Are Sleep Trackers Accurate?

February 15, 2023

Are Sleep Trackers Accurate?

According to a poll by the National Sleep Foundation, about half of Americans don't get enough sleep, and admit feeling sleepy more than twice a week. Given that sleep has resounding benefits to physical and psychological health, poor quality sleep can lead to several health issues. This explains why many sleepers are looking for different solutions to their sleep problems, including investing in sleep trackers.

Although these devices have become popular in recent years, many sleepers are not sure whether or not they are reliable. This article demystifies everything about sleep trackers to help you understand how best they can improve the quality of your sleep.

What are Sleep Trackers?

Sleep trackers are devices used to monitor and record an array of data relating to factors that reflect your sleep patterns. Examples of data sleep trackers records include heart rate, snoring, respiration, hours of sleep, and more. These devices detect physical signals of sleep rather than brain activity during sleep.

Sleep trackers come in different shapes and sizes. Most of them resemble a wristwatch you can strap around your wrist. Others clamp on your pillow or mattress while you sleep. They also differ in physical features, and can perform varying functions.

Many sleep trackers have an in-built movement detecting device called an accelerometer. These devices detect slight movements, enabling the trackers to record and analyze how much your body relaxes while you sleep. Trackers that record snoring come with an in-built microphone that can also pick up noises made by slight movements around you.

The thermometer is yet another feature of most sleep trackers. Besides recording your body temperature, the thermometer can detect the room's temperature to determine how your atmosphere affects your sleep quality.

How do Sleep Trackers Work?

Sleep trackers work by recording and interpreting data collected through your sleep. They have an internal algorithm that processes the sleep data, and displays it through a corresponding app. This process allows users to assess their sleep patterns, and determine ways of improving their sleep. Some trackers can also suggest changes sleepers can implement to achieve better sleep quality.

Most sleep trackers measure two things: heart rate and body movement during sleep. The heart rate readings determine the stage of sleep. Generally, your heart rate will slow down when you sleep, but if it remains high or drops too low, it may be a sign of a serious health problem.

Your movements when sleeping determine whether you are asleep or still awake. These results can determine how well you rest when you sleep, and reveal several issues that make you restless at night.

What do Sleep Trackers Monitor?

It is worth noting that sleep trackers rely on physical movements rather than detecting direct brain activity to track sleep patterns. These activities include:

Heart Rate (HR)

Some sleep trackers can determine sleep stages by measuring their heart rate. Although a sleeper's heart rate fluctuates throughout sleep, it generally slows down, and may drop to as low as 40 to 60 beats per minute. Depending on the heart rate recorded, the sleep tracker can help you tell whether you had a deep sleep, REM sleep, light sleep, or no sleep at all.

Respiratory Rate

Just like the heart rate, your respiratory rate can also reveal how well you sleep at night. Significantly low or high breathing rates may be signs of ill health that affect the quality of your sleep.

Some sleep trackers record respiratory rates through in-built microphones and accelerators, and analyze this data using different algorithms. Since the autonomic nervous system automatically regulates breathing, records of unusual breathing rates may help identify some other sleep disorders.

Environmental Factors

Environmental factors such as room temperature, lighting, and noise impact sleep quality. These factors make sleepers restless at night, leading to several symptoms of sleep deprivation, such as daytime drooling, reduced alertness, fatigue, brain fog, and so on. Luckily, sleep trackers use microphones and thermometers that record these factors to help you understand the causes of your restlessness at night.

Motion Detection

Accelerators found in the sleep trackers are small motion detectors that can record the slightest movements while you sleep. This data can be used to estimate how much quality sleep time you get every night. Although it may not accurately determine sleep stages, the sleep data can inform you of your sleep pattern and habits.

Sleep Scores

Sleep trackers score the quality of your sleep out of 100 after analyzing your sleep habits through the data collected. Most trackers regard scores below 60 as poor sleep quality, while scores above 90 as excellent sleep quality. These scores are only estimates, and may differ from one sleep tracker to another, depending on how they interpret data.

Measure Skin Temperature

Not all sleep monitoring devices are capable of measuring skin temperature. Those that do are wearable, and come in contact with your skin to record its temperature.

Studies show that your skin temperature can affect your sleepiness and alertness. Generally, when your core body temperature is high, your skin temperature lowers, causing you to be more alert. Therefore, measuring your skin temperature can determine sleep onset, phases, and other sleep metrics used to calculate the quality of your sleep.

Monitor Lifestyle Factors

Some trackers require sleepers to input information about their daily activities to determine how their lifestyles affect the quality of their sleep. For example, taking too much caffeine during the day or before bedtime may cause restlessness due to lack of sleep.

What are the Components of a Sleep Tracker?

The features of sleep trackers vary depending on their designs. Therefore, trackers in the market today differ in terms of performance.

Nevertheless, the following are the typical capabilities of most sleep trackers.

Sleep Duration

Sleep duration measures how much you sleep by tracking your idle time. These devices record when you fall asleep at night and when you wake up in the morning. The longer you sleep, the better your sleep score.

Sleep Quality

Sleep quality measures the number of sleep disruptions you had during sleep by recording your body movement. For example, if you often toss and turn while asleep, the sleep tracker may record that you have a poor sleep quality.

Sleep Phases

Some sleep tracking devices can determine the phases of sleep, and how much time you spent asleep in each. Generally, if you spend more sleep hours in the REM sleep state, you'll have a better sleep quality, and a higher sleep score.

Restoration Rate

The restoration determines how relaxed you are during sleep by measuring your heart rate. If you have a higher heart rate, you are more likely to sleep restlessly, affecting the overall quality of your sleep.

What are the Types of Sleep Tracking Devices?

The market has several sleep trackers brands that come in all shapes and forms. Despite their differences, these trackers have similar features, and perform the same function.

Here are the common types of sleep tracking devices found in the market today.

Wearable Sleep Trackers

Wearable sleep trackers can track more activities than sleep. Some are strapped, like wristwatches or wristbands. These devices collect data about your heart rate and movements, and perform several functions other than recording sleep patterns. For example, some wearable sleep trackers can record how many footsteps you take in a day, or how many calories you burn during a workout.

Non-Wearable Sleep Trackers

Non-wearable sleep trackers come in two forms.

Bed sensors

These devices go under your mattress, bed sheets, or on your pillow. They collect data by recording your respiratory and heart rate to determine the quality of your sleep.

Some mattresses come with in-built bed sensors, and relay the sleep tracker data collected through a smart phone app. These beds use the data collected to optimize the sleeper's comfort while in bed. For example, these sensors can change the firmness level of a mattress, or incline the bed to the sleeper's ideal comfort levels.

Bedside Devices

Bedside devices for tracking sleep don't need to be in your bed to function. Instead, you can place them near your bed, and they'll collect data by detecting your breathing and any movement around your bed. These devices can also detect other aspects of sleep, such as room temperature, noise, light, and humidity.


Ring sleep trackers have sensors on the inner part of the ring. This sleep tracker goes around your finger, and records various movements, such as heart rate and respiratory rate.

Are Sleep Tracking Devices Accurate?

The answer to this question lies in research findings that compare these gadgets to polysomnography tests. Polysomnography is the study of sleep that entails several tests used to diagnose sleep disorders. Unlike sleep trackers, these tests record brain activity, blood oxygen level, blood pressure, eye movement, skeletal muscle activity, and leg movement, among other aspects of sleep.

Polysomnography tests provide more details about a person's sleep patterns that sleep trackers can't capture. These tests are also carried out by experts, and involve sophisticated devices. For this reason, polysomnography tests take the upper hand when it comes to accuracy.

However, that doesn't mean sleep trackers are no good. Since sleep tracking devices detect several movements and aspects of sleep, these sleep tracking devices can help identify symptoms of several sleep issues such as sleep apnea. The data recorded in the sleep tracking devices can also help a sleeper gauge their overall sleep quality by identifying changes for improving how they sleep. However, the information recorded by the sleep tracker isn't clinical, and therefore can't form the basis of a diagnosis.

Factors to Consider When Buying a Sleep Tracker

Shopping for a sleep tracker isn't an easy task, given that they have different features. However, with some helpful tips, you can find the ideal sleep monitor that will tell you more than you need to know about your sleep pattern.

Sleep Tracking

Look for a sleep monitor that tracks all the information you need to know about your sleep behavior. Devices that record more aspects of sleep may have more accurate data about your sleep patterns and general health.


Comfort can mean anything from device size to its weight. For instance, some sleepers may prefer a wearable device to a non-wearable one because they can track other daytime activities. Others may not be comfortable wearing the sleep tracker all day, especially the large and heavy ones. Additionally, some sleepers dislike the lumpy feeling of a sleep tracker beneath their pillow or mattress.

App Compatibility

Since most devices use apps to display the analyzed data, it is important to consider an app's compatibility before buying a tracker. Additionally, you may want to find out more about how the app works, so you don't have a rough time analyzing, reading, and understanding the data.

Battery Life

If you want a sleep tracker that can monitor your activities all day, you should consider its battery life to determine how long it can last. That way, you'll record more accurate information without missing any data due to a dead battery.

Frequently Asked Questions About Sleep Trackers

Here are more questions and answers about a sleep tracker.

Are Sleep Trackers Effective?

Sleep trackers can improve your general health and well-being by providing data about your sleep patterns. Since sleep is an integral part of good health, the data collected by sleep trackers can help improve your general health and lifestyle.

Sleep trackers also promote healthy sleep hygiene. For example, data regarding room temperature, noise, and lighting help create a healthier sleep atmosphere by eliminating causes of sleep distractions.

How Can You Use Data from a Sleep Tracker?

Depending on the components of your sleep tracker, you can record a lot of information that you never knew about your sleep behaviors. Here are some of the ways you can use data from a sleep tracker:

  • create healthy sleep hygiene by eliminating sleep disruptions;
  • speak to your doctor about any unusual sleep patterns, and;
  • improve your sleep environment.

However, you can't use this data to diagnose a  sleep disorder or any other conditions you may have. Therefore, it is best to see a doctor for any diagnoses and medication.

Which Stages of Sleep Does a Sleep Monitor Detect?

Sleep monitors usually provide information regarding various stages of sleep. Examples include:

Light Sleep

Light sleep stage is shallow, restless, and leaves a sleeper half awake. In this sleep stage, the sleeper can hear noises from their surroundings, and wake up easily. This stage transitions into the deep sleep state. 

Deep Sleep

The deep sleep stage is when a sleeper feels more relaxed and less responsive to outside stimuli. Usually, the breathing rate slows down, and the heart rate stabilizes into regular beats per minute. In the deep sleep stage, the brain stops thinking, and the body releases growth hormones to help replenish and rebuild cells.

REM Sleep

The Random Eye Movement (REM) stage is where the brain becomes active, causing you to dream. As a result, your eye moves rapidly in different directions, the heart rate increases, and your breathing becomes irregular during this stage. REM sleep helps regulate emotions and memory, and coordinates how the body works.

All these sleep stages have important roles to play in replenishing the body. Although certain sleep trackers can detect these stages, they only provide estimated figures calculated by analyzing a sleeper's heart rate.

What Are the Limitations of a Sleep Tracker?

The potential limitations of sleep trackers include:

  • Limited insight into sleep stages. Since they use physical movements rather than brain activity to record data, they can't tell how long a sleeper spends on a particular sleep stage.
  • Can't diagnose sleep disorders because they are not clinical tests.
  • Non-wearable trackers may be inaccurate if you share a bed with a pet or partner.
  • Difficult to estimate the cost of a sleep tracker because of the wide price range.

Tips to Improve the Accuracy of Sleep Trackers

Here are some tips to help you improve the accuracy of your sleep tracker.

  • Ensure that the battery is full before setting or wearing the tracker
  • Inquire about the algorithms used to analyze the data captured by the sleep tracker
  • Select a sleep tracker with more metrics
  • Sleep in a good quality mattress and bedding to reduce discomforts.

How Eco Terra Beds can Improve Your Sleep

The wrong choice of bedding is part of the reason many people don't enjoy quality sleep. Poor quality bedding compromises the support and comfort of sleepers, causing sleep disruptions that lead to many other problems, like sleep apnea. Given that humans spend a third of their lives sleeping, or trying to fall asleep, it is logical that they invest in good quality bedding.

Eco Terra provides you with nothing short of top-quality bedding. Because we care about your health, our products are the most natural options you will ever find in the market.

Here are some great examples.

Eco Terra Hybrid Latex Mattress

Have you ever wondered what it feels like to sleep on a toxin-free mattress? If your answer is yes, we got you covered. Eco Terra's hybrid latex mattress is all you need. This mattress is supportive and soft feeling, promoting deep sleep as soon as you rest on it. In addition, the mattress also provides you with all the benefits of pure natural latex foams, including:

  • Allergy resistance
  • Breathability
  • Temperature regulation
  • Maximum support
  • Responsiveness
  • Plush comfort

Eco Terra mattresses also contain a layer of natural wool used as a fire barrier. Besides, this layer adds more comfort to your bed, and also promotes temperature regulation by improving air circulation around your bed.

If you frequently toss and turn in bed, chances are your old mattress is not as comfortable. Consequently, your sleep quality and your general health will deteriorate over time. Replacing your old mattress may be a vital step towards improving the quality of your sleep.

Natural Latex Topper

If you have a smaller budget, you can change the firmness level of your mattress using Eco Terra's all-natural latex mattress topper. Just like the natural hybrid mattress, this topper gives you all the benefits of natural latex to help rejuvenate your sleep.

For more plushness, you can add a cotton cover to your latex mattress topper that also improves breathability.

Sleep trackers are great for noting important aspects of your sleep pattern. However, there's more you can do to improve your sleep experience.

With or without a sleep tracker, Eco Terra's commitment to natural and comfortable bedding raises the bar for the health and wellness of sleepers. The mattress and topper are customized to optimize comfort needs for all types of sleepers. In addition, these sleep accessories improve your sleep hygiene, allowing you to rest better, and achieve a good night’s sleep.

Patrick Gunther

Patrick is an accomplished writer. He has been in the retail mattress space for the past 13 years, and more specifically in the natural mattress niche. He blogs on the subjects of natural mattresses, sleep, health, fitness, and green living.