Fitbit sleep monitor series#

That’s not to say they won’t be capable of better discriminating between sleep stages or providing even more data as the algorithms used by the devices evolve. However, Fitbit and Oura were deemed the most accurate out of eight commercial brands that were tested. The trackers tested also weren’t accurate in quantifying sleep stages (REM, non-REM). In fact, a 2021 study published in the journal Nature and Science of Sleep found that most wearable sleep tracking devices either overestimated or underestimated sleep metrics such as total sleep time, total wake time, and sleep efficiency. “These devices really shouldn’t be looked at for sleep staging at this point,” Chinoy adds. Translation: There’s only about a 50-percent chance your data is accurate. But “in terms of tracking light, deep, and REM sleep, basically all of the devices performed at only a medium level of accuracy,” says Chinoy. Most new wearables also track the sleep stages you cycle through throughout the night. They also tended to perform worse on nights with poorer or disrupted sleep, meaning your data in the morning may say you had a good night’s sleep, even if you were tossing and turning throughout, says Chinoy. The study authors hypothesized that Garmins’ relatively higher threshold for wake and lower threshold for sleep is what resulted in their poor performance. In general, the devices tended to overestimate sleep and underestimate wake. More Sleep Could Make You Less Injury-Prone That’s likely because, if you’re not moving and your heart rate is low, the devices-which typically use an accelerometer to detect movement and a light-based sensor to detect heart rate-have a harder time determining whether you’re actually awake or asleep. “However, if you’re in bed trying to sleep but still awake, they’ll only perform at a medium level of accuracy.” What that really means is “if you’re asleep, most these devices are going to correctly determine-with 90 to 95 percent accuracy-that you are indeed asleep,” says the Sleep study author Evan Chinoy, a sleep research scientist at the Naval Health Research Center in San Diego, CA.

Fitbit sleep monitor series#

The Apple Watch Series 3 and Garmin Vivosmart 4 fell at the other end of the spectrum. They found that all of the devices except the Garmin performed as well as or better than actigraphy on sleep/wake performance measures.Īdditional research published in the Nature & Science of Sleep Journal in October 2020 found that the Fitbit Ionic and the Oura Smart Ring possessed the lowest degrees of error in sleep tracking compared to an electroencephalography (EEG)-based device as well as other wrist-based trackers, including the Beddit Sleep Monitor 3.0, Fatigue Science Readiband, Polar A370, and WHOOP Strap 2.0. The gold-standard sleep assessment technique, polysomnography (PSG), isn’t possible outside of a laboratory or clinic, so researchers compared the results of four wearable sleep-tracking devices (Fatigue Science Readiband, Fitbit Alta HR, Garmin Fenix 5S, Garmin Vivosmart 3) and three non-wearable (EarlySense Live, ResMed S+, SleepScore Max) sleep-tracking devices against the mobile sleep assessment standard, actigraphy. But are these devices even accurate? It depends on the device you’re using, a December 2020 study published in the journal Sleep found. What Happened When I Tried a Sleep CalculatorĪ good night’s sleep is so crucial to exercise recovery and performance that the sleep tracking wearable business is booming sales are projected to grow 15.8 percent per year between 20, according to market reports.