Abstract: Taught herein is a strengthening device adaptable for the front and back side of the thighs comprising a solid or rigid frame, a weight set, connected with a swinging arm, the free end of which is provided with an action rest, and a seat which is freely movable forward and backward with respect to the swinging arm. An exercising person sits in the seat and kicks the swinging arm forward or backward, depending on the version of operation, against the tension provide by the force of gravity on the weight set as it is being lifted upward by a cable connect to the swinging arm. The sliding seat reduces negative reaction forces on the exerciser, and obviates the need for hand grips or straps.