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Caffeine Use and Athletic Performance


What is caffeine? Caffeine is a stimulant. A stimulant is a type of drug that makes people more alert, and increases heart rate and blood pressure. Caffeine may be found in coffee, tea, chocolate, cola drinks, sports drinks and foods, and some medicines. Some athletes use caffeine to improve their performance in sports activities.

How does caffeine affect an athlete's performance in sports activities?

  • Scientists believe that caffeine increases an athlete's energy and endurance levels during long-term activities. Endurance is a person's ability to cope with hardship, such as running, swimming or biking over long time periods or distances.

  • Caffeine may affect each person differently. Some people may feel like they have more energy and can exercise harder and longer if they use caffeine. Caffeine may make other people feel too jittery or nervous to do well during sports activities.

Does caffeine cause side effects? Large amounts of caffeine may cause side effects such as stomach discomfort, shakiness, dizziness, headaches, and trouble focusing and sleeping. The amount of caffeine that would cause these side effects depends on how sensitive you are to caffeine. It also depends on how much caffeine you normally take. You may have these side effects with only one cup of coffee if you normally do not use caffeine. These side effects may be worse for you if you normally get nervous or jittery before a sports activity.

How do I know how much caffeine is right for me? Talk to your caregiver before using caffeine to improve your sports performance. It is especially important to talk with caregivers if you do not usually take caffeine.

  • The International Olympic Committee and other sports groups do not allow high levels of caffeine use during sports activities. Talk with your caregiver about the amount of caffeine that you should use during sports activities.

  • If you want to try caffeine, start with a small amount. Scientists believe that a dose (amount) of three to six milligrams of caffeine per kilogram of body weight (mg/kg) works best for most people. To figure out how much caffeine to take, figure out your weight in kilograms first. To do this, divide your weight in pounds by 2.2. For example, an athlete who weighs 154 pounds weighs 70 kilograms. If he decides to take 3 mg/kg of caffeine, he would multiply 70 by 3. This athlete would take 210 mg of caffeine.

How do I know how much caffeine is in food, drinks and medicines? Caffeine is measured in milligrams (mg). The following lists show the amount of caffeine that is found in foods, beverages and medicines. Different brands may have slightly different amounts of caffeine.

  • Six ounce cup of brewed coffee (100).

  • Six ounce cup of instant coffee made with water (57).

  • One ounce cup of espresso (40).

  • Six ounce cup of decaffeinated brewed coffee (2).

  • Six ounce cup of tea, brewed for 3 minutes (36).

  • Eight ounce glass of iced tea, from powder (25-35).

  • Eight ounce cup of green tea (20-30).

  • 12 ounce can of diet or regular cola (35 to 50).

  • 12 ounce can of diet or regular cherry cola, Dr. Pepper®, or Mr. Pibb® (35-50).

  • 12 oz can of diet or regular Mountain Dew® (54).

Sports drinks and foods:
  • One package of sports gel (caffeine amounts vary by brand) (25-40).

  • One sports bar (caffeine amounts vary by brand) (50).

  • Six ounce cup of hot cocoa from a mix (4).

  • Eight ounce glass of chocolate milk (9).

  • One ounce of unsweetened baking chocolate (58).

  • One ounce of sweet, semi-sweet, dark, or milk chocolate (8-20).

  • Medicines for drowsiness (200).

  • Pain relievers (32 to 65).

  • Cold medicine (32-34).

  • Menstrual pain relief medicine (65).

  • Appetite suppressants (used for weight control) (200-280).


You have the right to help plan your care. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

© 2014 Truven Health Analytics Inc. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. All illustrations and images included in CareNotes® are the copyrighted property of A.D.A.M., Inc. or Truven Health Analytics.

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