Every day, about 90 percent of Americans consume some form of Mother Nature’s wake-up call: caffeine. A majority comes from the ritual morning coffee slam and the rest is spread across the day, through sodas, tea, energy drinks and chocolate.
We may be juiced about caffeine, but the instant jolt doesn’t deserve its reputation as an addictive, dehydrating or potentially dangerous drug. Used the right way, in the right amount, caffeine can provide a healthy stimulating effect for both your brain and brawn. Here is a look at what caffeine can — and cannot — do for you.
What Caffeine Can Do
Boost Your Brain
Researchers at the Medical University Innsbruck in Austria found it takes only 100 mg of caffeine (2 cups of coffee) to increase activity in the brain’s frontal lobe area that influences short-term memory. It also stimulates the anterior cingulum, the part that controls attention span. However, if you want to maintain this brain caffeine high, an extra double espresso won’t help. Instead, consume small amounts of caffeine — about 2 ounces of coffee — every hour, throughout the day.
Give Your Workouts a Kick
Some caffeine before hitting the gym can increase your endurance, which means more reps and longer sessions, says Jose Antonio, Ph.D., and CEO of the International Society of Sports Nutrition. Caffeine doesn’t directly pump up your muscles; instead, it affects the central nervous system to increase your pain threshold. This makes it easier to push through those final reps, extra sets or that last treadmill mile.
Liven Your Liver
About 30 percent of adults have non-alcoholic fatty liver disease. (The number more than doubles if you are obese or have diabetes.) Yet, Duke University experts have found that increasing caffeine (equal to four cups of coffee or tea) can reduce a fatty liver.
Help You Breathe Better
Do you huff and puff while running, power walking or shaking it up in Zumba? Taking caffeine within an hour before aerobic activity can reduce symptoms of exercise-induced asthma (EIA), like shortness of breath and chest tightness and effects up to 20 percent of adults. A 2009 study from Indiana University found that 9 mg per kilogram of body weight (about 720 mg for an 180-pound man and 567 mg for a 140-pound woman) was just as effect as an albuterol inhaler, which is often used to treat EIA.
What Caffeine Can’t Do
Sober You Up
Slugging coffee only makes you a “wide-awake-drunk.” And this can be dangerous, says research in Behavioral Neuroscience. You are more likely to partake in risky behavior, like driving while intoxicated or picking a fight.
Make You Dehydrated
Caffeine is not a diuretic. A review of 41 separate studies found that caffeine intakes up to 400 mg (four coffee cups) won’t dehydrate you. “Your more frequent bathroom breaks is from the extra fluids, not the caffeine,” says Steven Broglio, Ph.D., ATC, and assistant professor of kinesiology at the University of Illinois.
Make You An Addict
People hooked on their daily java are more addicted to the morning routine than the caffeine itself. Still, kicking a caffeine habit can trigger minor, temporary withdrawal symptoms. “If you’re a daily caffeine drinker, and suddenly quit, you may feel like crap for about 48 hours with headaches, irritability and drowsiness, but then your body will adapt,” says Antonio.
A few other questions:
How much do you really need for the best results?
Most studies suggest the ideal intake zone is from 100–200 mg to 500–600 mg, or about two to four cups.
How long before it takes effect?
About 45 minutes to 1 hour to reach its full impact. However, you often can feel the kick in as little as 10 minutes, according to a 2008 University of Barcelona study. Caffeine’s effects usually last between two and three hours.
What are the best caffeine sources?
Coffee and tea deliver the most. (Tea leaves have more caffeine than coffee beans, but lose more during brewing.) An 8-oz home-brewed cup contains an average of 133 mg of caffeine; black tea has 40 to 120 mg. If you want a slightly stronger shot, hit the coffee bar. For example, a medium-sized (or Grande) Starbucks coffee has about 330 mg per 16 ounces. Energy drinks? Spike Shooter (300 mg/8.4 oz), Monster Energy (160 mg/16 oz) and Full Throttle (144 mg/16 oz.) Other brands like Red Bull, Rock Star and Amp vary from 74 to 80 mg per can. But watch the extra sugar some drinks contain.