fenix 7 heart rate not accurate

hold on a minute, i posted this on another thread about 9.33 ruining f7SS hrm. These 2 are zwift recorded rides just using the watch broadcast hr feature then later uploaded to garmin connect. 1st screen was what’s happening on and off since fw 8.xx to 9.33. 2nd screen was after doing a factory reset a few days ago also after receiving 9.36 update. Before reset i would get very low figures and frankly unrealistic bpm from the watch, a reboot usually fixes it but not always. After the reset the watch worked flawlessly. Again only broadcast hr is used no activity whatsoever. So bug or intended? Whats your ideas.

OHR on Fenix 5,6 and 7 have always worked perfectly for me and have remained within 1 or 2 BPM of my H10, HRM Pro and OH1. I use a chest HRM for the HRV data otherwise I really don't need it. For those that it doesn't work for I would suggest that is a unit problem, fit problem or a problem with personal characteristics.

BTW that does include 1+ hours on an indoor trainer with zero arm movement and mode set to Auto.

I'm 65 with an HR range of 56 to 173.

I paddle surfskis for distances up to 30km (3 hours) with a stroke rate of about 70 to 110. SPM

I ride both indoor and outdoor (180km ish per week) with a cadence range of 80 to 120 RPM and power range of 130W to 850W and do Zone 2 stuff at a pretty steady state. The indoor cycling basically involves no arm movement other than a comfort adjustment every 10 mins or so.

Initially I had some issues with the OHR on the Fenix 5 using the steel band but solved that by using a silicon band fitted snuggly. This carried on through the F6 and now I use the F7 with the steel band from the F5 after removing one link.

I never have a variation between the OHR and chest HRM of more than about 2 BPM at any heart rate, 

Ok but to summarize, your cadence changes very slowly over time, youre not rushing into the upper zones. Which is the use case that is working perfectly fine.

Our issue is about fast changes in cadence, especially when beeing in the gym doing the short intense stuff, where youre cadence goes up and down like crazy. Or any other sport involving fast cadence changes except running. Because the arm movement is part of the filter function and affects the accepted slope of cadence.

Why would you assume that? High cadence activity is sprinting,

with 9.33 and 9.36 i get the same results, never had any issues, no need for reboots, I also only broadcast hr for Zwift. 

https://ibb.co/p3K5kKr

I've been experiencing the same issues on my VA3 and Fenix 6 Pro. I do a lot of incline treadmill where the speed is low, but I still manage to get my HR high as it's incline. And sometimes (not every time) the HR just stays at 90-100, even though my manually checked HR is more in 160 - 180 range. But if i start running for a couple of minutes, the HR starts catching up and then reports correctly even if I slow down later. This has happened with swimming too, where I had to change my style of swimming to involve faster arm movement to get the watch HR to the correct range.

And when the HR gets stuck in that 90-100 range, nothing works - I tried switching inside/outside of wrist, higher, tighter, more loose, etc. Basically everything that has been suggested. This was more prominent on my VA3 though than the fenix. Very frustrating when it happens.

So I've reported the same issue with my Epix2. Garmin HR strap records maybe 170BPM while on tubo, recorded in zwift and sent to Garmin connect. Watch OHR recording 70-80. So, I bind the watch to the strap via ANT+. when you view the HR on "glimpse" then it chooses to show you the strap HR. while in glimpse, that (higher) strap HR gets recorded. but once the watch goes back to standard watch face, it reverts to using the OHR - the widget on the watch face shows low HR and the watch records low HR.

My experience with Garmin was one of the least satisfactory i've had with any product support. No mention from them that this is a systematic issue as is clear from this forum. Or, anything like "thanks for buying our flagship activity watch, sorry it can't record activities when you are active"

Glad to see this forum, it makes me realise my watch is not broken, I don't have weird wrists; this is Garmin software coding, and is completely intentional.

Anyhow, next time I will try waving my arms around and see if I can get the OHR to allow my HR to jump to the correct level. And then try to start an activity (I suspect that will work but be careful, if you record 2 activities at the same time, the watch will ignore the off-watch activity, so i think one has to start an activity so its "paying attention" to the strap HR, and then delete the activity before finishing the zwift activity.

Fairly pathetic workarounds for lack of basic functionality on a ferociously expensive piece of kit.