HOW: Begin lying flat on your back with something under your heels to allow your feet to slide back and forth. Start the exercise by digging your heels into the ground and sliding your feet towards your butt. Bend your knees as far as you can, then bridge your hips up and off the ground, hold for a moment, lower down, straighten your knees, then repeat.
FEEL: You should feel your hamstrings and glute muscles working with this exercise.
COMPENSATION: Do not arch your back with the bridge, do not allow your knees to straighten as you bridge.