MATAWAN, NJ—Whether protein is needed in a sports drink may depend on the results one is seeking.

A Gatorade-funded study performed by researchers at McMaster University in Hamilton, Ontario, Canada, found that adding protein to a sports drink won’t make a person race faster. However, a study funded by PacificHealth Laboratories Inc., which makes Accelerade Sports Drink, found that a protein-containing sports drink was more effective in rehydrating athletes than a conventional sports drink or water.

The study by Gatorade (which does not include protein as an ingredient) tested a non-protein sports drink to a protein sports drink and water. The study found that sports drinks improved the performance of cyclists tested compared to a placebo drink, but there was no additional benefit of protein supplementation.

“Previous studies that suggested protein was beneficial used ‘ride to exhaustion’ tests that do not resemble normal athletic competition,” said Martin Gibala, an associate professor of kinesiology at McMaster University. “In addition, the subjects in those studies received less than the optimal recommended amount of carbohydrate. Our study shows that protein confers no performance benefit during ‘real life’ exercise when athletes consume sufficient amounts of a sports drink.”

Instead, Gibala contends, two sports drink ingredients improve performance during prolonged exercise: carbohydrate, which provides fuel for working muscles, and sodium, which helps to maintain fluid balance.

However, the study by the makers of Accelerade Sports Drink, which contains protein, found that protein in a sports drink was beneficial for rehydration. The PacificHealth study measured the effectiveness of a carbohydrate-electrolyte sports drink (Gatorade), a carbohydrate-protein-electrolyte sports drink (Accelerade) and water after study subjects lost 2.5 percent of body weight through exercise-induced sweat loss. Investigators found that the carbohydrate-protein-electrolyte sports drink rehydrated athletes 15 percent better than the carbohydrate-electrolyte sports drink and 40 percent better than water.

“The results clearly disprove the myth that adding protein to a sports drink negatively impacts rehydration,” said Dr. John Seifert, associate professor in the Department of Physical Education and Sports Science at St. Cloud State University and principal study investigator. “To the contrary, our results indicate that a carbohydrate-protein sports drink may actually be preferable to a conventional sports drink or water when rapid rehydration and maximum fluid retention are needed to help the body recover from the stress of exercise.”

Gibala with the Gatorade study said about protein, “Eating a little protein after exercise is important to help repair damaged muscles and promote training adaptations, but no compelling evidence suggests that endurance athletes need protein during exercise.”

The McMaster University-Gatorade study will appear in the August issue of Medicine & Science in Sports & Exercise. The PacificHealth Laboratories study will appear in the August issue of International Journal of Sport Nutrition and Exercise Metabolism.