Garmin’s new watches, the Forerunner 955 and 255, have something called the Garmin HRV Status report. Here’s how it works.
What you should know about heart rate variability (HRV)
Heart rate variability is important. For those not in the know this metric captures the variation in the time interval between consecutive heartbeats. This is recorded in milliseconds.
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What many people do not know, your heart does not tick evenly and there is a constant variation in beats. Rather counter-intuitively, HRV increases when you are at rest and it decreases during stress. This could occur both due to psychological stress or fatigue, for example, from doing an exercise. Both effect the parasympathetic and sympathetic branches of the autonomic nervous system similarly.
Parasympathetic dominance occurs when your body is in rest-and-digest mode, this is when your HRV is high. A lower HRV occurs with elevated sympathetic activity. This is an indication of stress or fight-or-flight response.
To calculate HRV something called RMSSD is tracked by the Elevate heart rate sensor on your Garmin watch. RMSSD is a standard statistical measure that represents the root mean square of successive differences between normal heartbeats for a given set of heartbeat data. Here’s a graphical representation.
HRV varies from individual to individual and many factors can affect readings. Some of these such as your age and gender you cannot influence. Others such as sleep, caffeine and alcohol intake, stress, exercise and more – you can.
It is not too difficult to figure out why professional athletes track their HRV on a daily basis. It is because the metric tells them how their body is handling physical strain. HRV readings show how fatigued you are at any particular point in time, and can be an indicator of potential signs of illness.
Should you take it easy or push hard on a particular day? Take a look at your HRV in the morning and you’ll have a better idea.
So far Garmin has allowed you to record HRV on certain devices through an on-demand test called Health Snapshot. This captures a bunch of metrics including heart rate, HRV, Pulse Ox, respiration and stress.
The watches that are compatible with this report include the D2 Air X10, D2 Mach 1, Epix (Gen 2) series, Fenix 7 series, Forerunner 945 LTE, Tactix 7 series, Venu 2 and Venu 2 Plus. There’s a two minute timer during which the test is taken. The results are displayed as per the screen-shot below.
This is all well and good but is not very useful for HRV. Ideally, you want something that tracks this value overnight and spits out a metric when you wake up in the morning. Step in the Garmin HRV Status report.
The metric was developed by Garmin’s Firstbeat Analytics team. It records HRV during sleep as a nightly average value. You also get a 7 day rolling average HRV along with a scale which shows how this compares to your baseline value that is calculated over the long term.
The watch must be worn for at least three weeks for this baseline to be established. This gives it time to establish what is normal for you. As mentioned above – a normal, healthy degree of variability is different for everyone.
It is only when your baseline range is calculated, that your overnight HRV will be used to enhance insight from other Garmin metrics. Also worth pointing out is that your baseline changes with time. No worries – the device on your wrist will automatically adjust the average when necessary.
Here’s what this looks like on the Garmin Forerunner 255. As you can see, a nice clean interface shows everything you need to know at a glance. Ideally, you want to be in the Green zone and avoid the Red zones. You will also get insights from Garmin based on your HRV value.
To make things simple, Garmin classifies your HRV Status into Balanced, Unbalanced, Low and Poor categories. Each of these is pretty self-explanatory and depends on how your daily values compare to your weekly and long-term averages.
Garmin has also had a Body Battery metric for a few years now, but HRV Status is much more useful. Hopefully, it will come to other devices soon via firmware updates. Presumably, all watches that can do a Health Snapshot have the underlying tech to dish out the HRV Status report. Which is devices with the Gen 4 Elevate heart rate sensors.
Compare this with Fitbit’s solution and you’ll see that it is more professionally done. Fitbit only shows your nightly average HRV over the past week in a simple line chart. Not nearly as useful as it doesn’t compare it to your baseline and averages.
In addition to HRV Status, the Forerunner 955 also has something called a Training Readiness Score. This takes into account your sleep quality, recovery, training load and more. Which means you’ll have plenty of recovery data to sink your teeth into.
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And let’s not forget the Morning Report. Introduced for the first time with Garmin Lily, it shows a summary of the weather, Body Battery, step goal and step streak, calendar and women’s Health tracking (if enabled).
You get a report with the same name on the Forerunner 255 and 955. But in their case Morning Report shows sleep, recovery time, training status and HRV status immediately after waking up. It also provides you with your daily training recommendation.
Garmin does not charge for access to data
These new Garmin recovery metrics will certainly give the likes Whoop and Oura something to think about. Their wearables are all about these types of metrics. But in both cases you need a monthly membership to gain access to the full set of data. Fitbit has also started charging for some of its statistics.
All credit to Garmin for not taking this route – the company has never charged users to gain access to their data. Let’s hope it keeps it this way, and that the new recovery metrics soon trickle over to other devices.
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