Fitbit Flex 2: Tracking Your Sleep, Including Rem

Fitbit Flex 2 is a fitness tracker that can help you understand your sleep patterns and quality. It automatically detects your sleep when you wear it to bed, and it is recommended to wear it as a snug wristband. The device records you as asleep when your body is completely at rest and you haven't moved for about an hour. It can also track your sleep stages, including light sleep, deep sleep, and REM sleep, by using your movement and heart rate patterns. This information can be synced and viewed through the Fitbit app, allowing you to gain insights into your sleep cycles and overall sleep health.

How does the Fitbit Flex 2 track sleep?

The Fitbit Flex 2 can track your sleep by detecting your sleep patterns. It does this by using a combination of your movement and heart-rate patterns. When you haven't moved for about an hour, the device assumes you are asleep. It also takes into account the length of time your movements are indicative of sleep behaviour, such as rolling over.

While you sleep, the device tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV). This fluctuates 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.

In addition to tracking your sleep, the Fitbit Flex 2 can also provide you with a sleep log. This log can be started manually by going to the Fitbit app and tapping on the Sleep Tile, then on the plus sign on the top right corner of the app, and then on "Begin Sleep Now" when you are ready for bed. However, it is not possible to manually override an auto-detected log.

The sleep log provides you with information such as your sleep pattern, including the time spent awake, restless, and asleep. It also includes details on your sleep cycles and the duration of each sleep stage. This data can help you understand your sleep patterns and quality, allowing you to make any necessary adjustments for a better night's rest.

How does it track REM sleep?

Fitbit devices with heart-rate tracking capabilities can estimate your sleep stages in a more convenient and comfortable way than traditional methods. They do this 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 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), which 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.

For best results, wear your Fitbit device higher on your wrist (about 2-3 finger widths above your wrist bone). The band should feel secure but not too tight. If you sleep in a position that prevents your device from getting a consistent heart-rate reading, your results may be inaccurate.

It's important to note that sleep stages vary naturally from night to night, and your Fitbit device provides estimates based on your movement and heart-rate patterns.

How to edit sleep data

To edit your sleep data on the Fitbit Flex 2, follow these steps:

• Open the Fitbit app on your phone.
• Navigate to the "Today" tab by swiping up from the clock face or pressing the crown.
• Find the "Sleep Tile" by swiping up. If you can't find it, tap "Settings" at the bottom of the "Fitbit Today" screen and ensure that the sleep tile is turned on.
• Tap on the sleep tile to view your sleep information. You may need to swipe left to see your sleep history for the past week.
• Tap on the specific sleep log entry that you want to edit.
• Tap the three dots in the top right corner of the log entry.
• Tap "Edit."
• Make the necessary adjustments to the start or end time of your sleep.
• Tap "Save" to confirm your changes.

It is important to note that while you can edit or delete sleep logs, there is no way to edit automatically recorded sleep data. If you need to make changes to the automatically recorded data, you will have to delete the automatic log and replace it with a manual entry.

Tips for better sleep tracking

Wear your Fitbit correctly

Ensure that you wear your Fitbit Flex 2 on your wrist, rather than as a clip or pendant accessory. Wear it snugly, about 2-3 finger widths above your wrist bone, and make sure the band is secure but not too tight.

Understand how your Fitbit tracks sleep

Fitbit trackers estimate your sleep using a combination of your movement and heart-rate patterns. When you haven't moved for about an hour, your tracker assumes you're asleep. Additional data, such as the length of time your movements are indicative of sleep behaviour (e.g. rolling over), help confirm that you're asleep. Your device also 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.

Sync your device each morning

Sync your Fitbit each morning to check the previous night's sleep stats, including your sleep score, on your wrist or in the Fitbit app.

Check your sleep log data

You can check your sleep log data by swiping up from the clock face to find Fitbit Today. Check the sleep tile to find your sleep information. You may have to swipe up to find it. If you can't find the sleep tile, tap Settings at the bottom of Fitbit Today and make sure you've turned on the sleep tile.

Check your average sleep stats

You can check your averages for the week or longer periods. This includes:

• Hours slept: The number of hours you slept each night that week and your weekly average.
• Sleep score: Your sleep scores throughout the week and your weekly average score.
• Sleep schedule: An overview of your sleep schedule that week (when you went to bed and when you woke up).
• Sleep stages: The number of hours you spent in each sleep stage each night and your weekly average minutes asleep.

Edit your sleep history

You can edit or delete sleep logs in the Fitbit app.

Set a sleep schedule

You can set a sleep schedule in the Fitbit app to help you maintain consistent sleep patterns. You can set either a bedtime or wake-up time target, or both.

Set a bedtime reminder

You can set a bedtime reminder in the Fitbit app to help you stick to a consistent sleep schedule. When it's time to wind down, you'll receive a notification on your phone.

Check your sleep sensitivity settings

For accurate sleep tracking, check that your sleep setting is set to Normal rather than Sensitive. In Normal mode, when you make significant movements like rolling over, your device records time spent awake. This setting is appropriate for most users.

Consider other sleep-tracking devices

While the Fitbit Flex 2 can track your sleep, you may want to consider other devices for more advanced sleep-tracking features. For example, the Oura Ring, the Apple Watch Series 10, and the Google Pixel Watch 2 all offer more comprehensive sleep-tracking capabilities.

How to track sleep without a Fitbit

While Fitbit devices are popular for tracking sleep, there are other ways to monitor your sleep patterns and quality.

Use a Sleep-Tracking App

There are many apps available that can track your sleep using your phone's built-in sensors. Simply place your phone on your mattress, and the app will detect and record your sleep patterns, including time spent in light, deep, and REM sleep. Some apps also offer additional features such as snoring detection and smart alarms that wake you up during a light sleep stage.

Manual Sleep Journal

If you prefer a low-tech option, consider keeping a sleep journal. Record the time you go to bed, how long it takes you to fall asleep, and the time you wake up. You can also note any disturbances or sleep interruptions. Over time, this data can give you a good understanding of your sleep patterns and quality.

Smart Mattress Pads

Smart mattress pads are thin pads that you place on top of your mattress, under your bedsheets. They contain sensors that track your sleep patterns, including body movement, heart rate, and breathing. This data is then synced to an app, where you can view detailed information about your sleep.

Wearable Sleep Trackers

In addition to Fitbit, there are other wearable sleep trackers on the market. These devices typically take the form of a wristband or ring and use similar tracking technology to monitor your sleep patterns and heart rate. They often offer additional features such as step counting and calorie tracking.

Visit a Sleep Clinic

If you have concerns about your sleep quality or are experiencing sleep disturbances, you can consider visiting a sleep clinic. They will perform a polysomnography test, which involves monitoring your brain activity, heart rate, breathing, and body movements during sleep. This comprehensive test can help diagnose any sleep disorders and guide treatment options.

Remember, understanding your sleep patterns is an important step towards improving your sleep quality and overall health. Each method has its advantages and disadvantages, so choose the one that best suits your needs and preferences.

Frequently asked questions