Sleep is the one part of life we might hope could remain blissfully free from trends. So when Gwyneth Paltrow wrote recently that she practises “clean sleeping”, and credits it as an even more powerful determinant of her appetite and energy levels than her diet, you may have been tempted to roll over and pull the pillows over your head.
Paltrow wasn’t advocating anything new, from a doctor’s perspective. “What she’s referring to is what the medical community would call sleep hygiene,” explains Dr Laura Lefkowitz, who contributed to the sleep chapters in Paltrow’s new book, Goop Clean Beauty. This simply means adopting good habits that help the body sleep and avoiding bad ones, like using your phone before bed or eating too late. “It’s how you take care of sleep, how you ensure a good night’s sleep day after day, which is so important for every vital function,” Lefkowitz explains.
This is unlikely to come as news to many of us. But while good sleep hygiene might seem like common sense, a whopping 39 per cent of people in England are suffering from disrupted sleep or insomnia symptoms at any one time, according to the most recent data from the British National Psychiatric Morbidity Survey — a figure that has been steadily increasing over the past 15 years. Now that research has connected lack of sleep to everything from heart disease to anxiety and burnout, say the experts, we need to stop taking it for granted and start treating it as a serious mental and physical recovery period.
“Our brains effectively wash away their waste toxins during sleep,” explains sports sleep coach Nick Littlehales, the author of a new book, Sleep. “Failure to get enough sleep and clear out these toxins is linked to a host of neurological disorders, including Alzheimer’s.”
At any given point in time, a person who gets an average of less than six hours a night has a 13 percent higher mortality risk than someone who sleeps between seven and nine hours, says a study by the not-for-profit research organization RAND Europe.
Modern life is full of factors that aren’t conducive to a good night’s rest. RAND Europe interviewed 62,000 people over the past two years and found that current smokers, for example, sleep, on average, five minutes less per day than non-smokers; while those without dependent children under 18 living in the same house sleep 4.2 minutes more per day than those with children. Even your commute can affect your kip: if your journey to work is between 30 and 60 minutes (one-way), you will likely sleep 9.2 minutes less per day than someone commuting for up to 15 minutes.
On a night-by-night level, meanwhile, a study by Loughborough University’s Clinical Sleep Research Unit found that 42 per cent of people said their partner snoring was the main thing keeping them from sleeping (in America, a quarter of couples now say they sleep better alone than with their partner). But if this is your main source of nightly frustration, fear not: a new bed might be about to change your life. The Sleep Number 360 Smart Bed, due to go on sale this year, can detect snores and will raise the sleeper’s head a few degrees in response, clearing the airways.
Besides snoring, 55 per cent said that getting up to go to the bathroom was what kept them awake at night. An old, uncomfortable bed was the next most common problem and 23 per cent said that a partner using an electronic device in the bedroom was what stopped them drifting off. All the above are common examples of poor sleep hygiene habits, according to Dr Lefkowitz – and we need to clean them up in order to train our bodies to sleep better.
How do I start getting better sleep?
According to Littlehales, working out what type of sleeper you are is a fundamental piece of the puzzle. “We’ve talked about owls and larks and so on, and we’ve always been aware that some people are better in the mornings, but now we know there’s a little genetic twist that determines our sleep characteristic.” This is your “chronotype”, he explains, and it governs what time your body naturally wants to do things such as waking up, having breakfast, exercising and going to bed. In Littlehales’s book, we’re all naturally “AM-ers” or “PM-ers”, no matter how much we try to disguise it with our job or lifestyle choices.
Take an online test to determine your type, such as the University of Munich Chronotype Questionnaire, but you probably already have an idea: PM-ers rarely prioritise breakfast, for instance. Don’t try using your chronotype as an excuse, however – the variation between types is usually only a couple of hours; very few people naturally want to wake up at noon.
Armed with this knowledge, says Littlehales, you can (in theory) organise your life around your inner hourglass, making sure that, if you are a PM-er, you go to bed later and wake up later if that’s what makes you feel best, and vice versa if you are in the AM camp. Your manager, of course, may take a dim view of this behaviour – but workplaces should take this more seriously, Littlehales thinks, at the very least acknowledging different chronotypes. “Instead of having desk hierarchies where the more senior people get the window seats, allocate them to the PM-ers struggling through their morning and the AM-ers for their afternoon, because daylight helps PM-ers’ slow body clocks catch-up more quickly.”
But how many hours do I actually need?
Perceived wisdom says eight a night; Lefkowitz claims that nine is the magic number and Paltrow says she aims for a quite unlikely-sounding 10. The average person in Britain, however, manages to get just over six-and-a-half hours per night, with over a third getting between five and six hours.
It’s an individual thing, the experts say. But recent research suggests that we should forget counting down the hours and start thinking about sleep according to the cycles it works in.
“The brain has a pattern of sleep. It’s not like you just fall asleep and hour one is the same as hours two and three and five and nine,” says Lefkowitz. “It goes through cycles. Within each there is what we call non-REM [Rapid Eye Movement] sleep, and then REM sleep.”
Non-REM sleep has three parts, which Littlehales calls dozing-off, light sleep and deep sleep. The latter is the most important phase, when the brain produces delta waves and the body cleans and resets itself. REM sleep follows, during which time the brain is firing up its neurons, making new connections and processing what happened during the day.
The time it takes for a person to go through one sleep cycle under clinical conditions, says Littlehales, is 90 minutes.
In the first part of the night the non-REM periods in each cycle are long. They get shorter towards the early morning hours as the REM periods get longer, and just before you wake up, you get almost no deep sleep. This means that if you can sleep for longer, you will complete more cycles and every part of the brain and the body has its time to recuperate. Lefkowitz’s nine hours is the equivalent of a healthy six 90-minute cycles.
This being said, it is possible to have too much sleep. “Probably more than 10 hours of sleep starts to have a detrimental effect,” says Lefkowitz.
“Over 10 hours of sleep starts affecting hormone function and makes the body too slow-functioning. But usually the body at older
ages won’t let you go that long, unless you are under the influence of drugs or alcohol, or you are sick.”
Can’t I train myself to need less sleep?
Yes, although it’s not so much about getting less overall but getting less all at once. Until Thomas Edison invented the light bulb, people used to sleep for a couple of shorter periods, Littlehales points out. Evidence suggests that up until Victorian times people tended to have a “first and second” sleep, dozing initially after dusk, then waking up for a couple of hours in which they were fairly active, perhaps reading or performing special “between-sleep” prayers, before falling asleep for a second stint.
As part of his work with sports stars, Littlehales assesses their timetables and integrates sleep in chunks of 90-minute cycles. “I’ll say OK, we can grab three cycles there, two cycles here, one in the afternoon, five at night, six over there; how many is that over seven days? Combined with a good pre- and post-sleep routine, we’re fine with that, off we go.”
This kind of extreme sleep scheduling doesn’t work overnight, he says: you need to train your body to do it. But once you’re in a good sleeping routine, most people can theoretically add or take out a 90-minute cycle or two and see how they cope.
THE CRUCIAL SLEEP HYGIENE RULES:
1 Fix your wake-up time
“The number one most important predictor of sleep hygiene and improving sleep is when you wake up,” says Lefkowitz. “If you get into a habit of having trouble falling asleep and going to sleep at different times at night, it’s really hard to reset the body’s circadian rhythm. The first thing to do is set your wake-up time. Every day of the week you should be getting up within 20 minutes of the same time.” Once you’ve worked out what time you can realistically wake up each day, count backwards from that in 90-minute cycles to work out your bedtime. If you miss it one night, you’re better off waiting until the start of the next cycle and just getting one less overall than falling asleep straight away.
2 Eat for sleep
“If you eat a high-sugar diet and your body’s blood sugars are going up and down throughout the day, or you eat sugar or drink alcohol before you go to bed, a few hours into sleep your blood sugar drops and your body wakes you up to rescue itself,” explains Lefkowitz.
As well as limiting sugar and alcohol, you should finish eating and stop drinking any liquids at least two hours before sleep to avoid night-time trips to the bathroom.
After a meal, body and brain are busy working on digestion which means that they aren’t as calm as they should be for sleep.
3 Set up a sleep-promoting bedroom
Body temperature naturally drops in the evening so make sure your duvet isn’t too warm or too cold to wake you up. Keep your bedroom cool: just over 18C/65F is recommended. Avoid blue light, which triggers production of melatonin and serotonin, the hormones that control our wakefulness and sleepiness. Sources include digital screens and fluorescent and LED lighting. You don’t have to be in a blackout before bed however; warm-colour lights, like red or orange bulbs or candlelight, are fine.
Silence is also key. “Men and women are sensitive to different kinds of sounds when they sleep, with some research showing that women are listening out for crying babies, dripping taps, and rowdiness, while men are more attuned to car alarms, howling wind, and buzzing flies,” says Professor Richard Wiseman in his guide to sleep, Night School.
4 Don’t fall for the marketing
Forget spending a fortune on mattresses or pillows that claim to offer the best night’s sleep you’ve ever had, says Littlehales. For a start, these products are part of an industry that is not heavily regulated. “The reality is we are designed to sleep anywhere, on anything and we do it on trains and sofas, when we go camping, or even hanging off the side of a mountain in a sack,” he says. “All the statements that people make about what these products are going to do is the biggest misconception you’ve ever come across.”
5 Embrace the nap
Even the shortest snooze causes significant improvements in people’s mood, reaction time, and alertness, concluded a 2009 review of the huge amount of psychological work on napping. But how long should you nap for? Scientists still can’t agree. A team of researchers at the University of Pennsylvania recently ran a study involving 3,000 elderly Chinese people, who were each given a range of mental ability tests. Those who took an hour-long nap after lunch performed better, but if the nap was longer or shorter they performed significantly worse.
Littlehales suggests a daily 20-30 minute “zone-out” period in a quiet corner. Nasa agrees: research on its pilots has also shown that a 26-minute nap during a flight (while a co-pilot is on duty) can enhance performance by 34 per cent and alertness by 54 per cent. It should take place after lunch – between 1pm and 3pm is a natural sleep window for most – and it doesn’t even matter if you don’t fall asleep: the disconnection from daily life is enough to boost your brain’s productivity.
So nap away: and if you need to feel wide awake directly afterwards, advises Wiseman, knock back a coffee before you doze off. “The caffeine will start to work its magic about 25 minutes later, just as you are waking up.”
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WHO ARE THE WORST SLEEPERS, MEN OR WOMEN
Officially, women. In November, a joint survey by Loughborough University’s Clinical Sleep Research Unit and Sealy, the world’s biggest bed maker, showed that men in the UK get an average of 28 minutes less sleep per night than they feel they need to function effectively the next day, amounting to five days lost per year. For women, the figures double: women are down 56 minutes’ sleep each night, totalling 10 days a year. This is particularly bad news given that women need 20 minutes more sleep per night than men, according to sleep neuroscientist Professor Jim Horne, because they tend to use more of their brains than men do.
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DO SLEEP TRACKERS ACTUALLY WORK?
The wearable tracker industry is predicted to be worth $5?billion by 2019. But can they accurately assess your sleep? “The problem with many of the wearables and apps available for use at home is that they provide their information through an accelerometer, which basically captures motion,” says Littlehales.
“Moving a lot indicates light sleep; no movement, deep sleep.” They can’t, of course, distinguish between interruptions caused by a cat jumping on the bed, say, or a partner moving, although wearables are better than apps at this. Littlehales is of the opinion that their main value is in getting people talking about sleep, and providing some education about sleep cycles. “Only a polysomnogram – in which things like brainwave activity, eye movement and muscle movement are monitored – can accurately record the stages within sleeping cycles,” he says.
