One of the best memes from the Mike Barwis era was about his love of chocolate milk (of course the best one was about his pet wolves). This study from the University of Texas at Austin proves that chocolate milk is indeed the correct drink of choice for athletes of any type.
After riding a bike for 90 minutes at moderate intensity, then for 10 minutes of high intensity intervals, 10 trained cyclists had significantly more power and rode faster (reduced their ride time by an average of six minutes) when they consumed low-fat chocolate milk rather than a carbohydrate sports drink or calorie-free beverage.
Compared to the other recovery drinks, chocolate milk drinkers had twice the improvement in maximal oxygen uptake after four and a half weeks of cycling, which included intense exercise five days a week, with each exercise session followed by one of the three recovery beverages. Maximal oxygen uptake is one indicator of an athlete's aerobic endurance and ability to perform sustained exercise. The study included 32 healthy, amateur male and female cyclists.