The study, published by a group of researchers from Canada in Iran in June in the European Journal of Clinical Nutrition, claims that "Chocolate milk (CM) contains carbohydrates, proteins, and fat, as well as water and electrolytes, which may be ideal for post-exercise recovery."
The results were found by examining data from 12 smaller studies that compared how chocolate milk influenced exercise recovery as compared to other common drinks like sports drinks. They found that chocolate milk had a positive effect on participants' heart rates and lactic acid levels, lengthened the time to exhaustion and improved perceived exertion at least as much as other drinks, Reuters reported.
Shockingly, the results not only showed chocolate milk to be better than the placebo, but also that the placebo was better than sports drinks! The time it took for athletes to reach exhaustion was one minute longer with chocolate milk than with the placebo, but six minutes longer than with sports drinks.
"Chocolate milk contains carbohydrates, proteins, fats, flavonoids, electrolytes, and some vitamins which make this drink a good choice for recovery in athletes," senior study author Dr. Amin Salehi-Abargouei of Shahid Sadoughi University of Medical Sciences in Yazd, Iran, told Reuters.
The effectiveness of a given drink, however, depends on the type of activity, noted Mike Saunders, director of the Human Performance Laboratory at James Madison University in Harrisonburg, Virginia, to Reuters. This study measured athletes engaged in aerobic exercise, mostly running and biking. Most sports drinks have carbohydrates and electrolytes, which water lacks and which are depleted by exercise, but usually lack protein, which promotes muscle repair and which milk contains.
Interestingly, this isn't the first time this has been claimed. A 2006 study published in the International Journal of Sport Nutrition and Exercise Metabolism noted that cyclists who drank chocolate milk before biking lasted about twice as long as those who drank Endurox, a recovery drink, and about as long as those who drank Gatorade, a sports drink.
Their findings suggested that chocolate milk has an optimal ratio of carbohydrates to protein to encourage muscle recovery, as Joel Stager, an author of that study and professor of kinesiology at the University of Indiana, told WebMD at the time.