Set-up: Begin by sitting on a mat with knees bent at 90 degrees and your torso at 45 degrees from the floor holding a medicine ball at your chest. The exercise can be made more challenging by increasing the distance of the medicine ball from your torso, or made easier by bringing your hands closer.
Lift: Rotating through the middle and upper back, turn your body 45 degrees to the side, return to the center and repeat in the other direction.
Emphasis: Keep the torso at the same angle to the floor throughout the movement. Do not use momentum or swing through the exercise. Use minimal rotation in the lower back.
Repetitions: Once rotation to both the left and right sides is complete, this counts as one repetition.
