fluid needs during exercise depend on how intense and long your workout is, weather conditions, and how much you sweat. It is recommended that you drink ½-1 cup (4-8 oz) of fluid every 15-20 minutes during your workout (approximately 1 gulp of water equals 1 oz). If you are going to be exercising intensely for more than 90 minutes, it may be helpful to drink water with electrolytes or a sports drink to replenish the electrolytes lost in sweat.

After exercise: Calorie-containing drinks (such as milk, juice, or a sports drink) can replace water and glucose. Milk will also provide protein to help rebuild and repair muscles. You can figure out if you’re well hydrated by looking at the color of your urine. A light yellow, somewhat clear color is a sign of good hydration. However, if you see a darker yellow color, this means that you need to drink more fluids. To restore hydration, you should try to regain lost fluids (between 16-24 oz or 2-3 cups) within the 2 hours after you finish the exercise.

Should I drink sports drinks?

In general, water is the best fluid to drink before, during, and after exercise. Sports drinks such as Gatorade® or Powerade® help replace water, carbs, and electrolytes. It may be useful to drink an energy drink when you’re playing a high intensity sport. If you are exercising for longer than 90 minutes it is likely that water will be the best source of fluid unless exercising vigorously or in the heat.

Remember: Athletes need more food and fluids than non-athletes. Regular meals and healthy snacks will help fuel your body before and after exercise. It’s important to give your body enough of the right fuel in order to feel good and have the energy you need to perform your best.

Our health guides are developed through a systematic, rigorous process to ensure accuracy, reliability, and trustworthiness. Written and reviewed by experienced healthcare clinicians from Boston Children's Hospital, a Harvard Medical School teaching hospital and consistently ranked as a top hospital by Newsweek and U.S. News & World Report, these guides combine clinical expertise, specialized knowledge, and evidence-based medicine. We also incorporate research and best practices from authoritative sources such as the CDC, NIH, PubMed, top medical journals, and UpToDate.com. Clinical specialists and subject matter experts review and edit each guide, reinforcing our commitment to high-quality, factual, scientifically accurate health information for young people.