09/08/2026
Blackout curtains. A cooler room. Phone down an hour earlier.
All reasonable, and none of them reach what set the clock that morning.
Light in the first half hour after waking is what tells your body's internal clock where in the day it is. That clock decides when sleep pressure arrives at night.
Two to ten minutes outside. Longer when it's overcast, because cloud cover still beats any room in your house.
No study prescribes a duration for this one. The two-to-ten-minute range comes from what I've watched work with clients.
Full issue of Built to Endure, link in bio.
builttoendure