How to measure HRV on a Garmin without a HR chest strap

Garmin does not currently provide access to raw heart rate variability (HRV) data on most of its watches. In our view, it’s just a matter of time before it does. But there is a workaround.

Why would I want to know my HRV?

We’ve written quite a few times about the benefits of knowing your HRV. It’s no wonder the metric is gaining in popularity. A heart does not beat at a regular rhythm. The intervals vary from one heartbeat to the next. This is healthy and normal. It is what HRV measures.

In essence, the metric lets you know how fatiqued you are. This could be due to psychological or physical stress, there’s no way to tell the difference. Should you head out for that long run or take it easy? Check your HRV and you’ll know.

Unlike your resting heart rate, the higher your HRV the better. High values are associated with parasympathetic dominance within your autonomic nervous system, a sign that you are in a recovery phase. Low values are an indicator of high sympathetic activity. This is associated with a stress or fight-or-flight response. While you are exercising your HRV will always be high, at rest it will be lower.

Because the metric varies between people based on age, gender and other factors, you’ll need to work out your baseline. And then follow where you are on the day as compared to your average. It is best to take the measurement at the same time during the day. Preferably, at early morning.

Garmin HRV Stress Test

As mentioned, most Garmin watches and fitness trackers do not provide access to raw HRV data. That is unfortunate and we are under the firm belief it will change in the near future. Even Fitbits have been upgraded to show these types of metrics.

Essential reading: Best wearables to track recovery with HRV

Garmin does use HRV in calculating a few metrics such as Body Battery, all day stress and sleep phases on newer Garmin devices. The wearables utilize the optical heart rate sensor to arrive at these estimates.

Certain performance metrics such as VO2 Max, Performance Condition and Lactate Threshold also use HRV. But they require a heart rate chest strap.

The default way of measuring HRV with a Garmin watch is by doing a HRV Stress Test. The end result is a value between zero and one hundred. The higher the score, the more fatiqued you are.

To initiate a reading, wrap a heart rate strap around your chest and pair it to your watch.

• On your watch, select START.
• Scroll down until you see HRV Stress.
• Press the button to initiate and
• follow the onscreen instructions.
• The test takes about three minutes.

There are a handful of newer Garmin watches that do provide raw HRV data

The most recent crop of Garmin smartwatches does provide access to raw HRV data. This includes the Epix (Gen 2) series, Fenix 7 series, Forerunner 945 LTE, Venu 2 and Venu 2 Plus. If you have one of these, you’re in luck.

They all have something called a Health Snapshot feature. This is a two minute test which requires you to be at rest. It captures your heart rate, heart rate variability, Pulse Ox, respiration and stress. The idea here is for this to be a simple test that provides you with an insight into your overall cardiovascular status.

The data from the Health Snapshot can be viewed on the watch itself, Garmin Connect or the web dashboard. You can also save the file as a PDF which can be easily shared with others.

Here’s what it looks like in the smartphone app.

You’ll notice that there are two HRV values that are displayed. Both are shown in milliseconds, and the difference in their values is not huge.

SDRR or Standard deviation of RR intervals is a useful indicator of overall cardiac health. The metric is more accurate when tracked over 24 hours because it shows how regular daily activities influence the cardiovascular system’s response.

More useful for training is the RMSSD. It stands for Root mean square of successive RR interval differences. It represents the successive time difference between heartbeats. Athletes use this value to assess how ready they are to perform. The value changes constantly as your body condition changes.

How do I measure HRV without a heart rate chest strap?

But what if you have one of the older watches? You don’t have the option to do a Health Snapshot. And doing the above mentioned HRV Stress Test will not get you raw HRV data. Instead, you get a score. Plus you need a heart rate chest strap to do the test.

Unless Garmin updates its older watches to be able to do a Health Snapshot you are out of native options. But you can resort to a third-party option – an app called HR Variability.

1. First you’ll need to download the app and install it to your watch. This is done via the smartphone app.
2. Open Garmin Connect, click on the picture of your wearable along the top. This will take you through to the Settings page.
3. Tap on Activities & App Management. Choose Activities & Apps.
4. Click on Get More Applications along the bottom. This will take your through to Garmin Connect IQ.
5. Do a search for an app called HR Variability. Install it and make sure to sync Garmin Connect to your watch.

The app is compatible with most Forerunner watches, the Fenix range and Vivoactives.

Once installed you can go to your watch and make it one of your favorites. That way it won’t require too many button presses to launch.

To start a HRV measurement simply start the “activity” as you would any other activity such as a run or a swim. The app will ask you to specify whether the measurement is After Waking Up, Before Bed, After Exercising, Before Exercising or Else. You’ll then have the option to choose between a 3 minute or 5 minute test. The app will remind you to remain still during the measurement.

Then the countdown will begin. When it finishes you’ll see your heart rate alongside your HRV. A FIT file will automatically be saved.

The metrics provided are raw HRV data. I found that my morning HRV fluctuated between 45ms and 85ms. In the evening it would be lower, and after strenuous exercise it would be even lower. This is not surprising – workouts cause stress to the body.

Compared to the built-in HRV stress test this is much more convenient. It doesn’t require a heart rate chest strap and it can be performed easily at any time. Plus, the data in the app is raw data.

You can now use this to monitor how fatiqued you are. Don’t compare your HRV to others. Instead, work out what’s normal for you and use that when monitoring fatique on a daily basis. You can even view a chart in the Garmin app of each individual reading.

While the app is good it should be stressed that these types of values are not going to be as precise as those taken with a chest strap. Also, there is one slight annoyance worth mentioning. The FIT files are automatically saved to Garmin Connect. There’s no way to switch this off. If you don’t want them there you will need to manually delete from the timeline.

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