Abstract: An efficient, narrow profile treadmill motor drive has a thin motor, a two-stage speed reduction using an intermediate countershaft between the motor and drive roller, a dual belt drive for the drive roller which reduces bearing stress, a support base of modular character facilitating removal and repair of the motor drive as a unit, and a motor-shaft mounted flywheel whose rotational inertia is effectively multiplied by the speed reduction ratio.

Abstract: A ski-pad simulating skiing leg motion is captively supported on tracks, and has individually adjustable sliding friction with respect to the tracks. A handwheel, threaded shaft, saddle and scrissors linkage transmit manually applied adjustment force to friction pads coacting with track friction surfaces. The ski pad and friction adjustment mechanism are removable as a unit from the tracks. The user stands upon the ski pad, and in one embodiment, is coupled thereto by breakaway ski-bindings and ski-boots.

Abstract: A load is supported by three subjacent parallel tracks. A u-shaped leg structure coupled to pivots fixed to the outer tracks defines a locus of intersection between swinging arc of the u-shaped leg structure and the ground. A third leg pivots from a slider selectably disposed along the central third track, and also pivots at its bottom end to the u-shaped leg structure, defining a range of loci at the ground which position the tracks upwardly sloping, downwardly sloping or horizontal with respect to a fulcrum. The support is mounted to the tracks by captive sliders, some fixed, others slideable between captive stops.