This move looks simple enough, but you'll really feel it in your legs, butt, and core.
Stand with your feet hip-width distance apart, and place your hands at the back of your head with your elbows opened wide.
Pull your abs to your spine, and keep your back neutral while pressing your butt backward, hinging at the hips, until your back is almost parallel to the floor. Keep a slight bend in your knees as you bend forward.
Return to standing, squeezing your glutes when you are upright. This completes one rep.