Here’s what I’ve learned:
- I always feel pretty good after a night with an unusually high amount of “deep sleep”.
- I fairly often feel great even when I don’t get very much deep sleep.
- Sometimes less sleep is totally fine.
- It takes getting significantly less than my normal sleep to feel bad after just one night of poor sleep. Normally, it will take 3-4 nights of low sleep to start having ill effects.
- Interrupted sleep has the most negative effect on how I feel in the morning, but is also nearly fully resolved by just staying it bed and getting an additional 2-3 hrs of deep sleep throughout the morning.
- Caffeine in the evening can cause me to stay awake later, but doesn’t have any discernable other impact on my sleep.
- Exercise helps me sleep well, but less than I thought.
- Anything over 6 hours and 45 minutes for me is absolutely fine. Anything over 7 hours and 15 minutes feels like “a lot”. I can sleep as little as 6 hours and 15 minutes with virtually no impact unless that goes on for days at a time.
I think the most important of these is (5)— if I find myself up at 2 AM, and again at 4 AM, I will do my best to send a few emails to say I’m having a rough night and make sure I can sleep from 7 to 10 or 10:30 AM whenever possible. This almost always ensures I won’t stack several days of bad sleep. If it’s not possible, I try and get a nap in around 4 or 5 PM that day.