Why you should do it: This Pilates exercise requires you to use your abdominal muscles, not momentum, to initiate and control the rolling motion. Bonus: It can also help massage a sore lower back.
How to do it: Sit up tall on your sit bones and bending one knee, then the other, lift your feet and put your arms inside your legs. Wrap your hands under your ankles and grasp the outside. The knees are just outside the shoulders, not too far apart, and the feet are together.
Initiating the movement with your lower abs, roll back onto your shoulders (not your neck) and then back up to sitting without ever letting go of your feet or putting them down on the floor. At the top, clap your feet together three times.