Heart Rate Wrist - Inaccurate especially at night

Could be the posture you sleep in, lying in your arm maybe. You could try to wear the watch on the inside of your wrist and see if that works better.

So for me the OHR readings work fine during the night. What you could try is to let an indoor activity running over night to see more detailed how it really behaves.

Depending on how you use the functions of your watch it will influence your sleep score / training readiness and so on, just in case you use those features.

I will try running an activity during the night.

Yes, my complaint about it is because inaccurate heart readins at night mess with sleep score, stress, etc ,etc. 

5578887 said:

**What could it be that affects heart rate more when i'm stopped?**

Besides the posture already mentioned, the worse reading could be caused also by peripheral vasoconstriction, which can be induced by cold, or quite often (though not necessarily your case) due to sleep apnoe or snoring. 

5578887 said:

it gets stuck in a number like 71/72 bpm for hours.

BTW, do you see the same data on the watch, and in Garmin Connect?

Hello there,

Since I've wrote the original message I have been observing it closely and it also started to happen during the day. It may be related to temperature...

1) It is not the position I sleep in. I woke up the other day, it was froze as usual. I stayed in bed moving my arm around and it kept froze for 10 minutes... then I got out of bed, walked around suddenly it started working again.

But more important than that...

2) I decided to look at the temperature widget graph and the "freezing" always happens when the temperature gets above 29c (I know this temperature is the watch inside temperature, not my skin or ambient...).

Its almost a perfect correlation. The temperature graph drops below 29c and then I go look the heart and at exact the same time HR started to work again.

Now during the day when it gets stuck if I put it for a few seconds under the tap, it starts working again! When i'm driving and it is stuck, I just put it in front the AC and it starts working...

3) As another hint, today, while driving, was the first time I noticed that while the heart rate was stuck , the altimeter also was....

so.. what could it be? Temperature rises (but we are talking about not a lot...) then it shuts off altimeter, HR sensor, etc....

ah! forgot to answer your second question. Yes, the same data on the watch and garmin connect. just a flat line.

I have the same problem only after 21.22 / 22.22

5578887 said:

Now during the day when it gets stuck if I put it for a few seconds under the tap, it starts working again! When i'm driving and it is stuck, I just put it in front the AC and it starts working...

That sounds like a hardware issue to me. In your place I'd reach out to the Support.

having similar observation.  Living in APAC time I got up to watch the champions league at 4am, and after the game finished, i didn't realize the watch was frozen as the clock face at 4am, until I started a strength program at 6:30 at the gym.

after upgrading to 22.22 for the past week or so, the HR graphs just randomly turn flat during sleep; along with SpO2 sporadic readings, after I turn it back on hoping it would keep the sensors "alive" for longer.

as for day time, I just check again, there are flat periods just like at night, randomly...

I see there's 22.24 coming out now, shall I update? sigh...

Yes, I already did. Here in Brazil I would have to send them through the mail to another town and they said they would have to keep it for at least a month....I'm currently training for a marathon so I can't do that. Im trying to find someone with an extra garmin to lend me...

I thought if there was some kind of way to trick the temperature sensor with a few degrees it could be a work around...