A short nap clears some of the sleepiness that builds through the day and improves alertness for a couple of hours. In one lab comparison, ten minutes worked best: longer naps took a while to pay off. Evidence: decent Past about twenty to thirty minutes you drop into deep sleep and wake up groggy, and a late nap eats the sleep pressure you need to fall asleep at night. Evidence: decent
If you're a bad sleeper at night, skip naps completely until that's fixed. Evidence: worth trying
Same theme: Morning
Morning
Daylight in the first hour
Get outside for ten minutes within an hour of waking. Overcast is fine. A window is a weak substitute.
10 minEvidence: decent
Morning
Ten screen-free minutes after waking
No phone until you've been up ten minutes. Water, light, a window, then the phone.
10 minEvidence: worth trying