18.20/19.18 HR bug still here

Here is another example, it's ridiculuous how bad the WHR works now. 

Structured training, the watch first crashed after 5 min, then I restarted.

Then, as usual, the first 10 minutes it was lagging for 7-8 minutes and all of a sudden it jumpt to the correct heart rate. That happens now every time consistently. When doing the intervals it messed up at least 6 out of 12 intervals. One interval is about 3 minutes, for at least 4 of them it only caught up with the real heart rate after I had slown down after the interval. 2 or 3 times it just caught up after 1-2 minutes. 

Comparing this to an interval session last August (2023!) (although less and slightly longer intervals 600m vs 800m), the software back then did just a great job and only lagged a little in the first interval and nailed ALL the others.

No it wasn't extra cold or warm, no I wear the watch as I am supposed to. I am not going to buy a chest strap, as the watch used to work perfectly fine for me.

Do you guys ever plan on fixing this or do we need to wait until running season is over? Just exchange latest HR software with the one from last Summer. Can't be too hard.

The only metric reliable seems to be GPS as of now.

Garmin-Sierra you wanted examples, you got them. Any updates, when we can expect a fix here? The beta forum also seems deactivated or dead?

I know this doesn't help anyone who has issues with heart sensor accuracy, but for me it's a whole different experience. The similarity with my Polar H10 heart rate monitor and the watch is more than acceptable. Here are 2 examples, one with short high intensity intervals and another is a 10k at 5.42km pace.

Well, proper axis scaling would probably reveal a different picture here: looking at the first plot I see a difference of what looks like 15-20bpm for several minutes (!) before the intervals start, and WHR lagging behind at the beginning of each interval by roughly 10-30s. This definitely is not acceptable, even more so considering that this extreme lag (I reported it for other activities elsewhere) was introduced with one of the more recent firmware versions.

it's always interesting to see that the WHR makes this kind of error in many cases up to minute 10 and then adaptes way better. I can observe similar issues here. If there is a learning courve for this device, why does it has to learn the same over and over again with every training? It proves itself that is able to do a usable measurement after 10 minutes - why not from the beginning?

I very rarely have differences between the wrist HR and strap HR, even in the beginning. Of course it might come down to differences in physiology, but I thought to mention that I usually stand still for a minute or so after selecting the activity but before pressing the final start. I mainly do it to let the GPS settle, but I started to wonder if that would also allow the wrist HR to lock on better after going int high-power-mode for the activity?

Here's an example of what I typically get:

I would imagine blood pressure may play a role here, but IMHO that would not explain the lag in WHR response further into the activity.

A lag of maybe ~5-10 s may be inevitable when the HR changes rapidly. A HR strap has it easy because it's quite easy to accurately measure exact timings of electrical signals produced by the heart muscle. But wrist HR has to do with more subtle and slower changes in capillary blood pressure. So where strap HR can mostly just detect and count signals (and get HRV from the time differences between consequtive signals), optical HR has to have a "guess" of the current HR, and then gradually change that guess when the sine-wave-like color changes on the skin do not correspond exactly to the estimate. That requires a time window to analyze, and that causes delay.

But that's not to say that a 30 second delay would be acceptable, that's clearly a failure for the wrist HR to latch onto the real HR.

Exactly, a couple of seconds would be "natural" due to the measurement principle, but 30s or more are a different thing. And as reported elsewhere, this also occurs during cycling or on an elliptical (fixed handlebar), where there is hardly any hand/arm movement that would superpose the blood pressure signal.

This is from a on-water rowing workout yesterday. HRM was a (optical) polar verity sense wearn on the same arm (past comparisons with my H10 showed that the verity sense gives accurate data from the beginning). I always select the activity before i sit down in the boat, so there are several minutes for the system to settle down. The first two minutes after pressing start i was just sitting in the boat doing nothing, but the HR was still completely wrong. It took another 6 minutes after i started rowing for the watch to get the data right.



But nethertheless there are at least two more huge and obvious wrong "glitches" during the activity.

I know that rowing is a lot more difficult to measure because of the involved arm activity. But the "10-minute error" at the beginning is not even connected to this sports, i can observe it even while cycling, running or even when i am just going for a walk. Or in other words - at no point at the day the WHR and the measurements depending on it is trustworthy.

Cycling or other activities which involve gripping something and twisting your wrist are also problematic, because that reduces bloodflow on the wrist. That's why I rarely get a good wrist hr reading when starting to ride a bike, even though my running wrist hr is usually really good. 

(Wasn't cycling one of the reasons why they added leds to the new Garmin hr sensor?)