Heart Rate Bug, Rapid rise

That's why I bought an external HR sensor.Because I didn't want a chest strap, I bought the "Polar verity sense" sensor.An optical sensor for the upper arm, but extremely accurate and super comfortable to wear. www.dcrainmaker.com/.../polar-verity-sense-optical-hr-sensor-band-in-depth-review.html

You are not alone.

The threads below show people with the Garmin 955 who have been sporadically experiencing this problem since software version 14.13 (February 2023).

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-955-series/325155/what-is-going-on-with-the-hr-readings-since-14-13

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-955-series/347210/broken-activity-heart-rate-in-forerunner-955

The cold weather does seem to make this worse as Garmin-Sierra's information link acknowledges and some level of warmup does seem to help a bit, but not reliably. No one seems to have noticed such a problem before software version 14.13.

The good news is that Garmin-Sierra is working to document everyone's problem to hopefully drive a fix. If you have data, I hope you will consider politely helping Garmin-Sierra out if you are contacted for help (a few people in the 955 threads are understandably upset but flaming Garmin-Sierra is not helpful).

EDIT: Also Epix: https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/epix-2/349624/new-heartrate-bug---hr-spikes-to-180-for-no-reason

Also having similar problems.  Will be on a nice steady Z2 run sitting around late 130's to mid 140's and all of a sudden it will ramp up to late 160's to 170's which is threshold effort.  No change in pace, no change in breathing, but heart rate "rises" dramatically. 

I also have this problem on occasion where the displayed heart rate is alot higher than what I am actually doing.

If I turn the heart rate sensor off.and back on, it is dually around 20beats lower than it was showing before.

Today, the example given above, was a 55 degree day and I was wearing the 965 with a snug nylon strap.  Wearing a T-shirt (no interfering fabrics)

So, after my last message I took a couple of weeks to gather some data and see if the problem would solve itself.

Long story short: it didn't. It even got worse.

First I tried to restart the garmin before every run. Not ideal, but it seemed to help. Some spikes, but it always corrected itself. 

The last week it got way worse. And especially when I give the Garmin multiple orders. So for example today I did a interval training (order 1) along a pre-made route (order 2). It was meant to be an easy run Z1 Z2 HR wise (I'm an experienced runner with a max HR OF 200). The first 2 k was okay with a HR around 135 (z1) but then the freak show started. On a downhill it went up to 185. Then it spiked on a climb after that to 189. It corrected itself to 150. But then went into the 160 en 170 (z3) while I was running flat on a Z1 pace. It spiked again on several occasions into the 180's.

Until I stopped to do my strides. I've never seen a heart rate going down so fast. From 180 to 105 in 5 seconds. As I was dying. After that it was okay again.

But come on Garmin. We can't train like this. As an athlete I rely on these data. I train in my heart rate zones and I want to see if my feeling while running matches the data afterwards.

What is the current situation? Is this about to be fixed? Can we reset the update? Because this is quite a *** show to be fair. 

I'll try to upload some of the graphs

So, after my last message I took a couple of weeks to gather some data and see if the problem would solve itself.

Long story short: it didn't. It even got worse.

First I tried to restart the garmin before every run. Not ideal, but it seemed to help. Some spikes, but it always corrected itself. 

The last week it got way worse. And especially when I give the Garmin multiple orders. So for example today I did a interval training (order 1) along a pre-made route (order 2). It was meant to be an easy run Z1 Z2 HR wise (I'm an experienced runner with a max HR OF 200). The first 2 k was okay with a HR around 135 (z1) but then the freak show started. On a downhill it went up to 185. Then it spiked on a climb after that to 189. It corrected itself to 150. But then went into the 160 en 170 (z3) while I was running flat on a Z1 pace. It spiked again on several occasions into the 180's.

Until I stopped to do my strides. I've never seen a heart rate going down so fast. From 180 to 105 in 5 seconds. As I was dying. After that it was okay again.

But come on Garmin. We can't train like this. As an athlete I rely on these data. I train in my heart rate zones and I want to see if my feeling while running matches the data afterwards.

What is the current situation? Is this about to be fixed? Can we reset the update? Because this is quite a *** show to be fair. 

I'll try to upload some of the graphs

One more

And another one