Although it is good practice to avoid sugar in the general diet, these high-glycemic carbohydrates provide the optimal substrate in a post-workout meal to restore glycogen (lost energy reserves) and maximize insulin response. In fact, if a recovery drink is not predominantly composed of quickly digesting carbohydrate, it is a gimmick. For a much more thorough discussion of this topic and supporting research visit Adding Protein to your Post-Workout Recovery Drink