When muscle glycogen levels are much lower than normal, the biological signals that trigger muscle growth after weight training are less active.
Mechanism
Synthesis from 1 study
The claim says low energy in muscles stops them from growing after lifting weights, but one study found that even with very low energy, the signals for muscle growth still turned on normally. So the proposed mechanism doesn’t match what was actually observed.
Most probable mechanism
When muscle energy stores are very low, the cell senses this as a stress and turns on a system that slows down growth processes. This system blocks the signals that normally tell the muscle to build more protein after lifting weights, so the muscle doesn’t grow as much.
Low muscle glycogen increases intracellular AMP:ATP ratio, activating AMP-activated protein kinase (AMPK)
Activated AMPK phosphorylates and inhibits the mechanistic target of rapamycin complex 1 (mTORC1)
Inhibition of mTORC1 reduces phosphorylation of downstream targets S6K1 and 4E-BP1, suppressing ribosomal biogenesis and cap-dependent translation
Evidence from Studies
Supporting (0)
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Contradicting (1)
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Influence of preexercise muscle glycogen content on transcriptional activity of metabolic and myogenic genes in well-trained humans.
Gold Standard Evidence Needed
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