# Setting HR Zones from 7 to 5 zone model

Hey guys and gals, so I’ve always stuck to the Strava 5 zone estimated model based on my max of 192, but then noticed that intervals.icu (which I trust a bit more from a data accuracy standpoint) has a 7 zone model and I can’t figure out how to translate this to my Strava 5 zone model. Below are two screenshots of the same ride to compare

Here is what Strava has as my 5 zones:

Here is what intervals has as my 7 zones:

My OCD question is how can I translate the 7 zones into the 5 zones and set my 5 Strava zones to mirror the intervals data as closely as possible. This is of course assuming that intervals has it right to begin with, but just figured the collective minds here would know

Well Intervals decided to use Friel zones which has been around for a long time. Not sure what Strava uses because I’ve never used it for analytics.

Go look up Friel zones and setting LTHR, and decide on that as opposed to Coggan classic zones.

I don’t know which is more correct, but I’ve got the Strava numbers etched into my brain to look at what I’m doing and say “ok this effort is not taxing me that much”. I hate to think of Strava as having much real fitness validity though, while I do value the platform from a social aspect

Wasn’t sure if there was just a method to take 7 zones and convert to 5 appropriately

Correct is in the eye of the beholder…

If I was to do this, I’d do something along the lines of the following, guided by Seiler’s three zones.

Seiler Z1 = below LT1/VT1
Seiler Z2 = the in between
Seiler Z3 = above LT2 (although for this purpose, I’d set the boundary to be a few percent above LT2 - similar to Intervals Z5)

So Intervals.icu would break down as:
Z1 and Z2 in Seiler Z1
Z3, Z4 and Z5 in Seiler Z2
Z6 and Z7 in Seiler Z3

And Strava as follows.
Z1 and Z2 in Seiler Z1
Z3 and Z4 in Seiler Z2
Z5 in Seiler Z3

And I’d adjust the boundaries of the Intervals.icu and Strava intervals to appropriately match the Seiler boundaries.

This is kinda butchering different zone philosophies - but I’d be happy enough with it to guide and track training intensities.