A good laugh and a long sleep are the two best cures for anything (Irish proverb). Dr Emma Plunkett, a consultant anaesthetist in Birmingham, explores the importance of sleep and how it supports learning.
’What you need is a good night’s sleep’. This is something I find myself saying regularly to my children when they are tired and grumpy. The more I learn about sleep, the more the phrase holds true and I am convinced that good sleep is the cornerstone of good health, both mental and physical. While the importance of diet and exercise are well established, I think we have been relatively slow to realise the importance of sleep. Indeed, if we are going to rank things that are good for your health, I think sleep comes before both diet and exercise. I certainly find that I am both less likely to do any exercise and more likely to reach for the biscuit tin / chocolate bar / crisps / cheese (or all of the above) when I am tired. My regular trick to try to stave off tiredness when driving home from a night shift was to munch through a packet of biscuits, and if this is also true for others then it may explain the association of type 2 diabetes with night shift workers. Anecdote aside, there is physiology behind the behaviour – we tend to crave carbohydrates when we are tired and our willpower is undoubtedly reduced – so there was probably not much I could do to resist it.
Having read a bit about sleep and fatigue recently, I am left wishing that I had learnt more about these subjects before. I’m not sure I learnt anything about sleep at medical school – either in physiology lectures or outside them. There was so much to learn, to practise and to experience that sleep was pretty far down the priority list. I don’t recall being told anything to help me prepare for working on-calls and shifts and to manage the sleep deprivation that came with working as a junior doctor. Like most people I expect, I worked some things out by trial and error – how to flip my body clock most effectively for example – but in all those years of undergraduate and postgraduate exams, I never thought about the importance of sleep to help my learning.
For those of you who are interested, here is a very brief introduction to sleep physiology.
Sleep cycles last about 90 minutes and are made up of different types of sleep, with the proportion of each type of sleep in a cycle varying throughout the night. The different types of sleep are non-rapid eye movement (NREM) sleep which can be either light or deep (slow wave) sleep and rapid eye movement (REM) sleep where our brain is active but our body is paralysed (slightly freaky when you think about it). Deep NREM sleep predominates in the early part of the night. During this, slow waves are generated in the frontal cortex and travel backwards across the brain in an amazing form of neural collaboration. Light NREM and REM sleep occur more towards the end of the night.
In terms of sleep and learning, the one-line summary is that all sleep is good for learning, so short-changing yourself of a night’s sleep doesn’t make any sense, especially when you are trying to learn something new. (It doesn’t make any sense from a general health and wellbeing perspective either.) Research is telling us more about the different types of sleep and their particular role in memory and learning but my simplistic view is that during NREM sleep facts in our short-term memory (in the hippocampus) are transferred to their long-term storage location (in the cortex), consolidating the memory and freeing up space to remember new facts. This is supported by experiments which showed that students were able to remember 20% more facts after a siesta. It is also during NREM sleep that we consolidate our ability to perform new motor tasks with other experiments showing an increased ability to play a sequence of notes on a piano after sleep. So it is practice – with sleep – that makes perfect. REM sleep on the other hand is important for problem-solving and emotional resetting; people suffering from post-traumatic stress disorder (PTSD) have reduced REM sleep. As healthcare professionals we never stop learning – new facts, new technical skills, new problems to solve. Sleep helps all of these. If you are interested in any of this and would like to know more, I thoroughly recommend Matthew Walker’s book, Why we sleep.
Throughout your life your sleep will be disrupted – sometimes by factors you can control, sometimes by those you can’t. At times when you can’t control your sleep disruption, the most important thing is not to worry about it. Instead, make a plan for your next opportunity to prioritise sleep and enable you to recover from your sleep debt (so maybe accept that you need to postpone catching up on the next episode of your current favourite TV series). When you do have some control, think about the following tips to help you get a good night’s sleep.
- The vast majority of adults need 7–8 hours of sleep each night; it is very unlikely that you can regularly manage on less than this. What is more likely to happen is that you become chronically fatigued and lack insight into how tired you really are. So plan your sleep accordingly.
- When you can, stick to a regular bedtime and wake-up time. If you can get to the point of waking after a full night’s sleep without an alarm, it is a sign you are sleeping well.
- Prepare your bedroom for sleep – make sure it is as dark and quiet as possible and not too warm. Choose an alarm clock without an LED light.
- Try not to look at electronic devices for an hour before bed. The blue light emitted suppresses melatonin release and can make it harder for you to get to sleep. If you have to use devices, use the night-mode setting or invest in some anti-blue light glasses.
- Avoid alcohol, caffeine and nicotine in the evening. The half-life of caffeine is 4–8 hours, so even a cup of coffee mid-afternoon can mean you have caffeine in your system at bedtime.
- Exercising regularly can help your sleep, as long as it is not too close to bedtime. Getting outside for some natural daylight every day is also important, especially in the morning, as it helps to regulate your circadian rhythm.
We need sleep to recover, repair and regenerate and we also need it to remember. I found this quote online, author unknown: ‘Go to bed and you’ll feel better tomorrow’. It’s the human version of ‘Did you try turning it off and on again?’. I think they are right.
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The RCP’s Mental health and wellbeing resource aims to support physicians to stay well and seek help when needed by opening up the conversation about mental health issues and their impact.