概日リズムニック・リトルヘイルズがより良い睡眠について教えてくれること

Why your body clock matters and how to realign sleep for better performance, recovery, and wellbeing.

Understanding your body’s natural circadian rhythm for healthier, more restorative rest.

Most of us live life against the clock — rushing to meet deadlines, fighting fatigue with caffeine, and trying to “catch up” on sleep whenever possible. But according to sleep coach Nick Littlehales, author of SLEEP: Redefine Your Rest, for Success in Work, Sport and Life, the real key to better rest isn’t more sleep — it’s the right sleep, aligned with your body’s natural clock.

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The Wake-Up Call

In his chapter “The Clock Is Ticking”, Littlehales begins with a familiar picture: you wake up groggy, check your phone, scroll through notifications, and wonder why you’re tired — even after a full night in bed. The truth is, modern life often disconnects us from the rhythms that govern how our bodies function.

For most of human history, we rose with the sunrise and wound down at sunset. Today, we live under artificial light, spend hours staring at blue-lit screens, and fill our nights with endless stimulation. The result? Our sleep suffers — not just in quantity, but in quality.

Littlehales argues that if we want to feel truly rested, we need to stop fighting time and start working with it.

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The Power of the Circadian Rhythm

Every human being operates on a 24-hour biological clock, known as the circadian rhythm. This internal system regulates everything — our alertness, hormones, temperature, appetite, and of course, our sleep. When we’re in sync with this rhythm, falling asleep feels natural. When we’re out of sync, sleep becomes a struggle.

Light is the biggest signal that tells your body when it’s time to wake or rest. Natural morning light triggers the release of cortisol (your body’s “get up and go” hormone), while darkness cues the release of メラトニン, the hormone that helps you wind down and sleep.

But exposure to blue light from screens and artificial lamps confuses this system — essentially “tricking” the brain into thinking it’s still daytime. That’s why a midnight Netflix session or endless phone scrolling can leave you tossing and turning long after you close your eyes.

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What’s Gone Wrong in Modern Life

Littlehales points out that our 24/7 lifestyle has turned sleep into an afterthought. We squeeze it between work, social media, and family responsibilities — then blame ourselves when we can’t drift off.

Modern sleep problems are often circadian problems.
Artificial lighting, late-night screen use, irregular work shifts, and even poor diet can all shift your internal clock. The mismatch between your natural rhythm and your schedule is what causes many forms of insomnia, grogginess, and “social jet lag.”

Sleep isn’t a luxury. It’s a core biological process that determines how well you function during the day.

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The 7 Key Sleep Recovery Indicators

In “The Clock Is Ticking,” Littlehales introduces what he calls Key Sleep Recovery Indicators (KSRIs) — seven elements that affect how well your body recovers during sleep:

1. Circadian Rhythm – understanding and respecting your body’s timing.
2. Chronotype – recognizing whether you’re naturally a morning person or night owl.
3. Recovery in Cycles – structuring sleep around 90-minute cycles instead of fixed hours.
4. Recovery Rhythm – aligning naps and rest periods with your energy dips.
5. Environment – designing a dark, cool, distraction-free sleep space.
6. Interventions – controlling light, caffeine, and evening routines.
7. Behavior – consistently applying small habits that reinforce your rhythm.

These indicators show that sleep isn’t just a single event each night — it’s a 24-hour rhythm of recovery that depends on when, where, and how you rest.

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How to Realign Your Body Clock

The good news? You don’t need to overhaul your life. A few simple adjustments can help your body and brain return to their natural timing.

1. Fix Your Wake-Up Time

Pick one consistent wake-up time — and stick to it every day, even weekends. This becomes your anchor point that resets your body’s internal rhythm.

2. Get Morning Light

Within 30 minutes of waking, expose yourself to natural daylight. It’s the single most powerful cue that tells your body, “The day has begun.” My wife and I have tried this in warm weather, it is confirmed to be effective.

3. Think in 90-Minute Cycles

Instead of aiming for “eight hours,” try sleeping in multiples of 90 minutes (e.g., 6 hours, 7.5 hours, or 9 hours). You’ll wake up between cycles — when your body is naturally ready — and feel more refreshed.

4. Plan Smart Recovery Breaks

Short naps (20–30 minutes) or mindful rest sessions during the day can restore focus without disrupting nighttime sleep.

5. Create a Wind-Down Routine

Start your pre-sleep ritual 60 minutes before bed. Dim lights, put devices away, stretch, read, or listen to calming sounds. This tells your body it’s time to slow down.

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Why It Matters — Not Just for Sleep

Littlehales doesn’t talk about sleep in isolation. He connects it to performance, focus, emotional balance, and health.
When sleep aligns with your body clock, your energy peaks at the right times, your mood stabilizes, and your mind becomes sharper. This is why world-class athletes, corporate leaders, and creative professionals now treat sleep as a training tool, not a passive state.

Misaligned sleep, on the other hand, increases the risk of heart disease, weight gain, anxiety, and cognitive decline — all consequences of living “out of rhythm.”

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The SlumberZon Takeaway

“The Clock Is Ticking” isn’t just a catchy title — it’s a reminder that every day, your body follows its own natural rhythm. You can’t control time, but you can align with it.

Start small:

• Keep a consistent wake time.
• Soak in natural morning light.
• Sleep in 90-minute cycles.
• Make your evenings a cue for calm.

で スランバーゾンを購読する, we believe sleep is the foundation for everything — not a luxury, but your body’s most powerful recovery system. The moment you respect your internal clock, your energy, focus, and mood all begin to shift.

Because in the end, the clock isn’t your enemy — it’s your guide to better rest and a brighter tomorrow.