Abstract: A multifunctional situp exerciser including a reverse T-shaped inclined main frame which is adjustable in length and a front and a rear beam pivotally connected with a middle upper section of the main frame by a pivot device to form a substantially L-shaped pattern. An upper end and a middle section of the main frame are respectively connected with two transverse soft stopper arms projecting leftward and rightward. A front rest pad is fixed on top face of the front beam. A locating device is disposed at rear end of bottom face of the front beam. A relative small diameter fitting bar formed with several locating holes extends forward from the interior of the rear beam. The fitting bar is fitted in the rear section of the front beam and located by the locating device which is inserted into the locating hole. A shorter rear rest pad and three movably rotatable massage rods are pivotally disposed on top face of the rear beam.