Weighted hyperextension (on stability ball)

Position yourself face down on a stability ball with your hips resting on the ball and your feet against a wall for stability. Place your hands behind your head or cross them over your chest. Engage your core and slowly lift your upper body off the ball, extending your back until your body forms a straight line. Pause for a moment at the top, then slowly lower your upper body back down to the starting position. Repeat for the desired number of repetitions.