If in the menu when you adjust the training zones of the athletes it allows you to use the option to use the reserve heart rate, which includes the maximum heart rate and the resting heart rate. However, when you are going to program a workout, it only allows you to use the maximum heart rate as a reference, which causes different values ​​of the adjusted zones (HR Reserve) I'll give you an example of this:

Athlete 41 years old Values ​​HR MAX 182 / HR Rest 46

     Zones adjusted with Maximum HR Z1 91-108 / Z2 109-126 / Z3 127-145 /         
                                                                      Z4 146-163 / Z5 163-182

     Zones adjusted with Reserve HR.    Z1 111-126 / Z2 127-141 / Z3 142-156 / Z4 
                                                                     156-169 / Z5 169-182 (Karvonen Methodology)

     In summary: Why is the reserve HR not used for training programming?