Combining HR Z1+2+3

Hi all,

I know it is possible to choose HR Z1+Z2 to be plotted in a graph.
But I would like to add Z3 to that (so combine HR Z1+Z2+Z3).
Anyone any clue how to do that?
Thanks!

Gr Johan B

It is possible to do things like that using custom activity fields. But I just added “HR1+2+3” to make it easier:

Many thanks David!
I will look into the custom activity fields also.

Gr. Johan