If you're already strength-trained, doing full lifts (like fully curling a dumbbell) won't make your muscles grow more than just doing the stretchy part of the movement—so maybe stretching your muscles under load is the real secret to getting bigger.

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.

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.

If you're already experienced with lifting weights, doing exercises where your muscles are stretched out—like lowering a dumbbell all the way down or just partway—gives you about the same muscle growth as going all the way to the extreme stretch. So you don’t need to stretch your muscles to their absolute limit to get big.

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.

Even if you don’t move through the full range, doing the exercise where your muscle is stretched the most (like halfway down in a squat) builds more muscle than doing it where the muscle is bunched up (like a shallow squat).