July 1, 2011 -- Drinking low-fat chocolate milk after a workout helps endurance, builds muscle, reduces fat, and seems to improve performance, according to new research.
The drink seems to have the right combination of carbohydrates and protein, says researcher John L. Ivy, PhD, department chair of kinesiology and health education at the University of Texas at Austin.
"When recovering from exercise, two things you want to do is replenish sugar stores in the muscle and turn on protein synthesis and stop protein breakdown," Ivy tells WebMD.
"The combination of carbohydrate and protein [found in chocolate milk] work synergistically to do those two things," he tells WebMD.
The low-fat chocolate milk beat out two other drinks tested -- a no-calorie beverage and a carbohydrate drink with no protein.
Ivy's research is published in the Journal of Strength and Conditioning Research and the Journal ofNutrition and Metabolism. He also presented the findings at the American College of Sports Medicine Meeting in Denver in June.
The research was funded by the National Dairy Council and the National Fluid Milk Processor Promotion Board.
In one of two studies, Ivy had 10 well-trained cyclists exercise over two hours to the point of fatigue. They then drank either the milk drink, the carb drink, or the no-calorie beverage right after the workout and then two hours later.
After four hours the cyclist did a 40K cycling time trial.
"The individuals, when they had received the chocolate milk, performed the time trials significantly faster," he says. They shaved six minutes off their time when they drank the chocolate milk compared to the carb drink.
The chocolate milk, he says, activates the proteins that block protein breakdown. This preserves protein and muscle, helping the recovery process.
In a second study, Ivy trained 32 untrained people, having them cycle 60 minutes a day, five days a week, for 4.5 weeks.
He gave one group the chocolate milk right after exercise and one hour later. He gave a second group the carb drink and a third the placebo no-calorie drink.
They looked at maximum oxygen uptake, a measure of aerobic endurance. ''The improvement in maximum oxygen consumption was twice as great [in the milk drinkers] than in the carb or placebo group."
"We also found individuals receiving the milk tended to have a greater increase in lean body mass and greater reduction in body fat."
Ivy says he was not trying to do a head-to-head comparison against sports drinks on the market. He says that sports drinks meant for use after workouts typically do contain protein.
The chocolate milk tested, he says, has a better carb-protein mix than white milk. The chocolate milk used has about 11.5 grams of carbohydrates per 100 milliliters, 3.5 grams of protein, and 2 grams of fat. The carbohydrate drink he tested has 15 grams of carbs, 2 grams of fat, and no protein.