You diligently track your steps, sleep schedule, and exercise routine using a smartwatch. But what about your stress levels? More fitness wearables, like smartwatches and rings, now have a stress tracking feature built right in. If you haven’t tried one yet, you might find that the extra personal info helps you zero in on what’s got you feeling overwhelmed or burnt out so that you can make a change.
Before you start eyeballing your stress tracker though, it’s important to keep in mind that stress is a very personal thing. “Stress tracking is unique in a sense because stress is perceived differently by everyone,” says Dr. Kristen Casey, a licensed clinical psychologist who specializes in stress management. You can go through a breakup or have a big meeting at work and perceive it as incredibly stressful, Casey says, while someone else might float through those same experiences with ease.
Because people have different situations and different dispositional traits, Casey explains that some folks simply handle stress better than others. That’s why it’s so important to focus on how you feel as you analyze your stress data — as in your perceived stress, or when the level of environmental strain exceeds your capacity to adapt and cope with it.
With that in mind, here’s everything you need to know about tracking your stress levels on a wearable so that you can keep it all in check.
How Stress Tracking Works On Smart Watches
If your smartwatch has a stress tracking feature, it’s looking at data that show what’s going on in your body, like heart rate variability (HRV) and mobility. HRV is the difference in time between each heartbeat, which can indicate stress. “HRV can be a helpful tool that we use to assess our autonomic nervous system state,” Casey explains.
As a refresher, the autonomic nervous system is divided into two parts: sympathetic and parasympathetic. The sympathetic nervous system is your stress response, kind of like fight-or-flight, while the parasympathetic is the opposite. “It manages our relaxation response, aka when our body returns to a calm state or ‘homeostasis,’” Casey says.
Sympathetic nervous system arousal can be indicated by subjective experiences — such as, “I’m noticing that I’m having stressful thoughts and emotions at the moment” — as well as physical markers like increased heart rate. “This is where HRV comes into play,” Casey explains. The stress tracker compares these highs and lows against your norms. “If it notices something out of the ordinary, it may alert you that your heart rate is too high or low,” she says.
Depending on the smartwatch you have, it will likely track other things like motion and mobility, which are measured by steps and exercise. Even though movement doesn’t necessarily indicate stress, Casey says it’s still great data to have if you’re looking to enhance your well-being or reduce stress through exercise.
How Stress Tracking Works On Smart Rings
Many smart ring models offer features that look at a few key data points like motion, skin temperature, and heart rate to reveal when your stress levels are high. “You might notice some heart rate variability throughout the day, which can allude to excitement, stress, or anxiety,” Casey says (just as you’d see on a smartwatch).
Smart rings often measure your temperature — and when it fluctuates, it can provide more info about your stress levels, explains Casey. Ever notice how stress can make you feel hot? “We notice slight fluctuations in temperature when someone is stressed,” Casey says. “It depends on the accuracy of the tracker of course, but in lab conditions, we notice a skin temperature change of 0.1 or 0.2 Celsius.” While it’s a slight change, Casey notes it is a physiological marker for stress since your temperature is controlled by your sympathetic nervous system.
Stress trackers also tend to pull from your sleep data, since how well you sleep is often connected to how stressed you feel during the day. “We notice that people have a dip in core temperature as they sleep, and we know sleep is helpful for memory consolidation, energy restoration, and emotional regulation,” Casey says. “If we aren't sleeping well, it's likely to affect our stress. And if we're stressed, it's likely to affect our sleep.”
How To Assess The Data
It’s helpful to jot down how you feel throughout the week so that you can combine that info with the data collected from your stress tracker. The reason? “These tracking devices may be helpful for noticing changes in your heart rate or movement,” Casey says, “but they may not necessarily indicate a stressful experience.”
Remember, your heart rate can spike when you’re feeling happy or excited or when you’re exercising, and as a result, the data don’t only indicate negative, stressful experiences. If you have notes, you can refer back to them and see that that huge spike on Wednesday wasn’t due to a stressful moment, but because you went on a two-mile run.
If you aren’t into journaling, Casey says you may prefer to use an app, like Stress AI, that allows you to click a box that offers a description of your stress or mood. “This app captures HRV and resting heart rate (HR), as well as sleep and activity levels, which we know help with stress management,” Casey says.
After tracking for about a week, Casey suggests looking over the info from your wearable to see if you can spot any patterns. “There might be some connections you can make, which is the most important part,” she says.
Both smartwatches and rings are still being validated in the research, Casey adds, but can provide helpful information that you may want to keep track of or bring to your therapist or doctor for more insight.
Why You Should Track Your Stress Levels
While you might not notice your stress day-to-day, tracking it allows you to look back and see that you were actually pretty on edge, say, four out of the seven days of a week. You can then use this information to see patterns and connections based on what was happening on those four days, Casey says, and from there make more informed decisions about your life.
It might become clear that certain aspects of your job cause you stress, or maybe it’s your commute or that Friday evening phone call home. “If you weren’t tracking stress, you wouldn’t know that it was the job stressing you out,” Casey says. “You might think it’s just your overall perspective on the world.” By tracking stress and taking notes, you can really zero in on the cause — and then do something about it.
If you’re experiencing a lot of stress, tracking it can also help you to see how it’s affecting your mood, work, relationship, and overall well-being, Casey says. Of course, it’s also nice to take note of when you aren’t stressed. “That’s just as important,” she adds. “What were you doing on the days you were less stressed?” Answer that question, and see if it’s possible to incorporate more of that into your life.
Asgari Mehrabadi, M. 2020. Sleep Tracking of a Commercially Available Smart Ring and Smartwatch Against Medical-Grade Actigraphy in Everyday Settings: Instrument Validation Study. JMIR mHealth and uHealth. https://doi.org/10.2196/20465.
Chalmers, T. 2021. Stress Watch: The Use of Heart Rate and Heart Rate Variability to Detect Stress: A Pilot Study Using Smart Watch Wearables. Sensors (Basel). doi: 10.3390/s22010151.
Choi, D-W. (2018). Association between Sleep Duration and Perceived Stress: Salaried Worker in Circumstances of High Workload. Int J Environ Res Public Health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5923838/
Hernando, D. 2018. Validation of the Apple Watch for Heart Rate Variability Measurements during Relax and Mental Stress in Healthy Subjects. Sensors (Basel). doi: 10.3390/s18082619.
Kim, H-G. (2018). Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature. Psychiatry Investig. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5900369/
Lecic-Tosevski, D. 2011. Stress and personality. Psychiatriki. PMID: 22271841.
Vinkers, C. (2013). The effect of stress on core and peripheral body temperature in humans. Stress. https://pubmed.ncbi.nlm.nih.gov/23790072/
Zaccaro, A. 2018. How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing. Frontiers in human neuroscience. https://doi.org/10.3389/fnhum.2018.00353.
Dr. Kristen Casey, licensed clinical psychologist