Abstract: An exercise device primarily for performing the so-called sit-up exercise is provided with a pivotably adjustable back-rest and a longitudinally adjustable hip-rest. The combined adjustability of the back- and hip-rests gives proper support to the back of a user during exercise and minimize the risk of back injuries notwithstanding that the spine sizes of different individuals depend on their physical particulars.

Abstract: A sit-up exercise belt adapted to be placed under and around a corner of a mattress in such a way that a person can perform sit-up exercise by hooking and restraining the feet under the belt during exercise. The sit-up belt comprises a length adjustable belt being connected at both ends to a trapezoid belt support member which is adapted to be placed under the corner of the bed. A bar member is removably and slidably connected to the belt to further support the feet during sit-up exercise.