Current heart rate much lower than "resting heart rate"

[Adrienna27]

Is it normal to consistently see a current heart rate while resting that is significantly lower than what Fitbit is showing as the day's resting heart rate? How does Fitbit figure what resting heart rate is for a given day?

[SilviaFitbit]

It's great to see you around @Adrienna27. I'll be glad to answer your question about how resting heart rate is calculated. 

Your current heart rate and resting heart rate won't always be the same because resting heart rate is the number of times your heart beats per minute when you are still and well rested. This metric can be an important indicator of your fitness level and overall cardiovascular health. The typical resting heart-rate range for adult Fitbit users is 50-90 beats per minute. Active people often have a lower resting heart rate. For more information, see the Fitbit Blog. 

Fitbit uses your heart-rate data from when you’re both awake and asleep to estimate your resting heart rate. For best results, wear your device to sleep. 

You can learn more about it by checking this article: How do I track my heart rate with my Fitbit device?

I'll be around if you need further assistance. 

[Adrienna27]

Thanks, but that doesn't actually answer my question. My question is, why can I be well rested and still and see that my current heart rate is a good 10 beats per minute LOWER than my resting heart rate for the day?  

I can see why it would be higher -- activity level, etc, especially since anytime I am looking at it I am obviously awake and not asleep.  What I don't understand is why it should be substantially lower, not just occasionally but almost every single time I think to check it while I am non-active.

My doctor defines resting heart rate as the lowest resting heart rate I see during the day.  That's clearly not the method of calculation that my Fitbit is using, so I'm trying to figure out how it *is* figured.

[SilviaFitbit]

Thanks for letting me know how it goes @Adrienna27. I would like you to provide me with a screenshot of the data you're seeing in your Dashboard, this will help me to provide you with accurate information. 

I'll be around if you need further assistance. 

[Adrienna27]

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@SilviaFitbit wrote:

Thanks for letting me know how it goes @Adrienna27. I would like you to provide me with a screenshot of the data you're seeing in your Dashboard, this will help me to provide you with accurate information. 

I'll be around if you need further assistance. 

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I don't understand how a screenshot is going to help, but okay. Here is a screenshot.  However, the heart rate showing instantaneously on my wrist a few minutes ago was 75.  Typical resting heart rate when I happen to look at my wrist while reading/resting during the day is nearly always in the 74-80 range even though my daily/weekly numbers that show up in the chart are consistently over 80.
.

[SunsetRunner]

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@Adrienna27 wrote:

How does Fitbit figure what resting heart rate is for a given day?

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It's Fitbit Magic. And therefore useless, because they don't tell you what their magic is.

The only possible useful thing about Fitbit's resting heartrate is when comparing todays value with the values of the past few days.

And yes, I see exactly the same thing as you: sitting at breakfast with a  53bpm pulse whereas Fitbit says the HRrest for today is 56bpm. 

[Adrienna27]

This morning's data: Fitbit says today's resting heart rate is 80 bpm. Seen on my wrist: 62 bpm.  Not an anomalous reading, because the next ten or so times I checked it were all 62-68 bpm.

[CollinM]

One thing I noticed is that the algorithm Fitbit uses is extremely sensitive to peaks when you're supposed to be sleeping. For example your heart rate going up because you've gotten up and went to the bathroom. So any peaks, for whatever reason, during sleep can really throw off the calculation.

[Adrienna27]

Thanks, @CollinM , that could be it. I usually get up at least a couple of times during the night. It doesn't make sense to me for that to totally disrupt the RHR measurement for the day but having some insight about what's causing the problem is helpful.

[Adrienna27]

Today's observation: Fitbit's calculated RHR 81 bpm, while observed right-this-moment RHR is 64-69 bpm.

I'm going to just assume I can't rely on Fitbit's RHR measurement, because it makes zero sense.

Thanks to everyone who helped me try to figure out what was going on.

[janel]

@Adrienna27  I switched to a Polar watch for tracking sleep and activities. At any given time, the watch itself shows me my current heart rate plus the high and low for the day and the low from sleep the night before, in addition to the high and low and range (time in each heart rate zone) for any tracked activity. And more detailed charts for each day are available in the app and the web dashboard.  Plus, the support people do not act like bots.

[Adrienna27]

Thank you, @janel , that's super helpful info.

[janel]

I bet that what they're calling resting heart rate is actually average heart rate. Is there anywhere you see average heart rate? How does it compare?

[Adrienna27]

Thanks, @janel.   No, I don't know of any location to view average heart rate, but I don't think that the numbers I'm seeing would correlate with average heart rate, either, given that I'm fairly active most of the day usually.  You give me an idea, though -- perhaps it's the average of all of the heart rate readings that come in under the threshold used for what it calls 'fat burn' level. So instead of giving an accurate resting heart rate, perhaps it's showing an average that includes low-level activity like cooking dinner, walking around the house casually, etc -- anything low-grade activity enough that it doesn't raise the heart rate above 88 or so (wherever it is that fat burn starts -- I'm not sure but it claims I'm in the "fat burn zone" anytime I'm more than very mildly active.)  That actually would make sense for the ballpark that I'm seeing -- low 60's for 8 hours or so at night averaged out with mid-80's for a large chunk of the daytime could definitely work out to around 80.

[CollinM]

It's not that. It definitely uses your sleep period for calculating you resting heart rate. Take a look at the app when you first get up. There won't be a resting heart rate. Quite soon after, at most half an hour later, you then see a resting heart rate. So wat you do during the day shouldn't influence the calculation.

I already mentioned one detail that influences my resting heart rate. The getting up multiple times during the night and my heart rate spiking. The second one I can consistently notice is when I'm active right after waking up and this causes my heart rate to be higher than if I'm resting.

However, this doesn't change the fact that Fitbit actually should provide some details how they calculate their resting heart rate and that the mods here shouldn't give canned responses to almost everything (though this is most likely because of a combination of policy and them not knowing a whole lot more than we do).

[Adrienna27]

Thanks, @CollinM . I just couldn't make it fully make sense if it was just night wakings because I don't stay awake, so it's just a quick trip to the restroom then back to sleep quickly -- not enough that it'd seem to make sense to take RHR up to 80-81, which is about the peak I'd expect it to reach with that little of activity. 

Rolling in data from shortly after waking up in the morning, though -- that could explain it better, since I usually rocket out of bed to the alarm, take the stairs several times getting 4 kids ready for school, and average a thousand steps in the first half hour of being awake.  Still, I don't do it like that on the weekends, and the RHR on weekends doesn't read substantially different than on weekends.

I don't know. It's baffling, and I agree Fitbit needs to provide more actual info.  Or even better, use a classic simpler measurement of RHR, like the lowest heartrate recorded per day.  As it is, I can't even figure out what goes into the measurement, so it's not useful information.

[Colinm39]

@Adrienna27  I can support @ColinM with the sleep period.

I realized that when the first Fitbit pulse devices were released. I found sleeping had a great affect on RHR, more so than very low or high atmospheric temperatures. It was how we slept....

I found the use of synthetic sleeping like doona covers with polyfill affects me as per the example.  We have had a cold snap to slightly warmer and cold again at night around 5oC to 12oC (41oF to 54oF) and I find I get restless because I sweat slightly in this sleep environment.  Because I'm a month off 80 I even fat burn at 71bpm while asleep on the very cold nights.. (220-79)*50%

Tonight I'm reverting to light weight woolen blankets which I tested last year and that kept my RHR around 52-53..

Why did I change ?. Because I don't like heavy over blankets or woolen doonas.

So, thru that I started recording my sleeping HR by creating a Manual Activity. I log this every morning.  Coming out of Autumn my RHR was typical 52-54 and my sleeping average HR was around 51-54.

My HR at 9-30pm as I type this is 53 bpm, with Airconditioner on heating and room is 21oC (70oF) and outside temperature 11oC (52oF) and forecast another 5oC (41oF) in the morning

[Colinm39]

Another 5oC (41oF) night and we don't heat the house at night.  Back to using woolen blankets last night the best sleep night since Fitbit introduced the Sleep Score.. 87 last night.  Best before was 82 previous to that  and the weekly averages have been 74-79.

I have selected a last nights manual record of my sleep and Saturday's to show the difference and the Fat Burn.

[Adrienna27]

This is really interesting. Thanks for sharing, @Colinm39.

Our night time temperatures are still around 80 F. I am looking forward to cooler weather in a few months!

[Colinm39]

@Adrienna27  Thanks.. Here is last years couple months of Summer and then Autumn.

The high temperatures hardly affected my RHR