A brisk walk is a better energy booster than a caffeine overdose.

RODALE NEWS, EMMAUS, PA—A new study suggests that the boost in blood pressure and heart rate triggered by energy drinks like Red Bull could be a problem for people with hypertension and heart disease—and, perhaps, even for people who are perfectly healthy.

THE DETAILS: Doctors at Henry Ford Hospital in Detroit gathered 15 healthy adults, none of whom suffered from any chronic health problems, and tracked their blood pressure and heart rate for 7 days. Each day, the participants drank 500 milliliters (ml), or two cans, of an energy drink. Their blood pressures and heart rates were measured at 30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours after downing the drink. At the 4-hour mark on the first and seventh days, the participants’ heart rate had jumped by 5 to 7 beats per minute, and their systolic blood pressure increased by 10 mm Hg.

WHAT IT MEANS: Energy drinks deliver more than energy. “It’s unlikely that the increases observed in this study would be clinically significant in healthy young adults,” report the study authors. “However, increases in blood pressure and heart rate of the magnitude observed in our study could be significant in persons with known cardiovascular disease.” The drink used in the study contained 1,000 milligrams (mg) of taurine, 100 mg of caffeine (the equivalent of one cup of coffee), and a host of sugars and nutritional supplements. Although the study didn’t try to tease out the ingredient responsible for the boosts in heart rate and blood pressure, previous research has suggested that taurine and caffeine can independently alter cardiovascular characteristics. “What strikes me in general,” says cardiologist David Lanfear, MD, one of the study authors, “is that there are some young people who drink a lot of this stuff, and we don’t know the long-term consequences of it. And this study proves there may be adverse consequences.”

If you’re managing heart disease or hypertension, here’s how you can boost your energy without putting your heart in jeopardy:

• Cut the Bull: Can’t give up on your favorite energy drink completely? Find a low-caffeine version and limit your daily and weekly consumption. A single 250-mg dose of caffeine can cause problems for some people, and nobody should be drinking 500 mg.

• Step it up—literally: That’s right, skip the brew and go for a 20-minute walk. University of Georgia researchers who analyzed 70 different studies concluded that moving your body increases energy and reduces fatigue. Regular exercise boosts certain fatigue-fighting brain chemicals such as norepinephrine and dopamine, which pep you up, and serotonin, a mood enhancer.

• Reach the deep-sleep zone: Not getting enough Zs? Get even more exercise. Women who walked or danced for at least an hour, four times a week, woke up half as often and slept an average 48 minutes more a night than sedentary women, according to a study in the journal Sleep Medicine. If you can’t find a dance partner who can keep up, you can extend that 20-minute walk—or simply do it three times a day.