Hello Marco, I appreciate you for providing all this information. Without it we might have great tools but would not be using their potential.
Since Oura and whoop are too expensive for me, I'm thinking about buying one of the devices you usually wouldn't recommend. I'm wondering why you don't recommend certain device, for example fitbits and Google pixels. Your criticism concerns
(1) sporadic sampling, or
(2) shorter time windows, or
(3) unclear processing".
However, as far as I understood (see source below)
(1&2) fitbits uses data from an entire night of sleep
(3) fitbit uses rMSSD to calculate hrv
Quote: "Fitbit uses the common formula called RMSSD to determine HRV from your recent heart-rate data. In the graph, your latest HRV measurement is from the longest sleep period over the past 24 hours. Only sleep periods greater than 3 hours are considered."
thank you Tino, I tried to contact fitbit a few times but always unsuccesfully. As far as I know they do not use the full night, but a few hours, and I dislike particularly how they compute resting heart rate (with a "engineer" mindset, more than a physiologist mindset, i.e. using periods of data at rest, as opposed to using your actual resting state in the same context each day), making the data tightly coupled to behavior, more than stress-related changes. The also hide HRV behind a paywall, similarly to other wearables, hence I thought it wasn't a great option, but if you have found different information, it might be worth looking into it. A validation of the HRV measurement would also be helpful, as I have not see that either for fitbit unfortunately (which might solve the sampling doubts, i.e. is it the full night, some hours, which hours, etc.).
I will probably buy the Pixel watch 2. If I do I will try to find out if they use the full night for the calculation of HRV and post it here. It seems that you can export heart rate data, so I will just do that, calculate HRV myself using rMSSD and compare that to the value the fitbit app provides.
I did not know that they calculate resting heart rate that way. Thank you for mentioning it. It seems that sleeping heart rate is indeed behing a paywall (fitbit premium). I think HRV isn't though. Also, I think there are some alternative apps that I can use to get sleeping heart rate, like sleep as android. Again, I'll post my results if i end up getting the watch.
hello Dennis, you should be able to do so via Bluetooth, going in our app Settings, and 1) selecting Bluetooth as sensing mode 2) tapping Scan to let the app find the sensor. In case of issues, please reach us at hello@HRV4Training.com, thanks!
Thanks, Marco! We have the Scosche Rhythm24 and Kyto2935 in our validation pipeline, and surprisingly, they don't seem to be promising, even during sitting still conditions. My observation is that there is considerable variation between individuals; I have participants for whom these sensors do not even transfer the data (potentially confounding factors such as BMI, skin color, or even blood pressure may play a role). When a sensor fails to provide a good signal - or even any signal at all in some cases - in a participant, out of curiosity, I sometimes test it immediately on my hand/earlobe, and it works just fine. Hopefully, the first draft of the paper will be ready in a few months and love to hear your thoughts on it :)
Hi Josh, do you mean sensors embedded in mirrors or other cameras that you don’t touch during a measurement? I wouldn’t use any of those, especially for HRV.
Hello Marco, I appreciate you for providing all this information. Without it we might have great tools but would not be using their potential.
Since Oura and whoop are too expensive for me, I'm thinking about buying one of the devices you usually wouldn't recommend. I'm wondering why you don't recommend certain device, for example fitbits and Google pixels. Your criticism concerns
(1) sporadic sampling, or
(2) shorter time windows, or
(3) unclear processing".
However, as far as I understood (see source below)
(1&2) fitbits uses data from an entire night of sleep
(3) fitbit uses rMSSD to calculate hrv
Quote: "Fitbit uses the common formula called RMSSD to determine HRV from your recent heart-rate data. In the graph, your latest HRV measurement is from the longest sleep period over the past 24 hours. Only sleep periods greater than 3 hours are considered."
https://help.fitbit.com/articles/en_US/Help_article/1565.htm
What exactly do you not like about hrv readings from fitbit devices then?
Thank you.
Tino
thank you Tino, I tried to contact fitbit a few times but always unsuccesfully. As far as I know they do not use the full night, but a few hours, and I dislike particularly how they compute resting heart rate (with a "engineer" mindset, more than a physiologist mindset, i.e. using periods of data at rest, as opposed to using your actual resting state in the same context each day), making the data tightly coupled to behavior, more than stress-related changes. The also hide HRV behind a paywall, similarly to other wearables, hence I thought it wasn't a great option, but if you have found different information, it might be worth looking into it. A validation of the HRV measurement would also be helpful, as I have not see that either for fitbit unfortunately (which might solve the sampling doubts, i.e. is it the full night, some hours, which hours, etc.).
I will probably buy the Pixel watch 2. If I do I will try to find out if they use the full night for the calculation of HRV and post it here. It seems that you can export heart rate data, so I will just do that, calculate HRV myself using rMSSD and compare that to the value the fitbit app provides.
I did not know that they calculate resting heart rate that way. Thank you for mentioning it. It seems that sleeping heart rate is indeed behing a paywall (fitbit premium). I think HRV isn't though. Also, I think there are some alternative apps that I can use to get sleeping heart rate, like sleep as android. Again, I'll post my results if i end up getting the watch.
Hi Marco & team, How do I connect garmin HRM pro to the app for HRV?
Thanks
Dennis
hello Dennis, you should be able to do so via Bluetooth, going in our app Settings, and 1) selecting Bluetooth as sensing mode 2) tapping Scan to let the app find the sensor. In case of issues, please reach us at hello@HRV4Training.com, thanks!
Thanks, Marco! We have the Scosche Rhythm24 and Kyto2935 in our validation pipeline, and surprisingly, they don't seem to be promising, even during sitting still conditions. My observation is that there is considerable variation between individuals; I have participants for whom these sensors do not even transfer the data (potentially confounding factors such as BMI, skin color, or even blood pressure may play a role). When a sensor fails to provide a good signal - or even any signal at all in some cases - in a participant, out of curiosity, I sometimes test it immediately on my hand/earlobe, and it works just fine. Hopefully, the first draft of the paper will be ready in a few months and love to hear your thoughts on it :)
looking forward to reading it!
Hey Marco could you recommend some non contact HR sensors that you like?
Hi Josh, do you mean sensors embedded in mirrors or other cameras that you don’t touch during a measurement? I wouldn’t use any of those, especially for HRV.
Hello Marco, got it thanks.
Best regards, Dennis