Dr. Oz's 20-Minute Workout
Sitting on floor with your hands behind you—palms down, fingers pointing backward, and elbows slightly bent—bring your feet up two feet from your tailbone. Keep the sole of your right foot flat on the ground, cross your left leg on top of your right leg, and sit up straight. Focus on pressing your lower back toward your left calf. If you want to go deeper, slightly press your left knee away from you. Hold for 15 seconds and switch sides.