A stationary one-wheeled cycle used as an ergometer to measure a person's work output under controlled conditions. The resistance (and therefore work output) is controlled usually by one of four main methods: varying mechanical resistance (by tightening or loosening a flywheel), electrical resistance (by changing the strength of the magnetic field through which an electrical conductor moves), air resistance (produced by fan blades displacing air as the wheel turns), or hydraulic fluid resistance. A cycle ergometer supports the upper body, keeping it relatively immobile so that the cyclist's blood pressure can be measured and blood samples taken. It also makes the cycle ergometer a good device for measuring physiological responses to a standard rate of work output (power output) in people whose weights have changed. Because much of the body weight is supported by the cycle, resistance is relatively independent of body weight (compare treadmill). Cycle ergometers are not very good at measuring peak performances in people not used to cycling because the leg muscles usually fatigue before the rest of the body.
Subjects: Sports and Exercise Medicine.