If you participate in endurance events such as marathons or triathlons or exercise sessions lasting longer than an hour, your body can become depleted of both energy and water, possibly leading to dehydration and decreased physical performance. Many commercial sports drinks claim to boost performance, but are they effective?

A study published in a recent issue of the journal Medicine & Science in Sports & Exercise examined the effectiveness of sports drinks containing carbohydrates and electrolytes, which are chemicals in the body that include acids and salts. Ten competitive athletes consumed either a carbohydrate-containing drink or a placebo that didn't contain carbs before completing timed physical and mental tests, such as shuttle runs and word games. In addition the study participants rated how fatigued they felt after each event.

When athletes consumed the carbohydrate drink, they had faster sprint times, better motor-skill scores and could run 37 percent longer before becoming fatigued. In general they rated themselves as being less fatigued than when they consumed the placebo. These results indicate that sports drinks, gels and bars that contain carbohydrates and electrolytes may improve physical and mental performance and may be a good choice for serious athletes who compete in endurance events or extended exercise sessions.

A word of caution, though: some sports drinks may contain more than just carbs and electrolytes. Many commercial sports drinks contain ephedra (also known as ma huang), an herbal stimulant that can cause serious side effects such nervousness, dizziness and even heart attack or stroke. Become an avid label reader to avoid extra additives.

Related information: Other fitness tips and hints | Carbohydrates

Sources:  Welsh RS, Davis JM, Burke JR, Williams HG. Carbohydrates and physical/mental performance during intermittent exercise to fatigue. Medicine & Science in Sports & Exercise, April 2002, Vol. 34, pp. 723-731.