Not sure if it’s time for stress management? Check your watch.
Toxic stress during the pandemic has spurred a wave of new stress management tracking tools. Health trackers from companies like Fitbit, WHOOP, Oura Ring, Samsung, Garmin and others aim to make users more aware of stress and learn tools to manage it.
Stress measurement
These trackers collect information on metrics such as heart rate, skin temperature, and sleep quality through state-of-the-art sensors in smartwatches, bracelets, and rings. They also continuously assess heart rate variability, or HRV, which is the balance between the body’s systems for approaching a challenge and slowing down to rest.
Some, such as Google’s Fitbit and Pixel, measure electrical changes in specific sweat glands that respond to stress and emotional arousal. This invisible “electrodermal” sweat “contains additional information about stress beyond HRV,” says Hugo Posada-Quintero, a professor of biomedical engineering at the University of Connecticut.
When combined, these metrics reveal psychological stress—such as chronic worry or a deteriorating job—that impairs health and might otherwise escape our awareness. This so-called “unrecognized stress” is common in people who lead a busy lifestyle.
Companions show that other causes of stress, such as exercise, are beneficial in the right amounts. Although some physical responses to exercise resemble unhealthy stress, tracking devices can distinguish good stress from bad. If you move your body in certain ways, I can tell that your racing pulse is the result of running, not anger.
Stress results and recommendations
All this information is compiled into a daily stress management score. For example, Fitbit and Garmin offer scales from 1 to 100, where 100 means you handled stress flawlessly. In various applications, these results usually focus on three main factors: mental stress, physical exertion and sleep quality.
If you’ve pushed yourself too hard, your app might advise you to go back to exercising. If anxiety is lowering your overall score, your app will recommend meditation sessions. In October, Oura partnered with Headspace to add guided breathing work and visualizations to its audio library.
These systems also notify you in real time when stress is at its peak, with suggestions for reducing it. This may take some time to get used to. When Hananeh Esmailbeigi, a biomedical engineer at the University of Illinois at Chicago, got her first notification from her Apple Watch that she was stressed, it made her even more stressed. Lately, though, she says the pop-ups have become much-needed reminders to use the stress-management techniques she’s learned from books and podcasts.
Quantifying your habits and experiences can encourage behavioral changes to manage stress. If, for example, you eat a large, sweet meal before bed, the stress number goes up because the digestive overload makes the heart beat faster. The sensors will additionally reveal how a late meal disrupts sleep.
Objective data make it difficult to overlook or rationalize mistakes, strengthening the motivation to avoid them. Stress tracking also reveals specific triggers of negative emotional stress, so you can mitigate or avoid those situations.
Trackers are also stepping up positive stress. This goes beyond exercise and includes intermittent fasting, saunas and cold immersion. These experiences burden us momentarily, but unlike toxic stress, they have a rebound effect that strengthens the body and mind.
“Our bodies need stress,” says Kristen Holmes, vice president of performance science at WHOOP. “It’s important to understand dose and frequency.”
Some trackers use AI trainers that analyze your stress data and provide personalized advice. In September, WHOOP partnered with OpenAI to integrate a large language model. “It’s like texting a friend about your health, but this friend knows more about you than your doctor,” says Holmes, Ph.D. candidate in psychology at the University of Queensland.
In early 2024, Fitbit will begin rolling out similar AI coaching. Overall, these models are attractive, but they are a work in progress, Posada-Quintero says. He thinks they will become more effective because they are designed more specifically for health.
Challenges and workarounds
One challenge with using these tracking devices is accuracy. People prefer devices designed for the hand area, but sensors work better in other areas. Constant movements of your hands can distort the data. “There’s a reason they haven’t been yet [FDA-approved] as medical devices for certain metrics like HRV,” says Esmailbeigi.
There are some workarounds. Algorithms remove many of the “motion artifacts”. With WHOOP, you can wear a band on your biceps, which produces less movement and more precision. To get more information about electrodermal sweating, you can place your palm on the watch face of a Fitbit watch, which measures multiple sweat glands while you are still for two minutes.
The remaining issue is the distinction between negative and positive emotions. Let’s say you were feeling excited after getting a promotion at work. Your device may confuse your happiness with anxiety. To address this issue, some apps allow you to record what’s actually happening when stress is detected through journaling tools, such as Oura’s recently launched AI-enhanced Reflections.
Rosalind Picard, an MIT Media Lab professor and pioneer in computational emotion measurement, says more research is needed to design markers that people can use to gain awareness of their feelings, including stress. “User devices oversimplify the complexity of stress,” says Picard.
Until then, Esmailbeigi recommends keeping a journal outside of the app to reflect on your stress levels, what you’re learning from the device, and issues that affect measurements — for example, a smartwatch that slides down your wrist too much. (Esmailbeigi is exploring a solution to that problem: putting sensors in mouthguards.)
Picard founded a smartwatch company called Empatica that meets FDA requirements for measuring electrodermal activity, HRV and more. It is available to participants in clinical trials. There’s still a long way to go before commercially available sensors and stress results, Picard says, but there’s reason to be excited. “When we built the first devices that worked, at first we thought this was crazy,” she says. “There it is, it’s happening.”
This story was originally published on Fortune.com