Specifications

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APPENDIX C
Appendix C
Z8/Z8m Elliptical Owner’s Guide
As you ride the Z8/Z8m Elliptical, your exercise intensity is
best measured as the amount of power received by the
elliptical 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 Z8/Z8m Elliptical 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 elliptical 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 AND
CONSTANT
TORQUE