Sleep is like shoe size: one size does not fit all. Sleep has become yet another aspect of our lives that makes us anxious. Advice about sleep often resembles the commands of a regimental sergeant major. I frequently read “you must get eight hours of sleep” or “waking up in the middle of the night is bad”, and in the business community “success means getting up at 5am”. Rather than enjoying our sleep, it is now an endless cause of worry. Sleep apps and trackers only reinforce this anxiety. These devices should be ignored as they are currently both inaccurate and deeply misleading. Getting the “perfect night of sleep” has become an unattainable obsession and has led to a condition called “sleep anxiety”. A state where people worry about not falling asleep or staying asleep, triggering a negative cycle of worse sleep and increased anxiety. While it is possible to make generalisations about the length and timing of our sleep, applying an average as a standard for all of us is absurd.
So, how much sleep should I get?
The answer is “it depends”. As adults, most of us sleep between seven to nine hours, but some perfectly healthily individuals sleep as little as six hours while others may need 10 hours. So how do we know if we are getting enough sleep? It’s not complicated. If you can function at your optimal level during the day, you are fine. However, if you need an alarm clock to get you out of bed, if you oversleep on free days, if you take a long time to wake up, if you feel sleepy and irritable during the day and crave a nap, if you need caffeinated drinks, and if you are less reflective and more impulsive — you are probably not getting the sleep you need.
Should I worry about waking at night?
In most cases “no”. We are often told that a single episode of sleep without waking (“monophasic” sleep) is normal. But this is not true for most of us. Sleep can occur in two episodes (biphasic sleep) or even multiple episodes (polyphasic sleep), separated by periods of wake. Such sleep cycles are the ancestral pattern of human sleep, and still seen in societies today that lack artificial light. Critically, if we wake at night sleep is likely to return if it is not sacrificed to social media or worrying about getting back to sleep!
Is it true that there are morning and evening types?
Yes. Our chronotype refers to whether we are a morning type or “lark” (10 per cent of the population), evening type “owl” (25 per cent of the population), or in-between “dove” (65 per cent of the population). But this changes with age. As teenagers and young adults, we tend to have later chronotypes, then move earlier in our middle and older years. On average young adults want to go to bed around two hours later than individuals in their sixties. Our chronotype depends on our genes, how old we are, and when we see light. Just seeing light around dusk tends to make us get up later. While seeing light around dawn can help us get up earlier.
Can I look at a Kindle before I go to bed?
Yes. Press reports have suggested that reading a Kindle before bedtime will massively disrupt sleep. In the original studies, four hours of Kindle use on five consecutive nights delayed sleep by just nine minutes. Later studies showed that even these small effects were abolished if people were exposed to moderate levels of light during the day. So while it is best to avoid really bright light before bedtime, there’s no harm doing some relaxing reading on a Kindle or smartphone, or even watching a moderate amount of television to unwind before we sleep. It’s not the light from these devices that is the problem, but the content. Social media, especially, can have a big alerting effect on the brain that will act to delay sleep.
What can I do to get better sleep?
Many people assume that we get the sleep that we get. But this is not the case. Yes, sleep is absolutely essential, and not getting enough will certainly harm just about everything we do. But as I discuss in my book Life Time, there is a lot we can do to achieve the sleep that each of us needs. Getting morning light, not drinking coffee after 2pm, de-stressing at the end of the day, avoiding excessive alcohol before bed, making sure your bed is comfortable, keeping to the same bedtime routine on workdays and free days — these are just a few easy tricks to get the sleep you need. The key thing is to embrace the sleep you get and stop worrying about the mythical “perfect” sleep.
