Sleep science is the peer-reviewed study of how the human body
and brain behave during sleep — covering sleep stages, circadian
rhythms, sleep disorders, and the biological mechanisms that make
quality sleep essential for health, memory, and performance. Every
article in this category is written using primary research from
institutions including NASA, Harvard Medical School, and the American
Academy of Sleep Medicine (AASM), and reviewed by Dr. Sarah Mitchell,
a Certified Clinical Sleep Health Specialist (CCSH). Whether you want
to understand why 90-minute sleep cycles matter, how REM sleep
consolidates memory, why sleep debt accumulates faster than it
recovers, or what the circadian dip at 1–3 PM means for your nap
schedule — this is your evidence-based resource for understanding
the science behind better sleep.
Why Men & People Twitch in Their Sleep: Causes, Types & When to Worry Sleep Science Why Men & People Twitch in Their Sleep: Causes, Types & When to Worry Twitching while sleeping is one of the most Googled sleep questions — whether you are asking why do men twitch in their sleep, why do…
Sleep Science How to Stop Sleep Paralysis in the Moment Sleep paralysis happens when your brain wakes up during REM atonia — the state where your body is intentionally paralyzed to stop you acting out dreams. You are fully conscious but temporarily unable to move. The episode feels terrifying, but it is not dangerous and…
Circadian Thermoregulation Body Temperature During Sleep: The Overnight Curve Your core body temperature does not stay constant during sleep. It follows a precise circadian trajectory — falling by up to 1.0 degree Celsius through the night, reaching its nadir around 2am, then rising again toward waking. This overnight drop is not a consequence of sleep…
Cardiovascular Sleep Science Heart Rate During Sleep: Stage-by-Stage Guide Your heart rate changes significantly across sleep stages — reaching its lowest point during N3 deep sleep and showing irregular, sometimes elevated rates during REM. This page explains what is normal at each stage, the cardiovascular significance of the nocturnal dip, and how accurately your wearable…
Sleep + Exercise Science Sleep and Exercise: The Bidirectional Relationship Exercise improves sleep quality and deep sleep. Adequate sleep improves physical performance, recovery, and exercise adherence. This page presents the specific evidence for both directions of the relationship — so you can build the virtuous cycle, not the vicious one. The vicious cycle: poor sleep…
Pregnancy Sleep Guide Sleep During Pregnancy: A Trimester-by-Trimester Guide Sleep changes at every stage of pregnancy — from first-trimester exhaustion driven by progesterone to third-trimester challenges with position, restless legs, and heartburn. This guide covers what to expect, the evidence-based sleep position guidance, and practical strategies for every stage. Trimester-by-Trimester Guide SOS Sleep Position Research…
Deep Sleep Science Deep Sleep (N3) by Age: The Ohayon Normative Data Guide N3 slow-wave deep sleep declines by approximately 2% per decade of adult life — from around 24% in childhood to under 5% in adults over 70. This page presents the Ohayon et al. (2004) normative data as the definitive reference for what…
Older Adult Sleep Guide Sleep After 65: What Changes, What Doesn’t, and What to Watch For Sleep changes significantly with age — but most of those changes are normal biology, not disease. This page explains exactly which sleep changes are expected after 65, which symptoms warrant a GP conversation, and the evidence-based habits that make…
School-Age Sleep Science Sleep for School-Age Children: Ages 6-13 Sleep is the most underrated academic performance tool available to school-age children. Understanding how sleep affects memory consolidation, attention, and emotional regulation transforms sleep from a parenting battleground into a competitive advantage. The research finding parents need to know: children sleeping 9+ hours perform 10-15% better…
🔒 AAP Safe Sleep Guidelines (2022)American Academy of Pediatrics — always follow these guidelines Always ✓Place baby on their back to sleep — every sleep, every time ✓Use a firm, flat sleep surface — approved crib, bassinet, or play yard with a firm mattress ✓Room-share (not bed-share) for at least the first 6 months, ideally…
