When men who don't usually exercise start lifting weights, the angle of their muscle fibers changes by about 9% in 12 weeks. It doesn't matter if they lift heavy or light weights, or if they push...

If you're a guy who lifts weights, going all the way to failure or stopping just short gives your muscles about the same kind of growth changes over 10 weeks.

After doing 12 weeks of static strength exercises, whether your quadriceps muscle fibers change their angle doesn’t seem to affect how much stronger you get.

If new guys lift weights for 15 weeks using only part of the movement—focusing on the shorter muscle position—they build more muscle size in that specific area and get stronger at certain joint angles, according to this claim.

Doing strength exercises with your muscle bunched up for 8 weeks can make the muscle fibers angle more sharply, which might help them generate more force.

Whether you use machines that change resistance as you lift or keep the same weight all the way through, after 20 weeks of training, healthy men gain about the same strength and muscle size either way.