Abstract: A unitary exercise device provides exercise of the upper and lower abdominal muscles and the lower back muscles over the full range of motion of the muscles. It is lightweight and portable and is used without any other equipment or devices. The exercise device is rectangular in shape with two end sections having inclined surfaces. The angle of the inclined surfaces determines the amount of strength required to perform the exercises as the exerciser lies on the device. Therefore, the device can accommodate individuals with stronger or weaker muscles by changing the angle of the inclined surfaces of the end sections of the device.