Apple Watch: Tracking Your Rem Sleep Accurately

Apple Watch users can track their sleep using the built-in Sleep app or third-party apps. The Sleep app was introduced in 2020 with watchOS 7, and while it covers the basics, it doesn't offer an in-depth analysis of sleep patterns. However, with the release of watchOS 9, Apple has enhanced the Sleep app with Sleep Stages, allowing users to track their time spent in REM, Core, and Deep sleep, as well as periods of wakefulness. This data can be viewed in the Sleep app on the Apple Watch or in the Health app on the iPhone, where it is presented in the form of graphs and sleep cycle trends.

How to set up sleep tracking on Apple Watch

To set up sleep tracking on your Apple Watch, you will need to make sure that your Apple Watch is running watchOS 7 or later on a Series 3 or newer, SE, or Ultra model. You will also need an iPhone 6s or later running iOS 14 or higher.

Firstly, update your watch's software by opening the Watch app on your iPhone and heading to General > Software Update.

Next, you will need to set up your Apple Watch for sleep tracking. In the Watch app on your iPhone, open My Watch and select Sleep. Tap 'Use this Watch for Sleep' to enable the feature. Make sure the switches next to Track Sleep with Apple Watch and Charging Reminders are turned on.

Now, you can set up your sleep schedule. Go to Settings > Focus > Sleep to set up the Focus mode and wind-down time. In the Allow Notifications section, tap People and select the contacts allowed to reach you or send notifications while you sleep. Tap Apps to decide which apps should be allowed to send notifications.

From the Customize Screens section, set the screen that appears during the night to minimize any distractions should you wake up and look at your watch or phone. Under Schedule, select a wind-down time to help you prepare for bed, along with a bedtime and wake-up time for the next morning (with or without an alarm).

You can also set up Focus filters to determine how your device behaves when you're asleep. You can review and tweak your sleep schedule from the Health app. Open the Health app, tap the Browse icon, and select Sleep. In the Your Schedule section, tap Edit to set the schedule for tonight, then tap Done.

You can now set a permanent schedule based on different days of the week, change the wind-down time, and indicate the number of hours you'd like to sleep as your goal.

You can also modify your sleep schedule from your Apple Watch. Open the Sleep app and tap the schedule, which will let you change the wake-up time, turn on an alarm, and change the bedtime. Tap Full Schedule from the main screen to turn off your Sleep Schedule for any specific nights or all nights. Here, you can also add a schedule and change your sleep goal or wind-down time.

Once everything is set up, just go to sleep with the Apple Watch on your wrist. Your Apple Watch won't run out of battery in the middle of the night if you give it a power boost before bed. Connect it to the charger for an hour or two before sleep, and it should last the entire night.

How to view sleep tracking data

To view your sleep data on your Apple Watch, open the Sleep app, where you can see how much sleep you got, a graph of the different sleep stages, a breakdown of the sleep stages by minutes or hours, and a record of your sleep for the past 14 days.

For a more detailed analysis, you can check the Health app on your iPhone. Open the app, tap Browse, and select Sleep. A bar graph will show your start and end times for sleep. As you record multiple nights of sleep, you will be able to see your history on a weekly or monthly basis. Tap the bar for a specific day to see the total amount of time you were asleep. Below the graph is your sleeping heart rate. Tap Show More Sleep Data to see how many nights of sleep were measured, your sleep goal, your average time in bed, and your average time asleep.

You can also view your sleep history on your iPhone by opening the Health app, tapping Browse at the bottom of the screen, and then tapping Sleep. The bar graph by default is set to daily. Tap W at the top of the chart to view your sleep history for the past week, M for the past month, or 6M for the past 6 months. Tap Show More Sleep Data and select a category to review additional sleep details. You can view the time and percentage you spent awake or in REM, Core, or Deep sleep. View your Sleep Duration details, such as your Sleep Goal and Time Asleep. View your Heart Rate and Respiratory Rate in relation to your time spent asleep.

If you have an Apple Watch Series 8 or later, or any model of Apple Watch Ultra, you can also compare changes in your nightly wrist temperature data.

Third-party sleep tracking apps

Third-party sleep-tracking apps offer a more comprehensive analysis of your sleep patterns than the built-in Apple Watch sleep tracker. These apps can be downloaded directly from the App Store on your Apple Watch.

AutoSleep

For $3.99, AutoSleep automatically tracks and records your sleep. It also provides a sleep rating and a readiness score, which are not available on the native sleep tracking app. It also reports the amount of deep sleep and keeps track of your nightly heart rate. The app also features a Sleep Bank, which helps you keep track of your weekly sleep and tells you if you're above or below your sleep goal.

Pillow

Pillow has a vibrant and engaging design, and it effectively tracks your sleep. The basic app is free, but unlocking all features requires a subscription of $4.99 per month or $36.99 for three months. It uses a combination of movement, sounds, and heart rate to track your sleep patterns and presents the data in clear, easy-to-read charts. It tracks deep, REM, and light sleep, time in bed, and the time slept. It also delivers a sleep quality score and tracks your heart rate throughout the night.

Sleep++

Sleep++ is a free app that gauges the duration and quality of your sleep. It has a simple interface, showing a start button, a stop button, and a blue chart to display your sleep patterns. It can also write your sleep data to Apple Health and automatically log sleep when activated on the companion iPhone app. Sleep++ also now includes respiratory rate data.

SleepWatch

SleepWatch records and analyzes your overall sleep time, quality of sleep, sleep stages, sleep disruptions, average sleeping heart rate, and blood oxygen levels. After a one-week free trial, the Premium version costs $3.99 a month or $19.99 a year. It also provides daily briefings and sleep trends over time.

Sleep Cycle

Sleep Cycle focuses on waking you up gently during a lighter stage of your sleep cycle, rather than at a specific time. It offers a range of smart alarm sounds and a snooze feature. It also provides sleep analysis and tracking, keeping tabs on sleep stages and quality, and presenting the data through nicely designed graphs. The premium version offers additional features such as snore detection, sleep sounds, and a notes system.

HeartWatch

HeartWatch is an app that focuses on your heart rate data and provides alerts for any unusual or potentially concerning activity. It overlays your sleep data with heart rate data, allowing you to compare your waking and sleeping heart rates. The iPhone app could be less cluttered, but it is a great choice if you're interested in the relationship between your heart rate and sleep.

Sleep Pulse 3

Sleep Pulse 3 is a standalone sleep app for your Apple Watch that tracks your heart rate and motion. It has a sleep view that shows your resting heart rate and how long you've been sleeping. It also allows you to track naps and record sleep talk, and all the sleep analysis is done on the Watch itself.

How to set up sleep tracking without a schedule

All Apple Watches offer sleep tracking, but the Apple Watch SE lacks a blood oxygen sensor, which is used to enhance sleep tracking accuracy. The Apple Watch's sleep-tracking function can display a graph of sleep stages, including REM, Core, and Deep sleep.

To set up sleep tracking without a schedule, you need to enable the feature in the Watch app on your iPhone. Here's how:

Enabling Sleep Tracking:

• Open the Watch app on your iPhone.
• Tap the "My Watch" tab.
• Tap "Sleep".
• Toggle the slider for "Use this Watch for Sleep" to enable the feature.
• Ensure the switches next to "Track Sleep with Apple Watch" and "Charging Reminders" are turned on.

Setting Up Sleep Schedules:

• Go to Settings > Focus > Sleep on your Apple Watch.
• Set up the Focus mode and wind-down time.
• In the Allow Notifications section, tap "People" and select the contacts allowed to reach you or send notifications while you sleep.
• Tap "Apps" to choose which apps can send notifications.
• From the Customize Screens section, set the screen that appears during the night to minimize distractions if you wake up and look at your watch or phone.
• Under Schedule, select a wind-down time, bedtime, and wake-up time (with or without an alarm).
• Set up Focus filters to determine how your device behaves when you're asleep.

Reviewing and Tweaking Your Sleep Schedule:

• Open the Health app on your iPhone.
• Tap the "Browse" icon at the bottom.
• Select "Sleep".
• In the Your Schedule section, tap "Edit" to adjust the schedule for tonight, then tap "Done".

Setting Up Additional Options:

• Tap "Full Schedule & Options".
• Set a permanent schedule based on different days of the week.
• Change the wind-down time.
• Indicate your sleep goal, which is the number of hours you'd like to sleep.

Modifying Your Sleep Schedule from the Apple Watch:

• Open the Sleep app (the icon is a bed in a circle).
• Tap the schedule to change the wake-up time, turn on an alarm, or adjust the bedtime.
• Tap "Full Schedule" from the main screen to turn off your Sleep Schedule for specific nights or all nights.
• Here, you can also add a schedule, change your sleep goal, or adjust your wind-down time.

Viewing Your Sleep Data:

• In the morning, check the Sleep app on your watch to see your sleep duration and a breakdown of sleep stages.
• For more details, open the Health app on your iPhone.
• Tap "Browse" and select "Sleep".
• A bar graph will show your start and end times for sleep.
• As you record multiple nights of sleep, you'll see your history on a weekly or monthly basis.
• Tap the bar for a specific day to see the total amount of time you slept.
• Below the graph, you'll find your sleeping heart rate and other details.
• Tap "Show More Sleep Data" for further information, such as the number of nights of sleep measured, your sleep goal, average time in bed, and average time asleep.

How to interpret Apple's sleep data

The Apple Watch's Sleep app can help you monitor your sleep patterns and cycles. It can estimate the time spent in each sleep stage: REM, Core, and Deep. It can also track when you wake up and how much sleep you get.

To access this data, open the Sleep app on your Apple Watch or the Health app on your iPhone. On the Apple Watch, you will see the total number of hours slept, a graph of the different sleep stages, a breakdown of the sleep stages by minutes or hours, and a 14-day record of your sleep. On the iPhone, you can view a bar graph of your sleep start and end times, as well as a breakdown of multiple nights of sleep on a weekly or monthly basis. Below the graph, you can see your sleeping heart rate and other details such as the number of nights measured, your sleep goal, your average time in bed, and your average time asleep.

While the Apple Watch provides detailed sleep data, it is important to interpret this information in the context of your individual needs and variations. Every person and night is different, so instead of making direct medical claims, the Apple Watch provides tools for you to draw your own conclusions. For example, if you had a bucket of fried chicken at 11 pm and then experienced poor sleep with little REM sleep and many wake periods, you can infer that your diet may have impacted your sleep quality.

Additionally, it is worth noting that the Apple Watch's sleep tracking may not be 100% accurate. For a more comprehensive assessment, a full sleep study monitored by a doctor would be necessary. Nevertheless, the Apple Watch's sleep tracking feature offers a good starting point for understanding your sleep patterns.

Frequently asked questions