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OHR Polling frequency when asleep/not moving (vs visualization on 4hr-graph)

Just wanted to check something I noticed.

When looking at the 4 hour HR-graph on the watch it looks great, frequent sampling and no weird spikes anymore it seems. Also, looking at Garmin Connect the sampling frequency has increased massively when movement is detected (in whichever form). When sleeping however, it decreased even more (as much as 4-5 hrs between measurements) and also yesterday when going to a meeting where I had to sit and listen to a speech for ~45 minutes no measurement seems to be taken in these 45 mins.

Before it was about the same frequency when sleeping vs when awake, easily 30-60 mins between sampling. Now when asleep it's 60-240 mins and while awake 1-5 mins... Again, suits me fine but also looking at the HR graph when waking up it appears as if it has been sampling just as frequently the last few hours while I was asleep and this does not appear to be the case from Garmin Connect.

Is Garmin simply 'pimping' the HR graphs with random noise around the last measurement in these hours? Making it look like it's very active, while in reality it just plots around the last measured value.

While I'm pretty happy with the current way of measuring I wouldn't be fond of hiding the low-frequency sampling this way. It just isn't reality and gave me a complete invalid impression.

Can anyone comment on this, or did someone else notice the same?

What would be the best way to check hr-sampling frequency? I already got the fit files from the monitoring folder and converted them to csv, but have a hard time interpreting the data...

0 Former Member over 9 years ago

I had a 2 hour gap between points last night which does seem typical before and after the update. How I'm not sure if GC is just averaging the data across this time or not. Like you the watch 4hr trace does seem more "noisy" than this.
Maybe Garmin is just trying to save database space by not storing all recorded readings? Having such a large gap however does seem totally unnecessary. Maybe I will try a broadcast HR tonight and see what that looks like.

0 NickMN over 9 years ago

Noticed same 'false added noise'

I noticed the same thing - all day they add in noise on the graph line for the watch to give a false sense of sampling?!?!?!.... kind of ridiculous...

my overnight sampling is very sparse... but occasionally it is maybe every 10minutes... sometimes 1.5hrs. Likely based on sleep movement (?)

0 Former Member over 9 years ago

Just wanted to check something I noticed.

When looking at the 4 hour HR-graph on the watch it looks great, frequent sampling and no weird spikes anymore it seems. Also, looking at Garmin Connect the sampling frequency has increased massively when movement is detected (in whichever form). When sleeping however, it decreased even more (as much as 4-5 hrs between measurements) and also yesterday when going to a meeting where I had to sit and listen to a speech for ~45 minutes no measurement seems to be taken in these 45 mins.

Before it was about the same frequency when sleeping vs when awake, easily 30-60 mins between sampling. Now when asleep it's 60-240 mins and while awake 1-5 mins... Again, suits me fine but also looking at the HR graph when waking up it appears as if it has been sampling just as frequently the last few hours while I was asleep and this does not appear to be the case from Garmin Connect.

Is Garmin simply 'pimping' the HR graphs with random noise around the last measurement in these hours? Making it look like it's very active, while in reality it just plots around the last measured value.

While I'm pretty happy with the current way of measuring I wouldn't be fond of hiding the low-frequency sampling this way. It just isn't reality and gave me a complete invalid impression.

Can anyone comment on this, or did someone else notice the same?

What would be the best way to check hr-sampling frequency? I already got the fit files from the monitoring folder and converted them to csv, but have a hard time interpreting the data...

I'm currently having problems with my laptop, so I'm unable to view my .fit files. Anyway, the timestamp is in seconds taken after midnight. The sample rate in the past was a recorded number every 15 minutes with an actual sample taken every 30. So, timestamps of 900, 2700 and 4600 would be samples taken at 12:15AM, 12:45AM and 1:15AM. Hope this helps.

Corrected original post: I meant seconds after midnight, not minutes.

0 Former Member over 9 years ago

OK, I got my laptop back up and viewed my .fit files for the last two evenings. WHR 2.60 is recording and sampling RHR every 900 seconds (15 minutes). Previous software versions of the WHR sensor were recording every 15 mins, but only sampled every 30 mins, so v2.60 is twice as often. Keep in mind, any disruption of your RHR will stop and restart this cycle.

0 ASmugDill over 9 years ago

WHR 2.60 is recording and sampling RHR every 900 seconds (15 minutes).

I haven't looked into the FIT files myself, and in fact am not familiar with the FIT file format specification, but just to be clear, surely the watch is sampling heart rate every 15 minutes and not just (or specifically) RHR? After all, RHR is logically a derived value by applying something like the MINIMUM() function over a range of data points (possibly constrained to waking hours), and not a physically measurable (or sample-able) attribute in its own right.

0 edlondon over 9 years ago

Pretty much a straight line between the time I go to sleep and wake up. It doesn't seem like more than one or two samplings over a 7 hour period. All new since 2.6 whr/4.2.

0 FlipStone over 9 years ago

Pretty much a straight line between the time I go to sleep and wake up. It doesn't seem like more than one or two samplings over a 7 hour period. All new since 2.6 whr/4.2.

THat's how it looks for me on garmin connect as well, but when looking at the watch it gives the impression of continues sampling...

0 edlondon over 9 years ago

Hard to tell from the tiny graphic on the watch, but given the supermoderator post about issues with Garmin Connect displaying hr, entirely possible.

0 Former Member over 9 years ago

I haven't looked into the FIT files myself, and in fact am not familiar with the FIT file format specification, but just to be clear, surely the watch is sampling heart rate every 15 minutes and not just (or specifically) RHR? After all, RHR is logically a derived value by applying something like the MINIMUM() function over a range of data points (possibly constrained to waking hours), and not a physically measurable (or sample-able) attribute in its own right.

As you know, the 235 "triggers" HR readings based on movement/activity. When I say it's sampling RHR every 15 minutes, I'm referring to while you're sleeping/at rest. It's not set in stone, but for most people their RHR is while they're asleep. Anyway, since there is hardly any movement while sleeping/at rest (unless you suffer from night tremors, lol) and no "triggers", the 235 starts sampling every 15 mins until something happens to elevate your HR.

0 edlondon over 9 years ago

Definitely not sampling every 15 minutes

As you know, the 235 "triggers" HR readings based on movement/activity. When I say it's sampling RHR every 15 minutes, I'm referring to while you're sleeping/at rest. It's not set in stone, but for most people their RHR is while they're asleep. Anyway, since there is hardly any movement while sleeping/at rest (unless you suffer from night tremors, lol) and no "triggers", the 235 starts sampling every 15 mins until something happens to elevate your HR.

You can see when you "press" on the hr reading in GC that its: 1:17, 3:53, 7:53 am. On the previous whr fw, it read regularly - every hour practically on the hour. I didn't start sleeping more soundly the day the new fw was released... so either GC isn't properly reflecting the watch reading, or they need to do some tweaking of the sensitivity.