I’m reading (not coincidentally) Dr Matthew Walker’s book “Why We Sleep.” I came across Matt’s work after listening to a conversation between Jocko Willink and Dr Kirk (Doc) Parsley, another sleep specialist, although from a different background to that of Dr Walker.

Matt Walker’s book is an eye-opener. I wish I had read it ten years ago. I wish I had known more about the importance of sleep twenty years ago. Walker comprehensively lays out the various biological processes that rely on sleep and how extremely detrimental chronic short sleep is on the body and the mind.

In my coaching practice, one of the conversations I have at the beginning of engagements is asking how my new coachee is sleeping. Having read Matt Walker’s book and listened to him on the Tim Ferriss podcast, I now have a decent neuro-biological reason for zooming in on that topic.

Most of us know the feeling of brain fog that settles in the day after a night of broken sleep. In Walker’s research and that of other neuroscientists, it becomes clear that this cognitive deficit is not imaginary. The ability to function rationally declines additively over nights of serial short sleep. In this case, short sleep is anything less than 7-8 hours per night. With just 7 hours per night, after ten nights, you are as negatively impacted as if you had stayed up for 24 hours straight. In other words, by the eleventh day, you are as cognitively impaired as if you have drunk enough alcohol to exceed the legal driving limit in most Western countries.

Sleep is a protective mechanism against the byproducts of neurological activity in the brain. These byproducts include tao and beta-amyloid proteins implicated in Alzheimer’s disease and dementia. Every night, in non-REM (Rapid Eye Movement) sleep, the brain runs a clean-up process called the glymphatic cycle to clean out the detritus. Studies have shown that just one (!) night of limited or broken sleep increases these proteins in the brain.

On a more fundamental level, sleep enables us to transfer memories successfully from the hippocampus to long-term memory structures in the brain. Numerous elegant studies referenced in the book show the impact on retention of learning from losing just a couple of hours of sleep per night. And the loss is immediate, and you can’t make it up after by “catch-up sleeping”. So if you don’t sleep after learning new information, you are very unlikely to be able to retain it efficiently.

From the point of view of our interactions with others, we are far more likely to be emotionally reactive due to lack of sleep. Our ability to regulate our emotions declines significantly; we’ve all experienced being grumpy due to lack of sleep. In addition, we’re more likely to gain weight because the hormones that regulate appetite (leptin and ghrelin) are also messed up. Consequently, research has shown we’re attracted to foods high in fat, salt and carbohydrates and that we eat more of them (typically 300+ calories more than on a day following a good sleep).

If the above wasn’t enough, lack of sleep has been shown to increase the inflammatory response in the body – the day after a night of limited or no sleep, we tend to run on cortisol. This has been shown to increase the risk of certain cancers over time – the International Agency for Research on Cancer has labelled night shift work as “probably carcinogenic”. Short sleep also negatively impacts the gut biome leading to higher rates of depression and various digestive disorders. A lack of sleep has also been shown to increase the risk of heart attack and strokes.

As someone who serially short-changed my sleep cycle at various points in my life (sometimes unavoidably due to having children, sometimes by choice because of work or leisure), I am genuinely wondering how much of the physical damage I carry around is a result of poor sleep practices.

This year, I’ve made a determined effort to correct that in my life, and I prioritise being in bed for at least 7.5 hours per night. I usually don’t sleep that long, but it’s better than the 5.5 hours I often got in the past. I don’t know how much of an impact this change will have, but having read Matthew Walker’s book and listened to him, Andrew Huberman, Doc Parsley and others discuss sleep from a scientific perspective, I believe it will be a very positive one. I strongly recommend you take the time to sleep because it might save or extend your life and health span. And read Matt’s book – it will hopefully change your mind about sleep.

What does it mean to be intentional? It starts with being present, which can be challenging at the best of times but is essential when things go sideways. It is easy for us to think about something that has yet to happen while dealing with something that is going on now. For example, instead of focusing on my writing, I could be thinking about a bill I have to pay (I may or may not be doing that now). Or, I could be conducting someone’s year-end review with them and start thinking about the next one I have to do; short-changing both the person whose review I am conducting and letting myself down.

Intentionality also has elements of prioritisation about it. According to Greg McKeown, until the 1900s, the word “priority” was singular – which makes a lot of sense when you think about the root of the word. Priority came into use in English in the 1400s, originating from the Latin word “prior”, meaning first. It was only in the 1900s that the term priority became plural, and it doesn’t make sense to me to have multiple priorities. There is only one. I recently came across a lovely little acronym describing this – “WIN” or “What’s Important Now” – neatly reflecting a singular priority. The critical thing about focusing on a single priority is that we have to deliberately decide not to do something else. Not to be distracted or attempt to multitask. Not to be thinking about what we “should” also be doing while working on that one priority. Marcus Aurelius puts it like this in Meditations – “Ask yourself at every moment – ‘Is this necessary?'”

When it comes to decision-making, being transparent and honest with ourselves about why we’re making a decision and then accepting the consequences of it are a part of the puzzle as well. Not making a definitive decision is a decision itself and should also be intentional.

We need to be deliberate about how we consume information. Napoleon provides an interesting example in a world of overwhelming information. He instructed his secretary not to open his mail until three weeks after it had been delivered. By then, many of the supposedly urgent problems within had resolved themselves. I’ve seen this approach put to good effect in my career – one of my peers, who is far less reactive than I am, consistently spent less energy on problems which ultimately resolved themselves because he was willing to wait. By contrast, I often felt the need to react immediately to the presented issue and wasted energy doing it.

As with many other areas of our lives, intentionality requires practice. We must be aware of when we mindlessly consume information or react rather than think. We need to acknowledge to ourselves when our responses are emotional rather than intentional. As a parent, I’ve made my most memorable mistakes when I’ve reacted rather than being present and intentional. And, by communicating our intent to others, we can make it clear why we’re doing what we’re doing (and maybe not doing something else). This clarity in our thinking and action, driven by intent, makes it more likely that we will fulfil the stated purpose of our lives.