Are Sleep Trackers Accurate? Here’s What Researchers Currently Know

Are you concerned about getting a good night’s sleep? You’re not alone. An estimated one in three people report regular sleep complaints, leading to a booming interest in sleep tracking devices. But just how accurate are these devices in tracking our sleep?

Sleep Tracking Devices: A Misconception

Sleep tracking devices are popular wearable devices that measure body movement and heart rate to track our sleep patterns. These devices are often marketed as a solution to our sleep problems, promising to give us a good night’s sleep every night. However, researchers have been studying the accuracy of these devices, and the results are alarming.

The Accuracy of Sleep Trackers

Research has shown that sleep trackers are only accurate 78% of the time when identifying sleep versus wakefulness. This means that almost one quarter of the time, these devices are wrong about whether we’re sleeping or awake. Even more disturbing is that the accuracy drops to around 38% when estimating how long it takes participants to fall asleep.

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The main issue with sleep trackers is that they measure body movement, which provides limited information about the stages of sleep. Sleep stages are crucial for understanding the quality of sleep we’re getting, but these devices fail to differentiate between deep sleep, light sleep, and REM sleep.

Heart Rate Data: A Slight Improvement

Some sleep trackers use heart rate data to estimate the stages of sleep. While this can improve the accuracy, it’s still limited. A study found that even with heart rate data, these devices can underestimate the amount of deep sleep by as much as 46 minutes.

The Limitations of Wrist-Mounted Devices

Wrist-mounted devices are limited by their inability to accurately measure the stages of sleep. People with insomnia, for example, tend to remain very still in bed, making it difficult for these devices to differentiate between sleep and wakefulness. The algorithms used by these devices are also unknown, making it difficult for scientists to determine the accuracy of the assumptions made by the devices.

The Impact of Sleep Trackers on Mental Health

A study published by our research group found that data from sleep trackers can actually change our emotional state and concentration levels during the day. Participants who were told they had a poor night’s sleep showed lower mood, difficulties with daytime thinking processes, and increased sleepiness. Those who were told they had a great night’s sleep showed the opposite.

This highlights the potential negative impact of sleep trackers on mental health. The constant stream of data from these devices can create anxiety and worsen sleep-related anxiety disorders. Even if the readings are accurate, the impact on our mental health should not be ignored.

Conclusion

While sleep trackers might be useful for some people, their accuracy is limited. For those who experience poor sleep or mental health conditions, it’s crucial to be aware of the potential negative impact of these devices. The best metric for measuring the quality of sleep is how we feel each day. If you’re tired and struggling to concentrate, going to bed a bit earlier each night may help you feel more rested – no device necessary.

FAQs

Q: Are sleep trackers accurate?

A: No, sleep trackers are only accurate 78% of the time when identifying sleep versus wakefulness, and accuracy drops to around 38% when estimating how long it takes participants to fall asleep.

Q: What is the main issue with sleep trackers?

A: The main issue is that sleep trackers measure body movement, which provides limited information about the stages of sleep.

Q: Can heart rate data improve the accuracy of sleep trackers?

A: Yes, some sleep trackers use heart rate data, but even with heart rate data, the accuracy can be limited. A study found that even with heart rate data, these devices can underestimate the amount of deep sleep by as much as 46 minutes.

Q: Can sleep trackers be useful for some people?

A: Yes, sleep trackers might be useful for some people who have generally good sleep but are interested in tracking or establishing a better routine. However, for those who experience poor sleep or mental health conditions, it’s crucial to be aware of the potential negative impact of these devices.