To grow your quads, biceps, and triceps best, it helps to stretch the muscle more during exercise—either by going all the way down or starting the movement early.

Working your muscles when they’re stretched out—either fully or at the start of the movement—helps them grow best in your thighs, biceps, and triceps.

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.

When guys who work out a little bit lift heavy weights (85% of their max), their triceps muscles grow faster and more reliably than when they lift light weights (30% of their max)—so how heavy you lift might change when your muscles start getting bigger.

All three types of muscle movements—squeezing, lengthening, and holding—can help build muscle in your thighs and arms just as well, as long as you train hard and often enough.

Going all the way to muscle exhaustion during one set of strength training might give you a tiny bit more muscle growth in your arms and legs than stopping two reps early — but the difference is small and not always clear.