You hear bodybuilders say it all the time: protein = muscle mass. Anyone who wants to “get ripped” can be found pumping out heavy weights at the gym, followed by consuming an excess amount of protein, often in the form of smoothies or shakes. Believe it or not, this outrageous intake of calories is not the way to achieving that goal.
Strength training exercises are the most important part of building muscle mass and resistance to sarcopenia, muscle degradation with age. Even though the bulk of the work comes from exercise, the anabolic building of the muscle is facilitated by amino acids and protein complexes, most often obtained from the diet. What many fail to realize, however, is that extra supplementation of protein does not affect muscle anabolism at all. Multiple studies, in humans and in rats, have shown that an excess of protein did little for long-term (six to twelve weeks) muscle growth in both species.
One of the most influencing studies was conducted by Alan Hayes and Paul J Cribbs at Victoria University in Australia. The researchers found that while supplementation in rats made almost no difference in the muscle composition, it did help to rejuvenate the anabolic response to meals with high concentration of proteins. In doing this, the body blocks protein breakdown, so when protein is introduced to the body, it can accumulate and build larger muscles, a process known as hypertrophy. In fact, eating more protein-filled snacks throughout the day is important for frequent muscle hypertrophy.
There are other reasons that one could take protein supplements, as they still aid in promoting natural accretion. First, supplementation in close time proximity to strength training helps prevent the breakdown of functional muscle fibers. Second, supplementation between meals (snacking) promotes frequent stimulation and synthesis of muscle protein, an act that prevents muscle atrophy, the degradation of muscle caused by disuse. Lastly, supplementation is most important for those who are genetically predisposed to troubles in protein breakdown. As those individuals age, they are at a higher risk of sarcopenia, so protein supplementation ensures they receive the nutrients they need daily.
Therefore, protein supplements should be used as just that: supplements. They do little to actually help build muscle, and are more important for maintaining the health of individuals who lack in these areas.
Hayes, Alan, and Paul J. Cribb. “Effect of whey protein isolate on strength, body composition and muscle hypertrophy during resistance training.” Current Opinion in Clinical Nutrition & Metabolic Care 11.1 (2008): 40-44.