Sales of energy drinks are expected to grow at an annual rate of 12 percent and exceed $9 billion by 2011, according to a recent study by the research publisher Packaged Facts. These figures are up from $1.2 billion in 2002, according to a recent article in the Progressive Grocer.
The growth in popularity of energy drinks, which are mainly marketed to athletes and adolescents, has several implications for consumers.
Caffeine is the most popular stimulant used in energy drinks.
Andrew Lokuta, a UW-Madison professor in the department of physiology, is not as worried about students consuming caffeine, as he is about their consuming too much of it.
""It's too easy to abuse. You can develop a dependence, suffer withdrawal symptoms, develop a tolerance,"" Lokuta said, adding that the diagnostic manual for doctors includes caffeine intoxication.
According to Lokuta, the Food and Drug Administration (FDA) does not regulate caffeine content in food because the agency considers it a flavor enhancer, and thus classifies it as a dietary supplement, not a drug.
Moreover, energy drink companies are targeting their products at adolescents, according to Lokuta.
""If caffeine is in fact a drug ... what is the population that is the most susceptible to the drug? That is the adolescents,"" Lokuta said. ""Anywhere from 16 up to 20 years old, you are the most susceptible to addictive drugs.""
UW-Madison psychology professor Jeffrey Henrigques explains how this addiction works. ""Energy drinks are drug delivery systems. Use leads to dependence and withdrawal, especially in users who are consuming large quantities of the substance, and energy drinks are providing a large dose in each can.""
The FDA does regulate caffeine in soft drinks, Dr. Steven Chang of RightHealth said in an Aug. 2009 RightHealth article. But because the FDA does not regulate the amount of caffeine in energy drinks, these beverages can contain much more than the 68 milligrams per 12 ounces allowed in soft drinks. An 8 ounces can of Red Bull has 76 milligrams of caffeine, according to the Mayo Clinic. However, one of the strongest energy drinks marketed in America, No Name, is almost four times as potent as Red Bull, with 280 milligrams of caffeine in an 8.3 ounces can.
UW-Madison junior Danielle Walter says she notices this difference in the amount of caffeine.
""The caffeine [in energy drinks] hits me quicker than pop will,"" Walter said. ""If I drink too quickly, I feel jittery, but otherwise just the caffeine will make me feel more energy than I would from any other drink.""
As a result, Walter says she consumes energy drinks like Rockstar or Amp to help her study, especially during finals week.
""Caffeine increases arousal, energy, alertness and concentration—that, of course, is the reason we use this drug to jump start our days and keep us awake at night,"" Henriques said.
Because it is a stimulant, caffeine also improves performance in endurance sports, according to Andrew Peterson, a sports medicine physician at the University of Wisconsin School of Medicine and Public Health.
""Stimulants help you preferentially shunt energy systems away from using glycogen towards using fatty acids,"" Peterson said. This helps in endurance sports because caffeine increases the availability of fatty acids that can be used for oxidation, according to a 2000 study conducted by Marleen Baak and Wim Saris published in Medicine and Science in Sports and Exercise.
""There's some evidence that some stimulants might improve mental acuity and reaction time,"" Peterson said. ""So they [also] help in sports that are more skilled.""
According to Lokuta, caffeine also improves endurance by increasing the effectiveness of second messengers, chemicals in your body that spur reactions like glycolysis, which creates energy.
With names like Full Throttle and slogans like ""Red Bull gives you wings,"" the marketing for energy drinks links these products to extreme sports.
What is not mentioned in the advertising is that the caffeine in energy drinks can have adverse physical effects on athletes if consumed in excess.
""You go from being able to be in an athletic event with more endurance as opposed to sitting there in your chair, and now you drank too much ... and your legs are shaking and your hands are trembling. All of [the] skeletal muscles [movements] are tremors,"" Lokuta said, adding that large amounts of caffeine put people at risk for seizures.
Energy drinks can also be dangerous for athletes because the caffeine in them can lead to dehydration.
UW-Madison student and long-distance track runner Hanna Grinacker has never consumed an energy drink for this reason.
""We all met with nutritionists and we were told to abstain from [energy drinks],"" Grinacker said.
But Grinacker said she does sometimes consume caffeine before a workout because it enhances her exercise.
""I feel like I have more energy, which is always a positive when you're running more miles,"" Grinacker said. ""It makes overall workouts seem more manageable and less taxing.""
Yet some athletes still consume energy drinks before games and simply find ways to counter the dehydrating effects.
""Endurance athletes, like cyclists, are going to have some caffeine before they compete,"" Peterson said. ""The most common [source] obviously is coffee. Most will have a cup of coffee with a fair amount of caffeine before a competition.""
In order to rehydrate after consuming caffeine, athletes often drink ""other substances that mitigate the dehydrating effect of the drug,"" Peterson explained. For example, Gatorade and Powerade have a special blend of sugar and salt that enhances hydration.
Peterson said energy drinks are perceived as being more dangerous than they really are.
""In terms of performance enhancing substances, there are more dangerous things that are being taken fairly widely,"" Peterson said, ""and our [efforts] should be trying to control things that are more dangerous or dangerous things practiced with sports.""
Red Bull's marketing slogan, ""Red Bull Gives You Wings,"" encourages consumers to drink it for a jolt of energy.
""Does it talk about what happens when your wings fall off and now you're addicted and you're crashing back to Earth? Do they ever bring that up? How about if you drink too many of the Red Bulls?"" Lokuta asks.
He says people may get caffeine intoxication., which results in symptoms of restlessness, gastrointestinal disturbance and an incoherent flow of thought and speech. Yet despite these effects, people still drink caffeine because ""it's too easy to abuse,"" Lokuta said.
Walter, who says she consumes about 24 ounces of soda a day, and larger cans of energy drinks while preparing for midterms or finals isn't too worried about the potential harm of caffeine.
""If you have [an energy drink] every day or have that be the main source of your drinks, it may be unhealthy; but sporadically they're not horrible for you.""
But when caffeine is taken in excess, students put their bodies at risk for neurological, muscular and cardiovascular problems.
""This increase in arousal [from caffeine] can have negative effects, including anxiety, insomnia, and tachycardia (rapid heartbeat),"" Henriques said.
He also adds that it can cause negative psychological effects.
""There is some evidence to suggest that caffeine use can result in increased symptoms of depression,"" Henriques said. ""Though it may be that the depression is a consequence of withdrawal symptoms experienced after the individual finishes their caffeinated beverage.""
According to Lokuta, overconsumption of energy drinks causes too much neuronal activity.
""Instead of having a focused attention, you become very unfocused,"" Lokuta said. ""It's almost like an attention deficit disorder. Rather than being able to sit and concentrate, you can't concentrate. Your mind is scattered.""
Lokuta, who strives to make students informed consumers when it comes to drinking alcohol, wishes he could give similar advice about energy drinks.
""The fact that [if] you drink that one Red Bull, it allows you to work for four hours— that doesn't mean you should drink three. That doesn't mean you should alter your lifestyle and rely on that Red Bull to get through your academics.""