Somewhere in May 2025 I started using a FR970 together with a HRM600. After a while I noticed al lot of intensity minutes during easy runs. I started a post about this issue, and had a (long) conversation with Garmin Support. It was/is under the attention of Garmin. But until now there is no follow up.
I'm using the Connect app on an iPhone 16 pro.
The post I started:
https://forums.garmin.com/sports-fitness/running-multisport/f/accessories-sensors/416513/activity-minutes-off-when-running-using-hrm600 and forums.garmin.com/.../weird-intensity-minutes
In the mean time I changed from a FR970 to a Fenix 8 pro, and still have the same issue. I even had a second HRM600 as a replacement for the difficulty to remove the pod. So it can't be a hardware issue.
When running easy only in Z1, I got a of vigorous minutes. it seemed like zone 1 heartrates where added to vigorous. When I did a mixed run and run in multiple zones, the light minutes where calculated correct. But again way to much vigotous minutes, as my easy warm-up heartrates (zone 1) are added to the zone 3 heartrates. Wierd thing was that when I finnished my run and saved it, and immediately looked in the Connect app the IM's where correct, but checking again after 5 minutes, they where wrong again.
I thought I solved this by removing the HRM from the Connect app, and only had it connected to my FR. This seemed to be a work around to solve the issue. But not anymore. Looking back at my runs, the issue started again at the beginning of October while still using the FR970. But only for a short period. The HRM still wasn't connected (as far as I know) to the Connect app, and only to the FR.
Now using the Fenix I see the same Some runs are ok, but others are off.
So there still, or again, seems to be an intermittent issue with the IM's. Maybe a true-up issue?
As I see no other complaints, I'm wondering if more people have this issue
