1. Wall squat
Stand with your feet shoulder width apart and your toes pointed out. Place the ball between the wall and the middle of your back. Bend your knees slightly as you roll your body down the ball into a squat. Stop when your thighs are parallel to the floor, press through your heels and return to the starting position.
Start in a plank position on the ball with your feet planted firmly, supporting your weight with your forearms and chest. Keeping your head up, lift your body off the ball. Focus on keeping your back flat and your abs tight, and hold for as long as possible. (Here are some more harder-working plank variations.)
Sit on the ball with your feet on the floor and your knees bent. Walk yourself forward so that your feet are in front of your body and your back is leaning on the ball. With your hands behind your head and your feet planted firmly on the ground, bring your upper body off the ball. Keep your abs engaged as you go through the motion.
Start in an upright position with your ball two or three feet behind you. Keeping your balance, place your back foot on top of the ball. Bend your front leg at a 90-degree angle while rolling the ball away from you with your left foot. Pull your leg back into the starting position, and repeat with the other leg.
Start with your chest on the ball, your feet planted firmly on the ground and your hands placed beside your chest on top of the ball. Keeping your core engaged, straighten your arms and push off the ball. Hold at the top and repeat, focusing on keeping your back straight.
Other than using a stability ball, next learn how to use your stairs for an effective, full-body workout.