Fitbit's Sleep Tracking: How Does It Work?

Fitbit's sleep tracking functionality helps users understand the quality of their sleep by quantifying the number of hours they sleep. Fitbit devices that track heart rate (except Charge HR and Surge) also track sleep stages. Fitbit estimates sleep stages by using movement and heart rate patterns. When the device detects no movement for about an hour, it assumes the user is asleep. The device tracks beat-to-beat changes in the user's heart rate, known as heart rate variability (HRV), which fluctuate as the user transitions between light sleep, deep sleep, and REM sleep stages. To track sleep with a Fitbit device, users must wear the device during sleep for at least 3 hours, and the device must have at least 40% battery before going to bed.

Fitbit Charge, Charge HR, and Surge automatically track sleep

The Fitbit Charge, Charge HR, and Surge automatically track your sleep. Similar to the Fitbit Force, you can use your Charge to automatically track your sleep. Simply wear your device to bed. You can also press and hold the button on the device before and after you sleep, similar to the Fitbit Force and Fitbit One. It is important to put the device into sleep mode as you're getting into bed and take it out of sleep mode once you're awake. After your first sync post-wake-up, you will see a sleep quality graph on your Dashboard (MAC/PS/iOS device, Android device, or Windows Phone).

To be eligible for a sleep profile, you must meet certain requirements. These include having a Fitbit Premium subscription, using a compatible device (Charge 5, Charge 6, Inspire 2, Inspire 3, Luxe, Pixel Watch series, Sense, Sense 2, Versa 2, Versa 3, or Versa 4), and wearing your Fitbit during sleep for at least 14 days during the previous month. Your sleep logs must include sleep stages data. You can check how close you are to getting next month's profile on the Sleep tile, located below your sleep graph. On the first of the month, you may check your sleep profile in the Fitbit app or on your Fitbit device.

Your Fitbit device detects and records naps that are at least an hour long. Fitbit estimates your sleep stages by using your movement and heart-rate patterns. When you don't move for about an hour, your tracker or watch assumes you're asleep. Additional data, such as the length of time when your movements indicate sleep behaviour (like rolling over), help confirm your sleep status. While you sleep, your device tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV), which fluctuates as you transition between light sleep, deep sleep, and REM sleep stages.

Sleep tracking is used to help quantify the hours and better understand the quality of your sleep. There are a number of different ways you can track your sleep, the easiest of which is using the sleep tracking functionality on your tracker itself. You can also set a bedtime reminder in the Fitbit app to help you maintain a consistent sleep schedule. When it's time to wind down for bed, you receive a notification on your phone. On certain Fitbit devices, you can also find a bedtime reminder on your device.

Fitbit Charge 3 may require manual input

The Fitbit Charge 3 can automatically track your sleep when you wear it to bed. However, you may need to manually put the device into sleep mode when you get into bed and take it out of sleep mode when you wake up. To do this, press and hold the button on the device for about 2.5 seconds until you feel a vibration and the display turns into a stopwatch. After your first sync post-wake-up, you will see a sleep quality graph on your dashboard.

If you have issues with your sleep data, you can try manually syncing your Fitbit device again. If the issues persist, check if your sleep setting is set to "Sensitive" and change it to "Normal" if it is. To accurately track your sleep, ensure that your device is positioned higher on your wrist, about 2-3 finger widths above the wrist bone. The band should be secure but not too tight.

Additionally, you can adjust a sleep session's start or end time in the Fitbit app. You can also set a bedtime reminder in the app to help you maintain a consistent sleep schedule. When it's time for bed, you'll receive a notification on your phone. Certain Fitbit devices will also show a bedtime reminder on the device itself.

It's worth noting that the Fitbit Charge 3 may not be listed as a compatible device for certain features on the Fitbit website. For example, to be eligible for a sleep profile, you need to use a compatible device, including the Charge 5 and Charge 6, but not the Charge 3.

Fitbit Premium subscription is required for a sleep profile

Fitbit's sleep-tracking feature has been available since 2009. The latest update, Sleep Profile, was launched in June 2022 and is available to Fitbit Premium subscribers with the following devices: Google Pixel Watch, Sense 2, Sense, Versa 4, Versa 3, Versa 2, Charge 5, Luxe, Inspire 2 or Inspire 3.

Sleep Profile provides a detailed monthly analysis of your sleep habits. It is based on ten key metrics, including sleep schedule variability, time before sound sleep, sleep duration, and disrupted sleep. The feature also assigns you a "sleep animal" that corresponds with common human sleep patterns. For example, a bear tends to have a consistent sleep schedule and reaches a sound sleep quickly, while a dolphin falls asleep later and sleeps for less time overall.

To be eligible for a sleep profile, you must wear your Fitbit during sleep for at least 14 days during the previous month. Your sleep logs must include sleep stages data, and your Fitbit must have recently synced. The more sleep you log, the more accurately your sleep profile will reflect your patterns.

In addition to Sleep Profile, Fitbit offers other sleep-tracking features. For example, you can set a bedtime reminder in the Fitbit app to help you maintain a consistent sleep schedule. You can also view a sleep graph with three different sleep states: asleep, restless, and awake.

Fitbit estimates sleep stages using movement and heart-rate patterns

Fitbit uses movement and heart-rate patterns to estimate sleep stages. When the device senses no movement for about an hour, it assumes you're asleep. Additional data, such as the length of time when your movements indicate sleep behaviour (like rolling over), help confirm your sleep status.

While you sleep, your Fitbit device tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV). These HRV fluctuations occur as you transition between light sleep, deep sleep, and REM sleep stages. When you sync your device in the morning, it uses your movement and heart rate patterns to estimate your sleep cycles from the previous night.

To track your sleep with a Fitbit device, you must wear it during sleep for at least 14 days during the previous month. Your sleep logs must include sleep stages data, which requires at least 3 hours of sleep. If you slept for less than 3 hours, you won't receive sleep stages data.

You can set a bedtime reminder in the Fitbit app to help maintain a consistent sleep schedule. Certain Fitbit devices also have bedtime reminders. The Fitbit device detects and records naps that are at least an hour long.

To track sleep with certain Fitbit devices, you must press and hold the physical button on the device for about 2.5 seconds until you feel a vibration and the display changes. For other devices, you can enter sleep mode by rapidly tapping the device's display for a few seconds until you feel a vibration.

Fitbit devices with heart-rate tracking can record sleep stages

Fitbit devices with heart-rate tracking capabilities can record sleep stages. This feature is available with a Fitbit Premium subscription and is compatible with devices such as the Charge 5, Charge 6, Inspire 2, Inspire 3, Luxe, Pixel Watch series, Sense, Sense 2, Versa 2, Versa 3, and Versa 4. To be eligible for a sleep profile, you must wear your Fitbit during sleep for at least 14 days in the previous month, and your sleep logs must include sleep stages data.

Sleep stages require at least 3 hours of sleep for analysis. Fitbit estimates your sleep stages by using your movement and heart-rate patterns. When you don't move for about an hour, your tracker or watch assumes you're asleep. It also tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV), which fluctuates as you transition between light sleep, deep sleep, and REM sleep stages.

While you're asleep, your body typically goes through several sleep cycles that last on average 90 minutes each. Each cycle alternates between two types of sleep: Light Sleep and Deep Sleep. Periods of deep sleep are usually longer earlier in the night, while REM sleep, associated with vivid dreams, tends to have longer periods as the night progresses.

To track your sleep, you can either use the sleep tracking functionality on your tracker or the "Begin Sleep Now" option in the Fitbit app. Certain Fitbit devices, such as the Fitbit Force, Charge, Charge HR, and Surge, can automatically track your sleep when you wear them to bed. For other devices, you may need to manually activate sleep mode before and after sleep.

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