How Do Wearable Fitness Trackers Monitor Your Sleep?

By Brian Acton

There are many ways to work on improving the quality of your sleep - you could get a more supportive mattress, upgrade your pillows, get more exercise, or establish a consistent sleep routine. But if you really want to understand your sleeping patterns, you may be interested in buying a wearable fitness tracker that can monitor your sleep.

But how does wearable sleep tracking work, and what information can fitness trackers tell you that will help you improve the quality of your sleep?

Most Wearable Fitness Trackers Double as Sleep Trackers

Many wearable fitness trackers, including FitBit, Garmin, and other brands offer sleep monitoring as a built-in feature (there are also devices available that only track sleep). These trackers are intended to monitor your sleep by tracking your movements, with the goal of giving you insights into your sleep quality.

Generally, when you’re ready to go to sleep, you’ll put your wearable fitness tracker on “Sleep Mode.” When activated, your tracker will start monitoring your sleep activity and recording data to give you a detailed sleep report in the morning. Over time, this data can, in theory, help the tracker app give you advice on how to improve your sleep.

How Wearable Fitness Trackers Monitor Your Sleep

Wearable fitness trackers use a method called “actigraphy” - essentially, tracking your body’s movements - combined with heart rate monitoring to monitor you during sleep and translate your movements into sleep data. According to many fitness tracker manufacturers, your movements and heart rate can help trackers identify when you’re asleep and when you’re awake and even track your sleep cycles.

While actigraphy can give you a high-level overview of your sleep, it isn’t the most accurate way to track sleep quality or sleep duration. According to News Medical, most fitness trackers have a high margin of error and aren’t the most reliable way to measure sleep performance.

The best method for sleep monitoring is polysomnography, which is typically performed in a sleep lab or sleep study center. The subject’s brain waves are detected and recorded using electrodes that are attached to the head. According to a study published by The National Center for Biotechnology Information, wearable fitness trackers can be a good supplement to polysomnography, but can’t surpass its level of accuracy.

What Can Wearable Fitness Trackers Tell You About Your Sleep?

Wearable fitness trackers can deliver sleep insights to you directly through a paired app. They may provide information about your sleep cycles (light, deep, and REM) and tell you how much time you spent awake and asleep throughout the night. Through these insights, they may be able to help you work toward establishing a more consistent sleep routine or take other steps to improve your sleep.

If you’re looking for daily monitoring and quick tips to improve your sleep quality, a wearable fitness tracker may be a good choice.

However, if you have a sleep disorder such as insomnia or sleep apnea, your wearable fitness tracker won’t be able to diagnose your condition or recommend a solution. In this case, it’s a good idea to undergo a sleep study to pinpoint the root of your problem and get treatment. 

Sources:

https://www.news-medical.net/health/How-Do-Wearables-Track-Sleep.aspx
https://exist.io/blog/fitness-tracker-sleep/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6025478/