An exercise system (10) for exercising at least one limb, such as the legs, of a subject with spinal cord injury or deficiency. The system (10) comprises an exercise bicycle (20) having a crank (17) and pedals (16) to which the feet of the subject can be mounted, and a functional electrical stimulation (FES) system (30). The FES system (30) stimulates the muscles of the legs and includes a transducer (51) mountable to at least one of the legs of the subject (12) that outputs signals representative of the position and/or movement of the leg when performing the exercise. The FES system (30) further includes a control means that receives and processes the signals output by the transducer (51) and outputs control signals to a stimulator (35) that through electrodes (53) provides electrical stimulation to the legs of the subject (12) so as to cause the legs to drive the crank (17) of the bicycle (20).