When muscles get bigger over time, it’s not because they’re just storing more water or sugar—those things don’t stick around. Instead, muscles grow mainly by adding more of the actual contractile parts that make them strong.

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Evidence from Studies

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Load-induced human skeletal muscle hypertrophy: Mechanisms, myths, and misconceptions

Narrative Review

2025 Nov 21

This study says that muscles grow bigger mainly because the actual working parts inside them (the fibers) get stronger and more numerous, not because they just fill up with water or sugar — so the idea of 'pump' growth lasting long-term is mostly a myth.

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Source Study

Load-induced human skeletal muscle hypertrophy: Mechanisms, myths, and misconceptions

Score: 1

DOI: 10.1016/j.jshs.2025.101104

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