265 HR inaccurate even after update

Having issues too. It started right before this last update rolled out. My watch keeps telling me my workouts are unproductive as well no matter if I go hard or take it easy. Just recently started acting up it makes me wanna get rid of it asap. 

Yes!  I came here to post the question on why my watch's optical HR is inaccurately low and this one came up as a suggested post.  I bought my 265 watch a few months ago to wear while running, and knowing that the optical HR sensor is never as accurate or reliable as a chest strap, I had been wearing a chest strap whenever running.  However, I've recently started lifting weights in the gym, and I don't like to wear a chest strap while lifting.

But for the past few workouts, I've noticed that immediately after finishing a set, my HR is seemingly way too low.  Just today, after a set of squats, my HR was showing in the 90s. I thought "that's weird, it feels a lot higher than that."  I took off the watch and then immediately put it back on.  The HR reading jumped up to 120s, which felt more realistic. 

This happened repeatedly during the workout:  Finish a set, look at my watch, not believe the reading, take off the watch, put it back on, HR reading jumps 20+ bpm from what it had been.  

So apparently optical HR is still completely unreliable and a useless metric.  Guess I'll have to wear a chest strap while lifting if I am at all concerned about an accurate HR reading.

Based on my experience optical HR while not perfect can work pretty well if Garmin gets out of their own way, meaning if it has been working pretty well, don't muck up the algorithm trying for some minor enhancement until the changes have been thoroughly vetted.

Garmin has had it sorted out, I was happy with the general HR reading and exercise average readings on the FR245 (did not let it automatically update software) and with the exception of the 1st 10 minutes or so of an exercise, I'm happy with the readings of the FR265 but I do longer duration activities and don't care that much about an instantaneous peak.

I have a Forerunner 245 (2019) that works perfectly. 

Two months sgo I invested in Fenix 7 pro solar. What a mistake. The HR is doing exactly this as described, showing inconsistencies and lower values constantly. 

They say  its the way it is and even refer to where its written in their documentation. After I proved to them that it is not my usage of the watch (I tried many fits and positions), after demonstration that multiple activities HR was completely off (it is not external circumstances) and after I showed them the data that their Forerunner I had previously worked like a charm (it is not the user’s physical characteristics), they still claim that their watch is perfectly ok and basically they say its not us, its you. They even wrote to me that I am physically special. 

While these disclaimers in their docs suggest limitations in sensor accuracy, they fail to absolve Garmin of its responsibility to provide a product that performs as advertised.

Garmin's marketing heavily emphasizes features such as "24/7 health and wellness monitoring" and "advanced performance metrics." but due to its inaccuracies to read a proper HR, they fail at following (which is advertised)

-       Training Readiness
-       VO2 Max Analysis
-       Recovery Time Analysis
-       Body Battery energy monitoring 
-       All-day stress
-       probably more

While Garmin acknowledges limitations in their HR technology, and I as a user also, they simultaneously position it as “state of the art” and capable of providing “accurate estimation” of heart rate during activities.

I was shocked by their reaction how this inacurate HR should be considered normal and I am even more shocked that the users will accept this at the price at >1k $ for their best watches and will agree to wear an additional chest strap. I mean, this should end up on a court, I am surprised that it is not already.

7800391 said:

I was shocked by their reaction how this inacurate HR should be considered normal and I am even more shocked that the users will accept this at the price

Agree 100% with your post fully, especially with this statement. 

Just chiming in to say I also have heart rate issues with the 265S. I got a chest strap, but after multiple hard resets due to the GPS disaster last week I guess I need to re-pair it. Anyhow, no chest strap data means I got to confirm that the watch HR is still way off. Yesterday I ran 6 x 800 at 5K pace. This usually gets my HR up over 190, even close to 200. That's what the strap would say, that's what my old Venu would say. According to my 265S, though, my first rep peaked at 164 and then the other reps were lower! 140s! It's not cadence lock and I did a warmup of 3 miles or so, plus drills and strides. I wear it in the right spot and it wasn't even that cold out yesterday. The data is just non-sense and has been for many months now. I want to stick with Garmin and I love many other features of the ecosystem and watch. But boy is this frustrating.