The Latest Buzz

Whether it’s consumed to enhance performance or as part of the daily diet, caffeine can be a negative for today’s competitive athlete.

By Laura Smith

Laura Smith is an Assistant Editor at Coaching Management. She can be reached at

Coaching Management, 13.9, October 2005,

When consumed, it triggers changes in the same area of the brain activated by nicotine, cocaine, and heroin. Used regularly, it leads to tolerance and addiction. Attempting to discontinue use prompts painful withdrawal. Many of your players may be using it, and in fact, you probably had a dose of it today yourself.

Caffeine. Eighty to 90 percent of American adults consume it every day, and student-athletes on college campuses are no exception. Increasingly, high schoolers are rivaling adults in their caffeine use, downing sodas and visiting coffee shops for frozen or sweetened caffeinated drinks. In addition, many student-athletes turn to the drug to enhance their athletic performance.

Certainly, concern about caffeine use pales in comparison to the use of substances like steroids and ephedra. But heavy consumption can have some very real downsides for student-athletes’ health and performance. And while there is laboratory evidence that caffeine enhances performance, athletes who use it as an ergogenic aid need to be educated about the risks and realities of competing under its influence.

The Daily Grind
When student-athletes become daily caffeine users, particularly with heavy use, both their health and performance may suffer in ways they aren’t even aware are happening. One of the biggest risks is that caffeine use disrupts sleep, and student-athletes are often sleep-deprived to begin with.

“High school and college students are notorious for not getting enough sleep, and especially when they are athletes, it’s absolutely essential that they get enough rest to repair muscle tissue and perform optimally,” says Laura Juliano, a caffeine researcher and Assistant Professor of Psychology at American University. “Caffeine increases the length of time it takes to fall asleep and decreases total sleep time.”

It doesn’t require downing a double espresso right before bed to see the effect, either. Studies have shown that consuming a moderate amount of caffeine early in the day can reduce the quality and quantity of that night’s sleep.

Another concern involves caffeine’s ability to produce anxiety. Again, the effect does not require huge doses. Starbucks reports that its 16-ounce coffee contains 400 milligrams of caffeine—the exact amount researchers administer in the laboratory to induce anxiety, according to Juliano. “There is already a lot of anxiety in the lives of most student-athletes,” she says. “And caffeine is going to magnify it.”

A student-athlete who has an exam looming, a paper due, and a game coming up may down a mug or two of coffee to make it through the day, then attribute feelings of stress and anxiety to the workload. “In reality, caffeine is probably making them feel much worse, but they don’t realize it,” says Juliano.

Daily consumption of coffee and colas also deprives the body of calcium, according to Barbara Lewin, a nutritionist based in Fort Myers, Fla. “Coffee and colas are high in phosphorus, and the body requires a certain phosphorus-to-calcium ratio,” Lewin says. “If your phosphorus intake is high, and you don’t ingest enough calcium, your body will pull calcium from your bones. Most student-athletes don’t get enough calcium in their diets as it is. Often, when I look at a student-athlete’s daily calcium intake alongside their use of coffee and colas, they are in a negative calcium balance.”

There are two other nutrition negatives to be aware of. First, since caffeine increases the production of stomach acid, large amounts can induce an upset stomach or acid reflux. Second, while caffeine is no longer believed to be a diuretic, most caffeinated beverages are not particularly good sources of hydration. If they replace water or sports drinks in an athlete’s diet, chances of dehydration increase.

Last but not least, student-athletes who use caffeine daily will build up a tolerance, gradually needing more and more to achieve the same effect. They’ll also develop dependence and feel like they need caffeine to function normally. “When it comes to chronic caffeine users, it’s often difficult to separate the effect of the drug from the effect of not having the drug,” Juliano says. “In other words, they may think caffeine makes them feel and perform better, but in reality, it just keeps them from feeling bad from not having it.”

Few sports nutritionists advise college athletes to avoid caffeine altogether. It’s simply too pervasive an ingredient in many foods and drinks. But how much is too much?

“If a student-athlete does not want to be physically addicted to caffeine, he or she needs to use well below 100 milligrams a day, which means drinking only one caffeinated soft drink or a very small cup of coffee a day,” Juliano says.

For student-athletes who find that recommendation unrealistic, nutritionists advise that they keep their daily intake under 300 to 400 milligrams a day. While this amount does cause dependence on the substance, other side effects, such as anxiety, sleeplessness, and digestive disturbance, generally don’t occur. Staying under 400 milligrams requires limiting intake to about two cups of coffee or three caffeinated soft drinks a day.

Caffeine & Performance
Beyond consuming coffee as part of their daily routines, many athletes are turning to caffeine as an ergogenic aid. “The prevalence of caffeine as a performance aid is something I’m seeing more and more,” says Josh Hingst, Assistant Strength and Conditioning Coach and Sports Nutritionist at Florida State University.

“I don’t see student-athletes taking caffeine pills, but I do see them drinking more caffeinated beverages, especially the so-called energy drinks, before games,” agrees Leah Moore Thomas, Sports Nutritionist at Georgia Tech. “And I’ve had more athletes ask, ‘If I drink coffee before my game, is it going to help me?’”

The answer, according to recent studies, is probably yes—but with some big caveats. “There is a wealth of information to suggest that caffeine allows people to exercise harder and longer,” says Lawrence Spriet, an exercise physiologist, caffeine researcher, and Professor at Canada’s University of Guelph. “As athletes get tired, they are better able to maintain focus and level of effort with caffeine. Caffeine also reduces perceived exertion, so athletes report that they don’t feel like they are working as hard.”

In laboratory studies, caffeine’s stimulant effect also seems to boost awareness, vigilance, and alertness, particularly during long-term exercise bouts. However, although caffeine may boost performance in laboratory tests, questions remain when trying to apply those findings to actual competition. “When you introduce all the variables that are involved with team sports, it becomes much harder to measure whether caffeine has improved an individual athlete’s performance,” says Spriet.

If caffeine can boost performance, should softball coaches encourage student-athletes to use it? When it comes to high schoolers, absolutely not, says Spriet. “I do not recommend caffeine use with developing individuals,” he says. “In fact, if it was up to me, it would be banned for athletes under 18.”

Juliano agrees. “From a chemical standpoint, we don’t know whether caffeine affects a developing central nervous system differently from an adult central nervous system, because that research cannot be done for ethical reasons,” she says. “We know that the brain is still developing, and that caffeine affects brain neurotransmitters, but beyond that, we just don’t know.”

In addition, advocating that high school athletes use caffeine to perform better may put them at increased risk for trying other, and more dangerous, ergogenic aids. “Telling a 14- or 15-year-old athlete that caffeine supplementation is an okay idea sends a dangerous message,” says Lewin. “It opens them up to the idea of a quick fix, of taking a pill to become a better athlete. Can it lead to abuse of other performance enhancers? We don’t know for sure, but it’s certainly an issue to be aware of.”

It’s also important for high school coaches to send the right message to their athletes regarding caffeine. “We know that children and adolescents are using more caffeine than ever before,” Juliano says. “They are a huge share of the market for soda and energy drinks. It’s critical to educate them that caffeine is a drug, that it causes physical dependence, and that there are much better ways to achieve more on the field.”

Information & Education
With older student-athletes, a message that combines information about caffeine’s risks with education about using it safely may be a more realistic approach. “Once athletes are in college, many of them are going to use it as an ergogenic aid,” Spriet says. “So someone needs to be there to say, ‘If you are going to use it, here are some guidelines so you don’t harm your body.’”

Hingst agrees. “I think the message for college athletes needs to be, ‘There are a lot more important things to consider when you’re trying to improve your performance, like nutrition, hydration, training, and rest. But if you are going to use caffeine in an attempt to boost your performance, here is how to do it safely,’” he says.

Education on the safe use of caffeine as an ergogenic aid needs to include the following factors:

Dose: Research indicates that doses of three to five milligrams per kilogram of body weight will provide a performance effect without health risks. “For a 70-kilogram (154-pound) athlete, three milligrams per kilogram is only 210 milligrams of caffeine,” Spriet says. “You can easily get that from two cups of coffee.”

Athletes who ingest too much caffeine before a game are more likely to see a performance detriment than a benefit, from caffeine-induced headaches, anxiety, stomachaches, and focusing problems. They may also approach the caffeine limits set by the NCAA, which require athletes to have less than 15 micrograms per milliliter of urine.

Source: Spriet advises against using energy drinks, since they typically contain many other ingredients not regulated by the FDA. He believes the safest source is simply coffee. “For an adult athlete, one to three cups of coffee before a game, depending on the athlete’s weight, is very safe and is likely to provide them with a performance benefit, without adding sugar or other ingredients,” he says.

Timing: In general, caffeine should be consumed a half-hour to an hour before the start of a game. “The blood level of caffeine is maximized one hour after it’s taken, but effects start to show up by 30 minutes,” Spriet says.

Tolerance: Athletes who use caffeine as part of their daily diet are less likely to see a performance benefit from using it prior to exercise. “To avoid building up a tolerance, an athlete needs to abstain from caffeine for a few days prior to taking it before a game,” Lewin says.

Testing: “Advise athletes to try it during practices or workouts before using it during a game,” Hingst says. “They need to have some experience using it first to see how they respond.”

Mixing It: Perhaps most importantly, advise student-athletes to be very aware of the ingredients in any other supplements they are taking. Combining caffeine and other stimulants often found in dietary supplements can put an athlete at higher risk for a sudden arrhythmic death.

Even with new research on caffeine and performance available, nutritionists still recommend downplaying its role to athletes. “When athletes ask me about boosting performance with caffeine, I ask them, ‘What have you done to improve your breakfast, lunch, dinner, and recovery meals? How is your hydration, training, and rest?’” Lewin says. “Depending on their sport, their individual response, and a host of other variables, caffeine may give them a slight boost. But it is not going to make up for not having these foundational pieces in place.”

A longer version of this story appeared in Training & Conditioning, a sister publication to Coaching Management. It can be accessed by searching “caffeine” on our Web site:

For student-athletes who need to lower their caffeine intake, it’s essential to develop a strategy, because withdrawal symptoms can hit harder than they expect.

Caffeine researcher and Assistant Professor of Psychology at American University Laura Juliano and her colleague Roland Griffiths recently conducted a review of existing literature on caffeine withdrawal. “One of our most important conclusions was that caffeine withdrawal is clinically significant,” she says. “Some people become so ill that they mistake the withdrawal for the flu. It’s important to take caffeine withdrawal seriously.”

Juliano suggests helping student-athletes cut back by letting them know what to expect. “Explain to the student-athlete that whenever you use a drug regularly, your body makes a series of adjustments,” she says. “When your body doesn’t get the drug, it is forced to go through a period of readjustment—and that can significantly interfere with performance in school and athletics.”

Leah Moore Thomas, Sports Nutritionist at Georgia Tech, advises student-athletes to reduce caffeine gradually. She first has athletes tally all the sources of caffeine they typically use, especially hidden ones like coffee-flavored yogurt, or caffeine-containing medications.

“Then I ask them to reduce it a little at a time,” she says. “If caffeine is present at three meals a day, I have them replace it at one meal with juice or water or a decaffeinated soda or coffee. Once they do that for a while, I ask them to try including caffeine only once a day, and then go to every other day. My goal is for our student-athletes to reach a level of use where if they don’t have caffeine for a day, they don’t feel any adverse effects.”

For many years, the idea of “caffeine as a diuretic” was common wisdom. But recent research suggests that, at least in this respect, caffeine has been getting a bad rap. Lawrence Armstrong, Professor at the University of Connecticut’s Human Performance Laboratory, published a study in 2002 debunking the dehydration myth.

“We took 59 healthy college males and studied them during 11 days of controlled caffeine intake,” Armstrong says. “One group took no caffeine, a second took three milligrams per kilogram of body mass, and a third took six milligrams per kilogram of body mass. We evaluated them on 20 hydration indices, and the results across all three groups were virtually identical.

“The amount of water retained by the body from a caffeinated beverage is virtually identical to the amount retained from a non-caffeinated beverage,” Armstrong continues. “There is no evidence that caffeine dehydrates the body.”

Other studies have found similar results, prompting researchers to conclude that any increases in urine output after consuming caffeine are not a result of the caffeine, but of the water typically ingested along with it.

Sports nutritionists, however, are quick to point out that caffeinated beverages still should not be the hydration source of choice for athletes. “Dehydration is such a huge issue for student-athletes,” says Leah Moore Thomas, Sports Nutritionist at Georgia Tech, “that the message still needs to be, ‘Caffeine itself may not dehydrate you, but colas and energy drinks are not designed to properly hydrate you, and they should not be your major source of fluids.’”

Student-athletes who ingest 100 milligrams or more of caffeine per day will develop caffeine dependence and experience withdrawal symptoms if they discontinue use. Those who ingest more than 400 milligrams per day are likely to experience anxiety, sleep disturbance, digestive problems, and other side effects. Below is a list of commonly used products along with their caffeine content.

Product Serving Size Typical Caffeine Content (mg)
Coffee (brewed) . . . .6 oz . . . . . . . . . . . . .100
Coffee (Starbucks) . . 16 oz . . . . . . . . . . . .400
Coffee (espresso) . . . .1 oz . . . . . . . . . . . . .40
Coffee (decaf) . . . . . . 6 oz . . . . . . . . . . . . . .4
Tea (brewed) . . . . . . . 6 oz . . . . . . . . . . . . .40
Tea (bottled, iced) . . .12 oz . . . . . . . . . . . . 20
Soft drink (caffeinated) . 12 oz . . . . . . . . . . 40
Jolt Cola . . . . . . . . . . . . 12 oz . . . . . . . . . . 71.5
Energy Drinks (typical) . .8.4 oz . . . . . . . . . 80
Red Bull . . . . . . . . . . . . .8.45 oz . . . . . . . . 80
Coffee ice cream . . . . . . 8 oz . . . . . . . . . . .50
Coffee yogurt . . . . . . . . .8 oz . . . . . . . . . . .50

Stimulants (typical) . . . . .1 tablet . . . . . . . .100 or 200
Vivarin . . . . . . . . . . . . . . 1 tablet . . . . . . . .200
Weight loss products/
Sports supplements (typical)..2-3 tablets . . . 80-250
Dexatrim Natural . . . . . . .1 caplet . . . . . . . . 80
Stacker 3 . . . . . . . . . . . . .1 caplet . . . . . . . 250

The above amounts were obtained from Substance Abuse: A Comprehensive Textbook, Fourth Edition, published by Lippincott Williams & Wilkins, with permission by authors Laura Juliano and Roland Griffiths.

To help student-athletes pinpoint their exact caffeine intake with an interactive calculator, direct them to the National Sleep Foundation’s Web site at: