More people are taking sleep-tracking devices to bed than ever before.
Generally speaking, a sleep tracker measures the length and/or quality of your sleep, and they are increasingly being incorporated into popular fitness “wearables” such as Apple, Garmin and Fitbit watches.
On a daily basis, users can access a range of statistics about their previous night’s sleep, including how much time they spent in REM (rapid eye movement) sleep, and how many times they were woken up.
By way of an algorithm, this data is often then translated into a sleep “score” (such as a percentage), indicating how “well rested” they are.
In the case of some fitness devices — particularly those marketed at elite athletes — this “sleep score” will also inform how much exercise it is recommended they do the following day.
However, just how accurate are they, and how much attention should you be paying to your data?
Johns Hopkins school of medicine neuroscientist Matthew Reid warns that fixating on daily sleep scores can have a negative psychological impact, especially on those people with existing sleep problems.
In one study led by researchers at The University of Oxford, participants with insomnia were divided into two groups and given fake or “sham” feedback on their sleep.
One group was told they had a “positive” night’s sleep, the other a “negative” night’s sleep, and were then asked to rate their mood and sleepiness.
Those who were given a fake “negative” score, rated themselves as much sleepier, and their mood significantly worse than those who were given a fake “positive” score, and vice versa.
“Where I do see tracking devices as being detrimental is in people with sleep disorders like chronic insomnia?” Dr Reid asks.
“Unfortunately, those are the kind of people who are generally attracted to these kinds of devices … they’re hyper-focused on their sleep, to the extent they’re preoccupied by it.