By Gabe Mirkin, M.D.
A review of 34 recent studies shows that taking caffeine before and during exercise can increase muscle strength and endurance (European Journal of Nutrition, published online October 18, 2016;1-15).
Taking 1-2 mg of caffeine per pound of body weight can enhance performance of athletes. A 150-pound athlete will get maximum benefit from two to three cups of strong coffee, which has about 100mg of caffeine per cup. Cola soft drinks contain approximately 35mg of caffeine per 12-ounce can. Higher doses of caffeine have not been shown to further improve athletic performance, may actually impair performance and can be dangerous. People who do not know that they have irregular heartbeats could die from taking caffeine during an athletic competition.
The World Anti-Doping Agency (WADA), which governs the use of drugs in international sports competitions including the Olympics, had to take caffeine off its list of banned substances in 2004 because almost all athletes were taking it in drinks and foods as well as in pills. WADA still monitors caffeine in an effort to discourage large doses that can be harmful.
Side Effects of Caffeine
Taking in more than 500mg of caffeine increases risk for side effects such as jitteriness, nervousness, headache, dizziness, tremors, stomach cramps, gas and insomnia, which can harm performance rather than help it. In high doses, caffeine can cause irregular heartbeats and increase risk of heat stroke. Caffeine can interfere with medications used to treat conditions such as heart disease and high blood pressure.
How Caffeine Works
- A neurotransmitter, adenosine, slows messages along nerve cells. Caffeine blocks adenosine receptors to speed up messages transmitted along nerves to reduce tiredness, increase alertness and attention, improve mood, and increase concentration, processing of information and reaction time. It helps athletes exercise at higher intensity for longer duration without feeling that they are pushing their limits.
- Caffeine stimulates your brain so you become less aware that you are hurting and exhausted so you can continue to endure suffering.
- When muscles run out of their stored sugar, they hurt and lose power. Caffeine causes fat cells to release their stored fat to raise blood fat levels. Muscles then use this extra fat to preserve their stored glycogen.
When to Take Caffeine
Athletes usually take their caffeine as a single dose 30 to 60 minutes before competition, or half a dose 30 to 60 minutes before competition and the second half-dose 45 minutes into competition. They may drink a cup of coffee or a caffeinated soft drink before a competition and a caffeinated soft drink every half hour four times during an event that takes two hours or more.
It makes no sense to take extra caffeine for training or just exercising. No good data yet show that a slight caffeine-induced-improvement in a workout translates into improved performance in competition. Taking extra caffeine for training may harm performance during competition because it will build up a tolerance to caffeine as you keep taking it. It also makes no sense to take large amounts of caffeine during competition unless the rewards are worth the risks, since caffeine at any dose can increase risk for irregular heartbeats and heat stroke.
Tolerance and Withdrawal
People who take caffeine regularly develop a tolerance so that they need higher doses to get the same effects. When they suddenly stop taking caffeine, they can suffer headaches that often disappear when they start taking caffeine again or after a week of abstinence from caffeine.
- Taking a beverage that contains sugar and caffeine before and during an event lasting longer than an hour can enhance endurance and strength.
- Although caffeine is found in many foods and is relatively safe, high doses during exercise increase risk for irregular heartbeats and heat stroke.
- Caffeine in pill form can risk your health because there are no adequate quality controls to protect you from over-dosage.
- Sugared beverages increase risk for dental cavities.
Caffeine Content in Drinks
- 8 ounces of brewed coffee – 100 mg
- 8 ounces of brewed tea – 50 mg
- 12 ounces of cola soft drink – 35 mg
- Caffeine pills – 100-200 mg (check the label)
Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana. His website is http://drmirkin.com/. Click to read Gabe's full bio.