According to a study at the Biomechanics Lab at San Diego State University, Ab Rocker by Body by Jake is the worst ab exercise . The study measured muscle stimulation (measured with EMG) in the rectus abdominus (the long, flat muscle extending the length of the front of the abdomen) and the internal and external obliques (the long, flat muscles extending along the sides of the abdomen at an angle) while using various abs exercise equipment.The best for rectus abdominus is the bicycle maneuver, while captain's chair is best for the obliques.
