When I was younger, I never thought about sleep. Why would I? I loved staying up late, watching TV and playing cards with my dad.  Sleep came easily, without preparation or conscious effort.  I always got enough, no matter how little that was. In my late teens and early 20s, I would often get home from a party at 3 or 4 in the morning, having to be up in time to work at 8 am.  Sure, I was tired, but only for an hour or so. Proof that I wasn’t one of those whimps who needed a lot of sleep.

My steadfast view that sleep was an utter waste of time was reinforced by a very influential and ultra-successful individual that I worked for, who only slept 3 or 4 hours a night (and kept a notepad by the bed for ideas that came through the night). It’s no wonder that I always chose “not having to sleep” over “flying” or “invisibility” whenever I played the superpowers game (though I don’t see why I should have to choose!).

And so, for the first 35 years of my life, I had the view that 5 hours was more than enough, and I’d sleep when I’m dead. It never occurred to me that sleep must be really important. Why else would evolution allow for a process that requires us (and all animals) to be unconscious and defenceless for up to a third of our lives?  I now know that sleep is crucial for virtually everything I care about: health, longevity, mood, relationships, physical and cognitive performance.

This article is about the importance of sleep, what happens when we don’t get enough, and some practical, evidence-based tips for how to improve sleep.

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Sleep enables the body and mind to recharge.

That sleep is a fundamental biological necessity that supports nearly every aspect of physical and mental health¹ is now uncontroversial. Sufficient sleep is essential for good physical health, immune function, mental health, and cognition².

Sleep enables the body and mind to recharge, promoting alertness, cognitive clarity, and emotional stability upon waking. During sleep, the brain consolidates memories, processes information, and facilitates learning³, while also regulating mood and supporting sound judgment and decision-making.

Physiologically, sleep is crucial for growth and tissue repair, immune system function⁴, and maintaining metabolic and cardiovascular health⁵,⁶.

The restorative processes that occur during high-quality, well-timed sleep help optimise daily functioning and overall well-being.

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More than Seven.

While kids need more, most adults require between 7 and 9 hours of sleep per night⁷,⁸. Individual sleep needs, however, can vary due to factors such as genetics, age, and lifestyle.

A small minority of people—sometimes called “natural short sleepers”—can function well on less than 6 hours per night without experiencing daytime impairment, but this is uncommon and linked to specific genetic variants⁹.

The most reliable indicator of sufficient sleep is our experience throughout the day with consistent alertness, focus, and lack of reliance on stimulants suggesting adequate sleep.

Importantly, sleep quality is as significant as sleep duration. Fragmented or poor-quality sleep leaves us feeling tired even after having enough time in bed¹⁰. Furthermore, (unfortunately!) sleep cannot be “banked” in advance to compensate for future sleep loss—regular, consistent sleep is necessary for optimal functioning¹¹.

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Chronic poor sleep severely impacts nearly every physiological system.

It heightens the risk of neurodegenerative diseases like Alzheimer’s and Parkinson’s¹², impairs the brain’s ability to clear toxins, and immediately diminishes attention, memory, and decision-making¹³⁻¹⁶. Sleep deprivation also increases emotional reactivity, anxiety, and the risk of mental health disorders such as depression and panic disorder¹⁷.

The connection between sleep and metabolic health becomes strikingly clear when tracked with a continuous glucose monitor. After just one poor night’s sleep, glucose readings often tell a different story.

When I did this experiment on myself, I noticed that on the days I didn’t sleep well, my average blood sugar was something like 30% higher even if I ate the same foods. Cardiovascular and metabolic health suffers, leading to increased risks of heart disease, stroke, hypertension, metabolic syndrome, obesity, and type 2 diabetes¹⁸⁻²¹. Immune function is compromised, raising susceptibility to infections and reducing vaccine effectiveness⁴,²²,²³.

Poor sleep also increases accident risk due to impaired coordination and microsleeps²⁴, and exacerbates chronic pain, stress, and gastrointestinal issues. Overall quality of life is diminished, marked by fatigue, reduced motivation, and impaired performance²⁵. Sleep is a biological necessity with critical short- and long-term health implications²⁶.

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Not all sleep is created equal.

Sleep comprises Non-Rapid Eye Movement (NREM) and Rapid Eye Movement (REM) stages, cycling approximately every 90 minutes. NREM progresses from light to deeper sleep, with deep NREM being particularly restorative for growth hormone release²⁷, memory consolidation³, and cellular repair.

REM sleep (20-25%), which occurs later in the night, is vital for emotional regulation, procedural memory, and brain development, and is characterised by rapid eye movements and vivid dreaming. Sleep architecture typically shows deeper NREM sleep occurring earlier in the night, with REM increasing towards morning; fragmentation disrupts these cycles, thereby reducing restorative sleep²⁸,²⁹.

In cases of sleep deprivation, deep NREM sleep rebounds first, followed by REM, emphasising their importance for physiological and cognitive recovery and highlighting that sleep quality, not just duration, is paramount.

Wearable sleep trackers (discussed later) do a reasonable job of measuring both non-REM and REM sleep. They’re not perfect, but they’re generally very helpful.

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Sleep and unconsciousness are not the same.

Pharmacological sleep aids are ok for occasional use, such as for long-haul travel or for jet-lag. It’s worth knowing, however, that sedation induced by sleeping pills, alcohol, or cannabis oils such as THC and CBD is fundamentally distinct from natural sleep (even though both states involve unconsciousness).

Natural sleep is characterised by predictable and rhythmic brainwave patterns, which are crucial for physical restoration, memory consolidation³, and cognitive processing.

In contrast, sedatives disrupt and often flatten these intricate brainwave patterns, eliminating or significantly reducing the deeper, more restorative sleep stages like slow-wave sleep and REM sleep.

Short-acting hypnosedative drugs have been implicated in complex sleep behaviours³⁰, and alcohol can induce sleepwalking or confusional arousal³¹.

This disruption explains why individuals may spend eight hours unconscious after taking a sleeping pill, yet wake feeling unrefreshed, fatigued, and cognitively impaired. The brain is prevented from completing the essential, restorative processes that occur during natural sleep²⁸, leading to a diminished quality of rest.

Why Sedation ≠ Sleep

1. NATURAL SLEEP

Organized, restorative brainwave patterns.

Shows distinct stages like deep slow-wave sleep and REM, crucial for memory and repair.

2. SEDATIVE-INDUCED STATE

Disrupted patterns prevent restoration.

Key restorative stages like deep sleep and REM are suppressed or absent. Memory consolidation is impaired.

3. ALCOHOL-INDUCED STATE

Initially sedating, then sleep-disrupting.

Suppresses REM sleep early on, leading to fragmented sleep and frequent awakenings later in the night.

EEG recordings reveal why sleeping pills leave you unrefreshed despite hours of unconsciousness. Natural sleep organised, rhythmic brainwave patterns essential for restoration. Sedatives flatten these patterns, eliminating the deep sleep and REM stages your brain needs for repair, memory consolidation, and emotional processing.

Four steps to better sleep.

The following evidence-based techniques work by retraining the brain to associate bed with sleep rather than wakefulness, restoring healthy sleep pressure by working with the body’s natural rhythms, and reducing the mental noise and performance anxiety that sabotage sleep. Unlike medications, these approaches address the root causes of sleep problems and create lasting benefits that persist long after treatment ends. These four steps represent decades of sleep research distilled into practical strategies that can transform sleep patterns fundamentally.

STEP 1. WIN THE MENTAL GAME

Improvements in sleep can often be achieved by directly addressing unhelpful thought patterns and beliefs such as unrealistic expectations (e.g. “I must get eight hours of sleep tonight”) or catastrophic thinking (e.g. “If I don’t sleep, I’ll be useless tomorrow”)³². By recognising that worry is a natural human response, individuals can learn to prevent it from spiralling into a debilitating nightly ritual that actively interferes with the sleep process.

We all know the paradox of sleep — that the harder one tries to achieve it, the more elusive it becomes. This heightened state of arousal, brought on by the self-inflicted pressure to fall asleep, creates arousal and counteracts the physiological relaxation needed for sleep onset. Consequently, the primary and most vital initial step in overcoming insomnia involves consciously releasing this pressure and redirecting the anxious energy that often accompanies the struggle to sleep.

These three interventions release that pressure:

Paradoxical intention: The strategy involves deliberately trying to “stay awake as long as possible.” This removes the performance anxiety that keeps the mind alert and creates a mental shift from forcing sleep to allowing it to happen naturally³³.

Scheduled worry time: Setting aside 15–20 minutes each evening, say after dinner, to deliberately worry, reflect, or write a to-do list prevents mental overflow at bedtime by giving concerns a designated time and place³³. When intrusive thoughts emerge while attempting to sleep, the individual can remind themselves, “I’ve already got this under control.”

Challenge catastrophic thoughts: When thoughts like “I’ll be useless tomorrow if I don’t sleep” arise, reframing them as “I’ve functioned on less sleep before, and one poor night won’t ruin me” helps counter anxiety. The body is more resilient than anxious thoughts suggest³³.

STEP 2. PREPARE FOR GREAT SLEEP

Establishing optimal conditions for sleep is crucial. Maintaining a consistent wake time, even on weekends, is the most impactful habit for regulating the circadian rhythm. Furthermore, it is advisable to avoid caffeine consumption after midday, as its effect on sleep well and truly outlasts the kick that it provides. As a committed coffee addict and enthusiast, I can report that since switching to decaf coffee in the afternoon (it tastes so much better than it used to), my sleep is deeper than it has been in recent memory. In the evenings, dimming screens and lights signals to the body that it’s time to wind down, promoting the production of melatonin. By providing clear environmental cues, the body is better able to transition into a state conducive to sleep.

Here are the elements of good sleep hygiene and preparation:

Cool. In order to fall asleep, our bodies must cool down slightly. Bedroom temperature between 15-19°C is crucial for optimal sleep and is often cooler than many people realise. Another option is to use a hydronic bed cooler such as Eight Sleep or Ooler. While these options aren’t cheap, they are an excellent way to dial in the right temperature, particularly important if sharing a bed. Many advocate using a sauna prior to bed as the ensuing heat dump leads to rapid cooling.

Dark. It is equally important to make the room as dark as possible, as even minimal light exposure can disrupt melatonin production, a key hormone for regulating sleep-wake cycles³³,³⁴. Tools to achieve maximum darkness and enhance sleep quality include blackout curtains or a cupped eye mask like the Alaska Bear sleep mask. Old-fashioned eye masks tend to put pressure on the eyes and can raise intraocular pressure, which is a risk factor for the development of glaucoma.  

Quiet. Research done by the National Sleep Foundation (2015) emphasises the importance of a quiet environment. If noise is an issue, then earplugs become the best option. There are a range of products on the market today, some of which are specifically designed for sleep.  

Good enough for the Navy. The military sleep method is renowned for enabling individuals to fall asleep in as little as two minutes, and consistently within six minutes, after approximately six weeks of regular practice. This method incorporates three key elements: progressive muscle relaxation, deep breathing, and visualisation.

Progressive muscle relaxation, which involves tensing and relaxing muscle groups from feet to head, can assist the body in shifting out of “fight or flight” mode³²,³³.  Mindful breathing, by placing one hand on the chest and one on the belly and breathing so only the lower hand moves, activates the diaphragm and the body’s relaxation response. Counting breaths from 1 to 10 and back down can aid in focusing the mind. Finally, visualising a calm, peaceful scene in detail, occupies the mind with pleasant thoughts instead of daily stressors, reducing physical and mental overstimulation³⁵.

STEP 3. TWO THINGS ONLY RULE

I want to declare that I don’t necessarily stick to this rule myself, but it is a way to improve sleep in those that are struggling. One way of enhancing sleep quality is to reinforce the association between the bed and sleep and excluding all non-sleep activities apart from sex (e.g. using electronic devices, working, or reading in bed³⁶). Ideally, the bed should function as an automatic sleep cue, rather than being linked to frustration or entertainment³⁷. In turn, bed becomes a dedicated space for rest (and if you’re fortunate, sex), ultimately promoting quicker sleep onset and more restorative sleep³⁸. Systematic reviews support this stimulus control as a core component of successful sleep therapy³³.

There are two caveats to the two things only rule:

Only go to bed when sleepy: Learning the difference between tired (low energy, wanting to rest) and sleepy (heavy eyelids, nodding off) prevents lying awake. Going to bed tired but not sleepy often leads to wakefulness³³.

The 15-20 minute rule: If sleep doesn’t occur within 15-20 minutes, getting out of bed and doing something calm in dim light until drowsiness returns is essential³². This might happen multiple times per night initially. That’s normal. Activities like gentle stretching, reading something boring, or quiet meditation work well.

STEP 4. REBUILD SLEEP PRESSURE

One of the most effective techniques in behavioural sleep therapy is also the most counterintuitive and difficult to perform: spend less time in bed. This breaks the cycle of lying awake and rebuilds natural sleep pressure. Sleep restriction consolidates fragmented sleep into deeper, more restorative blocks and essentially retrains the sleep system to be more efficient³⁵.

Originally developed by researcher Arthur Spielman in 1987, this technique has been extensively studied. In a large trial of 642 adults, 42% of patients receiving sleep restriction therapy met clinical response criteria compared to just 17% with sleep hygiene alone. It may feel challenging initially, but it often becomes the turning point for long-term sleep improvement.

Here are four elements to rebuilding sleep pressure:

Track sleep first: A simple sleep diary can be kept for one week, noting when getting in bed, when sleep begins, wake times, and when getting out of bed. This allows for the calculation of average total sleep time³². I’m not really a pen and paper guy. I prefer to use apps – I’ll mention a few, below.

Set the sleep window: Time in bed can be limited to average sleep time, with an aim for no less than 6 hours to avoid excessive restriction³². For example, if someone sleeps 5.5 hours on average and needs to wake up at 7 am, going to bed before 1:30 am would be avoided, regardless of tiredness.  I know this sounds crazy, but it is so effective.

Maintain consistency: Sticking to the sleep window every night, including weekends, is important. Naps are typically avoided completely during this phase because they reduce the sleep pressure that needs building³³.

Gradually expand: Once consistently sleeping 85-90% of time in bed for several nights, 15-30 minutes can be added to the sleep window³². This process can be continued until optimal sleep duration is reached.

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Tracking sleep is a beneficial practice for improving its quality.

Sleep applications enable individuals to identify patterns, monitor changes, and comprehend the influence of various behaviours—such as stress, alcohol consumption, and bedtime routines—on their sleep. These apps also offer a structured approach, facilitating consistent adherence to minor, daily adjustments that lead to improved sleep over time³⁹. Indeed, the very act of tracking sleep, much like the Hawthorne effect suggests, can itself lead to improved outcomes as individuals become more aware of and intentional about their sleep habits.

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For personal sleep monitoring, I use the Oura ring and Stellar Sleep.

Stellar Sleep provides daily coaching based on CBT-I (Cognitive Behavioural Therapy for Insomnia) to address behaviours that disrupt sleep. This includes techniques like sleep restriction, stimulus control, and cognitive reframing, alongside journaling, habit tracking, and progress monitoring.

The Oura Ring, a wearable device, tracks various sleep metrics including sleep stages, Heart Rate Variability (HRV), resting heart rate, temperature, and movement. It provides daily scores for Sleep, Readiness, and Activity, assisting users in optimising their training and recovery. Other devices in this category include the Withings ScanWatch, the Eight Sleep mattress, as well as watches made by Garmin and Apple.

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Gaining objective insight into sleep patterns, behaviours, and physiological signals is paramount.

We can leverage actionable data to refine routines, measure genuine progress, and guide evidence-based interventions. By systematically measuring our sleep, we unlock the true potential for optimisation.

‍1-page cheat sheet: If these four steps aren’t working, reread the four steps!

Unless there’s an organic medical problem, such as sleep apnea or restless leg syndrome, or another condition. These four steps work.

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