accuracy HR during sleep

RobLagendijk said:

Do I have to go to the cardiologist?

It seems that visiting a cardiologist is the best decision.

Try using a chest strap (polar h10) and record the night as a walk (or other activity). The optical HR could be erroneous.

Wow, good for you, you're a role model for activism.
I think there is nothing wrong with you and the low heart rate may be due to a software glitch in the watch. When this happens, the optical heart rate monitor usually shines with a lower brightness. Check. The usual resetting of the watch helps. Good luck.

Igor Petrov

Don't give medical advice while you have no idea what is going on. 

Could be anything. 

Might be you sleep on your arm and there is low blood flow. Might be you where your watch a bit to loose. Might be there is an bug in the garmin software. Might be hardware related. Might be personal.

If you are worried it might be personal, go and see a doctor. Don't use internet for medical advice. 

Some people have genetically low resting HR and coupled with fitness.. could be even lower.  So if not showing symptoms... could be nothing.  If you knew if it was a long term for years... then even less case for concern IMO.  However like people have mentioned, adjust watch, wear a strap, and another one is to look for other times when very relaxed while sitting / laying on couch relaxing... what is it then?!  My resting HR is fairly low (~45) but it kind of always has since I started measuring 10yrs back... also workout 8-15hrs a week.  My relaxing time my HR isn't much different then when sleeping... so i would expect most other peoples would be close.  I do as a result of the HR / bloodpressure - occasional stars in vision and lightheaded/blackishvision when standing ... you get that?  I have noticed that the blurr/black vision when standing does coincide with very low HR for me (have felt it pump slow... put on strap and sat on the couch... yep... 42-44!)  Whereas other times when resting/sitting/relaxing it might be 50-55

NickMN said:

Some people have genetically low resting HR and coupled with fitness.

Firstly, for 36 bpm this is not true, and secondly, a 58-year-old man probably knows his own characteristics. Bradycardia and possible arrhythmia threaten sudden cardiac arrest. Therefore, you first need to undergo an examination by a doctor; if the alarm turns out to be in vain, then you can indulge in all sorts of discussions about errors and so on.

THIS IS NOT TRUE????? how do you figure?!  Maximum and minimal heart rates are very genetic!  (i will agree with your edit , 36 is low... HOWVER, that is 4beats lower then my SIL's...  so...it is what it is)

My wife and her sister workout some are an good health... and they trigger low HR alerts when in the hospital!  RHR of 40-43, They are NOT super athletes that have fitness induced low resting HR.

On the flip side... my BIL has the opposite!  He is in good health, great BMI, runs/bikes multiples times a week and has a resting HR in the 80s+!  

All of them have been to the doctor and their hearts are just fine all are in their 40s.

ALSO... no , most people asking about  their concerning low HR on a forum... probably DONT know "their characteristics" (whatever that means)!  Really, I don't think most people do.  

NickMN said:

THIS IS NOT TRUE????? how do you figure?

36 bpm - where did you see that?

you edited that while i was typ0ing it appears (i edited mine too)

Your original was "Firstly, this is not true, and secondly...." ---- coupled with my quote of "Some people have genetically low resting HR and coupled with fitness."