Muscle tissue is constantly turning over, with the rates of muscle protein synthesis (MPS) and muscle protein breakdown (MPB) fluctuating throughout the day. Net protein balance is the difference between MPS and MPB. For an increase in muscle mass to occur, MPS must exceed MPB, resulting in a positive net protein balance.[1] MPS is very sensitive to exercise and diet (namely, essential amino acid intake).
How does muscle gain work?
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•Last Updated: May 16, 2025
Muscle gain occurs when muscle protein synthesis exceeds muscle protein breakdown, which leads to a positive net protein balance. This process is influenced by factors such as exercise and dietary intake of essential amino acids.