Further, and perhaps not surprisingly, across all age groups, 71 percent of those who were shown a Red Bull ad with a sports theme—the X Games, for example, or an image of an airborne snowboarder with accompanying text reading “RED BULL GIVES YOU WIIINGS”—thought the ad they viewed promoted the use of energy drinks during sports.
This is a problem, says Matt Fedoruk, the chief science officer at the U.S. Anti-Doping Agency (USADA). Though his organization is perhaps best-known for its role in testing Olympic athletes for banned substances, it also promotes a positive youth-sports culture. Fedoruk says it fields questions about energy drinks from athletes of all ages.
“Caffeine is the most studied ergogenic aid on the planet,” says Fedoruk, and its use is widespread among elite athletes. Research has even produced recommended guidelines for ingestion prior to exercise. But these guidelines were developed for adults. Young people who try to follow them could quickly surpass the American Academy of Pediatrics’ guidelines for adolescents: no more than 100 mg of caffeine per day, or roughly the amount in a typical cup of coffee. Further, because energy drinks are manufactured in adult serving sizes, says Fedoruk, it’s easy for a child to get too much. “Depending on the product you choose, you could definitely be dosing your young child or youth athlete in doses that far exceed what may be safe for their body weight and size.”
When it comes to youth athletes, “our experts recommend both water and sports drinks as the best options for hydration,” writes Danielle Eurich, a USADA spokesperson. Athletes exercising less than an hour probably don’t even need sports drinks, she adds. “Water would be best.”
Last year, John Higgins, the sports cardiologist, ran a small study in which healthy medical students downed a 24-ounce can of Monster Energy. Ninety minutes later, the students’ arteries were measured to test their ability to bounce back—or dilate—after being compressed by a blood-pressure cuff. Dilation helps control blood flow, increasing circulation when necessary, including during exercise. In this study, the medical students’ blood flow was “significantly and adversely affected,” says Higgins.
Higgins suspects that the combination of ingredients—the caffeine and other stimulants such as guarana, taurine, and L-carnitine, along with added vitamins and minerals—interferes with the endothelium, a thin layer of cells that control dilation. But he can’t say for certain because there hasn’t been enough research. Higgins’s own study was preliminary and lacked a control group. Further, a recent review by a group of Harvard researchers noted considerable limitations to the existing energy-drink literature. Most studies, the authors found, used small sample sizes or employed a cross-sectional design, which isn’t able to determine causation. Large longitudinal studies, meanwhile, require time and money.