By Gavin Newsham - Live Science
Find out how to sleep for longer, and just how much sleep humans really need.
Many of us have been wondering how to sleep for longer and it’s little wonder. The COVID-19 pandemic has wreaked havoc across the world with every aspect of people’s lives affected, from work to relationships, family to finances. But it’s also changed the way we are sleeping with one recent study by King’s College, London and Ipsos MORI, finding that 63% of people believed the quality and quantity of their sleep had worsened since the pandemic began.
But how can you sleep for longer and, post-COVID, how can you get back to something approaching normality when you head to bed? In the first instance, it can help to pin down just why you can’t sleep for as long as you would like. Is it your bed or your bedroom set-up? Perhaps it’s your age or your diet? Or maybe it’s anxiety or stress? It might even be a more serious sleep disorder like sleep apnoea, requiring specialist intervention. If you can put your finger on what is causing your restless nights, you can soon master how to sleep for longer.
The amount of sleep you need is dictated by your circadian rhythm. It’s the 24-hour body clock that helps to regulate a wide range of your body’s functions, from appetite to blood pressure to your temperature and, crucially, the sleep you require. But while some people, like, for example, former British Prime Minister Margaret Thatcher, can survive on as little as four hours sleep a night, most of us require a lot more, according to the BBC.
But it’s not straightforward, as Kirstie Anderson, Consultant Neurologist and founder of the sleep improvement program Sleepstation explained to Live Science. "How much sleep humans need is a little like asking someone their shoe size – it changes as you grow and it’s different for everyone," she said.
Teenagers, for example, will typically need an average of eight-10 hours a night while those under 50 will normally get by on seven to eight. Over-50s, meanwhile, should find six to seven hours sufficient while the over 65s will tend to wake much earlier than younger people, as an increased likelihood of sleep disorders and other age-related medical issues begin to interrupt their sleep, according to the Canadian Medical Association Journal. Indeed, as we age the human body clock edges backward, meaning we tend to wake up around half an hour earlier for each decade we have lived.
But while the amount of sleep you need changes as you age, measuring it in terms of hours gained is not the best method of assessing your sleep needs, as Anderson explained. "The most useful way to rate sleep is to ask yourself whether you feel refreshed on waking and whether you fall asleep within 20 to 30 minutes on most nights of the week," she said. "If you do feel refreshed, and then get through the day without napping, then your sleep is likely to be right for you."
If it isn’t, however, then you may be suffering from what is called ‘sleep debt’, where not getting sufficient quality sleep results in a deficit. Research from the CDC has shown that sleep debt can not only lead to chronic fatigue and reduced productivity but also to mood swings and anxiety. It also highlights not just how important getting enough sleep is but also the impact of what can happen if you don’t.
Conversely, having too much sleep can also be detrimental, as Samantha Briscoe, Lead Clinical Physiologist for the London Bridge Sleep Centre at London Bridge Hospital told Live Science. "Sleeping for longer is not necessarily beneficial and sleeping for longer than our body needs can have adverse effects," she said.
"It’s important to listen to our bodies to determine how much sleep we need. For optimum sleep quality consistency is the key."
"If you are frustrated and feel that you are having trouble falling – and staying – asleep, then fix your morning wake-up to the same time, every day, seven days a week," said Anderson. "That said, one of the biggest myths about sleep is getting into bed at a fixed time rather than really waiting until you are sleepy, not just tired. It’s a balancing act."
Harvard Medical School recommends trying to get a least an hour of natural light each day and factor in some activity that gets your heart beat faster and makes you out of breath, as it’s good for the body and brain. Ensure your bedroom is as noise and light-free as possible to reduce the risk of being disturbed. The temperature is important too. A 1999 study in the journal Sleep showed that high humidity can reduce the length of time the body spends in REM sleep, the phase of sleep that helps the body recuperate and recover. "People worry about the light at night and screens and the like but having an extra coffee at lunchtime rather than taking a walk is just as bad for those who are struggling to fall asleep as easily as they want," said Anderson.
"Covid has been bad for exercise and waistlines and the commonest sleep disorder that we now see that’s causing a broken and unrefreshing night – and a sleepy day – is obstructive sleep apnoea," said Anderson. It may sound obvious but concentrating on your breathing (in through the nose and out of the mouth) will help. Relaxation techniques, like meditation or a hot bath, can also help prepare your mind and body for a better night’s sleep.
A 2016 study in the Journal of Clinical Sleep Medicine found that a diet that’s low in fiber and high in saturated fats and sugar leads to lighter, less restorative sleep. Try limiting the amount of unhealthy, processed foods you eat and aim for a more balanced approach, backed up with regular exercise and a less sedentary lifestyle ("Ten thousand steps a day is a good sleeping tablet," added Anderson). Drink a little less too, not just alcohol, but also caffeine-based stimulants like tea and coffee. Cut back on your intake of other liquids as well to reduce the likelihood of having to wake up during the night to visit the toilet.