Zone 2 Power vs Zone 2 HR (Should I increase power to move HR to Z2?)

Lets start with Coggan remarks from 2003 paper he wrote for a USA Cycling coaches seminar on power based training:

“HR guidelines: Relating or translating the specified power levels to corresponding HR ranges or zones is somewhat difficult, due to the inherent variability of HR as well as individual differences in the power-HR relationship (even when referenced to threshold power). Nonetheless, approximate HR guidelines have been provided in Table 1, such that they can be used along with power to help guide training if desired.”

And table:

And using my threshold HR as the anchor, brought me to the which zone dilemma:

  • Coggan zone2 for me is 110-134bpm
  • Friel zone2 for me is 128-142bpm

big difference.

That bothered me, so when I got into cycling back in 2016 and 2017 I figured the thing to do was go out and do a bunch of 6-12 hour rides. Then looked at average HR and called that “all day” HR, which was 136-142bpm.

Pretty clear at that point the Friel zone2 HR align with all-day HR, for me.