once aerobic endurance is established, I drop the HR cap except when doing easy aerobic work on Wednesday. That is because Tue/Thur are cycling+strength days and very hard. I also did HR cap during the FasCat polarized sweet spot 4 stock plan - in fact they dropped TSS target to force you to think about really being disciplined on low-intensity the day before hard full-gas vo2max intervals.
my take:
- focus on HR target after a season break (2-3 months of strength work) until aerobic endurance reestablished (for me that was 2 full months Sept/Oct 2020!)
- power targets in general
- use HR cap to really keep easy days easy during a true polarized block