One embodiment of the apparatus for resisting motion comprises: a framework having spaced apart, first and second sides; a sun pulley fixedly mounted to the first side; a rotatably adjustable pulley mounted on the second side opposite the sun pulley; a load torque shaft fixed to the adjustable pulley; an input torque shaft positioned coaxial with the fixed sun pulley and with the load torque shaft and being rotatable relative to the fixed sun pulley; an arm having a first end fixed to the input torque shaft and a second end mounting a planetary shaft which extends transversely of the arm and parallel to an axis of the input torque shaft; a first planetary pulley fixedly mounted on the planetary shaft in alignment with the fixed sun pulley; a second planetary pulley fixedly mounted on the planetary shaft in alignment with the adjustable pulley; a first belt or chain trained over the sun pulley and the first planetary pulley; and a second belt or chain trained over the adjustable pulley and the second planetary pulley, whereby placement of a torque on the load torque shaft fixed to the adjustable pulley will place tension on one length of the first belt or chain and tension on the other length of the second belt or chain thereby to establish friction between adjacent moving parts throughout the apparatus thereby to establish resistance to rotary movement of the input torque shaft with the amount of resistance being dependent on the amount of torque placed on the load torque shaft.