Lie down on your back with your knees bent and stacked directly over your heels. Separate your feet and knees about three to six inches apart, and keep your knees and toes pointing slightly out.
Take a deep breathe in, and as you exhale engage your core. This is your starting position.
On your next exhale, push through your heels, squeeze your butt muscles, and lift your hips. Your knees, hips, and shoulders should make one line.
On your inhale, lower your hips and your ribcage to tap the floor. This counts as one rep.