When you do exercises that stretch your muscles more through a bigger movement—like doing full squats instead of tiny half-squats—you may build more muscle tissue than when you stay in a shorter, more restricted movement range.

When you do strength training with your muscles stretched out (like in a full squat versus a half squat), you tend to build more muscle. But this works better for people who are new to training than for people who already lift weights regularly. Scientists may have originally overstated how big this difference really is because studies showing bigger effects get published more often than studies showing smaller effects.

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.

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).

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.