... abdominal core system. Sit & Get Fit with the new Rock Fit -- the breakthrough abdominal core system. Featuring exercises inspired ... -shaping moves found in dance, you can rock, tilt, and rotate your abs firm and shapely on Rockfit.This easy-to-do, ... and add club quality power piston resistance and you have an ab-blasting, core shaping infinity movement that is simple, fun, and effective. Rock ...