Heart rate values from optical HRM still totally wrong with 20.26

notice that OHR will also fail when lifting weight because of TENSING MUSCLES

So after 10-15 minutes it changes how exactly? And why it was not the case with 18.xx firmware? )

I am not OP but I tried to answer the answer about why cycling might have some problems with OHR. I am runner and my OHR works perfectly :)

Well I am the Threadstarter and no, I doubt it has something to do with tensness of the muscles.
Here you can see another example, where I had to wait some time to cross a street later during the bike ride, my pulse dropped (shown correctly) and then when I continued the ride again pulse stays flat and suddenly jumps up.

Garmin-Sierra  Please have a look at this, the error persists.

By the way, some days ago we had a company run and a colleague has a FR 165 that she uses with "just" OHR and no strap. And guess what?
Same error, too low at the start, then suddenly jumping 40 beats up.

With running.

It is an error in the combination of OHR "Garmin Elevate V4" in combination with the firmware.

I think there's some confusion here. You seem to be missing half the context and are suggesting that it's either a faulty unit, or that OP is using it for an activity that might cause issues via muscle tensing. I'm not saying that a moving watch won't be a problem (it probably will), but that's not what's been going on here.

For context:

This is a long standing problem and there have been past posts on this forum about this before. Garmin have acknowledged this issue, and have also reached out to many users directly (myself included) to access our tracks (those exhibiting this problem). They were aware of it going back to 18.22 and it most definitely impacted runners. So much so that I'm betting a load of people have moved over to chest/electrode monitors (which, tbh, they should be using anyway for better accuracy, but that's another discussion entirely).

See https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-955-series/362273/heart-rate-values-totally-wrong-after-update-18-22 which I believe is the original report (and note there is no resolution there).

This post is just a bump post, basically saying "This is still an issue". I agree with Grumpy here. To my knowledge, it's an issue that is still unresolved.

I see a pattern – when you start cycling, you are full of energy and pedal intensively while standing on the bike, leaning your hands on the handlebars, gripping tightly. After 2 minutes, you sit down on the saddle. When you reach the street and have to wait a moment, you stand in anticipation, and your heart rate drops. When you can cross the street, you pedal standing again, pressing your hands firmly on the handlebars and tightening your muscles. I don’t know if that’s exactly what happened, I’m just guessing. Maybe you should analyze what you were doing when the heart rate readings were abnormal – this is just a theory and assumptions.

Yes, you're right. There’s a lot of confusion on this forum. The confusion is caused by every person reporting an issue, expecting help but not providing all the facts. Every error report should include as many details as possible about the issue. I suggest the following, and this is not a complete list:

• software version
• training temperature
• training weather description
• a link to Connect where the discussed training is located
• a detailed description of what you were doing at the moment the issue occurred
• If you are using custom Data Screens, provide the names of those you used during the training in question
• What accessories connected to the watch were used during the training
• What type of watch strap you are using
• How tightly do you wear the watch on your wrist
• How long before the training did you clean your watch

The list is incomplete, but practically everything can affect how the sensor behaves, such as rain getting under the watch, dirt, an improperly worn watch, sweat, temperature, or even buggy software in the data fields.

As mentioned before, the OHR has issues with multiple sport activities, including cycling and running.

Almost every running activity of my has a 40-50 bpm difference the first 15-20 minutes. It's an issue with the watch / firmware, not how you're cycling....

can you share link to your garmin connect profile? I want to see your activities

Jake_Grabowski said:

when you start cycling, you are full of energy and pedal intensively while standing on the bike, leaning your hands on the handlebars, gripping tightly. After 2 minutes, you sit down on the saddle. When you reach the street and have to wait a moment, you stand in anticipation, and your heart rate drops. When you can cross the street, you pedal standing again, pressing your hands firmly on the handlebars and tightening your muscles.

That is NOT what has happened.
Stop speculating about that stupid muscle tensness.

Jake_Grabowski said:

I don’t know if that’s exactly what happened, I’m just guessing

Yes, exactly. You are guessing wrong.
Please stop that.

Jake_Grabowski said:

I suggest the following, and this is not a complete list:

Well, who are you, the forum police?
Or are you just trying to kid us?
Anyway, stop it, please.

Jake_Grabowski said:

can you share link to your garmin connect profile? I want to see your activities

That will never happen, please leave this discussion, thank you.
And when somebody from Garmin officials wants information, they can collect it.

Back to topic, today I had the biggest jump ever Garmin-Sierra, 70 beats!!

I did nothing special.

Jake_Grabowski: NO, I was not standing in the pedals for 12 minutes and tensing my muscles while desperately grabbing the handlebars. Just don't ask.

Garmin-Sierra: This was the second ride today, back home and again the "usual" error of >40 beats up after some time: