Fitbit Charge: Tracking Your Sleep And More

Fitbit's range of fitness trackers and smartwatches can help you understand your sleep patterns and improve your sleep quality. All Fitbit devices have sleep-tracking functions that work in the same way and deliver the same information. They use a combination of movement and heart-rate patterns to estimate your sleep stages. When you haven't moved for about an hour, your Fitbit tracker assumes that you're asleep. It also tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV), which fluctuate as you transition between light sleep, deep sleep, and REM sleep stages.

Fitbit Charge 5 can monitor noise in your bedroom, including snoring

The Fitbit Charge 5 can monitor noise in your bedroom, including snoring. The latest update to the Fitbit app contains the beginnings of nighttime snoring and noise detection. The "Snore & Noise Detect" feature uses the microphone on the Fitbit device to monitor noise levels and detect snoring. The device can distinguish between different levels of noise, ranging from "Very quiet" to "Very loud". It is important to note that the Fitbit cannot identify whether the snoring is coming from the user or someone sleeping nearby.

To enable "Snore & Noise Detect", open the Fitbit app and go to the Today tab, then tap the Sleep duration tile. Tap the menu icon in the top right corner and select Settings. From there, you can turn on "Snore & Noise Detect" and follow the on-screen instructions. Fitbit recommends charging the device to at least 40% before bedtime as this feature can impact battery life. Additionally, it is recommended to avoid playing white noise or other ambient sounds during sleep as they can interfere with the detection.

The noise detection feature works by analyzing noise information every few seconds to track the overall noise level and check for snoring. When you wake up, a summary of your nightly results is provided in a report. This information can be useful for improving your sleep quality and understanding your sleep environment.

In addition to noise detection, the Fitbit Charge 5 also offers other sleep tracking functions. It can track sleep stages by using movement and heart-rate patterns to estimate the different stages of sleep, such as light sleep, deep sleep, and REM sleep. The device can also detect restless sleep by identifying excessive movement that indicates restlessness. By syncing the device each morning, users can review their sleep data, including sleep scores and a detailed breakdown of their sleep patterns.

The device can detect the difference between light, deep, and REM sleep

Fitbit devices that track heart rate (excluding Charge HR and Surge) can detect the difference between light, deep, and REM sleep. Fitbit estimates sleep stages by using movement and heart-rate patterns. When the device senses no movement for about an hour, it assumes you're asleep. It also takes into account additional data, such as the length of time when your movements indicate sleep behaviour (like rolling over), to confirm your sleep status.

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

Light sleep, which is characterised by less brain activity than REM sleep, serves as the entry point into sleep each night as your body unwinds and slows down. Deep sleep, which also falls under non-rapid eye movement (NREM) sleep, typically has longer durations early in the night. REM sleep, associated with vivid dreams, tends to have longer durations as the night progresses. During a sleep cycle, you usually switch from light sleep to deep sleep, then back to light sleep, and finally into REM sleep.

To view the start and end times for your different sleep stages, go to the “Today” tab in the Fitbit app and press and hold the “Sleep timeline graph”. Move your finger left or right to check the time spent in each sleep stage. Tap “Benchmark” to view the percentage of time spent in each sleep stage.

Fitbit Charge HR and Surge do not track sleep stages

Fitbit devices that track heart rate can monitor sleep stages, except for the Fitbit Charge HR and Surge models. These two models do not track sleep stages, but they can still monitor sleep patterns. Sleep stages refer to the different phases of sleep, including light sleep, deep sleep, and REM sleep.

Sleep tracking on Fitbit devices works by using movement and heart rate patterns to estimate sleep stages. When the device detects no movement for about an hour, it assumes you are asleep. It also tracks changes in heart rate, known as heart rate variability (HRV), which fluctuate as the body transitions between different sleep stages.

To track your sleep with a Fitbit, simply wear it to bed. The device will automatically detect when you are asleep and begin tracking. It is recommended to charge your Fitbit to at least 40% before going to bed, as the sleep-tracking feature uses battery power. Additionally, the device must be synced each morning to review your sleep data, such as your sleep score and the number of hours slept.

If you want more detailed sleep insights, you can consider upgrading to a Fitbit Premium subscription. This subscription provides access to Sleep Profiles, which offer a detailed breakdown of your sleep behaviours, including 10 monthly metrics and a sleep animal characterisation. The Premium subscription also includes access to a library of workout videos, audio tracks, guided meditations, and sleep aids.

Fitbit Premium offers tools to help you get better sleep

Fitbit Premium offers a range of tools to help you get better sleep. Firstly, you can access a Sleep Profile, which provides a detailed monthly breakdown of your sleep, including 10 metrics and a sleep animal characterisation of your long-term sleep behaviours. This feature is available on the Google Pixel Watch 2, Google Pixel Watch, Sense 2, Sense, Versa 4, Versa 3, Versa 2, Charge 6, Charge 5, Inspire 3, Inspire 2 and Luxe.

Secondly, with a Premium subscription, you can turn on the snore and noise detection feature, which allows the microphone on your Fitbit to track noise while you sleep. This feature is available on the Fitbit Sense and Fitbit Versa 3. The device can distinguish between snoring and other noise, and it will provide a summary of your nightly results in a report when you wake up.

Thirdly, Fitbit Premium provides access to your sleeping heart rate, which is often lower than your resting heart rate. Factors such as caffeine, alcohol, stress, and illness can impact your sleeping heart rate.

Finally, with a Premium subscription, you can access a detailed breakdown of your sleep score. Your overall sleep score is the sum of your individual scores for time asleep, deep and REM sleep, and restoration, for a total score of up to 100. The average score ranges from 72 to 83. Restoration provides insight into how restful your sleep was and is based on your sleeping and resting heart rates, as well as how much time you spent tossing and turning.

Fitbit uses movement and heart-rate patterns to estimate sleep cycles

Fitbit uses a combination of movement and heart-rate patterns to estimate sleep cycles. While you sleep, your Fitbit 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. 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.

Fitbit's sleep feature estimates sleep stages by assuming you are asleep when you haven't moved for about an hour. Additional data, such as the length of time of movements that indicate sleep behaviour (like rolling over), can also help confirm that you're asleep. Your Fitbit will also be able to detect restless sleep through the way your body moves, and if your Fitbit has a heart rate monitor, it can tell the difference between light, deep, and REM sleep.

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. In the restoration component, you can check the estimated oxygen variation graph. Blood oxygen saturation normally fluctuates, but high variations in the estimated blood oxygen saturation levels can indicate that a person had variations or disturbances in breathing during sleep.

Sleep experts note that sleep trackers can help people improve their sleep by understanding their sleep patterns, although some fretful sleepers can get so wrapped up in the data that it mostly increases their stress in a counterproductive way. It is important to note that the sleep staging data is less important than how much sleep you are getting overall. Sleep experts say that unless you have serious sleep problems, your body tends to do a good job of allocating the total amount of sleep among the various stages.

Frequently asked questions