Garmin's stress score: is your smartwatch in tune with your mood?

My Garmin Forerunner 265 doesn’t know me at all, especially when it comes to stress. Or does it know me better than I know myself?

It was early Saturday morning, just me, my daughter, and a couple hundred other toddlers gathered for the premiere of some Lithuanian cartoon. As this wasn’t horrific enough, the projector broke and we had to wait for nearly an hour before they managed to turn on the movie. An hour killing time with a couple of hundred toddlers.

“You had almost no restful moments on this day,” my smartwatch told me at the end of the day, giving me a stress score of 44 (out of 100).

But it wasn’t only the movie theater experience that irked me that day. I’d had quite a few drinks the night before and noticed that my Garmin is almost always able to recognize a hangover by indicating higher stress levels the day after.

Garmin stress tracking

Garmin gives you a stress score (0-100), estimated by the Firstbeat Analytics engine. Using the optical heart rate sensor on the back of a smartwatch, it records HR (heart rate) and HRV (heart rate variability) data and comes up with a stress score.

It does not measure your stress level during physical activity, be it a hard-core exercise like boxing or just a quicker stroll through a park. This is because although your heart rate is elevated, you might be as happier than ever – not every higher-intensity moment should be mistaken for stress.

The goal is not to reduce your stress level to 0 – that’s not even really possible. The idea is for you to establish a healthy balance between the heart-racing and restful moments.

When your stress level is above 25, the activity within your sympathetic (so-called fight-or-flight) autonomic nervous system (ANS) is greater, and when it’s below 25 – you’re in rest-and-digest mode (higher activity within the parasympathetic ANS).

While your watch can show you some trends, Garmin stresses that your device doesn’t really know the reasons why you are stressed, and it’s up to you to tap into that data to boost the quality of your life.

“Elevated stress levels could also be the result of happier situations, such as the excitement of a new job, the thrill of a first date, or the jitters a runner feels the morning of a big race. Keep in mind that excessive exercise, consumption of stimulants, poor nutrition, and getting sick can also produce higher than normal stress levels,” Garmin explained.

Curious to learn more about the technology and what it can do for me, I turned to some experts to see whether this stress-tracking obsession makes sense.

Not a magic wand

We have a very different reaction to stress – one of my girlfriends suddenly gets nauseous and nearly vomits, another suffers headaches, while I myself suddenly feel very sleepy and my heart rate goes down. No smartwatch is (yet) able to capture the subtleties of human nature and our response to stressful situations.

“Stress is a complex beast that affects not only our bodies but also our minds and lives. So, while a sudden increase in heart rate may indicate a stressful moment during a workout, it could also be because you're excited about setting a new personal record or have just had a caffeine shot,” Benedict Ang, a personal coach from Total Shape, told Cybernews.

However, the ample data can help us form some healthier habits after learning how to recognize stress patterns.

“Perhaps you've noticed that when a deadline is approaching, or you're stuck in rush hour traffic, your stress levels rise dramatically. Armed with this knowledge, you can begin taking proactive steps to better manage your stress, whether through mindfulness techniques, exercise, or simply taking a break when you feel overwhelmed,” Ang added.

Alex Reijnierse, a stress management expert at Paleo Stress Management who has personally navigated the turbulent waters of chronic stress, says that smartwatches are useful tools in self-monitoring, but they aren't the magic wand that provides all the answers.

“Relying solely on them to manage stress would be like trying to fill a pot of water with a strainer – full of big holes and destined to disappoint!” Reijnierse said.

And, of course, let’s not forget the question of privacy.

“Mixing stress data with other health info that your watch collects can give a pretty full picture of your personal health. A study from 2022 found that almost half of the people wearing these watches are worried about who else might be peeking at their health data,” Joseph Harisson, an IT expert with a background in technology and a CEO of IT Companies Network, told Cybernews.

You might get stressed just by constantly tracking how stressed you are.