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Nutrition for Athletes

Last Updated October 2023 | This article was created by familydoctor.org editorial staff and reviewed by Beth Oller, MD

As an athlete, your physical health is key to an active lifestyle. You depend on strength, skill, and endurance, whether you’re going for the ball or making that final push across the finish line. Being your best takes time, training, and patience, but that’s not all. Like a car, your body won’t run without the right fuel. You must take special care to get enough of the calories, vitamins, and other nutrients that provide energy.

An athlete’s diet is not much different than that of any person striving to be healthy. You need to include choices from each of the healthy food groups. However, athletes may need to eat more or less of certain foods, depending upon:

  • The type of sport
  • The amount of training you do
  • The amount of time you spend in training

Path to improved health

Every person’s needs are different. The amount of food you need depends on your age, height, weight, and sport or activity level. In general, you need to replace the number of calories you burn each day with athletic activity. Calories measure the energy you get from food. Most people need between 1,500 and 2,000 calories a day. For athletes, this number can increase by 500 to 1,000 more calories.

Talk to your doctor about your nutrition needs. They can help you determine a healthy daily calorie count. Over time, you will learn how to balance your intake and outtake to avoid extreme weight gain or loss.

Calories come in different forms. The main types are carbohydrates, fats, and proteins.

  • Carbohydrates (carbs) are your body’s biggest source of calories. Simple carbs (fruits, milk, and vegetables) are easier for your body to break down. They provide quick bursts of energy. Complex carbs take longer for your body to break down. They are a better source of energy over time. Complex carbs in whole grain products are the most nutritious. Examples include whole-grain bread, potatoes, brown rice, oatmeal, and kidney beans. Doctors recommend that 55% to 60% of your daily calories come from carbohydrates.
  • Fat is another important source of calories. In small amounts, fat is a key fuel source. It serves other functions, such as supporting good skin and hair. Do not replace carbs in your diet with fats. This can slow you down, because your body has to work harder to burn fat for energy. Fats should make up no more than 30% of your daily calories. When you can, choose unsaturated fats, like olive oil and nuts. These are better for your health than saturated and trans fats. Too much fat or the wrong kinds can cause health problems. It can raise your bad (LDL) cholesterol level and increase your risk of heart disease and type 2 diabetes.
  • Protein should make up the remaining 10% to 15% of your daily calories. Protein is found in foods like meat, eggs, milk, beans, and nuts. Some athletes think they should consume large amounts of protein. While protein does help build muscle, high doses won’t help you bulk up. Over time, too much protein can be harmful to your health. The digestion process can put strain on your liver and kidneys.

Athletes need the same vitamins and minerals as everyone else. There are no guidelines for additional nutrients or supplements. To stay healthy, eat a balanced, nutrient-rich diet. It should include foods full of calcium, iron, potassium, and fiber. You also need key vitamins in their diet, such as A, C, and E. Try not to be tempted by junk foods, which are an empty source of calories. Instead, focus on lean meats, whole grains, and a mixture of fruits and vegetables to fuel your body.

Know when to eat and rehydrate

For athletes, knowing when to eat is as important as knowing what to eat. Try to eat a pre-game meal 2 to 4 hours before your event. For a race, this could be dinner the night before. A good pre-game meal is high in complex carbs and low in protein and sugar. Avoid rich and greasy foods. These can be harder for you to digest and can cause an upset stomach. You may find it helpful to avoid food the hour before a sporting event. This is because digestion uses up energy.

Staying hydrated is the most important thing athletes can do. This is especially true on game day. Your body is made up of nearly 60% water. During a workout, you quickly lose fluid when you sweat. Thirst is a sign of dehydration. Don’t wait until you are thirsty to drink. A good rule of thumb is to take a drink at least every 15 to 20 minutes. But don’t drink so much that you feel full.

Water is the best way to rehydrate. For short events (under an hour), water can replace what you lose from sweating. For longer events, you may benefit from sports drinks. They provide electrolytes and carbohydrates. Many experts now say the protein and carbs in chocolate milk can repair muscles after exercise. Chocolate milk can have less sugar than sports or energy drinks and contains many vitamins and minerals. Avoid drinks that contain caffeine. They can dehydrate you more and cause you to feel anxious or jittery.

Things to consider

Athletes require a lot of energy and nutrients to stay in shape. Because of this, strict diet plans can hurt your ability and be harmful to your health. Without the calories from carbs, fat, and protein, you may not have enough strength. Not eating enough also can lead to malnutrition. Female athletes can have abnormal menstrual cycles. You increase your risk of osteoporosis, a fragile bone condition caused in part from a lack of calcium. (These potential risks are worse in adolescence but still present for adults.) Get medical help if you need to lose weight. Be sure to talk to your doctor before making major nutrition changes.

People often overestimate the number of calories they burn when training. Avoid taking in more energy than you expend exercising. Also, avoid exercising on an empty stomach. Every athlete is different, so consider:

  • How long before working out is best for you to eat
  • How much food is the right amount for you

If you need to gain or lose weight to improve performance, it must be done safely. If not, it may do more harm than good. Do not keep your body weight too low, lose weight too quickly, or prevent weight gain in unhealthy ways. It can have negative health effects.

Work with a registered dietitian and don’t experiment with diets on your own. This can lead to poor eating habits with inadequate or excessive intake of certain nutrients.

Talk to your family doctor find a diet that is right for your sport, age, gender, and amount of training.

Questions to ask your doctor

  • How many calories do I need to eat each day?
  • Should I cut out carbs?
  • Are super restrictive diets healthy for me?
  • Are there any supplements they should take?
  • Is it okay to eat sweets if I have to gain weight fast?


Academy of Nutrition and Dietetics: Sports, Cardiovascular, and Wellness Nutrition, Nutrition Resources for Collegiate Athletes

National Institutes of Health, MedlinePlus: Nutrition and athletic performance


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