Chocolate milk is shown by one study to perform as well, if not better than, leading sports recovery drinks.
US gymnast Aly Raisman stunned Olympic viewers by winning two gold medals and one bronze medal at the London 2012 Olympics. Many fans were surprised to learn that Raisman drinks chocolate milk after every workout. However, given the scientific research behind chocolate milk as a recovery drink, such a habit is not surprising. Perhaps most exercise enthusiasts are surprised to learn that chocolate milk is one the most efficient post-workout drinks because chocolate milk is not marketed as an athletic recovery drink. Gatorade, which is simply sugar, salts and water, has a sports-specific marketing campaign behind it as well as paid endorsements by many top athletes. The purpose of a recovery drink is to replace depleted glycogen stores. Chocolate milk, with a high concentration of carbohydrates, fats and protein, is well qualified at restoring glycogen stores.
One study supporting chocolate milk's workout recovery ability compared the recovery efficiency of chocolate milk with a carbohydrate replacement drink and a fluid replacement drink (Chocolate Milk as a Post-Exercise Recovery Aid; 2006; Jason R. Karp, et al.). A carbohydrate replacement drink, such as Endurox, focuses primarily on replacing carbohydrates lost during exercise. A fluid recovery drink, such as Gatorade, focuses primarily on rehydration and replacing lost electrolytes. Chocolate milk is closer to a carbohydrate replacement drink because both have a similar composition of carbohydrate and protein.
In the aforementioned study, nine healthy, highly-trained cyclists from Indiana University took part in a maximum effort interval workout designed to deplete glycogen stores. The subjects then had a four hour recovery period in the lab. During the recovery period the subjects received either Kroger low-fat chocolate milk, Gatorade fluid replacement drink, or Endurox carbohydrate replacement drink. Each drink was administered in an isocaloric amount. Following the four hour recovery period each subject did a maximum effort endurance test at 70% of VO2max. As Figure 1 (below) shows, both chocolate milk aided recovery and the fluid replacement drink (Gatorade) aided recovery saw significant increases in total work and time to exhaustion in the post-recovery workout compared to carbohydrate replacement drink (Endurox) aided recovery.
To understand the physiological differences resulting from each recovery drink, heart rate, blood lactate and water mass measurements were taken. As Figure 2 (below) presents, trials with chocolate milk aided recovery had a lower heart rate. In addition, blood lactate levels were lower at the end of the four hour recovery period in the chocolate milk aided recovery trial.
The authors suggest that because the endurance test was at 70% of VO2max, chocolate milk's fatty acids may have played a role. This is because at 70% of VO2max the body is primarily aerobic where it is using both glycogen and fatty acids in the blood. In addition, because the recovery time was only four hours the muscles were able to take up the simple monosaccharides and disaccharides found in chocolate milk, but possibly not more complex carbohydrates found in Endurox. As a footnote, the authors used many precautions to prevent scientific bias, but they did receive money from the Dairy and Nutrition Council.
In conclusion, chocolate milk appears to perform as well as, if not better than, commercially marketed sports recovery drinks.