Sleep
The 90-Minute Sleep Cycle Rule Is Mostly Wrong
Set your alarm for a multiple of ninety minutes and you will wake up refreshed — so the advice goes. The number is an average of a distribution nobody bothered to look at.
Mara Ellison
Mara covers sleep and circadian biology. She has worn a sleep tracker every night since 2019 and has strong opinions about what the resulting graphs do and do not mean.
4 articles by Mara Ellison
Sleep
I Tracked 400 Nights of Sleep. Five Things Moved the Needle
Fourteen interventions, one spreadsheet, four hundred nights. Most of what I tested did nothing measurable. Here is the short list that survived.
Sleep
Why Your Sleep Score Is Not a Diagnosis
Wearables are good at some sleep questions and poor at others. Knowing which is which turns a source of anxiety back into a useful instrument.
Sleep
Morning Light Is the Cheapest Circadian Intervention You Are Not Using
It costs nothing, takes ten minutes, and has better mechanistic support than most of what gets sold to people with sleep problems.