Caffeine can be found in coffee, tea, “energy” drinks, gels, pills such as NoDoze, and a relatively new category of caffeinated water. Caffeine is a legal supplement with the NCAA, professional leagues, and international competition. There is an upper legal limit but it would generally take 6-8 cups of coffee depending on your weight to exceed the limit.
Benefits for adult athletes: The U.S. Olympic Committee has a nice Fact Sheet indicating that there are several positive effects of caffeine consumption for adult athletes. These include enhanced endurance exercise performance (e.g. triathlon), team sports (e.g. basketball, soccer) and even for short duration sports. There are some folks who believe caffeine is dehydrating because it’s a diuretic (may cause water loss) but the effects of caffeine on hydration have been studied extensively in the military and found to be a myth -- meaning that water loss after caffeine consumption in legal limits is insignificant.
There are certainly negative effects possible after caffeine consumption, especially if your body is not used to regular caffeine intake. These would include anxiety, nervousness, jitteriness, elevated heart rate, stomach upset, and inability to focus. Most sports dietitians recommend that if you’re going to use caffeine as a performance aid then you definitely want to test different types during your training. Coffee, tea, gels, and caffeinated water are good choices. Avoid carbonated soda as a caffeine source as it can cause stomach bloating and gas. Also avoid “energy drinks” as they may contain banned substances or other stimulants such as guarana, guayaki, guayusa, etc.
Verdict for Adult Athletes: generally OK
As far as the research goes for possible benefits and dangers of caffeine use in teenagers, we unfortunately don’t have a lot of data compared to adults, but what we do have points to the greater potential for harm than good.
It’s estimated that about 25%-50% of energy drink sales in the USA is in the 12- to 18-year-old age group.
There are four commonly cited concerns with caffeine use in teenagers. First, as noted above, energy drinks may have banned substances and widely varying amounts of caffeine. This has the potential for harmful effects in adults as well as teenagers. Second, teenagers will metabolize caffeine differently than adults creating a scenario where it is easier to become caffeine toxic and overdose. Third, performance and behavior related side effects are far more common in teenagers than adults. We typically see this as inability to focus, being jittery, sleep disturbance, nausea, and vomiting. And fourth, many teenagers are taking prescription stimulants for ADHD and adding caffeine to their bodies can be a dangerous combination.
Verdict for Teenage Athletes: avoid
Children and Preteen Athletes
It’s remarkable how powerful the effect of advertising and peer pressure is in promoting caffeine and energy drink consumption even in the preteen age groups. What’s definitely known is that a child or preteen athlete can reach dangerous toxic levels of caffeine much faster than an adult. For those of you who are interested in the broad range of bad things that can happen to a child ingesting caffeine for sport performance I recommend you take a look at this comprehensive review article: Health Effects of Energy Drinks on Children, Adolescents, and Young Adults
Verdict for Child and Preteen Athletes: must avoid.
• Caffeine ingestion for sport performance is generally fine for adults and associated with performance benefits. Side effects must be closely monitored.
• A large number of teenage athletes consume caffeine and other stimulants but the potential for more harm than good is substantial. Caffeine consumption for sport performance is best avoided.
• Pre-teens and children must avoid caffeine consumption for sport performance.
(Dr. Dev K. Mishra, a Clinical Assistant Professor of orthopedic surgery at Stanford University, is the creator of the SidelineSportsDoc.com online injury-management course, now a requirement for US Club Soccer coaches and staff members. Mishra writes about injury recognition and management at SidelineSportsDoc.com Blog.) , where this article first appeared.