Lie on your back on the mat with your knees bent and your feet off the floor, heels close to your glutes. Holding a dumbbell in each hand, place your arms on the floor and bend your elbows so that your wrists are over your elbows. Use this position to anchor your upper body.
Keeping your arms and upper back on the floor, slowly rotate your lower body and bring your knees toward the floor. Engage your abs even more and pull your knees back up to the starting position. Lower your knees to the other side.