Muscle Damage Does Not Cause Growth
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Damas et al. (2018). The development of skeletal muscle hypertrophy through resistance training: The role of muscle damage and muscle protein synthesis. European Journal of Applied Physiology, 118, 485-500.
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The purpose of this study was to review the role of muscular damage (think: soreness—a useful proxy) and its involvement in hypertrophy (muscular growth).
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In this study/review:
>Historically, muscular damage from resistance training, which leads to delayed onset muscle soreness (DOMS), has been thought of as a primary mechanism driving hypertrophy. This paradigm is currently being challenged.
>Muscle damage is the morphological disruption of cellular homeostasis within the muscle’s cytoskeleton and extracellular matrix (think: the muscle’s scaffolding).
>This study found that short-term resistance training programs create relatively large amounts of muscular damage but do not create much true hypertrophy.
>Contrastingly, it was found that long-term resistance training programs create much smaller amounts of muscular damage but create much greater amounts of hypertrophy.
>These two findings demonstrate an apparent disconnect (a negative/inverse relationship) between muscular damage and muscular hypertrophy.
>Seemingly, each pathway—the muscular repair and muscular hypertrophy pathways—compete over protein resources.
>Furthermore, muscle protein synthesis seems to allocate its resources sequentially only producing muscular hypertrophy after the required repairs are completed.
>These researchers concluded that muscle damage does not directly create muscle hypertrophy. Moreover, they demonstrated that they, in some ways, act antagonistically.
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Take-home:
>Muscular damage, and therefore soreness, is not a requirement for cross-sectional hypertrophy (radial muscular growth).
>Excessive muscular damage/soreness appears to diminish muscular hypertrophy due to the muscle protein synthesis response being biased towards tissue repair rather than subsequent growth (the typical goal).
>It should be noted that there are many strength/resistance training variables that certainly do lead to muscle growth while simultaneously increasing the likelihood of causing some damage/soreness (e.g., increases in muscle tension/load, increases in volume, etc.). Some occasional light-moderate soreness should still be expected from a high-quality strength program.
>As a final note, while muscular damage may not be directly connected with cross-sectional hypertrophy, it may be mechanistically connected with longitudinal hypertrophy (growth increasing muscle length). That is an entirely different topic.
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