An exercising machine which consists essentially of a main frame, a handrail, a tread roller and two fluid pressure cylinders, wherein the main frame is designed to support and install all members concerned, the handrail may be fixed or adjustable in favor of being adjusted up and down so as to fit the height of different exercisers. The tread roller is a cylindrical roller body whereon two-pair of steps are positioned in an upward and downward position in the center of a roller body, separated from each other by an angle of 90.degree.. The roller body is pivotally installed, roughly, in the center of the main frame capable of rotation clockwise and counterclockwise. One crank coupling each is fixed on the two ends of roller body; the two fluid pressure cylinders are equipped with a bilateral resistance action and respectively and pivotally installed in a position nearby the front, on the side of the main frame. The end of thrust rod on these cylinders is respectively connected to and pivotally installed on the crank coupling, on the two sides of tread roller. The positions of pivotal installation have to be separated from each other with a 90.degree. to 135.degree. angle.

The present invention relates to a low-impact, time-efficient way to exercise both the cardio-respiratory system and the muscular system, particularly the abdominal and back muscles. The exerciser uses his muscles to oscillate a pivoted carriage within a frame. In one embodiment, the exerciser pedals a crank to pump hydraulic fluid through a hydraulic circuit to a hydraulic cylinder connected between the carriage and the frame so as to urge the carriage to oscillate with respect to the frame. A limit sensor detects when the carriage is positioned at one extreme of its oscillation and signals the hydraulic circuit to reverse the flow of hydraulic fluid to the hydraulic cylinder.

Weight lifting simulator apparatus includes a primary pneumatic cylinder providing the principal resistance for simulating weight lifting exercise with at least one secondary cylinder in free fluid interconnection with the primary cylinder whereby constant and balanced loading is achieved, with provisions for dynamic simulation of weight inertia effect, and control thereof, as in lifting a real weight. The primary and the secondary cylinders are associated with a guideway, the primary cylinder being fixed to the guideway and the secondary cylinder being slidable relative to the guideway and pivotable relative to the piston rod of the primary cylinder. Variation of the securement position of the primary cylinder on the guideway is available and valving is provided in the fluid interconnection.

A stationary bicycle trainer includes a stand for supporting the rear of a conventional chain-drive bicycle in a normal riding position, and a chain-drive resistance device which is especially configured to be received at the rear drop outs of the bicycle between the chain stays and the seat stays of the bicycle frame in substitution for the rear drive wheel and tire assembly.