Brace yourself in the raise station with your forearms on the pads and your back pressed lightly against the support, legs hanging straight down. Tighten your core before you move anything, so the lift comes from your abs rather than your hip flexors swinging your legs up. Raise your legs, knees bent or straight, until your thighs are at least parallel to the floor, keeping the motion slow enough that you're not using momentum from your shoulders. Lower them back down under control rather than letting them drop; that lowering phase is where most of the work actually happens.