I like to kick-start my workouts with energy drinks, such as Red Bull. Is this OK?

Answers from Edward R. Laskowski, M.D.

Occasional energy drinks are safe for most people. Caution is important, however, especially if you have underlying heart problems.

Energy drinks — which are often loaded with caffeine, sugar and herbal stimulants — may pose various health risks, including:

  • Restlessness and irritability. The caffeine in energy drinks can make you irritable, restless and nervous. Excessive caffeine is also associated with headaches, tremors, nausea and insomnia.
  • Increased blood pressure. The caffeine in energy drinks can increase your blood pressure and make your heart beat faster. In some cases, this can trigger potentially dangerous changes in heart rhythm. Mixing energy drinks and alcohol compounds the effect, since alcohol also makes your heart beat faster.
  • Possible dehydration. Some studies suggest that the caffeine in energy drinks may increase the risk of dehydration during exercise, but results are mixed. Other studies don't associate caffeine with dehydration.
  • Weight gain. The sugar in most energy drinks can contribute to weight gain, especially for people who don't exercise regularly and those who struggle with their weight.

In addition, excessive amounts of energy drinks have been associated with manic episodes, seizures, chest pain, heart attacks and sudden cardiac death.

Before and during exercise, plain water is usually best. During workouts that last 60 minutes or longer, you might sip sports drinks — typically made of water and carbohydrates — to boost your endurance. If you choose to drink energy drinks, do so only in moderation.

Aug. 08, 2009