Exercise apparatus

An apparatus for an exercise task includes a pneumatic arrangement, which includes a pressure source, a pneumatic controller, pneumatic transfer channels, and at least one pneumatic resistor element, which includes a pneumatic cylinder with its piston. The apparatus additionally includes a mechanical lever arm structure or another mechanical connecting structure, which is for a user's limb contact and which is at a second end connected to the pneumatic resistor element. The apparatus additionally includes a sensor structure, a calculation arrangement and a display. The sensor structure is arranged to measure at least one measurement quantity of the exercise task and, based on the measurement, the calculation arrangement is arranged to form information on the display of the apparatus, regarding the power and/or force and/or range of motion of the exercise task. In the invention, regardless of the number of pneumatic resistor elements, the sensor structure includes one pressure sensor only, and to compensate for the small number of sensors, the calculation arrangement includes a correlation-taught calculation unit, which comprises a correlation algorithm taught with a larger number of sensors than the number of sensors in the apparatus, concerning the correlation between power and/or force and/or range of motion of the exercise task and the measured information.