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

Stationary bikes are also used for physical testing, i.e. as ergometers for measuring power. Traditionally this is done by imposing a certain level of resistance mechanically and/or measuring this. gives a good overview. Modern ergometers and even many consumer exercise bikes are fitted with electronic sensors and displays.
Ergometers, such as CEVIS (Cycle Ergometer with Vibration Isolation and Stabilization System), are used in space (e.g. in the ISS) to counter cardiovascular deconditioning in the microgravity environment.
Stationary bikes are also used for physical testing, i.e. measuring power, and exercise .