Sit on a fitball and place the entire soles of your feet on the floor. Place your left hand on your left hip and lift your right arm just above your head.
Slowly bend your body from your waist to your left side until you feel the stretch in your oblique muscles. Exhale during the movement. Maintain the stretch during the required time and then do it with the other side.TIPS: You should feel the stretch of the muscles but not pain.