When you lift weights, it's the pulling force on your muscles—not the tears or burn—that makes them grow bigger, and scientists think a specific molecular signal inside the muscle cells is behind this growth; other things like soreness or muscle burn probably don't cause the growth on their own.
Evidence from Studies
Supporting (3)
Community contributions welcome
The cochaperone BAG3 coordinates protein synthesis and autophagy under mechanical strain through spatial regulation of mTORC1.
When muscles are stretched or worked out, a protein called BAG3 helps turn on muscle growth by activating a key growth switch (mTORC1) in the right place, without needing muscle damage or burn to make it happen.
Load-induced human skeletal muscle hypertrophy: Mechanisms, myths, and misconceptions
This study says lifting weights (mechanical tension) is the main reason muscles grow, and things like muscle burn or swelling aren’t really what cause growth — which matches the claim. It doesn’t talk about the exact molecular switch, but it backs up the big idea.
This study says lifting weights (mechanical tension) is the main reason muscles grow, and it points to a specific molecular pathway (mTORC1) as the key signal — not muscle tears or burn from exercise. That matches what the claim says.
Contradicting (0)
Community contributions welcome
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.