Abstract: An exerciser includes a shaft rotatably disposed on a base, a housing rotatably engaged on the shaft and having a chamber formed by an outer peripheral wall which has a groove, a belt wound around the tube for rotating the housing, a barrel received in the chamber of the housing and secured to the shaft and having a slot. A coil spring is received in the housing and has two ends engaged into the slot of the barrel and the groove of the outer peripheral wall of the housing. A cover includes a space formed by an outer peripheral fence, to suitably enclose the chamber of the housing.

Abstract: An exerciser includes a shaft rotatably disposed on a base, a housing rotatably engaged on the shaft and having a chamber formed by an outer peripheral wall which has a groove, a belt wound around the tube for rotating the housing, a barrel received in the chamber of the housing and secured to the shaft and having a slot. A coil spring is received in the housing and has two ends engaged into the slot of the barrel and the groove of the outer peripheral wall of the housing. A cover includes a space formed by an outer peripheral fence, to suitably enclose the chamber of the housing.

Abstract: An exerciser includes a wheel and a housing rotatably engaged on a shaft, a unidirectional bearing disposed between the wheel and the housing for allowing the wheel to be rotated in an active direction by the housing and to be prevented from rotating in a reverse direction by the housing. A strap may be used to rotate the housing in the active direction. A spring may bias the housing to rotate in the reverse direction, and will not bias the wheel when the spring biases the housing to rotate backward in the reverse direction, such that the spring will not be damaged by the wheel.

Abstract: An exerciser includes a wheel and a housing rotatably engaged on a shaft, a unidirectional bearing disposed between the wheel and the housing for allowing the wheel to be rotated in an active direction by the housing and to be prevented from rotating in a reverse direction by the housing. A strap may be used to rotate the housing in the active direction. A spring may bias the housing to rotate in the reverse direction, and will not bias the wheel when the spring biases the housing to rotate backward in the reverse direction, such that the spring will not be damaged by the wheel.

Abstract: A magnetic load applying device includes a plate secured on a spindle, and a rotating disc rotatably secured on the spindle and having a peripheral fence engaged on the plate. One or more arms each supports one or more magnets and each has one end rotatably secured to the plate for moving the magnets toward and away from the peripheral fence of the rotating disc and for adjusting the brake torque of the magnets applied onto the rotating disc. One or more springs may bias the arms and the magnets toward the peripheral fence of the rotating disc.