I’ve never needed much convincing to laze in bed on a Sunday morning, or, compensate for lost sleep by drifting into a marathon snoozefest. Sleeping and dreaming are in my opinion, two of life’s greatest pleasures.
The trouble is that the recommended 8 hour dosage often feels like more of an indulgence than a necessity. After all, who has the precious time to spend 1/3 of their life in the land of nod?
Mostly, I can get by on 6 hours per night and repay the debt during weekends, holidays and the odd early night. Less time wasted on unnecessary slumber, more time for catching up on episodes of The Good Place.
Or so I thought, until I read Matthew Walker’s, Why We Sleep: The New Science of Sleep and Dreams. Now I’m frantically trying to sleep off years of deprivation, even though Walker keeps reminding me that I can’t.
Walker is a neuroscientist and sleep evangelist. He’s spent over two decades analysing our need to snooze. His book seeks to answer every question we’ve ever wanted to ask about sleep. In the five months since its publication (which took five years to complete) the book has skyrocketed to the top of many bestseller lists and boasts a 4.4 rating on GoodReads.
In all honesty, this is a tremendously terrifying book and one you won’t forget in a hurry. I wanted to share some of the main points that the book addresses in the hope that it will encourage you to get more sleep, more often. The book covers 15 chapters, but I’ve distilled what I found to be the most important takeaways below.
Sleep Deprivation is a Catalyst for Poor Health
Cancer, small testicles, cardiac arrest, Alzheimer’s disease, depression... The list goes on. Walker argues that 8 hours of sleep is more important for us than exercise and diet. He cites many convincing case studies in which sleep deprivation serves as a gateway drug for every ailment you can think of.
At best, a lack of sleep fries our brain, inhibits our ability to memorise information and learn new skills, encourages weight gain and wrecks our immune system. At worst, a lack of sleep increases our risk of cancer, diabetes, cardiac arrest, dementia and significantly shortens our life span.
6 Hours of Sleep Does Not = 80%
We’ve all been in a situation where we need to wake up uncharacteristically early and end up losing out on a couple of hours of sleep. What is worrying is that snoozing from say, 00:00 - 6:00 does not fulfil 80% of our sleep requirements.
The brain and body require equal parts of REM (dreaming) and NREM (non-rapid eye movement) sleep which flip-flop back and forth every 90 minutes through the night. The late stages of REM sleep (the last 2 hours) are critical as this is where most of our motor-skill consolidating takes place, so losing out can hamper both our mental and physical abilities. There’s no shortcut for tapping into these final hours, and even one night of shortened sleep can do long-term damage.
Repaying a Sleep Debt is Harder Than You Think
Can we compensate for lost sleep with excess sleep the following evening? The short answer is no.
Walker cites an example in which a group of volunteers slept for 6 hours, 10 nights in a row. At the end of the experiment, volunteers were as cognitively impaired as they would be had they stayed up for 24 hours on the trot. Following this, the volunteers enjoyed 3 weeks of 8 hours sleep. Their brains did not properly recover from the initial sleep deficit.
Sleep solidifies our capability to learn and memorise
We’re all familiar with the phrase ‘practice makes perfect’ but Walker asserts that a new phrase should be coined, ‘practice and sleep makes perfect.’
Walker believes that sleeping and napping can store our memories and recalibrate learning capabilities. Sleep enables the hippocampus and cortex parts of our brain to work in unison, moving short-term memories to a larger, more permanent storage base. In terms of memory, sleeping after learning can be as effective as hitting the save button on a computer document.
Caffeine can spoil our chance of slumber
Adenosine levels in the brain allow us to feel sleepy, this usually occurs after 12-16 hours of consciousness. However, when caffeine comes into play, the adenosine receptors are artificially blocked.
It can take up to 5-7 hours for half a shot of caffeine to leave your body. This means that consuming a cup of Joe at dinnertime is likely to result in tossing and turning long past 1am as the caffeine fights against the adenosine. The older you are, the longer caffeine tends to take to leave the body and very few people have the capability to break down the caffeine at a faster rate.
The solution? Drink less coffee and tea. This includes decaf, which according to the book does not mean caffeine-free. This was a surprise to me. It turns out that most decaffeinated brands of coffee contain 1/3 of the amount of caffeine as a normal cup.
We Are All Bound by an Internal Circadian Rhythm
It doesn’t matter if you’re a Swiss cheese plant or a tiger, we’re all operating on a 24 hour internal clock running in the background of our brain and bodies. Light and dark are the main indicators of sleep and wakefulness, but your circadian rhythm can alter slightly depending on whether you’re a night owl or a morning lark.
8 Hours of Sleep is The Best Possible Use of Your Time
The book covers a huge range of topics but every single one is underlined with the importance of a full night's sleep. This opening quote sums it up well, “There does not seem to be one major organ in the body, or process within the brain that isn’t optimally enhanced by sleep, and detrimentally impaired when we don’t get enough of it.”
At the risk of sounding evangelical myself, I implore you to read this book. At the very least, prioritise sleep, put it on a pedestal of the highest order and never feel guilty for enjoying 8 hours again. You’ll be doing your brain and body a favour.
If You're Not Sleeping Well, You May Need a New Mattress
If you're struggling to get a good night's sleep, it may be time to replace your mattress. Shop our range of mattresses today and achieve the quality shuteye your brain and body needs.