Human power vehicles, such as bicycles, are often used for purposes where it would be very desirable for a rider or other interested party to know the amount of physical quantities such as force exerted by the rider, and work (or energy) input into the vehicle by the rider, and time rate of energy input (power). Stationary devices for these measurements are common in laboratories, gymnasiums and health spas. However, there may be a preference for exercising on a moving vehicle, e.g., a track cyclist who wishes to study cycling or a cycling enthusiast who is bored on a stationary machine.
Accurate measurement of these physical quantities would allow objective evaluation and therefore, control of performance. Such a device will help high performance riders and researchers to instantly read and record performance objectively in the desired environment. At the other end of the scale, the casual exercise rider can see how much effort (calories) has been expended and note improvement in his or her performance for psychological motivation and individualized controlled training.