How Your Circadian Rhythm Actually Controls When You Feel Sleepy
Your internal 24-hour clock decides when you feel alert or drowsy. Learn how light, the SCN, and melatonin set your circadian rhythm every single day.
Elise Moreau
Sleep & Circadian Editor
Elise Moreau
Elise has spent years reading the sleep literature and, more importantly, testing it against real life. She translates circadian science into plain, usable advice, and is careful to separate what's well-evidenced from what merely sells sleep gadgets.
Articles
11 articles by Elise
Elise Moreau
Understanding Sleep Debt and Whether You Can Ever Repay It
Sleep debt accumulates fast but repays slowly. Learn what a night of lost sleep really costs and whether weekend catch-up can ever square the account.
Elise Moreau
Chronotypes 101: Are You Really a Night Owl or a Morning Lark?
Night owl, morning lark, or somewhere between? Discover how your genetic chronotype shapes your ideal bedtime, peak focus hours, and social jet lag.
Elise Moreau
Deep Sleep vs. REM: Which One Does Your Body Need More?
Deep sleep repairs your body while REM consolidates memory and mood. Learn which stage matters more, how much you need, and what happens when you skimp.
Elise Moreau
Melatonin Explained: What the Hormone Does and When It Peaks
Melatonin is your body's darkness signal, not a sedative. Learn when it naturally peaks, how light suppresses it, and why timing beats dosage.
Elise Moreau
Why Sleep Pressure Builds All Day and How Adenosine Drives It
Sleep pressure builds from the moment you wake as adenosine accumulates in your brain. Here is how it works and why caffeine only borrows time from it.
Elise Moreau
Exercise and Sleep: Timing Workouts for Better Rest
Exercise deepens sleep, but timing matters. Learn how morning, afternoon, and evening workouts affect your rest, and when to stop for better shut-eye.
Elise Moreau
Power Naps Done Right: Timing, Length, and the Science
A well-timed nap boosts alertness without wrecking your night. Learn the ideal nap length, the best time of day, and how to avoid grogging out.
Elise Moreau
Caffeine and Sleep: How Late Is Too Late for Coffee?
Caffeine can linger in your system for hours and quietly steal deep sleep. Learn how late is too late for coffee based on your own sensitivity.
Elise Moreau
What Happens in Your Brain During REM Sleep
During REM your brain is nearly as active as when awake, yet your body is paralyzed. Explore what dreaming, memory, and emotion do during this stage.
Elise Moreau
The Four Stages of Sleep, Explained Without the Jargon
From light N1 drifting to deep slow-wave sleep and vivid REM, here is what each stage of a sleep cycle does for your brain and body while you rest.
Elise Moreau