True Manufacturing Company ES9.0 - Manual (Page 84)

ES9.0 Recumbent Bike Owner’s Guide
84
Appendix C
As you ride the ES9.0 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 ES9.0 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.
Constant
Power &
Constant
Torque