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Low HR during first 15mins of run ever since updating software to v20.32

Has the algorithm changed in software version 20.32 for recording the Heart Rate and Performance Condition during a run activity?

Ever since I updated my Forerunner 265 to software version 20.32 the other week, when I start a run activity the heart rate reading is abnormally low for about 15 mins or so.

In the following example from today you can see the steep climb of my heart rate from 113 bpm at 13:48 mins up to the correct rate of 147 bpm at 14:30 mins, that's a 34bpm increase in 42s. My pace is in the background and a fairly steady pace, no sprints or hills etc.  But waiting 15 mins or so into the run to determine what heart rate zone I'm in is too late. 

It even takes about 5mins to climb above 100 bpm, as much as I'd like to think my fitness has improved significantly recently, sadly that's not the case.

It must be stated that the watch is very responsive to my heart rate outside a run activity, i.e. if sitting down resting then I get up to walk for a brief period it will climb accordingly and promptly. So the heart rate sensor itself must be functioning correctly.

Ultimately this issue causes the Heart rate zones to be incorrect, abnormally low, its recording too much time in zone 1 and 2.

Given the time of year I don't believe the issue is temperature related. Today was fairly warm 10.6°C and was slow to record my increase in heart rate, yet I have a few runs before i updated the watch software from a few weeks ago down at 2.2°C - 3.3°C that were happily tracking my heart rate correctly.

I have also noticed that the Performance Condition metric has changed too.  It used to always pop up on my watch at 06:00 sharply into a run, now its been popping up at various times between 12:20 and 25:45 mins.

Anyone else experience this?

  • To be honest, i had this similar experience but during all the activity. I found a workaround (that i mentionned in an other post to the developper). For avoiding this problem, i broadcast the Heart Rate. I don't use the heart rate broadcasted, i juste broadcast it. Following that, the heart rate is accurate all along the activity.

  • install the beta 21.19 looks like its solved

  • Thank you for sharing. Since sw version 21.19 is available, please update and test out a few more activities. If you still see HR inaccuracies, please create a new thread!