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If you prefer to fine-tune or program your own limits, this can also be done in the HR Setting Mode (see page 43). The internal automatic TZ calculation is based on the following example: 84 TARGET ZONE CALCULATION FORMULA 207 - Your age x 0.7 = max HR For a 30 year old person, your calculations would be as follows: 207 - 30 x 0.7 = 186 Maximum Heart Rate 65% of this number = 121 85% of this number = 158 TARGET ZONE CALCULATION FORMULA 207 - Your age x 0.7 = max HR For a 30 year old person, your