It is generally agreed by experts that consuming protein following a workout is beneficial for muscle recovery, but the best type of protein remains debatable. A study published in the American Journal of Clinical Nutrition determined that whey protein (a group of protein found in milk and milk-based products) has an advantage over casein for muscle development.
Researchers used smaller doses of whey to mimic casein and compared them to a one-time dose of whey. After doing eight sets of 8-10 leg repetitions on a leg extension machine, subjects with an average age of 22 were then given either the one dose or multiple smaller doses.
Study author Daniel W.D. West, a PhD student at McMaster University in Hamilton, Ontario explained that “Whey is high in leucine and the fact that it is rapidly digested means there is a rapid appearance of essential amino acids, including leucine. Those amino acids act as a signal to elevate muscle protein synthesis–crucial for ongoing growth, repair, and maintenance of muscles.”
Another study, also published in the American Journal of Clinical Nutrition, found that protein which includes higher concentrations of the amino acid leucine works better than protein with lower concentrations. Subjects were active duty members of the military with an average age of 24. After pedaling on an exercise bike for an hour at moderate intensity, they drank a high-protein drink with 10 grams of protein.
According to study author, Stefan M. Pasiakos, PhD, a research physiologist with the U.S. Army Research Institute of Environmental Medicine, “It appears more leucine is beneficial in the context of muscle recovery.”
So, why do you need protein after exercise?
The damage and subsequent recovery your muscles undergo as a result of working out is actually a healthy cycle that improves muscle strength and builds muscle mass. Nutrition is a critical factor in the process. Because your muscle tissue is made up predominantly of protein, it needs supplementation of dietary protein, such as whey, that is rich in essential amino acids and can repair the naturally occurring damage caused by exercise. The recovery process involves creating new muscle fibers as well as bulking up existing muscles. Including whey in your post-workout nutrition ensures your muscles have the nutrients they need to begin the repair process and speed recovery.