How Does a Fitbit Track Sleep?

Fitness trackers are a popular way to monitor physical activity and sleep habits, but can you trust the data they provide? According to an expert at the Stanford Center for Sleep Sciences, these devices are beneficial because they encourage greater emphasis on sleep. However, they provide relatively little data compared to the gold standard for measuring sleep, polysomnography.

Polysomnography is a combination of different physiological measures used to define and characterize sleep. It involves EEG electrodes that measure brain waves, as well as other measures such as a snore mic, chest and abdominal belts for breathing, and muscle and EKG monitors. Patients stay overnight for these sophisticated sleep studies that require extensive equipment.

In contrast, fitness trackers use accelerometers to measure movement, which provides an indirect approximation of sleep. While an algorithm is used to estimate deeper and light sleep based on the relative amount of movement, they cannot precisely measure sleep latency (the time it takes to fall asleep) or the time spent awake during the night.

Despite their limitations, fitness trackers still serve a valuable purpose in monitoring sleep habits. A lack of sleep can affect mood, concentration, and overall health. Fitness trackers can help motivate individuals to prioritize getting enough sleep in addition to physical activity.

In conclusion, while fitness trackers are not as accurate as polysomnography, they are still beneficial in encouraging healthy sleep habits.


How does Fitbit know when you sleep?
Fitbit estimates your sleep stages using a combination of your movement and heart-rate patterns. When you haven't moved for about an hour, your tracker or watch assumes that you're asleep.
Does Fitbit accurately track sleep?
Sleep Trackers Don't Measure Sleep Very Well So, do FitBits, Apple Watches and Oura Rings track sleep with accuracy? The answer is, not really. Particularly when it comes to sleep stages. These wearables measure movement very well and are great when used for tracking steps and exercise.
Can Fitbit detect sleep apnea?
Can the Fitbit Detect Sleep Apnea? Newer models of the Fitbit report on almost all of the health data signals used to detect sleep disorders, but they cannot combine that data to diagnose sleep apnea.
Do you have to tell Fitbit you are sleeping?
Most Fitbit activity monitors come with built-in sleep monitoring that works automatically — there's no need to tell your Fitbit you're going to bed, as it will just sense it. Fitbit uses several methods to detect that you're asleep.