A method for exercising one or more muscles of the body wherein one or more muscle(s) are contracted to move a limb through a range of motion in opposition to an oscillating resistive force. In accordance with the method, during a muscular contraction, the direction and/or the magnitude of the resistive force changes in an oscillatory fashion. The oscillations in the magnitude and/or the direction of the resistive force include a plurality of cycles during a single repetition of muscular contraction. The waveform and frequency of the oscillations may vary during a repetition or remain constant. Embodiments of devices providing an oscillatory resistive force are presented. The embodiments provide means for enabling an exerciser to perform resistance-type exercises in accordance with the method.