A cup of 1% milk has 8 grams of protein and 2 grams of fat. According to the Cleveland Clinic, protein and fat take longer to digest, so milk might have your stomach gurgling as it tries to digest during your run. That could leave you feeling a little sick and sluggish for the track. Milk also contains 13 grams of lactose, which can be difficult to digest for two-thirds of the world with lactose malabsorption, according to the National Institutes of Health. While not everyone with lactose malabsorption experiences symptoms, others could experience gas and bloating, which are not fun when running with friends.
While milk may not be the best choice before a run, chocolate milk can play a valuable role in post-run recovery, according to Runner’s World. Chocolate milk contains two essential nutrients for recovery: protein and carbohydrates. The protein in milk provides the amino acids necessary for repairing and building muscle tissue damaged during exercise. Additionally, the carbohydrates help replenish the glycogen stores in the muscles that are depleted during a run. Chocolate milk will also help you rehydrate (via Shape).