Morefit's Sleep Tracking: How Does It Work?

MoreFit is a fitness tracker that can be used to monitor sleep. The device uses actigraphy, a method of tracking sleep by monitoring an individual's movements. This is achieved by measuring the user's heart rate and motion to determine the length and quality of sleep. The data is then translated into periods of sleep and wakefulness. This technology is also used by popular fitness trackers such as Fitbit, which can also monitor sleep stages and provide a sleep score.

Movement tracking

Actigraphy is particularly useful for people with sleep disorders or disrupted sleep patterns as it allows them to study their sleep patterns without having to stay in a lab. This method of sleep tracking is considered generally accurate for healthy adults with regular sleep patterns. However, it may struggle to accurately differentiate between sleep stages due to its sole reliance on movement tracking.

Sleep researchers have developed more advanced methods, such as polysomnography (PSG), which is considered the "gold standard" for measuring sleep. PSG involves monitoring brain waves through an EEG test, providing a more accurate understanding of sleep phases. However, this method can be inconvenient for participants.

To enhance the accuracy of movement tracking, some sleep trackers, like Fitbit, combine actigraphy with heart rate monitoring. By tracking heart rate variability (HRV), these devices can better distinguish between light sleep, deep sleep, and REM sleep stages. Additionally, features like snore and noise detection further contribute to understanding sleep quality.

It is important to note that movement tracking through actigraphy may have limitations in accurately distinguishing between sleep and wakefulness, especially during periods of stillness or restlessness. Calibration and positioning of the device on the wrist can also impact the accuracy of movement tracking.

Heart rate monitoring

Fitbit devices with heart rate monitoring capabilities can offer a more comprehensive analysis of your sleep. They can distinguish between different sleep stages, such as light, deep, and REM sleep, and provide a monthly Sleep Profile feature with a detailed breakdown of your sleep data. This feature, however, requires a Fitbit Premium subscription and is only available on specific models, such as the Charge 5, Charge 6, Inspire series, Luxe tracker, or any Sense or Versa watch (excluding the original 2018 model).

The heart rate data collected by these devices is essential for understanding your sleep quality and patterns. Each night, your body cycles through different sleep stages based on your heart rate, and getting sufficient time in each stage is crucial for feeling refreshed and energised. By tracking your heart rate, devices like Fitbit can provide insights into your sleep efficiency and help you identify areas for improvement.

It is important to note that while heart rate monitoring provides valuable insights into your sleep, it is not the only factor determining sleep quality. Sleep researchers emphasise that brain waves and eye movements are also critical for assessing sleep phases accurately. Therefore, it is recommended to use heart rate monitoring in conjunction with other sleep-tracking methods for a more comprehensive understanding of your sleep health.

Sleep stages

Sleep is divided into several stages, and a good night's rest involves getting enough time in each of these stages. The three main sleep stages are light sleep, deep sleep, and REM sleep. Light sleep occurs at the beginning of the night and is characterised by a relatively low heart rate. Deep sleep is when the heart rate is at its lowest, and REM sleep is when the heart rate begins to increase and the eyes move rapidly. REM sleep is also when vivid dreams are more likely to occur.

Fitbit devices use movement and heart rate to measure the time spent in each sleep stage. When a Fitbit detects that you have been still for about an hour, it records that you are asleep. If it detects movement that wouldn't be possible during sleep, it stops logging sleep. Fitbit devices with heart rate monitors can also discern between light sleep, deep sleep, and REM sleep by tracking beat-to-beat changes in heart rate, known as heart rate variability (HRV). However, it is important to note that actigraphy, the method of tracking sleep based on movement, has a high margin of error and may not be accurate for people with disrupted sleep.

The Sleep Profile feature on Fitbit provides a more detailed breakdown of sleep stages and is available on specific models, including the Charge 5, Charge 6, Inspire 2, Inspire 3, and Luxe trackers, as well as the Sense and Versa watches (except the original 2018 model). To access Sleep Profiles, a Fitbit Premium subscription is required.

In addition to tracking sleep stages, Fitbit devices offer other features to improve sleep quality. These include a silent alarm that can be set to go off during the optimal stage of sleep, bedtime reminders, and a monthly personalised analysis of key sleep metrics. Fitbit's snore and noise detection feature also allows the device to track noise levels and check for snoring throughout the night.

Sleep quality

Actigraphy:

Actigraphy is a widely used method for sleep tracking, especially in wrist-worn devices like the Morefit tracker. It involves monitoring an individual's movements during sleep. By tracking periods of activity and inactivity, the device can distinguish between sleep and wakefulness. However, actigraphy has limitations, particularly in individuals with disrupted sleep patterns or sleep disorders. It may not accurately capture wakefulness if a person lies still, and it can be challenging to differentiate between sleep stages based solely on movement.

Heart Rate Variability (HRV):

Heart rate variability is a more advanced metric that some fitness trackers, including those with heart rate monitors, use to assess sleep quality. HRV tracks the beat-to-beat changes in your heart rate as you transition between different sleep stages: light sleep, deep sleep, and REM sleep. This information can provide a more nuanced understanding of your sleep quality by examining the fluctuations in your heart rate throughout the night.

Sleep Stages:

Some fitness trackers can differentiate between various sleep stages, such as light sleep, deep sleep, and REM sleep. This is often achieved through heart rate monitoring and movement detection. By understanding the time spent in each sleep stage, you can gain insights into the quality of your sleep. For example, sufficient deep sleep is associated with feeling well-rested and energised the next day.

Sleep Duration and Restlessness:

Fitness trackers can also provide information about your total sleep duration and the number of awakenings during the night. This data can help identify patterns of restlessness or interrupted sleep, which may impact your overall sleep quality. By tracking your sleep duration over time, you can establish a baseline and work towards improving your sleep habits.

Environmental Factors:

Certain fitness trackers, like the Fitbit Sense or Versa 3, offer snore and noise detection features. These devices use microphones to analyse noise levels in your surroundings and detect snoring. This feature can provide insights into potential sleep disturbances caused by environmental noise or snoring, allowing you to make necessary adjustments for a better night's rest.

In summary, sleep quality tracking in devices like the Morefit tracker often involves a combination of movement detection, heart rate monitoring, and environmental factor analysis. By providing insights into your sleep patterns, duration, restlessness, and sleep stages, these trackers can help you understand and improve your sleep quality over time.

Accuracy

The accuracy of sleep tracking by Morefit devices is dependent on a few factors. Firstly, it is important to understand the technology behind sleep tracking. Sleep tracking in fitness devices is often based on actigraphy, which involves tracking an individual's movements to determine sleep patterns. This method is widely used as it is convenient and does not require individuals to sleep in a lab. However, it is important to note that actigraphy only tracks movement, and disrupted sleep patterns or sleep disorders can affect the accuracy of the data.

Morefit devices, similar to other fitness trackers like Fitbit, use actigraphy to track sleep. They are equipped with motion detectors and, in some cases, heart rate sensors to monitor sleep. The devices can detect when the body is completely at rest and has not moved for about an hour, indicating that the wearer is asleep. They can also detect restless sleep through the wearer's movements and, in the case of devices with heart rate monitors, changes in heart rate.

The accuracy of sleep tracking by Morefit devices can be influenced by several factors. Firstly, the placement of the device is important. It is recommended that the device be worn on the wrist, positioned snugly about 2-3 finger widths above the wrist bone. This ensures optimal detection of movements and heart rate changes associated with sleep.

Additionally, the settings of the device can impact accuracy. Morefit devices may have different sensitivity settings for sleep tracking, and adjusting these settings can improve accuracy. For example, if the device is set to "sensitive", it may overestimate sleep time, while the "regular" setting may result in an underestimation. Users can experiment with these settings to find the optimal configuration for their sleep tracking.

It is worth noting that while Morefit devices can provide valuable insights into sleep patterns, they may not be able to distinguish between different sleep stages accurately. Sleep researchers emphasize that accurate sleep data requires the measurement of brain waves and eye movements, which are not currently tracked by commercial fitness devices. Therefore, while Morefit devices can offer a general understanding of sleep duration and quality, they may not provide precise information about sleep stages.

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