Finding the best post-exercise drink

“Because fluid bovine milk is considered a high-quality protein in that it provides all essential amino acids and the carbohydrate content provided in chocolate milk exceeds that of white milk, fat-free chocolate milk holds particular intrigue as a recovery beverage for endurance athletes,” said Dr. William Lunn and colleagues in Medicine & Science in Sports & Exercise.

Eight male runners took part in the studies. Both studies had two parts, separated by seven days. In each part, the men completed a 45-minute run. Afterwards, they were given 480 ml (16 ounces) of fat-free chocolate milk or a carbohydrate-only beverage during a three-hour recovery period. Both drinks had 296 calories; the chocolate milk had 16 grams of protein as well. Men given the chocolate milk during the first part of each study were given the carbohydrate-only drink during the second part, and vice versa.

• In the first study, muscle biopsies were taken throughout the recovery period to assess muscle protein status and muscle glycogen (a storage form of glucose in the body). Researchers found that the participants’ muscle recovery was enhanced after drinking chocolate milk compared with the carbohydrate-only drink. Chocolate milk seemed to promote muscle synthesis (as opposed to breakdown) and inhibit protein breakdown after exercise. Glycogen stores were similar after drinking chocolate milk and the carbohydrate-only beverage.
• In the second study, after the initial 45-minute run and recovery period, the men completed a “time-to-exhaustion” exercise test where they ran on a treadmill until tired out. Time to exhaustion was 23% longer after drinking chocolate milk compared with the carbohydrate-only drink, meaning that the men were able to run longer before they became exhausted.

Before you gulp

This isn’t the first time that chocolate milk has made the news as an exercise recovery drink. A 2011 study in the Journal of Strength & Conditioning Research concluded chocolate milk promoted recovery between exercise sessions as well as a combination carbohydrate-electrolyte replacement drink.

It makes sense that a protein-rich drink (like chocolate milk) would help spare muscle protein during recovery from intense exercise. Future studies should investigate other (nondairy) protein sources and complex carbohydrates as components of post-exercise drinks.

(Med Sci Sports Exerc 2012; DOI: 10.1249/MSS.0b013e3182364162)