How do sleep trackers work?

Digital fitness and sleep trackers are very trendy and are considered a simple tool for analyzing and improving your own sleep behavior. Here we clarify how exactly sleep trackers work, what values ​​are actually measured and whether they can really help to improve sleep.

Table of Contents

1. What are sleep trackers?
2. How do sleep trackers work?
3. What do sleep trackers measure?
4. Can sleep trackers improve sleep?
5. Conclusion

1. What are sleep trackers?

Like little digital laboratories for the home – more and more people are wearing fitness watches and sleep trackers to take a closer look at their own body function and sleep behavior. Sleep trackers are mobile or permanently installed technical devices that measure and record certain body functions while you sleep in order to evaluate them in combination with software or an app. The results are intended to provide a conclusion about sleep behavior and help to identify irregularities or sleep problems.

2. How do sleep trackers work?

Sleep trackers usually have several sensors to measure movements and vital parameters. The exact functionality also depends on the model type of tracker. Portable devices, so-called wearables, such as smartwatches or fitness/activity bracelets, are particularly popular. But there are also trackers that are permanently installed and, for example, integrated as a sensor pad under the mattress.

Wearables such as the well-known Apple Watch or the Oura Ring are worn directly on the body and usually have a 3-axis acceleration sensor, a gyroscope and an optical sensor. They record movements, measure heart rate and breathing and can also determine blood flow or the oxygen saturation in our blood. This data is recorded during sleep and processed and evaluated in a software or app to draw conclusions about sleep behavior.

3. What exactly do sleep trackers show?

Sleep trackers can give us information about the time it takes to fall asleep, sleep duration, sleep cycles, sleep phases or even heart and breathing stops based on the measured values. During sleep, we go through different sleep phases in several sleep cycles in which our body behaves in different ways. You can find out exactly how sleep works in this article. Using the heart rate or the intensity of our movement, a pre-programmed algorithm should then be able to determine, for example, how much time we spent in deep or REM sleep.

4. Can sleep trackers improve sleep?

Whether a sleep tracker can really help you improve your sleep depends particularly on how you deal with the results of the analysis. From a scientific point of view, heart rate, breathing and movement at night are not important enough to make an accurate statement about the quality and structure of sleep. Although our breathing, heartbeat and physical activity change throughout the night, sleep occurs primarily in our brain and is measured primarily by changes in the activity patterns in our neural networks. In sleep research, sleep behavior is analyzed based on brain activity, eye movement, body temperature and muscle tension in combination with the bioparameters measurable by sleep trackers.

In addition, the measurement accuracy of the trackers can be easily influenced, for example if sensors are not placed correctly on the skin or there are other people in bed. And even if our body functions and vital parameters deviate from the known “normal values” due to an illness, for example, a sleep tracker cannot provide a truly reliable assessment of our sleep.

Sleep trackers are practical and are good for getting a rough overview of your own sleep-wake behavior and especially the sleep duration or for pointing out possible breathing irregularities. However, it is important not to rely too much on details such as the sequence of sleep phases or deep and REM sleep, because the measured data does not have to correspond exactly to our real sleep behavior. If we feel fresh and rested the next morning, we should still trust our personal feelings and not be influenced too much by a sleep score or recovery score from our sleep tracker. In combination with good sleep hygiene, the popular trackers can be helpful in taking a closer look at our own sleeping behavior and finding out how we can improve sleep.

Our tip: Relaxing evening routines and healthy sleep hygiene are the most important basis for ensuring good sleep in the long term. With a sleep tracker you can then check what your body values ​​look like after a restful night and whether any abnormalities in your personal feeling can also be found in the measured parameters.

5. Conclusion

• Sleep trackers are portable or permanently installed devices that use various sensors to measure and record heart rate, movement, breathing and other vital parameters during sleep.

• Sleep trackers can provide information about how long it takes to fall asleep, sleep duration, sleep cycles, sleep phases or even heart and breathing stops.

• The measurement accuracy and evaluation function of sleep trackers can easily be influenced, which is why the devices are recommended as a guide, but not for a reliable assessment of sleep.