Resources — How Sleep Cycles Actually Work
Welcome to the resources page for How Sleep Cycles Actually Work. Everything below is curated to go alongside the guide.
Your Free Worksheet
The companion worksheet to How Sleep Cycles Actually Work is yours to print and use as long as you need it. It includes a 14-day sleep diary, disruptor audit, bedroom environment check, wind-down routine builder, 30-day action tracker, and weekly reflection prompts.
Download the Sleep Worksheet →
Already inside your purchased PDF as a clickable link.
Free Sleep Medicine Resources
National Heart, Lung, and Blood Institute — Sleep Disorders
The U.S. NIH division responsible for sleep research. Plain-language explanations of every major sleep disorder, evidence-based treatment information, and links to clinical trials. nhlbi.nih.gov/health/sleep
American Academy of Sleep Medicine — Find a Sleep Center
Directory of accredited sleep centers across the U.S. If you suspect sleep apnea or another sleep disorder, this is where to find a qualified specialist. sleepeducation.org
Sleep Foundation
Independent nonprofit dedicated to sleep education. Their articles are well-sourced and clinician-reviewed. sleepfoundation.org
CDC — Sleep and Sleep Disorders
Government overview of sleep statistics, recommendations, and risks of chronic sleep deprivation. cdc.gov/sleep
National Sleep Foundation — Sleep Diary
Their free printable sleep diary, used in many sleep clinics. A solid alternative or supplement to our worksheet. thensf.org/wp-content/uploads/2021/03/SleepDiaryv6.pdf
Recommended Books
Why We Sleep — Matthew Walker, Ph.D.
The most-cited popular sleep book of the last decade. UC Berkeley sleep scientist explains the research that should change how you think about sleep. Some of his interpretations are debated by other researchers, but the foundational science is solid and important. Find it on Bookshop.org
The Sleep Solution — W. Chris Winter, M.D.
Sleep medicine doctor with 25+ years of clinical experience. More practical and clinical than Walker's book; less hype, more application. Find it on Bookshop.org
Internal Time — Till Roenneberg
Chronobiology researcher on circadian rhythm and chronotypes. The science of why some people are night owls and others are early birds — and why "owning your chronotype" matters. Find it on Bookshop.org
Say Good Night to Insomnia — Gregg Jacobs, Ph.D.
The CBT-I (cognitive behavioral therapy for insomnia) protocol in book form. Used in clinical practice for decades. The evidence-based alternative to sleeping pills for chronic insomnia. Find it on Bookshop.org
Note: Book links go to Bookshop.org. These are not affiliate links — we don't earn a commission. Find any of these at your local library for free.
Tools & Apps
Insight Timer
Largest free meditation app. Excellent free guided sleep meditations and bedtime stories. insighttimer.com
CBT-i Coach
Free app developed by the U.S. Department of Veterans Affairs. Implements the clinical CBT-I protocol. The most evidence-supported insomnia treatment, available free. [Available on iOS and Android app stores]
Sleep Cycle
Sleep tracking app with smart alarm that wakes you in light sleep. Free tier is functional; premium adds features. Best of the consumer sleep trackers. sleepcycle.com
Verilux HappyLight (or any 10,000-lux light box)
For getting morning bright light when outdoor sun isn't available, especially in winter or for shift workers. The most evidence-supported home device for circadian rhythm regulation. (Available at most major retailers; we don't link to a specific seller.)
Curated Video Lessons
Sleep Is Your Superpower — Matt Walker (TED)
UC Berkeley sleep scientist on why sleep matters more than people realize. Watch on YouTube
Master Your Sleep Toolkit — Andrew Huberman
Stanford neuroscientist with practical, evidence-based sleep protocols. Watch on YouTube
How Caffeine Affects Your Sleep — AsapSCIENCE
Animated explainer of caffeine's 6+ hour half-life. Watch on YouTube
Why You Need to Stop Hitting Snooze — TED-Ed
The science of sleep inertia. Watch on YouTube
Insomnia — What Actually Helps — Therapist Aid
CBT-I explained simply. Watch on YouTube
Continue Your Knowledge Stack
The rest of the Health & Body library and the Mental Health library both build on this:
Browse Health & Body → • Browse Mental Health →
Sleep doesn't exist in isolation. Anxiety, depression, exercise, and nutrition all interact with it.
This page is a free companion to the How Sleep Cycles Actually Work PDF. All links above are to free or third-party resources. We do not earn a commission on any link on this page. Last updated May 2026.