You've probably seen them in stores, those colourful cans promising to energize and stimulate your body. Energy drinks are popular among college students, who drink them while studying or partying to help them stay up longer.

Energy drinks are also popular among some athletes, who claim the drinks give them extra stamina. Yet a few high schools have gone so far as to prohibit energy drink consumption before games, reporting respiratory distress in some students who consumed energy drinks prior to playing.

Most energy drinks contain a lot of caffeine and sugar. Caffeine is known to stimulate the mind and body, and may be helpful when used in small amounts. Too much caffeine, however, can raise the heart rate and cause sleep difficulties and irritability. Caffeine also dehydrates the body, a problem compounded when energy drinks are used during exercise. Long-term consumption of too much caffeine has been linked to high blood pressure, insomnia, and pregnancy problems. One especially dangerous aspect of energy drinks is the popularity of mixing them with alcohol. The caffeine may mask the effects of the alcohol, causing you to feel more alert and less drunk than you really are.

When used rarely and in limited quantities, energy drinks are unlikely to cause harm, but the safest tactic is avoidance. If you need a cup of coffee to perk you up in the morning, go right ahead. Otherwise, basic measures like getting sufficient sleep, eating well, and exercising daily are safer ways to improve your energy.

Marlene Veloso