The Claim
Does training with muscles at longer lengths make them grow bigger?
What the research says
Roughly balanced
Support and challenge are close. The picture may shift as more studies come in.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Lifting weights when your muscles are stretched out more (like at the bottom of a squat or a full bicep curl) tends to make them grow bigger than lifting with your muscles mostly shortened, as long as there's still resistance pushing back when they're stretched.
See the scientific wording
Training resistance exercises that impose relevant external torque at longer muscle lengths is associated with greater muscle hypertrophy compared to exercises performed at shorter muscle lengths, particularly in muscles like the quadriceps, hamstrings, and gastrocnemius, because mechanical tension and passive tension from titin are amplified in lengthened positions.
What the research says
1 studyStudy: The interplay between muscle length, range of motion, and exercise selection: a review
This study says that lifting weights when your muscles are stretched out more (like at the bottom of a squat or deep lunge) makes them grow bigger—especially if the weight feels heavy in that stretched position—and that’s exactly what the claim says too.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.