Editing Openai/691758fe-9cf4-8009-9395-a2bf64f4b5c9 (section)

=== Assistant: Yeah, this happens a lot. ===
Yeah, this happens a lot. Strava and Garmin don’t use the same zone system by default, so the numbers won’t match unless you manually sync them.

Here’s the quick breakdown:

===== 1. Different max HR / threshold HR =====
* Garmin uses your LTHR (lactate threshold HR) if you’ve set it or if the device estimated it from rides.
* Strava uses percentage of max HR unless you go in and change it.

So even if both apps show “Zone 2,” they’re talking about totally different boundaries.
# Different zone definitions
* Garmin uses 5 zones based on your chosen method: LTHR, max HR, or percent threshold.
* Strava’s default zones are based on percent max HR and are more generous at the low end.

This usually results in Strava pushing more of your time into Zone 2, while Garmin pushes you into Zone 3.

===== You need to make both apps use the same numbers. =====

====== Check what zones your Edge 840 is using: ======
* Garmin Connect → More → User Settings → Heart Rate Zones
* Look at the method (LTHR vs Max HR)
* Look at the actual bpm boundaries for Z1–Z5

====== - Strava app → You → Training → Heart Rate → Heart Rate Zones ======
* Switch to Custom zones
* Enter the exact same bpm boundaries from Garmin.

===== Both will match almost perfectly. =====

===== Strava thinks your Zone 2 goes up to something like 140–150 bpm based on max HR. =====
Garmin (using LTHR) might put Zone 3 starting at something like 135–140 bpm.

So the same HR number falls into:
* Strava: Zone 2
* Garmin: Zone 3

Which is exactly what you’re seeing.

If you want, tell me:
* your Garmin HR zone boundaries
* your Strava zone boundaries (screenshot works)

I’ll tell you exactly where the mismatch is.