Sleep Changes Everything
The most underrated tool in human health, mental and physical fitness, and disease prevention. A comprehensive guide to the science of sleep, and why it matters.
Most of us know, at some level, that sleep matters. We have felt the fog of a bad night’s rest, the clarity that follows a long and uninterrupted sleep. We know it in our bodies. Yet for decades, perhaps for most of the modern era, sleep has been treated with something close to contempt: it has been dismissed as an inconvenience, a waste of time, a biological tax, a competitor to productivity. You name it.
We glorify people who claim to need only five hours a night. We treat the exhausted as the industrious. We have built a culture that is, in every measurable sense, profoundly, dangerously under-slept.
And I was a part of it. In medical training, lack of sleep was a badge of honour. Symbol of resilience.
That culture is now beginning to change largely thanks to scientists who have spent their careers doing what most people do not: studying sleep with the same rigour and seriousness we apply to cancer biology or cardiovascular medicine.
What that science reveals is fascinating.
And scary (if you don’t sleep enough).
Sleep does not simply rest the body - it actively repairs it. It consolidates memories, regulates appetite, clears the brain of toxic proteins linked to Alzheimer’s disease, regulates our genes, modulates our emotional lives, and determines (with fascinating accuracy) our risk of dying prematurely from cardiovascular disease, cancer, dementia, and a range of other conditions.
The evidence now suggests that no major physiological system in the human body, and no psychological operation of the human mind, is left untouched by the quality and quantity of our sleep.
You’ve probably heard and read about this before, numerous times. Why then, if it’s so important, do we still de-prioritise and compromise on our sleep?
In this article we will cover all that matters. It is long because the subject demands it.
Sleep science has undergone a transformation in recent years. Old certainties have been revised. New mechanisms have been uncovered. And a set of practical, evidence-based strategies has emerged that any person (whatever their relationship with sleep) can use immediately.
Whether you are an insomniac who has not had a full night’s rest in years, someone who wants to age healthily, someone who wants to lose weight, someone navigating the lifestyle factors that disrupt sleep without fully realising it, or a high performing athlete or a business executive who wants to extract the last few percentage points of advantage from their biology, this article is written for you. In the world of sport and business, a consistent 5% advantage translates to the difference between the gold medal and not even qualifying, or to tens of millions of dollars – compounding year on year. And sleep can offer advantage estimated to be in tens, rather than single digits.
We will move through the material systematically. We begin with the biology of sleep — what it actually is, what happens inside the brain and body while we sleep, and why evolution preserved such a metabolically costly and apparently dangerous behaviour. We then examine the four pillars of good sleep: quantity, quality, regularity, and timing. We look at new and important research on sleep debt and sleep banking, the architecture of the sleep cycle, the extraordinary functions of REM sleep, and the profound connections between sleep and mental health.
We explore the science behind common interventions (you can click the links for extended guides as well):
- melatonin,
- magnesium (99% of our clients get this wrong!)
- other supplements,
- digital detox (essential for more than just healthy sleep)
- light management,
and distinguish what the evidence supports from what it does not.
There is also a lot what we will not cover (like alternative sleeping schedules, or management of common conditions – the former are either not recommended for civilians, and the latter should be discussed with your doctor.
Sleep
In 2013, a landmark study published in the Proceedings of the National Academy of Sciences exposed 26 volunteers to one week of insufficient sleep: an average of 5.7 hours per night, and then measured the activity of their genes using whole-blood RNA transcriptome analysis. The results were striking.
The researchers, led by Carla Möller-Levet at the University of Surrey, very close to where I live, found that 711 genes were significantly up- or down-regulated by insufficient sleep.
What counted as “insufficient”?
