I finally nailed my 18 minute nap window last week
For like two years I kept waking up groggy and mad at myself. Then I read somewhere that 18 to 20 minutes hits the sweet spot before deep sleep kicks in. Last Tuesday I set my phone alarm for 18 minutes, put on a sleep mask, and crashed on the couch at 1:45 PM. When the alarm went off I sat up and felt actually awake, not like a zombie. I used to do 30 or 40 minutes and that extra time was ruining my whole afternoon. Now I'm wondering if anyone else has played around with 17 or 19 minutes to see if there's a better mark, or is 18 pretty much the magic number for everyone?
The 20 minute thing is more of a rough guide than a hard rule, since it's not the clock that matters, it's whether you actually fall asleep and how fast. If you're a person who drops off in 2 minutes, 18 could already be pushing it, and if you lay there for 8 minutes first, 18 might be too short. So testing 17 vs 19 won't tell you much on its own unless you keep your falling asleep time the same, which is pretty much impossible to control. The real trick is figuring out your own timing and just sticking with it.