Slower lowering movements during weight training lead to greater muscle damage and higher rates of muscle protein synthesis than faster lowering movements.
Mechanism
Synthesis from 1 study
Slowing down the lowering phase of a lift stretches your muscles longer under tension, which causes tiny tears and builds up chemical byproducts. This signals your body to make more muscle protein to repair and strengthen the fibers, leading to greater growth than when lowering the weight quickly.
Most probable mechanism
When you lower a weight slowly, your muscle fibers stretch under tension for a longer time, which pulls on the muscle structure harder and builds up more waste products. This pulls apart tiny parts of the muscle fibers and signals the body to start repairing and building more muscle protein to make the fibers stronger.
Prolonged eccentric contraction increases mechanical strain on sarcomeres and the extracellular matrix, causing microtears in muscle fibers and disruption of cytoskeletal structures
Sustained muscle lengthening elevates metabolic byproduct accumulation (e.g., hydrogen ions, lactate) due to prolonged ATP demand and reduced clearance
Mechanical strain and metabolic stress activate integrin-based and intracellular signaling pathways, including mTOR and MAPK, which upregulate mRNA translation and ribosomal biogenesis
Increased signaling drives elevated rates of muscle protein synthesis, exceeding baseline degradation rates and leading to net protein accretion
Evidence from Studies
Supporting (1)
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Contradicting (0)
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