Fitbit's Sleep Tracking: How Does It Work?

Sleep is an essential component of health, and its timing, duration, and quality are critical determinants of a person's overall health. Fitbit offers advanced sleep tools that can help users get better rest, boost energy, and improve their well-being. Fitbit's sleep feature estimates sleep stages using a combination of movement and heart-rate patterns. When the user hasn't moved for about an hour, the tracker or smartwatch assumes that the user is asleep. Fitbit Premium also has guided programs developed with sleep experts, including Habits for Restful Sleep and Get More Sleep.

Fitbit's sleep tracking features

The sleep tracking function on Fitbit works by monitoring your heart rate and physical movement while you sleep. It uses these metrics to estimate the different sleep stages you go through, including light sleep, deep sleep, and REM sleep. When you sync your device in the morning, you can access this data and view your sleep stats for the previous night. Fitbit's sleep tracking is automatic, so you only need to wear your device to bed to start collecting data.

The Fitbit app provides additional insights and tools to help you understand and improve your sleep. It offers a daily sleep score, which is based on your heart rate, time spent awake or restless, and sleep stages. You can also set sleep goals, bedtime reminders, and silent alarms through the app. Fitbit Premium offers more advanced sleep features, such as Sleep Profiles and guided programs developed with sleep experts to help you achieve better sleep.

The snore and noise detection feature on the Fitbit Sense and Versa 3 devices allows the device to track noise levels and check for snoring throughout the night. This feature provides a summary report when you wake up, giving you insights into your sleep environment.

Overall, Fitbit's sleep tracking features aim to provide a comprehensive understanding of your sleep patterns and quality, offering personalized recommendations to help you optimize your sleep.

Heart rate monitoring

Fitbit devices can track your heart rate while you sleep and record it in the Fitbit app to help you understand your sleep habits. This is done through the heart rate sensors on the device. The Fitbit Charge 6, for example, is equipped with heart rate sensors. The Fitbit Alta HR, an update to the original Alta, also includes heart rate sensors. The company had to develop a new chip to fit its heart rate technology into the tiny Alta wristband, which is 25% smaller than the Charge 2.

The heart rate data is used to calculate your Sleep Score, which is based on your sleep duration, quality, and restoration. A lower heart rate during sleep indicates more restorative sleep. The Sleep Insights tool in the Fitbit app can show you how much time you spent in each stage of sleep: light, deep, and REM. This is important because the amount of time spent in each sleep stage can affect the quality of your sleep. For instance, Dr. Heneghan says that "to feel refreshed in the morning, you want about 15-20% of your night's sleep to be deep sleep."

Fitbit's heart rate tracking can help you improve your sleep quality by allowing you to make adjustments to your routine. It can tell you if you've gotten enough deep sleep, how restorative your sleep is, and how consistent your sleep is night after night. You can also use the data to correlate restless nights with factors such as stress, intense workouts, or alcohol consumption.

It is important to note that some studies and users have questioned the accuracy of Fitbit's heart rate tracking, particularly during intense exercise. However, Fitbit maintains that its technology meets industry expectations, with an average percent error of less than 6%.

Sleep stages

Sleep is an essential component of health, and its timing, duration, and quality are critical determinants of a person’s overall health, playing a role in metabolic and emotional regulation, performance, and memory. Fitbit's sleep feature estimates sleep stages using a combination of movement and heart-rate patterns. When you haven't moved for about an hour, your tracker or smartwatch assumes that you're asleep. Additional data, such as the length of time of movements that are indicative of sleep behavior (such as rolling over), can also help confirm that you're asleep.

Fitbit's sleep tracking functions monitor your slumber, recording the amount of time you're asleep as well as the quality of the sleep you're getting. Fitbit uses movement and heart rate patterns to estimate sleep cycles from the previous night. A quick way to gauge your sleep is the Fitbit Sleep Score, which is based on heart rate, the time spent awake or restless, and sleep stages. The overall sleep score is a sum of your individual scores using three components: sleep duration, sleep quality, and restoration, for a total score of up to 100.

While you’re sleeping, your device tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV). These numbers fluctuate as you transition between light sleep, deep sleep, and REM sleep stages. Fitbits with heart rate monitors can discern between light sleep, deep sleep, and REM sleep, when vivid dreams are more likely. The Sleep Profile feature, a more detailed breakdown of your sleep that appears once a month, is available only on specific models.

Fitbit Premium offers several tools that may help you get better sleep, including a daily sleep score breakdown that can help you understand where you can improve your sleeping habits and receive personalized guidance. Fitbit Premium also has guided programs developed with sleep experts, including: Habits for Restful Sleep, aimed at helping you build better daytime habits to help achieve deeper sleep at night. Another program in Premium is Get More Sleep, which may help you improve your nighttime routine and work towards longer sleep with goals and relaxation tools.

Fitbit Premium

Additionally, Fitbit Premium provides access to a library of audio content, including guided meditations and sleep aids, which can help you relax and prepare for sleep. The subscription also includes a monthly personalized analysis of 10 key metrics, offering a comprehensive understanding of your sleep habits and quality.

The Fitbit device itself plays a crucial role in sleep tracking. When you wear your Fitbit to bed, it automatically detects when you're asleep by sensing periods of inactivity and changes in your heart rate. It tracks your sleep stages, including light sleep, deep sleep, and REM sleep, and provides insights into your sleep patterns and quality.

Fitbit app

The Fitbit app is an essential tool for tracking your sleep patterns and quality. It provides a detailed analysis of your sleep habits and offers various features to help you improve your sleep.

To get started with sleep tracking on the Fitbit app, you need to pair it with a Fitbit device. The app is compatible with both Android and iOS smartphones. Once you have the Fitbit device, simply wear it to bed, and it will automatically start tracking your sleep when it detects that your body is going into sleep mode.

The Fitbit app offers a Sleep Score, which is a quick way to gauge your sleep quality. This score is based on your heart rate, time spent awake or restless, and sleep stages. The app also provides a breakdown of your sleep duration, quality, and restoration. You can view your sleep stats for the previous night, as well as trends over time, by accessing the Today tab in the app.

Additionally, the Fitbit app allows you to set sleep goals and bedtime reminders. You can adjust your total sleep target and target bedtime through the app's settings. It also offers a silent alarm feature, which vibrates gently to wake you up without disturbing your surroundings.

For more personalized insights and guidance, you can subscribe to Fitbit Premium. This subscription service provides a monthly sleep analysis of 10 key metrics, helping you to better understand and improve your sleep habits. Fitbit Premium also includes guided programs developed with sleep experts, such as "Habits for Restful Sleep" and "Get More Sleep," which offer relaxation tools and help you establish a healthier nighttime routine.

Frequently asked questions