NOVELTY - The apparatus has a microprocessor based unit (800) e.g. personal computer, including a display. A microprocessor is arranged to alter a display in response to inputs received from each sensor. The display includes an indication that indicates whether a determined ratio is less or more than a target ratio. The microprocessor is arranged to cause the display to change relative positions of the representations of the user and the representations of the opponent dependent on the comparison of the determined and target ratios.    USE - Exercise apparatus such as stationary bicycle.    ADVANTAGE - The apparatus enables the relative position of the saddle to fit different people effectively. The bottom bracket and the handlebar are adjustable, so that the handlebar and the saddle are the same height above the floor as the handlebars and saddle of a normal bicycle. The apparatus maintains the required degree of motivation needed to complete regular exercise effectively. The target ratio is reduced, if the opponent is too far ahead, and is increased, if the opponent is too far behind, thus equalizing the progression of the representations of the user and the opponent, if the opponent reaches the limit. The apparatus provides an automatic way of selecting gears without the complexity of determining the force being applied to the pedals by the user.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a method for operating an exercise apparatus    (2) a simulation apparatus comprising a control device    (3) a method for simulating progress of a user through a course    (4) a computer-readable medium comprising a set of instructions that performs a method for operating an exercise apparatus.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a complete exercise apparatus including a bicycle, a microprocessor based unit and a display screen.    Stationary bicycle (1)    Gear selector (442)    Microprocessor unit (800)    DVD-ROM drive (803)    Display screen (900)