Sports drinks may have a place for teen athletes, but not energy drinks. Many teens may take energy drinks to give them an “edge” in sports, but the American Academy of Pediatrics warns that safe consumption levels of energy drinks have not been established for adolescents. Sports drinks provide fluid along with substances called electrolytes (sodium, potassium, magnesium) that are lost in sweat. They provide carbohydrate in an amount and form that can help athletes who exercise intensely more than an hour, or in very intense short bursts (as in hockey). Sports drinks contain about two-thirds the calories of regular soft drinks. Energy drinks are completely different. They are a source of caffeine and other stimulants, and often sugar.
Studies show that 100 to 200 milligrams (mg) of caffeine (about 1 to 2 cups of regular coffee) increase energy and alertness. Many 16-ounce cans of energy drinks provide caffeine in this range. But extra large portion sizes and additional stimulant ingredients may bring caffeine as high as 500 mg per can or bottle; and some energy drink users consume more than one can.
Although relatively small amounts of caffeine taken shortly before sports or exercise can enhance and prolong ability to exercise, using caffeine to raise energy can end up worsening energy problems in the long run. When people consume more than 250 mg caffeine per day, they may experience headache, sleep difficulties or increased anxiety. Beyond 1000 mg they may have heart palpitations. Deaths from seizures or cardiac arrest are rare, but have been reported. Caffeine stays around longer than people realize, impairing nighttime sleep that leads to daytime sleepiness and low energy. It takes three to ten hours to clear even half a caffeine load from the body, and 15 to 35 hours to eliminate virtually all of it. And you can get a lot of sugar from the 15- to 24-ounce containers. Sugar-free versions are available, but energy drinks typically contain 200 to 300 calories, with over a quarter cup of sugar per 16-ounce can.