It is often mentioned in the fitness and athletic circles that it is imperative to get protein in immediately after a workout, in particular a fast digesting protein like whey protein.
However, how essential is it really?
Above are three studies that have been conducted investigating these claims.
The first two studies compared the muscle anabolic response to whey (fast digesting) and casein (slow digesting) protein after a resistance workout. Both found that both had an overall equal effect despite temporal differences.
The third study investigated whether there was difference between consuming a protein-carbohydrate drink 1 hour after exercise compared to 3 hours after exercise. It found that there was there was no real difference in net protein synthesis whether the drink was consumed 1 hour or 3 hours post-workout.
So to answer the original question, no you don't have to consume whey protein post-workout, nor do you need to consume any protein immediately. If you are hungry go ahead and eat a meal or drink a protein shake, otherwise stick to an eating schedule that works best for you.