Appendix C

As you ride the CS 8.0 Bike, your exercise intensity is best measured as the amount of power received by the bike from your pedaling. This power is usually expressed in watts. The watts measurement is calculated from your pedaling speed (called cadence) multiplied by the amount of resistance on the pedals (called torque). (See Feynman, Lectures on Physics, 1971.)

In most cases it is desirable to keep the exercise intensity constant, no matter what the pedal cadence, since it allows accurate control of the rider’s workout. This kind of workload control is called constant power. If you pedal faster, the resistance on the pedals (torque) is reduced by the same amount. If you pedal slower, the resistance is increased.

If, instead, the amount of resistance on the pedals stays the same when your cadence changes, your workload intensity will vary directly with your cadence. If you pedal twice as fast, your exercise intensity doubles. This kind of workload control is called constant torque.

Constant power is used by the CS 8.0 Bike in most cases, in order to provide the most accurate workload control. This is especially important in heart rate control workouts and the Calorie Goal program.

A negative side-effect of constant power is that at very low cadences, such as below 55 rpm, the amount of extra torque applied to the pedals to keep power constant is so great that the rider may not be able to keep the pedals moving. To reduce this problem, the bike changes to constant torque at cadences below 55 rpm, preventing any further increases in torque. The computer will also warn you that it is no longer able to control exercise intensity.

98CS 8.0 Owner’s Guide

Constant

Power &

Constant

Torque

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True Fitness CS8 manual Appendix C