Abstract: An exercise apparatus is provided wherein two platforms engage separate legs of the user. The platforms are controlled by a drive means which permits operation of the platforms in a plurality of modes. In one mode, the platforms move up and down together, and in a second mode, the platforms move up and down alternatingly. The apparatus may be switched between modes by activating a solenoid which allows a first element to be disengaged from a rotating shaft. Relative movement between the first element and the rotating shaft changes the operation of the exercise apparatus from the first mode to the seocnd mode.