An exercising bicycle is proposed, having a rear hub thereof being mounted with a spring seat, a coupling member, a spiral spring, a turning mechanism and a braking system. The spring seat is formed with a shaft for being sleeved with the coupling member. The spiral spring is placed between the coupling member and spring seat. The turning mechanism is operatably driven by body motion of a user, whereby the coupling member is urged to rotate with respect to the spring seat for twisting the spiral spring tight, and the spring seat is actuated to rotate by resilient force from releasing the twisted spiral spring. By this mode of operation as to urge the turning mechanism for making the spiral spring store kinetic energy, and then to release the stored energy for driving the bicycle to move, the user can be elicited with a large amount of whole body exercise.
An exercise device includes pedals, a belt and a hydro-kinetic brake. A user applies muscular force to the pedals and the pedal belt transfers the motion of the pedals to a flywheel shaft of the fluid brake. The pedals may be configured to accept force from a hand, foot, arm, leg and/or neck of the user. The amount of work performed by the user is derived by measuring the relative rotational speeds of two radial-blade impellers of the fluid brake. The wattage exhibited by the fluid brake during the exercise session may be recorded and associated with an identified user, whereby records of the exercise performance of an individual may be updated.
