For more than nine months, Alex Whitecross’s routine on waking was to check the data about his sleep on his fitness tracker. And then he would feel quite anxious. “I started getting paranoid about how much sleep I was getting,” he says. Whitecross, a computer-aided-design technician from south Wales, says he bought his tracker in order to measure exercise, but became interested in the sleep-monitoring function. “I’m a lighter sleeper than my fiance so I thought it would help me, but it ended up having the opposite effect.”
Sometimes he would check it in the night and feel panicked about how many hours he had until his alarm would go off. In the morning, “I would wake up and look at it, and it would say I’d had five hours and 44 minutes sleep, and spent an hour and 25 minutes awake at night. It made me feel more tired, knowing how little sleep I’d got.” He noticed, as time went on, “I was getting less and less sleep as I was wearing it”.
We are chronically underslept – in the UK, the average person is getting an hour less than they need – and the market has taken notice. The sleep aids market is predicted by the market-research firm Persistence to be worth $81bn (£64bn) by next year. There are a wealth of gadgets, aids and apps that claim to improve and monitor your sleep. You can buy a mattress that adjusts to your needs throughout the night, anti-snoring masks and headbands that are claimed to track your brainwaves.
Alongside this booming industry is a rise in what has become known as orthosomnia, a term coined in a 2017 case report in the Journal of Clinical Sleep Medicine. The researchers chose the term, they wrote, “because the perfectionist quest to achieve perfect sleep is similar to the unhealthy preoccupation with healthy eating, termed orthorexia”.
Although orthosomnia is not a formal diagnosis yet, Alanna Hare, a consultant in sleep and ventilation at the Royal Brompton hospital, says it is something she is familiar with in her clinic. “I’ve seen patients coming in with their sleep trackers and telling me they have a sleep problem because their tracker tells them they’re not having enough sleep, or that all their sleep is light sleep.” When she asks how they feel, many of them say they feel fine, but they are worried about what the data from their tracker is telling them.
She is seeing people, she says, “who probably didn’t have a problem until they started to become overly focused on their sleep. A hallmark of insomnia is “effortful” sleep, or trying to get to sleep, and that is what will happen if you become overly focused on getting eight hours and a particular type of sleep. It can cause a problem that was never there in the first place.”
Guy Leschziner, a consultant neurologist and the author of The Nocturnal Brain, says that about 20% of his patients show signs of orthosomnia. Michael Farquhar, a consultant in paediatric sleep medicine at Evelina London children’s hospital, says he has seen parents who have put a sleep tracker on their child’s wrist, or teenagers who use them. “They’re quite tempting – they give nice graphs, pictures, numbers,” he says. “People are trying to metricise their sleep and really think about it in a way we didn’t before. I think that has positives and negatives.”
Sleep trackers can be helpful in making an effort to get a good night’s sleep, says Hare. “They can be part of a move towards appreciating how important it is to get sleep. It’s only a problem if people read more into the data than the data can give them.” And much of it depends on the personality and sleep habits of an individual. For someone who is not getting enough sleep because they are staying up bingeing box sets rather than because they are vulnerable to sleeplessness, says Leschziner, “it’s unlikely sleep trackers will have any negative consequences. In those individuals, it may have a beneficial effect because it highlights they are spending very little time in bed.”
There have long been serious doubts about the accuracy of the data from sleep trackers, most of which rely on sensing movement, heart rate and even the sounds you make. “When we assess sleep, we do something called a polysomnogram, and that includes monitoring brainwave activity, eye movement, muscle tension, movement, breathing,” says Hare. “There’s a huge amount of data that you have to have to be able to say what sleep stage that person is in and how much sleep they have had.”
Another problem with trackers is that sleep requirements are unique to each person. The “ideal” eight hours sleep a night is an average – some people will need more, some less; being told you are falling short can cause anxiety. “The population level data would suggest most adults need somewhere between seven and nine hours sleep a night, on average,” says Hare. “Eight hours just happens to be in the middle. As an individual, you need whatever sleep it takes to wake up feeling refreshed.”
If you have sleep problems, or are the sort of person who might be worried your sleep isn’t as good as it should be, tracking how much you are getting can become an unhealthy fixation. “If you have a device that is telling you, rightly or wrongly, that your sleep is really bad then that is going to increase your anxiety and may well drive more chronic insomnia,” says Leschziner. “We’re seeing that, but we’re also seeing people saying: ‘My sleep tracker is telling me I’m awake at night,’ but when you talk to them, they have no recollection of being awake and they sleep well, they wake up feeling refreshed. They start becoming concerned that their sleep tracker is telling them they have been awake for half the night.”
Sleep trackers, he adds, could “have quite significant opportunities [and] different roles in research, clinical medicine and as consumer devices.” Or, as an article in the Economist last month put it: “Sleep-tracking is at exactly the stage that fitness-tracking technology was at a decade ago.” The article predicted that people will soon be sharing their sleep stats on Facebook the way they share their fitness data.
Despite Silicon Valley’s best efforts, it is worth remembering that sleep, as Leschziner points out, is “an objective brain state, [but] is also subjective, so can be influenced by your expectations of sleep, by environmental factors, behavioural factors, a whole range of things. If your sleep tracker is telling you something, that may well influence your subjective experience of sleep as well.”
Whitecross recognises this. Seeing what his fitness tracker was telling him each morning about his supposed lack of sleep “made me feel more tired than if I’d just woken up and thought: ‘Last night was a bit restless.’” It took a couple of weeks, but once he had stopped using it, he started to sleep much better.
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