I ask because I can sleep 4.5 hours (3 REM cycles I'm guessing) and wake up and be fine(no obvious loss of energy/mental acuity), though I have to force myself out of bed(but don't we all?). On the other hand I can sleep 8 hours and easily go back to sleep for a couple more REM cycles(or maybe they aren't full REM cycles at all, but broken messed up cycles doing me harm...) and go for 10 or 11 hours. Any more than that and it just becomes tedious. How does one know when to wake up? I want to sleep more instinctively; maximizing the efficiency of my sleep without compromising long term health/fitness goals.
Thoughts? Anecdotes? Thanks.
If everything's working well, and you've got a set pattern of going to bed at the same time, then waking up at a fixed time and exposing yourself to bright light when you do, you'll find that you'll start to wake before the alarm clock.
If you've got trouble getting out of bed, something isn't right - maybe you need more sleep, maybe your adrenals aren't working properly, maybe your thyroid is a bit low, etc.