Trendy sleep trackers could cause insomnia, as people lose sleep worrying about how much they are getting.
‘Obsessing’ about sleep, through monitoring sleeping patterns on an app, can make it harder to get the right amount, according to experts.
There is a word for this affliction – orthosomnia – and it can cause stress and anxiety, producing hormones like adrenaline and cortisol which keep people awake.
Dr Guy Leschziner, a sleep expert at the Sleep Disorders Centre in Guy’s Hospital, London, says trackers rely on data which ‘doesn’t truly represent sleep’.
The consultant neurologist, speaking before a talk on the science of sleep at Cheltenham Science Festival, said: ‘We’ve seen a lot of people who have developed significant insomnia as a result of either sleep trackers or reading certain things about how devastating sleep deprivation is for you.
‘My view of sleep trackers is fairly cynical. If you wake up feeling tired and you’ve had an unrefreshing night’s sleep, then you know you’ve got a problem.
‘If you wake up every day and feel refreshed, are awake throughout the day and are ready to sleep at the same time every night, then you’re probably getting enough sleep for you and you don’t need an app to tell you that.
‘That obsessional state about sleep makes sleep even more difficult.’
In a briefing on sleep last year, the Parliamentary Office of Science and Technology reported doctors’ concerns that sleep trackers may lead to ‘normal sleepers becoming anxious about non-existent sleep problems’.
The British Sleep Council says people should not be trying to ‘micromanage’ sleep, as the best sleepers tend not to think about it very much at all.
Sleep physiologist Stephanie Romiszewski told an audience at Cheltenham Science Festival: ‘When it comes to tracking in general, I think the research tends to show just using tracking as an anecdotal thing, because you’re curious, is fine.
‘But if you’re starting to look at it and starting to worry about what’s going on, and that worry starts to make you anxious around your sleep, and then you start worrying when you go to bed at night, it might not be very good.’
She added: ‘We are effectively making sleep problems worse through tracking, through ill-reported research, and it can be slight scaremongering sometimes, and that’s actually not helping – it’s hindering.’
Four million people a year in Britain are estimated to buy smart watches and fitness trackers, which often record sleep as well as exercise.
The cheapest can cost as little as 拢50 and are worn on the wrist where they measure movement patterns via an accelerometer.
More expensive models include a heartbeat monitor which measures your pulse by illuminating and measuring the movement of arteries close to the skin.
A 2017 study from the University of Chicago coined the term ‘orthosomnia’, stating that people become fixated on improving their recorded sleep data in the ‘quest to achieve perfect sleep’.
Dr Leschziner sees a high proportion of people with insomnia bringing data from smartphone sleep apps into his clinic.
He said: ‘No matter what people say, they rely on data that doesn’t truly represent sleep. A lot of them work by tracking movement.
‘Some are a little more advanced, they probably give a reasonable measure of how you’re sleeping.
‘They don’t tell you about the stage of sleep or sleep quality. That’s even more the case if you’ve got a sleep disorder.’