Why Sleep Matters – 4 Keys to Living Better
Sleep. Eat. Move. Connect.
Sleep comes first — Eat comes second. And that looks different than It Starts with Food (a book that my name is on the cover of).
But putting sleep first on a list does not mean that the others aren’t important.
Diet is vital for everyone. Thousands have even improved their sleep simply by making the dietary changes I’ve recommended over the years.
I’m just becoming increasingly convinced that the bidirectional relationship between food and sleep (or movement and sleep; connection and sleep) is skewed heavily in favor of sleep as the more important driver.
That’s because our sleep patterns anchor our circadian rhythms. And this essential relationship with the natural, rhythmical order of the Earth’s light/dark cycle affects everything about our health.
Illuminating our planet with artificial light has helped us create wonders that past civilizations could only dream of. It may also be one of the main reasons why so many of us are struggling to feel good about any of it.
A World Desperate for a Good Night’s Sleep
I’ve travelled the world talking about so many aspects of health and well-being, and without exception, everyone leans in to listen closer when the discussion turns to strategies for improving sleep.
Before we address how to improve our sleep, we must understand why it suffers so much in the first place.
Let’s start with an overview of what we know.
Light Regulates Your Sleep Cycles
Our sleep-wake states are regulated by the light-dark cycle of the Earth’s 24-hour rotation. The light wakes us up.
The absence of light — darkness — puts us to sleep.
The light-dark cycle has occurred with such consistency in the evolutionary history of all living creatures on this planet that, one way or another, it has become entrained in their biology as a circadian rhythm.
You are most aware of your own circadian rhythm when it is disrupted.
Travel across multiple time zones by jetliner and experience jet lag, and what you are actually experiencing is your internal body clock being desynchronized from the new local light-dark cycle (time zone) you are now in.
The sun may be at midday, but your body clock (and all the downstream biological functions which follow the clock, which is virtually all of them) thinks it’s 3 am.
Similarly, shift workers experience much the same phenomenon.
A doctor working a day shift may be well synchronized with getting up just after sunrise and going to bed a few hours after sunset, but suddenly change their shift so they are starting work several hours after sunset and finishing work at sunrise, and they are on the fast track to deep mental, emotional, and physical fatigue.
Choose Your Light Carefully
Our power to control light, via the flick of a switch, or the push of a button, has clearly opened up our world.
But as per Jared Diamond’s thesis on the advent of agriculture, our “light-on-demand” world has perhaps become a double-edged sword for us and our relative well-being. Our human ancestors’ earliest after-dark light source — fire — sits closer to the red spectrum of light.
The red spectrum is closest to the light of sunset and provides very little disruption to our body’s sleep processes.
For our more recent ancestors, lamps and electric light bulbs, while perhaps being the genesis of our modern addiction to staying awake longer than we otherwise should, were still closer to that red spectrum of light of fire.
Jump forward to the humans of present day, and we are bombarded by light sources in the blue spectrum — the light of sunrise and broad daylight — our signal to wake up.
Your phone, tablet, computer, television — those ever larger and super intense screens, all beam out blue light — “sunlight.”
We also have the rise of LED and fluorescent lighting, which emit a lot of blue light relative to their old incandescent counterparts.
If you settle yourself in on the couch at night, with energy-efficient LED lights on, surrounded by a phone (for messaging), tablet (for browsing & shopping), and big-screen television (entertainment), to unwind before bed, there’s a much higher likelihood you won’t be able to sleep even if you want to.
Change Your Behavior When You Can’t Sleep
The modern default when you can’t fall asleep?
Watch more TV or surf the ‘net some more, typically in the dark, oftentimes in the bedroom. Your phone is next to your bed because it’s also your alarm clock.
When you wake up, or get woken up by your phone, what do you do? Power the bright screen up, check your messages, emails, news feeds, and maybe update your status to “wide awake at 3 am:(.”
I have worked with nurses whose hospital shift finished at 1am. By 11pm, struggling to maintain energy and focus, they’d have a cup of coffee to “get through that last couple of hours” (we’ll visit the caffeine story at a later date).
Arriving home at 1:30-2:00 am, they were fatigued, tired, but wired and over-stimulated by the nature of their work — the bright lights, the late night coffee, and invariably, the sugary food all too available to them throughout their shift.
Unable to fall into bed and asleep once home, they dive into their phones, computers, and/or televisions. Often only through sheer exhaustion, sometime around 3-4 am, do they fall into some semblance of a sleep state.
By 10 am, with light, noise, and heat seeping into their bedrooms, they are awake again, still tired, unrecovered, and facing more of the same again on a new day.
Rinse and repeat.
We Don’t Get Enough Light Inside
Those who work “office hours” don’t get off lightly either. While there might be daylight outside, many modern workspaces are set up such that this daylight barely permeates the inside, if at all (think retail stores deep in the heart of shopping malls).
Such a lack of bright natural light requires a lot of artificial lighting to take its place. A brightly-lit workplace may be 500-1,000 lux in light intensity, compared with 10,000-100,000 lux outdoors (depending on the time of day and time of year).
So even if the artificial lighting offered light in a similar spectrum to sunlight, the overall intensity, for the time of day, doesn’t come close to matching it.
You are working and trying to stay awake and alert in a light environment which is, in effect, a semi-twilight. In such environments, due to the reduced light intensity, melatonin (the hormone tasked with putting you into a sleep state), begins to rise in your system at the wrong time of day.
You feel sleepy and lethargic when you are supposed to be wide awake and alert. Cue caffeine and sugar in an attempt to boost your flagging energy levels. By the evening, in your tired-but-wired state, you are back to blasting your eyes with concentrated “sunlight” from blue-screen devices.
Feeling like a tightly coiled spring in the last few hours before bed, you might decide you need an alcoholic drink or two in order to help you relax enough to sleep.
Our World is Confused
Our days have become nights. Our nights have become days. We stay up late when we should be asleep, relying on a couple of sleep-ins each week (if we’re lucky) in order to “catch up” — a strategy which itself can further disrupt our circadian rhythms.
The acute and chronic consequences of this social jet lag has become virtually inherent to our modern society, and leaves no aspect of our biology, and thus, health, untouched.
Hopefully, through this overview, it has become apparent how our mismatched relationship with light can disrupt our energy and well-being in every other area of our life. I’ve already outlined the impact of mismatched light exposure on sleep, but what happens to the other keys to health when we are tired and sleep deprived?
Sleep Deprivation Makes Everything Harder
Our ability to plan and prepare meals, due to a lack of mental energy, tanks, and we become increasingly reliant on highly-processed, sugar-laden convenience foods and snacks to get us through.
Our appetite and satiety signals become disrupted; we get cravings for sweet and savory foods, can all too easily overeat them, and rarely experience true long-term satiety from their consumption.
Our bodies become increasingly insulin resistant (just the circadian rhythm disruption and sleep deprivation alone will cause this to happen), our body composition rapidly changes, abdominal fat increases, and lean body mass declines.
Being chronically sleep deprived and fatigued reduces our physical and mental energy, robbing us of the resources needed to engage in regular non-exercise activity, let alone any activity more planned, structured, and intense.
Those who do muster the energy for their daily WOD or run, invariably steal this energy from other aspects of their lives (such as their work focus or relationships), fuel their workouts with sugar, stress hormones, or both, and find, over the long term, they are training hard but going backwards in performance, health, and body composition.
Finally, our low emotional energy from sleep deprivation (plus poor nutrition and a lack of healthy movement) quickly diminishes our ability to connect, in a positive way, with the people and world around us.
We become snappy, less tolerant, less trusting, and less empathetic to the people around us.
While we might seem relatively courteous to strangers, those closer to us may be forced to ride our emotional roller coaster.
We may become withdrawn and isolated, unable to muster the emotional energy resources to foster good, deep connections with the people and places that may otherwise help to recharge such energies in us.
Given what I’ve summarized here regarding light and its inextricable relationship to our sleep, our eating, our movement, and our connections, you may see why I now feel that our health journey starts with light a bit more, perhaps, than it starts with food (though please don’t take this as a diminishment of the absolute importance of eating well).
As part of this journey and exploration, I’ll be further discussing sleep, light, and the inherent concepts of rhythm and seasonality.
In the meantime, here’s how I relate to sleep in my life.
Why Sleep is Key
I aim to build restorative sleep, and establish a good circadian rhythm, from a schedule of regular sleeping and waking times — something that is at least as important as the total number of hours slept. Besides the benefits to my long term health, prioritising a regular sleep schedule helps with my physical energy, mood, mental focus, appetite control, and just my general outlook on life.
I know that building a good night’s sleep starts from the time I wake up, and includes getting enough bright, natural light exposure during the day, as well as eating the right foods from which my body builds sleep hormones. I know that things such as caffeine, alcohol, stress, and the mental and light stimulation from digital devices can all affect my ability to get a good deep sleep, so I actively work to manage my exposures to these common sleep disruptors.
Knowing that my sleep and circadian rhythms are inextricably linked to the changing seasons, I enjoy the longer daylight hours of summer knowing that I will need to go to bed a bit earlier in the depths of winter.
Getting a good restorative sleep each night is perhaps more essential to health and well being than many aspects of food and movement. Yet curating regular and consistent sleep patterns is often not a priority for many people, often coming into conflict with the common social and cultural norms of modern life.
Get my newsletter to learn about the next Key — Eat.