For those of you with Garmin watches, when you set your heart rate zones, what do you leave the “based on” set to?
For cycling, I really don’t care, but for running, these different options give a pretty wide swing on what is anaerobic work and what isn’t so I’m curious what other have set.
I have mine set to %Max HR. Mainly because I am pretty familiar with my self against it. I know at below 70% I can sustain it all day. At 70-75% I can sustain it for hours with bursts when I need too. At 89-94% I can also sustain it for hours but not with too many bursts but I can recover quite quickly; and if a burst goes over 95% it’ll take me a bit longer and I’ll save them for a finishing sprint. Other people are probably more familiar with the other HR protocols so don’t take mine as a must 
I appreciate the rational. My thinking and feeling is the same as yours but all of these choices got me second guessing myself. 
There are very solid reasons to use LTHR for both running and cycling. The “LTHR vs HR Max” zone discussion is an easy web search, here is one: LTHR vs HR Max Huge differences | 80/20 Endurance
That’s a good read but seeing those differences is what made me question so much…like the OP of that article. I’ve never done the LTHR test so maybe that would help things make more sense.
Honestly, I think Garmin is just getting to my head. It’s constantly saying I don’t have enough Anaerobic work, but I can’t get to the HR they want for anaerobic and actually be functional! This is why I like power. I know those numbers. Running for me is hard no matter the HR measurement!
Just pick something and go with it, for some of the reasons in the 8020 forum I standardized on LTHR a long time ago.
Different zone systems is also another discussion topic. I’ve posted pics of cycling workouts and Coggan (loosely recommended) HR zones vs Friel zones and they look very different (both use % LTHR). Friel zones will show a zone2 ride, while Coggan zones will show a large amount of time at zone3. But I’m riding at my all day pace, so I picked Friel zones.
Thread resurrection: what did you settle on?
I’m stuck in a similar situation, %Hrmax gives me an impossibly low z2. %LTHR gives a good z2 but calls a threshold run z5.
An Apple Watch Ultra. 
I put in my best guess at max HR into Work Out Doors and everything seems to feel AND look “right”.
