The experts give us the low-down on how to get the best shut-eye possible.

Every one of us needs good sleep. It is an essential which ensures we look, feel and perform at our very best. And yet, while we instinctively know that sleep is good for us, for some there remains a sort of cultural dismissal of it as dead time, getting an early night being seen by some as a sign of weakness. The cliché of the superhuman CEO or politician who only needs four hours of sleep still abounds.

Slowly but surely, this attitude is changing. In 2016, Ms Arianna Huffington wrote a book called The Sleep Revolution after her famously punishing schedule caused her to pass out, fall and break her cheekbone. In 2016, the Rand Corporation calculated the economic cost of poor sleep in the US at $411bn a year – a gross domestic product loss of 2.28 per cent. In the UK, this amounted to 1.86 per cent of GDP loss, or £40bn.

According to The New York Times, Silicon Valley entrepreneurs believed that in 2012, the sleep market in the US was worth $32.4bn, and it has continued to rise. Sleep is now seen as a status symbol – a must-have for the upwardly mobile worker. Indeed, a quick Google search reveals a plethora of experts offering products, services and gizmos to help out. Many of them have the whiff of snake oil about them.

“While it’s great that more people are interested in sleep, it’s still a relatively new field of research, and I fear that anyone can be a ‘sleep expert’,” says Dr Chris Winter, neurologist of 24 years, and author of The Sleep Solution. “There’s a bunch of stuff out there that’s exploitative,” he adds.

Dr Neil Stanley, who has published 38 peer-reviewed papers on sleep research, says: “I’m afraid advice on how to sleep better is pretty much all common sense.” It is, however, the kind of common sense that is increasingly uncommon. So, here is how to always get a good night’s sleep, according to the people who really know.

“The amount of sleep you need is mainly down to genetics,” says Dr Stanley. “Generally speaking, you need between six and nine hours of sleep a night. The problem with the eight-hour figure is that it causes anxiety if people are sleeping for more or less. The amount of sleep you need is determined by how you feel during the day. If you feel awake and alert, then you’re getting enough sleep. I like to get nine-and-a-half hours.”

Dr Winter agrees: “Everyone is slightly different. Sleep duration is genetically determined. Eight hours is an arbitrary figure, a nice round number, but when it comes to sleep you cannot have a ‘one size fits all’ approach.”

“Very few people actually have insomnia,” says Dr Winter. “What’s more common is that people are struggling to sleep when they want to in order to do their jobs or live the life they want.”

People are either “night owls” or “morning larks”, which means they have a genetically determined preference for mornings or evenings. Dr Winter believes that with the use of light and exercise, it’s possible for night owls to cope better with early mornings. “For instance, a regular 6.00am bike ride will help your body advance its sleep cycle, and eventually it will become easier to wake in the morning,” says Dr Winter.

You can also manipulate your circadian rhythms using intelligent light bulbs (Dr Winter recommends a brand called Soraa). These emit blue light in the morning to rejuvenate and energise you, and, gradually, soft white light in the evening to help prepare you for bed. “Melatonin – the hormone that  regulates sleep – interacts with different colours of light to influence sleep cycles,” says Dr Winter. “When you’re trying to reset your sleep cycle, it’s important to stick to a consistent schedule, just as parents do with babies.”

Dr Stanley also believes that consistency is key: “Your body craves routine and predictability. The more you chop and change your sleep time, the more confused your body will become. I’m in bed by 9.30pm every night, as I know that this is the time I need to go to sleep in order to wake up early.”

The first third of a night’s sleep is the deepest and most restorative, and the latter two-thirds comprise lighter, yet still restorative, sleep categorised as stage 2; sleepers typically pass through five stages: 1, 2, 3, 4 and REM (rapid eye movement) sleep. “Have you ever noticed that you wake up before your alarm clock goes off?” asks Dr Stanley. “That’s because your body knows when you’re about to wake, and starts to prepare 90 minutes before you wake up. That’s why it’s essential to stick to a routine.”

Unfortunately, this means no lie-ins at the weekend as this would confuse matters come Monday morning. Also, ensure regular mealtimes and exercise sessions as this will also help to set sleep rhythms. And definitely do not hit the snooze button. “You’re better off setting your alarm for the latest possible time and make sure you definitely get up at that time,” says Dr Stanley. “Hitting snooze confuses the body further, making it even more difficult to get up.”

“It is far better to sleep alone. You can have kisses and cuddles before retiring to your own bed,” says Dr Stanley. “It’s only very recently that society decided it was a sign of a close relationship to sleep in the same bed as our partners.” Differing sleep patterns (your partner might be a night owl and you a morning lark), snoring, sleep talking, increased temperature from the other person's body and less room can also mean that sleep may be disturbed.

“A standard UK double bed measures 4ft 6in, whereas a standard UK single bed measures 2ft 6in, says Dr Stanley. “This means an adult sleeping in a double bed with their partner gets three inches less space than the average child sleeping in a single bed.”

According to Mr Simon Williams, marketing manager of the National Bed Federation, you need to replace your mattress at least once every seven years. “Telltale signs that you need a new bed include: waking up with a sore back and or neck, the sound of creaks and crunches when you move around, the feeling of springs and ridges, uneven sagging, stains and tears on the mattress. Think to yourself: ‘Is it embarrassing when someone sees my bed without the covers?’ Then it’s time to get a new bed.”

Finding the right bed for you is a matter of trial and error, and it’s best to lie in a bed for at least 10 minutes before deciding that it’s right for you. “It’s quite subjective, and it’s often down to personal preference and body size and weight,” says Ms Jessica Alexander, spokesperson for The Sleep Council. “While comfort is a matter of personal preference, your bed must be hard enough to give proper support to your spine and body. A six-foot tall, 18-stone person may need something more robust than someone who is a more petite eight stone. When it comes to materials, quality and durability, on the whole, you get what you pay for. I would always try before you buy and avoid the temptation to buy a mattress online.” Dr Stanley agrees, adding, “A good bed is worth more than the cost of an iPhone.”

“In order to sleep, your body needs to lose 1ºC of temperature,” says Dr Stanley. “Carbon dioxide also disturbs sleep, so if you can, try to sleep with the window and bedroom door open all year round. The room temperature should be between 16-18ºC. If you’re cold, it is better to keep the bed warm with a hot-water bottle, and have the window open a couple of millimetres.”

Central heating can raise room temperature to 20-24ºC – the point at which it becomes uncomfortable to sleep. Synthetic foam beds, which are often sold as premium products, do not regulate heat as effectively and can lead to overheating, as can pillows and duvets made from cheap, synthetic fibres. Dr Stanley says it is far better to use products made from 100 per cent-natural cotton, feather or woolin order to help regulate bed temperature and prevent overheating.

Eating your main evening meal three or four hours before bedtime is also essential. If not, your body will still be working hard to digest the meal, which means it won’t have cooled down by that essential 1ºC needed for a comfortable night’s sleep.

According to the World Health Organization, the average noise outside your bedroom window should not exceed 40 decibels, similar to that of a library, otherwise you won't get a decent night’s sleep. Long-term average exposure to levels above 55 decibels, about the same as a busy street, contribute to elevated blood pressure and even heart attacks.

Blue-light pollution from electronic devices disturbs the production of melatonin and can trick the brain into thinking that it’s still daytime. Although there are now blue-light-blocking sunglasses, this does not mean it’s OK to binge-watch a boxset into the early hours, as cognitive stimulation from the excitement of a Maniac marathon do not make for a restful night’s shut-eye. Ideally, invest in an alarm clock and make a point of keeping laptops and mobile phones out of your bedroom.

“A quiet mind and rested body are essential for a good night’s sleep,” says Dr Stanley. “So whether it’s meditating, yoga, having a warm bath or settling any arguments you might have had with your partner, make sure you are nice and relaxed before getting into bed. Never go to bed angry or worried.”

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