Sleep Knowledge Articles

Deep-dive explainers on sleep science and method. New pieces added regularly.

Which Exercise Helps You Sleep Best? A Study of 1,348 People Ranked!

A 2025 BMJ network meta-analysis of 22 RCTs ranks the most sleep-friendly exercises: yoga > tai chi > walking/jogging — plus the brain mechanisms and a practical exercise-for-sleep plan.

The Sleep Revolution: Rethinking Your Sleep

A faithful, section-by-section breakdown of Nick Littlehales' book — the 8-hour myth, 90-minute sleep cycles, a fixed wake time, chronotypes, pre/post-sleep routines, caffeine, alcohol, naps, and a practical action checklist.

Why We Sleep — A Deep Dive: Matthew Walker's Core Arguments

A faithful, section-by-section breakdown of Matthew Walker's Why We Sleep — the two-process model of sleep (circadian rhythm and adenosine), NREM/REM architecture, the costs of sleep deprivation on brain and body, the emotional and creative functions of dreaming, three modern threats to sleep, and 12 practical sleep tips.

Asleep on the Couch, Wide Awake in Bed? The Science of Conditioned Arousal

Why you nod off on the sofa in minutes yet lie awake in your proper bed — explained through Richard Bootzin's stimulus control theory and conditioned arousal: how the bed gets mis-trained as a wakefulness cue, why the couch carries no "must sleep" pressure, and the 6 stimulus-control rules to rebuild the bed–sleep link.

What Is Insomnia, Really?

From the 38.2% insomnia rate in the 2023 China Sleep Big Data Report: prevalence, causes (the 2025 Lancet Public Health review by Academician Lu Lin — biological / lifestyle / social / environmental), consequences, diagnostic criteria (chronic / short-term / other), the 7-dimension PSQI assessment, and self-tracking with a sleep diary.

The Science of Sleep, Explained: A Definitive Guide

A comprehensive knowledge map based on Wallace B. Mendelson's The Science of Sleep — the physiology of sleep (NREM/REM stages, the 90-minute cycle, homeostatic pressure and circadian rhythm), the functions of sleep (memory, emotion, immune repair), sleep disorders (the 3P model of insomnia, apnea, narcolepsy, restless legs, circadian and parasomnia), the history and risks of sleeping pills, the truth about melatonin, the science of dreams, sleep across the lifespan, and sleep hygiene with CBT-I.

A Sleep Habit That Raises Cancer Risk and Shortens Life — Break It Early

More hidden than staying up late: a broken sleep schedule. Data from 60,000 people and over 10 million hours show sleep regularity predicts mortality more strongly than sleep duration — people with the steadiest rhythms had 20–48% lower all-cause death risk. The fix is one rule: keep your bedtime within 30 minutes of the same time every day, and put the phone far away.

World's Leading Sleep Expert: Magnesium Won't Help You Sleep — and This Habit Raises Heart Disease Risk 57%

Nine truths from a two-hour interview with Matthew Walker: how thin the evidence really is for supplements (melatonin buys the average person about 3.4 extra minutes of sleep), why weekend catch-up sleep rescues your heart but not your brain, and how people whose bedtime swings more than 90 minutes run 49% higher all-cause mortality and 57% higher cardiovascular risk — plus why the last hour of night is prime REM, the 20-minute rule, and three things to do tonight.

Insomnia? What You Should Know About CBT-I — The First-Line Treatment Most People Never Hear About

Why cognitive behavioral therapy for insomnia (CBT-I) is ranked first for chronic insomnia in adults by the AASM, the ACP, the European Insomnia Guideline and the 2025 VA/DoD guideline: how the 3P model explains why insomnia "renews its own subscription", the two systems that decide whether you can fall asleep (sleep drive and circadian rhythm), sleep diaries and sleep efficiency, the five rules of stimulus control, the time-in-bed restriction algorithm and its safety limits, cognitive restructuring and de-arousal — plus the evidence (a 1,162-person meta-analysis: roughly 19 minutes faster to sleep, 26 fewer minutes awake at night, +9.9 points of sleep efficiency) and the red-flag list for seeing a professional first.

Why Do We Get Insomnia — and Do Melatonin, Sour Jujube Seed or Daridorexant Actually Work? Sleep Science, Insomnia and the Latest Treatment Guidelines

Built on China's 2025 Insomnia Diagnosis and Treatment Guideline: what insomnia is medically and how it is staged (short-term vs chronic), the 3P model (predisposing "dry kindling", precipitating "match", perpetuating "fuel on the fire"), how common it is (30–48% of the general population report insomnia symptoms), and what it actually costs (60% higher hypertension risk, 45% higher coronary heart disease, 40% higher type 2 diabetes, 2–3× depression risk, 30% higher Alzheimer's risk). The core is treatment: a stepped pathway (CBT-I first, physical and TCM therapies next, medication as support) plus a side-by-side comparison of melatonin, sour jujube seed, traditional hypnotics and the newer daridorexant (a DORA) — ranked across short-term effect, long-term effect, safety and dependence.

These 4 Hours Are the "Golden Window" for Sleep — Miss Them and It's Hard to Catch Up

A "golden four hours" reading from two Chinese sleep specialists (Yu Fengchun of Tsinghua Changgung Hospital's Sleep Medicine Center and Tuo Houzhen of Beijing Friendship Hospital's neurology department): why the window from 11pm to 3am matters so much — the TCM view (gallbladder and liver meridians) alongside the Western evidence (melatonin peaking from 11pm, an Oxford study linking 22:00–23:00 bedtimes to the lowest cardiovascular risk, and deep sleep with growth-hormone release peaking between 1am and 3am). Plus a self-check for whether you actually slept well (falling asleep in under 30 minutes, no more than one awakening, sleep efficiency above 85%), the three habits that damage sleep most (chronic late nights, a disrupted rhythm, self-medicating with sleep aids), and three tailored plans for office workers, older adults and people with chronic conditions.

More articles coming soon — each one written to pair with a Restcalc tool.