Precor EFX manual Heart rate target zones

 After you put on the chest strap, face the display console for a minimum of 15 seconds. This allows the receiver in the console to recognize the signal from the chest strap.

 If Hr blinks in the HEART RATE display, it is detecting a signal, but has not yet determined your heart rate. Make sure the chest strap is positioned properly around your chest and against your skin.

 If you prefer to use the touch-sensitive grips, grasp both and wait five to ten seconds. Make sure both hands are moist (not dry).

 When a signal is detected, a number flashes in the HEART RATE display and indicates your heart rate.

Figure 4: Heart rate target zones

The calculation used for the heart rate target zone is: (220 minus your age) multiplied by a percent.

For example:

Warmup range: (220 minus your age) multiplied by 55%

Peak range: (220 minus your age) multiplied by 85%

User's Reference Manual: Heart Rate Features 12