Last decade has been significant in a better understanding of how our nightly rest impacts every aspect of our daily life. Doctors now promote good sleep as a factor that is as important as exercise and diet for our overall health. Along with the more information available to the public, came the technology that was supposed to help you get the personalized information about your sleep habits. The importance of nightly rest made sleep trackers so popular, and the market is full of these gadgets.
But besides being a fancy little gadget, is there any benefit in using sleep trackers? Do they provide accurate information about your sleep or are they just showing some standard measurements? Can sleep trackers negatively affect your rest and health?
How Do Sleep Trackers Work?
Sleep trackers are useful pieces of technology that should help you learn more about your sleep. They can be in the form of a smartphone app, a device that is usually wearable around your wrist, or special pads that you put on or under your mattress that track you throughout the night.
No matter what option you go for, sleep trackers should be able to tell you how long you slept during the night and how good your sleep was. That estimation is based on whether you have woken up during the night or if you’ve been tossing and turning around. Some devices can measure sound, and they can warn you if you are prone to snoring or if they notice any other sounds during the night that might be an indication of a sleep-related breathing disorder. Some claim that they can show you how much time you spend in the various stages of sleep: deep, light, and REM. You can check out the extensive review and our favorite sleep trackers here.
This all sounds pretty useful, so how are they able to do that? There is a device called accelerometer embedded in the sleep tracking device, and it measures your movement. The principle behind tracking sleep is simple; lack of action means that you are sleeping. Unfortunately, that would mean that the device would think that you are sleeping even when you are laying down reading or watching television. Because of that, some devices track heart rate and combine the results to give you more accurate data about your sleep. Some sleep trackers also rely on infrared technology, and they can even track your respiration, which gives a useful additional set of information.
Are Sleep Trackers Accurate?
The thing that everybody is interested in is how accurate sleep trackers are. There is some research done on this subject, and the results are mixed. While it looks like sleep trackers can be pretty precise in determining whether you are sleeping or being awake in most cases, there is just no evidence that they are useful for determining how much time you spend in each stage of sleep. This is hard to decide based only on your body movements, as they are very similar in both deep and light sleep. There is an absence of action in the REM phase so that we don’t act out while we are dreaming, but our muscles might twitch which can be recognized as being awake. We also naturally turn around and move our body parts during the night, so that we maintain proper circulation in our body. This can be seen by the device as being awake and active.
To figure out which sleep stage you are in, you would need to measure your brain wave activity, and these devices can’t do that. To make things more complicated, it is not even important if your device precisely told you how much time you spent in each stage. Sleep is an individual activity, so these parameters vary based on many factors like your age, sex, race, and other demographic factors. A perfect rest for a 70-year old would be rated as terrible by a 20-year-old, so don’t think much about it. Just learn to recognize your body’s needs, and if you are feeling well-rested in the morning, it doesn’t matter what your sleep tracker says.
A 2011 study confirmed this when they looked at the abilities of wrist actigraphy. Actigraphy is a technique of measuring movement, and it is the essence of these devices. The method is good at determining total sleep time and night disturbances, and in combination with other sleep assessment tools can provide useful information about sleep patterns.
An article from 2013 looked into how wrist actigraphy compares to polysomnography, which is an overnight sleep study done in a laboratory by the professionals. It is used to detect sleep disorders and any problems with your sleep, and while it is currently our best options, researchers think that sleeping in a lab is not a natural environment and that it affects results as well. Like the previous study, they found that wrist actigraphy is useful in determining total sleep time and sleep disturbances.
The reviews of commercially available sleep trackers include Fitbit, Withings, Jawbone, and other popular brands. The results are all mostly similar. While they accurately describe total sleeping time, there is an inability of sleep trackers to determine time spent in each stage of sleep, and more importantly to recognize the symptoms of sleep disorders such as obstructive sleep apnea. Some other reviews are more positive and say that with the continual progress of technology, we will soon be able to see highly accurate devices, which will save time for sleep specialists and make their job a little easier.
Are You Sleeping Worse Because of Your Sleep Tracker?
Your sleep tracker can be beneficial if you use it correctly. You can learn more about how long it takes you to fall asleep if you have any nocturnal interruptions that you don’t remember in the morning, and how much you sleep on average. A data of a period of a month can tell you a lot about your habits, and if you fill out the questionnaire about your daily activities, you might also figure out what is causing your sleep problems. Many devices have these regular questionnaires where you state your actions, like exercise, alcohol consumption, stress, and other things that can affect your rest. This information is crucial in understanding your sleep habits and correcting them.
It all sounds pretty useful, but there is also a big downside for some users, and that is when psychology comes in play. A 2014 study researched the effects that placebo had on sleep and cognitive performance. The subjects in the study were told that the researchers were able to measure brain wave activity and determine how much time they spent in each stage of sleep. The researchers weren’t able to do that, and they randomly picked two groups, where they told that one had good quality sleep, and the other didn’t. Participants would rate their sleep before that, and this is when it gets interesting. Individuals who rated their sleep as good and were told by the researchers that the brain waves showed they didn’t sleep well, performed worse on tests measuring their cognitive ability. They acted so poorly that the results were actually similar as if they were sleep deprived. Inability to focus, concentrate, and form memories, learn things, and perform are all effects of sleep deprivation. These findings tell us that our minds are just so complex and that the attitude about sleep is essential to get sufficient rest.
Overthinking is the reason while sleep trackers can be problematic. People become so obsessed with getting sufficient sleep, sleeping correctly and the results that their devices show, that it has the opposite effect of what they want. Sleeping is a time of relaxation, and when you are thinking about how to get 8 hours of sleep or trying hard to fall asleep as fast as you can, it is the opposite of relaxation. It leads to increased stress and can even cause anxiety. It is important to remember, while these devices can be useful, you can’t completely rely on them. If your sleep tracker is showing you that you didn’t get enough deep or REM sleep, but you feel good and well-rested in the morning, believe your body. It is the best sign there is, and finding some stats on your phone more reliable than how you feel can make it seem like you are not getting sufficient sleep and that you are even suffering from a sleep disorder. People tend to overanalyze mild symptoms, and overthinking can also lead to insomnia that wasn’t there in the first place.
Authors of an article named this condition orthosomnia, and they describe it as the obsession with sleeping well so much, that it impairs the sleep quality. Orthorexia is a similar condition obsessing about eating well, where patients end up with terrible diet habits. They reported a few cases in this article, where the patients would see a doctor, and when the overnight study done by the professionals showed that they don’t have any sleep problems, they would dismiss those findings as their smartwatch showed otherwise. Waking up in the middle of the night and watching at your phone to see how well you are doing have terrible effects on your sleep. Screens emit blue light that tricks your brain into thinking that it is daytime, so whenever you are checking your phone at night, know that you are disrupting your natural rhythms.
How To Avoid the Negative Side of Sleep Trackers?
The usefulness of these devices depends on how you use them. Sleep trackers can help you stick to a regular schedule, get more sleep, and they can also give you useful personalized tips on how to improve your nightly rest. However, you need to remember that this is just a helpful tool that should benefit you. You should objectively observe the data that the sleep tracker provides, and you shouldn’t obsess and over-analyze the results.
The key is to recognize if a sleep tracker is doing more harm than good. Next step is to catch yourself during obsessive thoughts and take some action to make them go away. You can try meditation or finding a hobby that interests you, to keep your mind occupied, and to drift away from those negative thoughts.
If thinking about your sleeping results gives you stress and anxiety, maybe it’s time to throw away your sleep tracker for some time. To improve your nightly rest, you can try to maintain healthy sleep hygiene. Make a schedule where you go to bed and wake up at nearly the same time daily, create a relaxing sleeping routine, make your bedroom dark, quiet and cool, don’t use electronics half an hour before you go to bed, and remember to eat healthily and exercise regularly. Following these steps improves sleep quality in most people, and it can also be useful to you too, even more than some sleep gadget. If you experience sleep problems and disruptions regularly that make you fatigued and extensively sleepy during the day, you should see a doctor. They can refer you to a sleep facility, where they’ll do the overnight sleep study and determine what’s causing your sleep problems.
Dusan is a biologist, a science enthusiast and a huge nature lover. He loves to keep up to date with all the new research and write accurate science-based articles. When he’s not writing or reading, you can find him in the kitchen, trying out new delicious recipes; out in the wild, enjoying the nature or sleeping in his bed.