Thumbs Up Ab-Twister
Sit on the floor with your legs in front, knees bent and close together. Hold one or both tubes securely in both hands in the thumbs up position. Create tension on the tubes and lean back slightly. Lift your chest so your torso and legs form a V shape, bracing your abdominal wall to engage your core. Flutter the tubes horizontally and rhythmically so they follow each other side-to-side. The Ab Twister method is total engagement of the rectus abdominis, and oblique system.