Doing partial-range weight exercises with a longer muscle stretch can build arm and thigh muscles just as well as doing full-range exercises, as long as you’ve been training for a while and do it for 12 weeks.

Lifting weights through a shorter movement range can build muscle just as well as lifting through a full movement range — no difference in muscle growth.

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 strength-trained and do upper-body workouts for 8 weeks, it doesn't matter much if you lift all the way up and down or just do part of the motion—your muscles grow and get stronger about the same either way.

Doing partial reps with extended muscle stretch and full reps with normal movement build your arm and thigh muscles about the same amount over 12 weeks — neither one is clearly better than the other.

If you're already someone who lifts weights, doing either static holds with your muscles stretched out or full-range weight exercises won't make the outer part of your thigh noticeably bigger in just six weeks.