How does Garmin measure stress? [Final Answer]

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If you read our articles regularly, you already know that we consider the Fitbit Charge 5 one of the best health fitness trackers currently available. You also know that we think of the Heart Rate Variability (HRV) as a way to understand better how we feel.

Just a reminder, the Heart Rate Variability corresponds to the interval between each heartbeat. Our heart does not tick like a metronome, and minuscule milliseconds differences will occur each time the heart pumps blood in our body.

Fitbit devices measure the HRV while you sleep, and the metrics will be used to compute the Daily Readiness Score that will help you know if today is a good day for training for a marathon or if you’d better lay on the sofa to watch TV.

Garmin devices and algorithms put a great deal of emphasis on stress monitoring. Actually, you would be surprised to know that even if you sleep eight hours, your sleep score may not be as good as you may expect…and all of that because of your underlying stress. 

The natural question is then to wonder how a Garmin device manages to detect stress. So we checked it using the Garmin Vivosmart 5 and were surprised by the measurement of the Garmin Stress Score.

Do you want to know? So, keep on reading. We will tell you everything we learned.

How does Garmin measure Heart Rate Variability and calculate a stress score?

In June 2020, Garmin acquired Firstbeat Analytics, and it changed everything. Up to this point, Garmin was mainly known for being on the top of its game for GPS analysis. 

FirstBeat Analytics develop sensors and algorithms that make the most of vitals data and especially heartbeat detection.

As we mentioned, the Heart Rate Variability refers to the slight time differences between two consecutive heartbeats

Your heart beats at a consistent rate no matter the circumstance. This pace fluctuates based on what you are doing at any time. When you are at rest or relaxed, your heart rate will be slower, but it will speed up when you are active, under stress, or when you are in danger. Your breathing patterns and the demands placed on your body both affect the rate of your heartbeat, which might change. As you get older, there is a typical tendency for your heart rate variability to decrease as well.

The heart’s beating is managed by a part of the neurological system known as the autonomic nervous system. Even when you’re asleep, this region of your brain and a group of nerves continue to function without your conscious awareness of what they’re doing. Your sympathetic nervous system and parasympathetic nervous system are the two primary components of your autonomic nervous system. In a nutshell, the sympathetic nervous system and the parasympathetic nervous system function as follows:

  • Sympathetic: This is where the “fight or flight” response originates in the human body. In times of danger, it prevents dangerous spikes in the heart rate and blood pressure by regulating blood flow.
  • Parasympathetic: Especially after you’ve been in the “fight or flight” phase, doing this can assist restore equilibrium to the sympathetic nervous system and taking control of the body’s natural relaxation reaction. It does so by, among other things, lowering both your heart rate and your blood pressure, which it does most effectively while you are relaxing.

By analyzing the HRV, a Garmin smartwatch will detect episodes of low stress, medium, or high stress that will be used to compute the overall Garmin Stress Score.

What differentiate Garmin from other smartwatch makers is that the Hear Rate Variability is detected and calculated at all time. Interestingly, Garmin devices will not present the results as a millisecond metric but will define a stress score ranging from 0 to 100.

  • Being at rest is indicated by a score between 0 and 25, 
  • A score between 26 and 50 indicates a low-stress level
  • A score between 51 and 75 indicates a moderate stress level,
  • A score between 76 and 100 indicates a severe stress level.

The days’ measurements will be combined to define an overall stress level. Thanks to the Firsbeat algorithms we described.

How to make the most of Garmin Stress Score?

First, let’s describe how to access the Stress Score. It could not be easier. First, you have to open the Garmin Connect App on your smartphone and push on the My Day icon.

The next step is to tap on the stress level score that will let you access how the different levels of stress were divided throughout the day. 

It is important to note that the heart rate meaning influences the HRV that your heartbeat will increase when you exercise, which may impact your heart rate variability.

Thanks to its sensors and accelerometers, your Garmin watch or tracker will understand that you are exercising and not penalize you and your stress score for staying healthy and practicing regular physical activity.

Another way to analyze the evolution of your stress is to use the Garmin Connect website. Just log into it using your email and password, and your results will be accessible in the Health Status, Stress folder.

As a side note, stress levels will also impact the Garmin Body Battery, which measures the body’s energy reserves. When on the Garmin Connect website, we suggest that you click on the Body Battery tab. You will then obtain a graphical representation of how your stress impacts your energy reserves.

According to Garmin, the “Body Battery is calculated by analyzing signals from your heart like heart rate variability (HRV) and stress and sleep quality and activity.” It makes a lot of sense that measuring the HRV and the stress will impact how energetic you feel. We all know that having a stressful day at work will directly influence how drained we feel.

We like Garmin devices because, unlike Fitbit, you will not have to pay to check your results for up to one year. We are thinking of you, Fitbit Premium.

As a side note, the Garmin Vivosmart 5 lets you measure your stress on-demand, meaning that you have to push on the stress icon to get an instantaneous measure. We love it. A nice and easy way to check if your body is in line with how you feel.

Garmin as the reference device for scientific studies involving stress measurement

We hope to have convinced you that the Garmin Stress Level measurement is a key indicator that will also impact your sleep tracking and overall sleep score. Physiological stress is good, but too much stress will impact your overall energy level. An accurate Heart Rate Monitor such as the sensors included in a Garmin device will extract relevant stress information from raw heart rate data.

Interesting, numerous scientific studies relied on Garmin devices to measure stress levels. One interesting one was conducted in Poland and aimed at measuring the level of stress of dental students during training. The results were expected but demonstrated two things: First, studying dental science is stressful, and two, Garmin association with FirstBeat provided one of the best stress level detection devices.

To Wrap Up

Garmin Devices rely on analyzing the small-time discrepancies between two heartbeats that form the Heart Rate Variability. The stress score is informative to look at as it is directly related to your autonomic nervous system and can be seen as the mirror of your brain.

Thanks to Garmin’s acquisition of FirstBeat, Garmin is now one of the best wearable companies for stress tracking. Unfortunately, measuring the HRV and calculating your stress levels continuously will impact the battery life, which may be one of the reasons the Garmin Vivosmart 5 comes with a grey levels basic screen that can not compete with AMOLED bright displays but has the advantage of giving up to six days of battery life. The perfect fitness tracker is not there yet, but we are getting close.