Sleep Better
Easy, science-backed habits to improve your rest, recovery, and boost your energy.
Explore the ProtocolSleep By The Numbers
The clinical context and optimisation target behind each number.
<6 h raises metabolic, cardiovascular, & dementia risk. >9 h may signal underlying health issues.
Each 90-minute cycle moves NREM 1→2→3→REM. 5 complete cycles = 7.5 h
Cool rooms help to initiate sleep. (65°F) is ideal.
The first 1–2 hours deploy the body's repair crew (deep sleep). Maintain a consistent schedule so you don't miss this prime recovery window.
The Science of Restoration
Sleep is not passive rest — it is an active, multi-stage recovery process. Optimising sleep allows your body to repair tissue, detoxify the brain via the glymphatic system, and consolidate learning, leading to measurable improvements in performance and longevity.
- Cognition: Memory consolidation, decision-making, and learning integration occur during NREM and REM stages.
- Immunity: Cytokine production peaks during sleep; chronic deprivation triples cold susceptibility.
- Metabolism: Ghrelin rises and leptin falls with sleep loss, driving hunger and insulin resistance.
- NREM Stage 3: Critical for tissue repair, human growth hormone release, and slow-wave memory consolidation.
- REM Sleep: Emotional processing, synaptic pruning, and creative insight generation.
- Glymphatic Flush: Brain cells shrink 60% during deep sleep to clear metabolic waste including amyloid-beta.
Circadian Rhythm
Your master clock — the SCN — drives every cell. Light is its primary signal.
- Light Exposure: Morning sunlight (10–30 min within 30 min of waking) anchors cortisol and suppresses late melatonin.
- Melatonin: Rises ~2 h before habitual sleep time; blocked by blue-spectrum light at night.
- Consistency: A fixed wake time is the single strongest circadian anchor — even after a late night.
- Disruptions: Shift work, jet lag, and screen exposure all fragment rhythm and reduce deep sleep.
- Temperature: The ideal bedroom temperature to induce and protect deep sleep is 60°F to 67°F (15.5°C to 19.5°C).
Sleep Health Cheat Sheet
Essential sleep optimisation tactics at a glance. Implement these science-backed strategies for immediate improvements.
Same sleep and wake times daily, even on weekends. Fixed wake time is the most powerful circadian anchor.
Keep bedroom between 16–20°C (60–68°F). A cooling mattress pad or open window can make a significant difference.
Blackout curtains or a sleep mask. Even dim light through eyelids suppresses melatonin production.
No screens 90 minutes before bedtime. If unavoidable, use amber-lens glasses (covered in detail below).
None 6–8 hours before sleep. Caffeine’s half-life is 5–6 hours; it still reduces deep sleep even if you fall asleep fine.
Finish intense workouts 3+ hours before bed. Morning or afternoon exercise boosts adenosine pressure and deep sleep.
90-minute pre-sleep relaxation protocol: dim lights, calm activity, coherent breathing (see section below).
Even one drink fragments REM sleep. Alcohol may help you fall asleep faster but drastically reduces restorative sleep quality.
Blue-Light Blocking Glasses
Short-wavelength blue light (380–550 nm) from screens and LED lighting shuts down your body's sleep hormones at night. Wearing amber- or red-tinted lenses after sunset protects your internal clock so you can wind down easily. If you don't have blockers, turn down room lights, switch devices to night mode, and lower screen brightness 1–2 hours before bed.
How Light Hijacks Sleep
Intrinsically photosensitive retinal ganglion cells (ipRGCs) contain melanopsin, a pigment with peak sensitivity at ~480 nm. When activated by blue light, they signal the suprachiasmatic nucleus to halt melatonin release from the pineal gland.
Visible Spectrum — Blue Zone (380–500 nm) is highest risk
A 2020 Current Biology study found that wearing amber-tinted lenses for 2 hours before bed increased melatonin onset by 23 minutes and improved next-day alertness scores compared to a clear-lens control group.
- Screen Blue Light: Modern OLED and LCD displays emit peak energy at 450–470 nm — directly in the melanopsin sweet spot.
- LED Overhead Lights: Cool-white LEDs (4000K+) produce significant blue output. Swap for warm (2700K) bulbs after sunset.
- Candlelight / Fire: Spectral energy peaks in the red-amber range (600–700 nm) — essentially no melatonin suppression.
When & What to Wear
Begin dimming overhead lights. Clear anti-glare or very light yellow lenses reduce eye strain without fully blocking light.
Switch to amber lenses. These block 60–90% of blue light while preserving reasonable colour perception and vision clarity.
Red lenses block virtually all sub-600 nm light. Ideal for those with severe circadian disruption, shift workers, or heavy screen users. Vision is noticeably tinted — best for home use only.
Switch overhead lights to warm bulbs (2700K or lower). Use salt lamps, candles, or red light panels in the hour before sleep.
Lens Tint Comparison Guide
Choose the right tint based on screen time, timing, and sensitivity level.
| Lens Type | Blue Blocked | Colour Distortion | Best Use | Timing |
|---|---|---|---|---|
| Clear / Anti-Reflective | ~5% | Minimal | Daytime screen work; eye strain reduction | All day |
| Light Yellow | 15–30% | Subtle warmth | Afternoon screen use; mild evening exposure | Afternoon onwards |
| Amber / Orange (FL-41) | 60–90% | Moderate — warm world | Primary evening glasses; readable text; TV viewing | 2 h before bed |
| Red (DeepSleep / AltRed) | >98% | Strong — red world | Pre-sleep protocol; shift workers; severe insomnia | 90 min before bed |
Pair amber glasses with f.lux or Night Shift on screens for layered protection. The glasses handle ambient LED light that software cannot touch. On the phone: enable Greyscale Mode in accessibility settings — desaturation reduces stimulation even before melatonin suppression is considered.
Healthy vs. Unhealthy Sleep Habits
Understanding the contrast between sleep-promoting and sleep-disrupting behaviours is essential for consistent optimisation.
Healthy Habits
Evening Light Management
- Dim Lighting: Reduce light intensity 2–3 hours before bed.
- Amber Glasses: Wear amber lenses if screens are unavoidable.
- Red / Warm Light: Use 2700K or lower bulbs in evening spaces.
Evening Activities
- Reading: Physical books or e-readers with warm filters.
- Meditation: 10–20 minutes of mindfulness or body-scan practice.
- Journaling: Brain-dump and gratitude practice reduces cortisol.
- Coherent Breathing: 5–6 bpm resonance breathing for HRV upregulation (see below).
Sleep Environment
- Temperature: 16–20°C room; cooling mattress pad optional.
- Darkness: Complete blackout; tape over device LEDs.
- Sound: Pink noise or silence (< 30 dB).
- Bedding: Breathable, natural-fibre materials.
- EMF & Clutter: Turn off nighttime EMF devices and clear visual clutter to promote sleep.
Unhealthy Habits
Evening Light Exposure
- Bright Screens: Phone, tablet, TV within 2 hours of sleep.
- LED Overhead Lights: Cool-white 5000–6500K light at night.
- No Glasses: Unfiltered screens suppress melatonin for hours.
Evening Activities
- Social Media: Stimulating, anxiety-inducing content scrolling.
- Work Emails: Stress response activates cortisol and alertness.
- News Consumption: Emotionally charged content raises arousal.
- Intense Exercise: Raises core temperature and sympathetic tone.
Sleep Environment
- Temperature: Too warm (>22°C) or too cold (<15°C).
- Light Pollution: Streetlights, phone displays, LED alarm clocks.
- Noise: TV left on, irregular traffic, inconsistent sounds.
- EMF & Clutter: Active near-bed electronics and visual noise may delay sleep.
Coherent / Resonance Breathing
Slowing your breathing to the baroreflex resonance frequency — 5–7 breaths per minute — maximises heart-rate variability, activates the parasympathetic nervous system, and primes your body for deep, restorative sleep.
Live Breathing Guide
Recommended: 5–10 minutes nightly during your wind-down routine. Breathe nasally, exhale through pursed lips. Relaxed body.
At 5–7 breaths per minute, your breathing oscillations synchronise with your baroreflex loop, amplifying HRV amplitude to its physiological maximum. This window is sometimes called cardiac coherence.
Why the Exhale Must Be Longer
Inspiration activates the sympathetic branch (heart rate rises). Expiration activates the parasympathetic branch (heart rate falls). By making the exhale longer than the inhale, you spend more time in parasympathetic activation, progressively downregulating arousal and cortisol.
Ratio shown: 4:6 (the 6 bpm standard protocol). For advanced practice, try 4:7:8 or a 1:2 inhale:exhale ratio at any comfortable pace.
Resonance breathing synchronises baroreflex oscillations, producing the largest possible HRV amplitude — a marker of vagal tone and cardiovascular adaptability.
As few as 5 minutes of coherent breathing can measurably lower salivary cortisol and self-reported stress — making it an ideal wind-down tool before the sleep window.
Downregulating the sympathetic nervous system via slow breathing reduces sleep-onset latency — the time from lights-out to first sleep — by activating parasympathetic dominance.
RSA is the natural variation in heart rate linked to breathing. Coherent breathing maximises RSA, which is predictive of better deep-sleep duration and next-morning HRV scores on wearables.
Resonance Breathing Protocols by Goal
All protocols use nasal breathing unless stated. Breathe diaphragmatically — belly rises first.
4s in · 6s out · 5 minutes. Use with amber glasses. No breath-hold. Nasal only.
Physiological sigh: double inhale (2s + 1s) then long exhale (8s). Repeat ×5. Rapidly lowers arousal.
5s in · 5s out · 20 minutes daily. Used in clinical HRV biofeedback protocols. Maximises SDNN.
Box breathing: 4s in · 4s hold · 4s out · 4s hold · ×8 rounds. Balances HRV before cortisol peak.