Regulating sleep schedules

Mai-Kero

So, normally, I'm up to around midnight and I wake up at 5:30. The thing is, somedays, I will feel incredibly exhausted(and this could be with me going to sleep earlier and getting more sleep too), and other days, I'll feel fine, even with like two hours of sleep. I never really get into any strenous physical labor or anything, so I'm wondering what the difference is in my sleep cycles or whatever.

I heard somewhere that there's a set amount of time where the body goes through a complete sleep cycle, and if you wake up during it, you'll feel a lot more tired than if you wake up right before it starts a new one or right after one ends. I'm thinking this is my thing.

Is there any way to accurately measure the length of my sleep cycles so I can wake up in the right period of time?

Andrew

If you keep sleeping and waking at the same time every night, your sleep cycles will adjust to those times.

Marravica

There's varying degrees of "depth" to your sleep cycles. We're not machines so it isn't an exact science. I've heard it said that during times of mental stress due to work, school etc your sleep requirement increases, although for the most part its just a psychological phenomenon.

And yeah, sleeping the exact same amount of hours at the exact same times every night in a row will force your body to adapt, although everyone has their "minimum" that they simply need every night, and to date I've not found a way to lower this naturally. (I need six hours a night no matter what or I'm downright unpleasant the next day)

Zek

I'm curious about this too. Is it really true that your body can adapt down to 4-5 hours of sleep with no adverse side effects if you just do it often enough? Somehow that just doesn't really seem plausible to me. I'd love it if it were true, it would help a lot of scheduling issues(i.e. me getting up much earlier than my roommate). Does anybody have any personal experience with doing this?