The obliques are the muscles found on the sides of your ribcage. They get called into play when you make rotational or lateral movements with your torso. To add a variation with obliques exercises, you can use a medicine ball. This is a tool made of hard rubber, leather or vinyl and it can be tossed, held or swung for resistance.
Stand with your back to a wall, the ball held outside of your right hip and your feet shoulder-width apart. You should be approximately 4 feet in front of the wall. In a fast motion, rotate your torso to your left and throw the ball behind you into the wall at shoulder height. After catching the ball off the rebound, rotate back to the starting point and repeat. Once you've completed 12 to 15 repetitions, switch sides. When you throw the ball behind you, pivot your feet.
Russian twists can be done from a standing or seated position. Sit on the floor with your knees bent, feet flat and your back angled 45 degrees to the floor. The ball should rest on the floor just outside of your left hip at this point. In a steady motion, lift the ball and rotate your torso toward your right side, touching the ball to the floor outside your hip. Quickly reverse the direction and continue to go back and forth for 12 to 15 repetitions.
Diagonal chops work your obliques with the addition of a stability ball. Sit on the stability ball with your knees bent, feet flat on the floor and the medicine ball held above your right shoulder with your arms extended. In a chopping motion, swing the ball at a downward angle across your body until it is outside your left shin. Slowly lift the ball back to the start and repeat. After doing 12 to 15 reps, switch sides.
Place your left hip on a stability ball, your feet in a staggered position against a wall and hold the medicine ball straight above your head with your arms extended. Slowly lower yourself laterally over the ball and lift yourself up by contracting your obliques. After holding for a second, lower and repeat. Once you've done 12 to 15 reps, switch sides.
Rollovers work your obliques and lower back muscles. Lie on your back with your legs lifted, knees bent 90 degrees and shins parallel to the floor. After pinching the ball between your knees, alternate lowering your legs down to the floor on your right and left side. When doing this, go in a steady and controlled motion. Perform 12 to 15 repetitions.