Lyle McDonald, a notoriously detail-oriented nutrition and exercise science geek, has published quite a few articles on his website detailing the benefits of chocolate milk as a post-workout recovery drink.
In ”Milk: The New Sports Drink?”, he reviews a study which concludes that milk provides a superior anabolic environment after a strenuous workout, and also rehydrates the body better than water. In “Milk as an Effective Post-Exercise Rehydration Drink”, he comes to similar conclusions after reviewing another study.
Most of these studies discuss low-fat milk, which is fine; fat tends to slow digestion, especially of glucose and similar sugars, which are in short supply after exercise. It’s typical to avoid fat around workouts to maximize the absorption of sugars. Paleo adherents propose avoiding dairy altogether, and hypothesize that it causes similar gut issues as gluten. However, as an athlete interested in performance recovery (and I’ve traditionally handled dairy pretty well) I’m not too worried about this.
My favorite article from McDonald is actually a guest article from Alan Aragon, another obsessively detail-oriented researcher. It’s called “An Objective Comparison of Chocolate Milk and Surge Recovery”, and while it might be a bit sciency for many of you, it’s worth a thorough read if you’re currently wasting money on expensive protein-filled fitness concoctions.