Garmin's Sleep Tracking: Daytime Dozing Detected?

Garmin's sleep tracking feature, officially known as Advanced Sleep Monitoring (ASM), is available on most of the company's smartwatches and fitness trackers. The system tracks several metrics, including sleep time, quality, stages, and duration to help users monitor and improve their sleep. While the feature requires both heart rate and heart rate variability alongside the device's accelerometer to understand when the user is sleeping, it does not track sleep during the day or daytime naps, and users have reported issues with the accuracy of sleep tracking.

How does Garmin track sleep?

Garmin's sleep tracking is known as Advanced Sleep Monitoring (ASM). It relies on motion sensors, heart rate monitoring, and algorithms to track sleep patterns. The device detects movement and changes in heart rate variability to determine sleep stages, including light, deep, and REM sleep.

The optical heart rate monitor measures heart rate and heart rate variability (the intervals between each heartbeat) in conjunction with the device's accelerometer to determine when you are asleep, the sleep stage you're in, and when you wake up. The watch will get more accurate the more often you wear it because it will start to figure out what your heart rate is when you fall asleep. It will also use the accelerometer to track movement to account for any times that you get up in the middle of the night.

Garmin breaks down your sleep spells into understandable chunks. It explains to its users how these differ and why. It keeps tabs on four sleep stages: awake spells, REM, light sleep, and deep sleep. Each stage marks a change in heart rate, restlessness, and heart rate variability. Your Garmin watch makes a note of how long you spend in each during each sleep and how long you should be spending in each. For example, Garmin recommends spending between 17-35% of total sleep within the deep sleep stage as this stage is important for restoring body tissue, improving bodily immune health, and preparing the mind for the following day.

Garmin also provides an all-encompassing sleep score. This score considers your sleep duration, average stress during sleep, total time spent in specific sleep stages, the amount of time you were awake, and overall restlessness, and reduces it to a single number between 1 and 100. A sleep score between 80-89 is considered "good."

Garmin also keeps track of other metrics, such as blood oxygen saturation and respiration rate. The former is measured using a SpO2 sensor, which can indicate potential sleep issues like sleep apnea. The respiration rate metric tracks how many breaths you take per minute while sleeping, which can also be used to understand potential sleep disturbances.

To get the most out of Garmin's Advanced Sleep Monitoring, it is recommended to wear your watch for at least two hours before you plan to sleep to allow the device to gather baseline readings when you are awake. It is also important to ensure that the watch is snug but not too tight on your wrist and that it is positioned just below your wrist bone. Additionally, make sure that heart rate tracking is enabled, and Battery Saver is disabled during sleep.

How to set up Garmin sleep tracking

To set up sleep tracking on your Garmin device, follow these steps:

Firstly, ensure you have a compatible device. Most Garmin smartwatches and fitness trackers with optical heart rate monitors support Advanced Sleep Monitoring. These include the Forerunner 955, the Venu 2 Plus, the Garmin Fenix 7, and the Garmin Epix Gen 2.

Next, during the initial setup of your Garmin watch, you will be prompted to enter your usual sleeping hours. The watch uses this information, along with its onboard sensors, to start tracking your sleep.

To get the most detailed sleep information, download the Garmin Connect app on your smartphone. Open the app and tap the three lines in the top left corner of your screen. Navigate to Settings > User Settings and edit your Bed Time or Wake Time. This will also ensure your watch does not disturb you during your set sleeping hours.

Additionally, make sure that heart rate tracking is enabled on your device. On the watch, press and hold UP or MENU, then go to Settings > Power Manager > Battery Saver > Edit > Activity Tracking to disable Battery Saver during sleep. Also, ensure that your watch fits snugly on your wrist, just below the wrist bone. It should be comfortable but not too tight.

It is recommended that you wear your Garmin watch for at least two hours before you plan to sleep. This allows the device to gather baseline readings when you are awake, improving the accuracy of sleep tracking.

With these steps, you should be all set to start tracking your sleep with your Garmin device.

What can Garmin tell you about your sleep?

Garmin's Advanced Sleep Monitoring (ASM) can tell you a lot about your sleep. It can provide insights into your sleep quality and duration, and help you to understand your sleep patterns. Here's what you need to know:

Sleep Stages

Garmin's ASM breaks down your sleep into four stages: awake, light sleep, deep sleep, and REM sleep. Each stage corresponds to specific changes in physiological markers such as heart rate, restlessness, and heart rate variability. By tracking these markers, Garmin can determine how much time you spend in each stage and provide recommendations for improving your sleep. For example, Garmin recommends spending 17-35% of your total sleep in the deep sleep stage, as this is when your body does most of its recovery.

Sleep Score

Garmin provides a Sleep Score that summarises your sleep quality. This score is based on multiple factors, including your sleep duration, average stress levels during sleep, time spent in each sleep stage, time spent awake, and overall restlessness. The score ranges from 1 to 100, with a score of 80-89 considered "good". In addition to the numerical rating, Garmin provides insights into why your score turned out the way it did and offers tips for improving your sleep.

Respiration Rate and Blood Oxygen Saturation

Some Garmin devices can also track your respiration rate and blood oxygen saturation during sleep. This data can help detect potential sleep disturbances, such as sleep apnea. The respiration rate of an average adult is typically between 12-20 breaths per minute. For blood oxygen saturation, a level between 95-100% is considered normal, and levels outside this range could indicate health issues.

Body Battery

While not directly integrated into ASM, the Body Battery feature uses sleep metrics to provide insights into how your sleep will impact your energy levels for the day ahead. It gives you a score between 1 and 100, with 100 representing maximum energy. This feature can be especially useful for exercise planning, helping you gauge whether your body has enough fuel for a particular workout.

Naps

Garmin devices can also track naps, provided they are outside your usual sleep window and last no longer than three hours. However, sleep stages are not recorded during naps, and naps longer than three hours will be counted as regular sleep.

Is Garmin sleep tracking accurate?

Sleep tracking is a feature available on most Garmin smartwatches and fitness trackers. The company's Advanced Sleep Monitoring (ASM) technology relies on motion sensors, heart rate monitoring, and algorithms to track sleep patterns. It detects movement and changes in heart rate variability to determine sleep stages, including light, deep, and REM sleep. The optical heart rate monitor measures heart rate and the intervals between each heartbeat, in conjunction with the device's accelerometer, to determine when the wearer is asleep, the sleep stage they're in, and when they wake up.

While Garmin's sleep tracking technology has improved since 2018, no device is 100% accurate. According to one source, sleep tracking devices like Garmin watches are about 78% accurate in measuring sleep versus awake time, and only about 38% accurate in measuring how long it takes the wearer to fall asleep. The accuracy in detecting and measuring sleep stages is possibly lower, with research suggesting inconsistent results. Another source claims that sleep scientist Matthew Walker has worked with all the wearables companies (including Apple and Samsung) and said that the better ones are still only 60% accurate.

Some users have reported that their Garmin watches often think they are asleep when they are awake but not moving much, and that the device cannot tell the difference between deep and light sleep. However, others have found that the watch's REM sleep tracking correlates fairly well with their dreams and overnight stress. One user said that their watch is "spot on" for detecting when they are sleeping or awake, while another claimed that their device is "pretty accurate within 10 minutes".

To ensure the most accurate results, Garmin suggests wearing the watch for at least two hours before sleeping to allow the device to gather baseline readings when the wearer is awake. It is also important to wear the watch snugly but not too tightly on the wrist, just below the wrist bone. Additionally, users should ensure that their birth date is saved correctly in the Garmin Connect app, and that sleep and wake-up times are set.

How to ensure your sleep tracking is accurate

To ensure your sleep tracking is as accurate as possible, there are a few steps you should take. Firstly, wear your watch for at least two hours before you plan to sleep. This allows the device to take baseline readings when you are awake, which will help it determine when you fall asleep. Make sure that your watch is snug on your wrist, but not too tight, and that it is positioned just below your wrist bone. You should also ensure that your device is set up correctly, with your usual sleeping hours entered, and heart rate tracking enabled. Double-check that Battery Saver is disabled during sleep, as this will impact the accuracy of your results.

It is also important to be aware of the limitations of sleep tracking devices. While they can provide valuable insights, they are not 100% accurate. Research suggests that they are only about 78% accurate in measuring sleep versus awake time, and only about 38% accurate in measuring how long it takes you to fall asleep. They may also struggle to differentiate between different sleep stages, and can be impacted by factors such as stress, sleepwalking, and alcohol consumption.

Frequently asked questions