Back Extension
Position the ball under your hips and lower torso with the knees straight or bent. With hands behind the head or behind back, slowly roll down the ball. Lift your chest off the ball, bringing your shoulders up until your body is in a straight line. Make sure your body is in alignment (i.e., head, neck, shoulders and back are in a straight line), your abs are pulled in and that don't hyperextend the back.
Ball Balance
Position the ball under your abs and hips, hands on the floor and legs straight and off the floor. Hold that position for 20 to 30 seconds, keeping your body in a straight line, abs pulled in. Keeping balance, slowly raise your right arm out to the side, taking care not to roll or allow any part of your body to collapse. Hold that for a few seconds and switch arms. This is tougher than it looks!
Butt Lift
Lie on the ball with the head, neck and shoulders supported, knees bent and body in a table-top position. Lower the hips towards the floor without rolling on the ball. Squeeze the glutes to raise hips until body is in a straight line like a bridge. Hold weights on the hips for added intensity and make sure you press through the heels and not the toes.
Hip Extension
Lie down with feet heels propped on ball. Keeping abs tight, slowly lift your hips off the floor (squeezing the glutes) until body is in a straight line. Hold for a few seconds and lower. For added intensity, lift the hips and then take one leg off the ball, hold for a moment and lower. Repeat, lifting the other leg off the ball.
Ab Roll
Place your hands on the ball in front of you, arms parallel. Pulling your belly button towards your spine and tightening your torso, slowly roll forward, rolling the ball out as far as you can without arching or straining the back. Push the elbows into the ball and squeeze the abs to pull the body back to start. Avoid this move if you have back problems.
Ball Rotation
Lie with ball under shoulders and lower back, arms straight up over chest, palms together. Hold your body in a straight line from hips to knees. Tightening your glutes and abs, slowly twist your body to the left, sweeping arms parallel to the floor, then back up, repeating on the other side. Try not to collapse the body or roll too far, but really use your abs.
Ball Twist
Get into a pushup position with the feet on either side of the ball (turning your ankles so that you are hugging the ball). Hold body in a straight line with abs pulled in, hips straight and hands directly under shoulders. Slowly twist the ball to the right while trying to keep your shoulders level, then to the left. Don't sag in the middle.