There are few things as good for you as a good night’s sleep. Sleep replenishes body and mind and keeps you operating at optimal levels. If you want to track your sleep habits, you’ll find that many smartwatches and fitness trackers come with sleep-tracking capabilities. The best fitness tracker for sleep is one that’s comfortable to wear in bed, provides accurate data and lasts all night.
At a fraction of the cost of other options, the Fitbit Versa 4 impressed us with the overall accuracy of its sleep tracking, recording various sleep stages that you could then examine in its companion app. For more granular data, you do need to subscribe to the Fitbit Premium service. Nevertheless, it was comfortable to wear, and its battery life impressed, taking two days just to get down to half capacity.
It might look crazy to use something this big and rugged as a sleep tracker, but the Apple Watch Ultra 2 surprised us the most with its comfort. Made of titanium, which is lighter and stronger than steel, the Ultra 2 was easy for us to forget despite its size and dazzling screen. That screen gets as dim as 1 nit, too, so it won’t disturb you if you glance at it at night. Apple’s Health app provides sleep-stage tracking, heart rate and breath rate, and works with the watch functions to provide scheduled sleep times and soothing wake-up alarms.
The sleek lines of a flagship Apple Watch like the Series 9 made it easier to wear to bed than some other options, and it delivered clear results that didn’t make any demands. Like the Ultra 2, the Apple Watch Series 9 has a bright screen that can get as dim as 1 nit in a dark room. Its gently rounded corners and edges make it less obtrusive than other fitness trackers and smartwatches we tested, especially when paired with a soft fabric watch band. It tracks the same metrics as the Ultra 2 and, notably, can estimate time spent in bed even if you’re not wearing it.
The Vivoactive 5 from Garmin is an excellent value overall for a fitness tracker with smartwatch capabilities. As a sleep tracker, its data was accurate and thorough based on our comparison with other devices. It provides statistics such as total hours of sleep, sleep stages and sleep movement, and your “sleep coach” provides recommendations based on this data to help you improve your overall sleep score. While some may find its bulky design uncomfortable to wear in bed, if you don’t anticipate that being an issue for you, for goal-oriented types, the Vivoactive 5 provides all the information you need and then some.
Sleep monitoring can do more than tell you how long you slept. Fitness trackers can measure how many times you wake up, how much time you spend asleep versus simply lying in bed, and estimate how long you spend in various stages of sleep.
Our sleep can be divided into three stages, with various effects and benefits.
How long we sleep versus how long we need to sleep varies from person to person, but getting less sleep than we need is always a bad thing.
It can be difficult for a consumer to know how accurate a fitness tracker is at sleep monitoring. These devices don’t measure sleep directly, but infer your sleep based on data they gather from movement and heart rate sensors. No consumer device currently compares to the accuracy of a medical sleep study.
The key to accurate sleep tracking is comfort: if a fitness tracker is uncomfortable to wear in bed, you’re probably not going to want to sleep in it consistently.
When it comes to sleep tracking, you need a fitness tracker or smartwatch that not only lasts a full day of activity, but also all night without running out of charge.
We tested fitness trackers and smartwatches in real-life situations including wearing them to bed with sleep tracking enabled. For sleep tracking, we noted how easy it was to set up sleep tracking and how detailed the sleep data was afterward, as well as how much data we could access on the watch itself versus on a smartphone with an app. We specifically paid attention to:
Aside from the devices listed here, we also tested the Samsung Galaxy Watch6 and Watch6 Classic as well as the second-generation Apple Watch SE. We didn’t feel that either Samsung was particularly accurate with their sleep tracking, at least in our testing, while the Apple Watch SE was less comfortable to wear to bed than the other Apple Watches..
Wearing a smartwatch or fitness tracker to bed each night can give you fascinating insights into your sleep habits. Over time, you’ll come to notice what’s normal for you, as well as what might trigger a poor night’s sleep (such as a lack of exercise).
The last thing you want to do, however, is make your fitness tracker become the source of sleep anxiety rather than a remedy; you don’t want a fitness tracker to keep you up worrying about how well you’ve slept. At the end of the day, everyone has different sleep needs. And if you do get a poor sleep score, don’t fret — just consider it a good excuse to take a nap.
Jmar Gambol is a writer, product tester and experienced sleeper who personally tested several smartwatches for BestReviews, including sleep tracking. He has worn a smartwatch to bed regularly but has learned to take it off if it’s going to bother him overnight.
