There are fast digesting and more slowly digested proteins for different usage occasions. You also have a variety of carbohydrates to choose from, and a study published in the journal Medicine & Science in Sports & Exercisecompares different combinations for distance runners involved in several races at one event.
Eight experienced endurance athletes ran on a treadmill at 70% of exercise capacity until exhausted. During 4 hours of recovery, they drank 90 grams of a carbohydrate blend per hour. Some got a 1:1.5 ratio of glucose to maltodextrin while others consumed the same ratio of fructose to maltodextrin.
The second time trial was identical to the first. Athletes who got the fructose and maltodextrin supplement ran for an average of 81.1 minutes compared to the 61.4 minute average time to exhaustion for the glucose and maltodextrin group.