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.

Just stretching your muscle under light weight won’t make it grow — you need to push hard while it’s stretched out, like doing a bicep curl slowly at the bottom where it’s fully extended.

Even if you lift heavier weights with your muscles mostly bent, you don’t grow bigger muscles than if you lift lighter weights with your muscles stretched out — the stretch matters more than how heavy the weight is.

When you stretch your muscles fully during workouts, the ends of the muscles grow more than the middle parts — the stretch makes the muscle ends bulk up more than the center.

Even the middle parts of your muscles grow more when you stretch them fully during workouts — it’s not just the ends that benefit from full range of motion.

When you do strength exercises where your muscles are stretched the most (like lowering a weight fully), you build more muscle than when you only move partway through the motion, no matter which muscle you're working.