Muscle gain is dependent upon the difference between muscle protein synthesis (MPS) and muscle protein breakdown (MPB), otherwise known as net protein balance (NPB). For muscle gain to occur, the rate of MPS must exceed the rate of MPB, resulting in positive NPB.
This framework makes the importance of diet especially clear: Mechanical loading of skeletal muscle — commonly achieved through resistance exercise — stimulates MPS, but it also increases MPB. The ingestion of amino acids — particularly essential amino acids — helps further stimulate MPS while also suppressing MPB, helping ensure a positive NPB overall.[1]
References
- ^Stokes T, Hector AJ, Morton RW, McGlory C, Phillips SMRecent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise TrainingNutrients.(2018 Feb 7)