This will help recruit more muscle fibers in your butt and make the exercise more effective. (ashotofadrenaline.net)
Using proper exercise performance to increase muscular contraction in your exercises activates more muscle fibers than normally possible, leading to far more muscle exhaustion. (muscleandbrawn.com)
And as a result of working out harder and longer, you stimulate more muscle fibers for greater growth. (truegritness.com)