Young Blonde Girl Reveals Her White Top And Short Jeans On The Stationary Exercise Bicycle

The ancestors of modern stationary bicycles date back to the end of the eighteenth century. The Gymnasticon was an early example.
Types
Some models feature handlebars that are connected to the pedals so that the upper body can be exercised along with the lower body. Most exercise bikes provide a mechanism for applying resistance to the pedals which increases the intensity of the exercise. Resistance mechanisms include magnets, fans, and friction mechanisms. Some models allow the user to pedal backwards to exercise antagonist muscles which are not exercised in forward pedaling. Exercise bicycles are typically manufactured using a crankshaft and bottom bracket, which turns a flywheel by means of a belt or chain. The bearings on these moving parts become worn with use and may require replacement.