An exercise bicycle is usually a special-purpose exercise machine resembling a bicycle without true wheels, but it is also possible to adapt an ordinary bicycle for stationary exercise by placing it on bicycle rollers or a trainer. Rollers and trainers are often used by racing cyclists to warm up before racing, or to train on their own machines indoors.
Exercise bikes are used for exercise, to increase general fitness, and for training for cycle events. The exercise bike has long been used for physical therapy because of the low-impact, safe, and effective cardiovascular exercise it provides. The low-impact movement involved in operating an exercise bike does not put much stress on joints and does not involve sporadic motions that some other fitness equipment may require.