Fit-ball Split Squat and Twist
Step 1 Stand tall with a gym ball above your head. Place one foot about 3 feet behind the other, at hip width, parallel to each other.
Step 2 Squat down, keeping your body totally upright and weight even between your front and back foot.
Step 3 As you hit the bottom, twist and touch the gym ball to the floor, on the side of your front foot. Repeat.