Hi,
During analyzing the intervals I would like to see target power range for my workout. So It would be nice if on custom chart I can add simple straight lines (or even range) on particular HR\Power value.
If you have a planned workout on your calendar it should pair with your actual activity and you will get lines on the chart. Thats probably the easiest way to do this. Then you can have ranges or whatever you can put together in the workout builder.