- More than a third of Americans have used a device to monitor sleep, according to a recent survey from the American Academy of Sleep Medicine.
- Experts say the devices can offer a sense of what’s happening while you sleep, but they have some limitations.
- Whether or not you should use a sleep tracker depends on your anxiety levels and attitude towards sleep.
Using a sleep tracker seems like an easy way to learn about overnight habits, but can it really lead to a better night’s sleep?
According to a 2023 survey by the American Academy of Sleep Medicine (AASM), more than a third of Americans have used a device to monitor sleep.
Unlike medical sleep studies that record brain activity at labs, sleep trackers measure markers like breathing and movement to give insight into sleep patterns at home. While the devices can offer a sense of what’s happening during shuteye, experts say they have limitations as well.
Here’s what you need to know about these trackers, including whether you can rely on them to optimize sleep.
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How Sleep Trackers Work
Sleep trackers fall into several categories: apps that ask you to add information about sleep and other lifestyle habits, “wearables” such as rings and wristbands, and “non-wearables” that you typically keep under a mattress, pillow, or elsewhere on the bed. Devices often pair with an app that provides data and some analysis.
Each tracker works differently, but many of them offer insight into sleep duration, the quality of sleep, and sleep stages entered throughout the night. Some might also tell you about your sleep environment, such as the noise level or temperature in the room.
Many wearables gather data using a method called photoplethysmography (PPG), which involves shining a light into blood vessels to estimate the time between each heartbeat.
Additionally, devices often have motion-detecting accelerometers or gyroscopes, which sense the device’s position, Greg Potter, PhD, a sleep researcher and wellness speaker from Worcester, England, told Health.
How Much Deep Sleep Do You Need?
Are Sleep Trackers Accurate?
Experts agree that sleep trackers do a decent job of measuring sleep duration.
“The published research shows that many of the sleep trackers on the market likely give a decent estimate of how much sleep you are getting,” Michael Grandner, PhD, a licensed clinical psychologist who heads the Sleep and Health Research Program at the University of Arizona, told Health.
A recent study, for example, compared five commercial sleep-tracking devices to research-grade actigraphy (which measures body movements) and polysomnography (which measures brain waves, respiration, heart rate, and body movements). And for a 2021 study, researchers concluded that the seven total wearable and non-wearable devices tested performed well overall at detecting when 34 healthy younger adults were sleeping.
However, Daniel A. Combs, MD, an assistant professor of medicine and pediatrics at the University of Arizona, said the tools don’t generally provide reliable information about time spent in different stages of sleep, such as REM.
“The technology in these devices is robust, but we need to bear in mind that the trackers don’t measure sleep per se,” Potter said.
Experts also expressed skepticism about any guidance trackers offer.
“Some devices provide advice,” Grandner said. “Most of that advice, though, is not very good.”
The Benefits of Sleep Trackers
This tracks with the AASM survey, which found that 77% of sleep tracker users said the device was helpful, and 68% changed their behavior after using it.
“By making us more aware of our sleep habits, sleep trackers enable us to make adjustments to our sleep routines based on the data they provide,” de Zambotti said.
But he cautioned that people shouldn’t interpret sleep tracker data or use it to make decisions without relying on solid “guidelines.” “Without proper contextualization, the data can be rendered useless,” de Zambotti said.
Grandner acknowledged that a sleep tracker can be a valuable tool for managing sleep but that it should be used in conjunction with other strategies.
“Think of it this way—a bathroom scale won’t help you lose weight on its own,” Grandner said. “It’s an important part of a weight loss program but on its own, it can be helpful for some people, stressful for other people, and just not useful on its own most of the time.”
What Really Happens to Your Body When You Hit Snooze?
To Track (or Not Track) Your Sleep
Experts said that whether a sleep tracker makes sense for you can depend on your temperament and attitude toward sleep.
For some people, using a sleep tracker has the potential to fuel a phenomenon called orthosomnia, which is an unhealthy obsession with getting a perfect night’s sleep.
“I see this often in my clients with insomnia,” Joshua Tal, PhD, a clinical psychologist from New York, told Health. “The sleep tracker ends up causing more worry because the user worries about achieving certain levels of deep sleep or sleep continuity. The extra pressure to sleep ends up backfiring, causing more restless nights.”
That’s why Tal doesn’t recommend sleep trackers for people with high anxiety about their sleep habits.
Instead, “sleep trackers are good for people who are health conscious and motivated to make changes in their lives,” he said, “but who also can tolerate slip-ups and understand the overall goal of health rather than ‘success.’”
