When trained people lift weights using either a partial range of motion at long muscle lengths or a full range of motion, and both methods use the same total workload and effort, the amount of muscle...
Mechanism
Synthesis from 5 studies
Muscle grows when it's stretched under load, because the tension triggers a signal that tells the muscle to build more protein. This happens whether you move through a full or partial range, as long as the muscle stays stretched during the lift. The growth is the same because the key stimulus—the...
Most probable mechanism
When a muscle is stretched under load, the fibers and surrounding structures experience high tension, which triggers a molecular signal that tells the muscle to build more contractile proteins, leading to growth. This happens whether the movement is full or partial, as long as the muscle stays stretched during the lift.
Resistance training with partial range of motion at long muscle lengths maintains sustained mechanical tension on muscle fibers during both concentric and eccentric phases.
Prolonged mechanical tension increases strain on sarcomeres and extracellular matrix, activating integrin-linked and cytoskeletal mechanotransduction pathways.
Mechanotransduction signals converge on the mTORC1 pathway, upregulating ribosomal biogenesis and translation initiation machinery.
Increased mTORC1 activity elevates muscle protein synthesis rates, leading to net accretion of actin and myosin filaments.
Accretion of contractile proteins increases muscle fiber cross-sectional area, measurable as hypertrophy at multiple longitudinal regions, with greater effect distally where stretch is maximized.
Less supported by current evidence, but not ruled out
When a muscle is stretched under load, the region closest to the tendon experiences higher strain, which triggers more local protein buildup in that area, leading to uneven growth along the muscle.
Sustained stretch during partial range of motion maximizes strain gradients in distal muscle regions near tendon insertions.
High strain in distal regions activates satellite cells and increases myonuclear accretion locally.
Localized protein synthesis and sarcomere addition increase cross-sectional area specifically in distal muscle fascicles.
Evidence from Studies
Supporting (4)
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Contradicting (1)
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Full Squats Enhance Performance and Body Composition, but Not Hypertrophy, Compared to Half Squats in Elite Young Tennis Players
Gold Standard Evidence Needed
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