Incorrect HR record during exercise.

There are a number of factors here:

1. The OHR samples less frequently in 24/7 mode than it does in exercise mode. It also samples more frequently with the HR graph activated. Peek under your watch and look at the LED's to see this happening.
3. The all-day graph high and low numbers report what has been sustained for 60 seconds. While the Edge with a chest strap (or even if you just re-broadcast your watch's OHR) will report the highest and lowest instantaneous HR. So if your HR is 100, then you do a short 15s interval and your HR rises to 120, then drops back to 100, the all day graph will show just 100, as this is the maximum that was sustained for 60s.
2. It is widely acknowledged that OHR is less responsive to sharp changes in HR than chest straps, so it probably will miss sharp peaks that will be picked up by the HRM-TRI.

70 beats sounds pretty high for a difference, but I suspect that I could generate such an example with a sprint effort from a standing start.

Hi @mcalista.
Thanks for your reply.
1. I realise that the samples would be less frequent, but the cycle ride used as an example was for over an hour and averaged at 159 so don’t believe it is sampling rate.
2&3. Again it was a race situation, not intervals. (See data from HRM-TRI below)

It seems like OHR being incorrectly recorded when exercise started (F5 auto identifies activity rather than me explicitly starting it) until I select HR widget (and only whilst active) or (unlikely) widget picks in HRM-TRI HR when in the widget.

i will try later to start manually Activity with OHR recording and see if it records correctly.

Thanks
Shaw
ciq.forums.garmin.com/.../1445459.jpg

Hi,
Since the last update I have some big issues with OHR too:

1/ I have the same problem of underestimated HR during exercice, even with indoor cycling, the fenix'HR is often 20-30 bpm under the HR given by the bike's HR monitor (while fenix and bike always used to be exactly the same before). Therefore the calories count is false and useless and I can't work at my target heart rate.

2/ Each night, I get a lack of HR at the end of the night when I'm sleeping : somewhere between 4 and 6 am the watch does'nt record any HR during a few minutes (10 min to more than an hour). It never occurs at the exactly same time and during the same amount of time.... As a consequence, sleep datas are totally inaccurate (for exemple 5 hours of sleep recorded when I slept 7 hours).

Of course I tried to tighten the fenix' band : no change.
So I made a hard reset : no change.

Everything used to work very well since I bought it in july 2018, I think it all started with the last update.

Anyone with the same issues ?

I have no faith in the OHR for training, and use a strap, with the watch over the sleeve if my jacket when skiing (cross country). No way it could optically detect my HR. Jacket over shirt over base layer. A couple times I’ve forgotten the HR strap, yet it still gave me a number. Sometimes one that makes sense, and sometimes not. Jumps around. I’m fine with using the strap, so this doesn’t upset me, but it does tell me something.

Might be a coincidence, but I have just installed a new watch face which includes a Heartrate field and lo and behold the recorded heartrate during today’s bike session was recorded correctly. It was a recovery ride so interested to see on Tuesday when I race if it records higher heart rates correctly.

My F5 used to be fairly accurate. Now during sustained exercise it’s 50 plus beats low over a 45 minute duration.
Not an acceptable level of performance for a premium product.