(This is the second half of what should have been ‘Twofer Tuesday Tech Tidbits’ earlier this week, until this tidbit broke free and decided to go live on Thursday instead. Thus…enjoy!)
As of this morning Garmin has rolled out additional sleep analytic data within Garmin Connect, which breaks down your sleep cycles based on leveraging additional data from the wearable to get more details which are in turn translated to specific sleep stages. These stages are defined as follows (according to Garmin):
1st Stage: Light Sleep. Your eye movements and muscle activity start to slow down as your body prepares for deep sleep. This stage of sleep helps with relaxation.
2nd Stage: Deep Sleep: Your eye and muscle movements stop completely, and your heart rate and breathing slow down. Your body goes into restoration mode, helping with recovery, building bone and muscle, and boosting your immune system.
Last Stage: REM Sleep: Which cycles from short bursts to longer stretches as you leave deep sleep. This is the dreaming stage, when your brain is almost as active as when you’re awake. REM sleep is important for forming memories and processing information.
Garmin says they’re starting to leverage heart rate variability data from the optical HR sensor to assist in this data, alongside the existing accelerometer data they’d been using to date. It’s not as well known, but Garmin has actually been leveraging HRV data since early 2017 for non-workout data purposes, such as measuring stress. Early 2017 is when Garmin updated their ELEVATE optical HR sensor to be truly 24×7 at 1-second interval rates. Whereas previously the interval rate (for something like a Fenix 3HR) was anywhere between a few seconds and tens of minutes. The new hardware introduced back then opened up this door, alongside others.
To understand the difference between what these data points used to look like, versus today, here’s two nights side by side. One from a month ago where the new sleep cycle data isn’t enumerated (before/left), and then one from last night where it shows the data (after/right):
And for fun, here’s that data within the context of the weekly planner view for the last two weeks. Day’s that are grey/blank are those I didn’t wear the watch, or in the case of this week, remain in the future.
And finally, a few more days of my life with the new data details, as well as the secondary view too:
Garmin says that by adding in the HRV data, the side-effect is that they’re also slightly increasing the fall-asleep/wake-up timing as well. And at least insofar as the last few days of data that I can remember, these fall-asleep/wake-up times are within 1-2 minutes (or less) of my actual times. The one exception, however, is the 4:30AM wake-up, which didn’t totally capture the cluster-fudge of up and down for the next 3 hours of trying to get two timezone-upset babies to stay asleep for more than 16 minutes at a time. Not sure I can really blame Garmin there though.
As for compatibility, here’s the watches that are compatible. Basically though it’s any optical-HR sensor laden unit introduced since January 2017. Anything prior to that lacks the optical HR resolution (frequency) of data to make it work. These first watches will work as of today (immediately:
- D2 Charlie
- Forerunner 645
- Forerunner 935
- Vivoactive 3
- Vivoactive 3 Music
- Vivosmart 3
- Vivomove HR
This next set of watches will work “soon”. My guess is this is a ‘really darn soon like days or weeks at worst type soon’, and not a ‘next year type soon’. But ya never know.
- Fenix 5 series
- Quatix 5
- Tactix Charlie
And of course, be sure that your Garmin Connect Mobile app is all updated as well. Oh, and this will all show up in the ‘My Day’ summary tab totaling each day.
Now I don’t have any meaningful/handy/easy-access way to validate this sleep stage data. I could possibly compare it to other sleep platforms out there, but I didn’t bring any on my current trip. And for that matter, I haven’t even unpacked them yet and installed them under the bed since moving to Amsterdam. Perhaps someday my unpacking journey will take us there.
In any case – go forth and enjoy more sleep data.
With that, thanks for reading!