Usually go to sleep at 3-4 am why am i up like a bolt at 5am if i get an early night?

[Harambulus]

This seems to happen almost without fail.

6 nights of the week i go to sleep at 3 or 4 am and on sunday when I get an early night of 10pm or so I will wake up like a light at 4-5am and proceed to toss and turn trying to get to sleep unfruitfully. After an hour or two of this I usually get up and work for a couple of hours but its not that Im awaking ;refreshed and rejuvenated' ie that isnt all the sleep I required because Ill work for a couple hours then get really tired again and now after working for a bit ill go back to sleep and usually have some good steady rem for a couple of hours at which point I feel refreshed ready for the rest of the day.

So what's going on here? Ive read about circadian rhythms but this doesnt explain that does it since the rhythms should follow my usual routine which this doesnt.

Also the simple explanation of me waking early because I have had enough sleep is not sufficient since I get tired again and go back to sleep after working for a while.

Any better explanations cos Ive been stumped by this for a while now?

 

[Foreigner]

I'm surprised you can sleep at all at 10pm if you're used to being awake until 3-4am for 6 days a week. From 10pm-4am is six hours. If your normal routine of going to bed at 4am yields a longer sleep time, then you're probably having a shortened sleep on Sunday because your mind has had a shortened day. It doesn't have as much to process. So you wake up sooner and do something mentally active, so your mind/body finally gets its full day. Then you can sleep the remainder of your normal cycle.

Most people break sleep down into the traditional REM and non-REM states only, but in your case becoming fully conscious on Sunday morning is part of the sleeping process. To complete the standard cycle, your brain needs to wake up for a while before it can resume the rest of the sleep sequence.

To make this even simpler to understand: you normally sleep everything in one large block after a full day, called monophasic sleep. But then, on Sunday, you have a shortened day and go to bed earlier. In order to compensate for the lack wakeful activity, your brain divides your sleep into a bi-phasic pattern: one large chunk of sleep with one nap later (6 hours and 2 hours = 8 hours, the standard cycle for a monophasic sleeper).

 

[Harambulus]

Interesting, although adding it up the 10-4/5 equates to the same as 4am-10/11 yet I still wanna sleep more on the sunday to monday.

I was wrong about getting a good sleep after being up for a cpl hours and going back again (i had just typed that as i woke at 5am). i went back to bed and felt like total shit with a weird light rem which i would wake from every half hour or so. This went from like 8-11 at which point i feel sort of refreshed but not like a full nights sleep.

I remember now this is how it usually would be. On this second phase id have regular nightmares where im unable to move like being pinned down in dangerous situations and having difficulty breathing in the dream then id awake feeling like dogshit. I knew that if i woke up id feel like crap but also if i go back to sleep more restless nightmares for another cpl of hours till finally im half refreshed.

Counting the total sleep time im not sure why it is i want to go back to sleep since as you say i had the same 6 hours id get during a 4am bedtime, so on the sunday to monday when i go to sleep earlier i end up having more sleep overall (including the 8-11 nightmare zone) yet still feeling worse than if id slept just 6 hours on a normal night.

Thing is i usually feel tired at these 10pms which is why i go to bed but i think ill try making myself stay up to closer to my normal sleep times and see if that allows me a ore restful sleep like my usual nights.

Interestingly though often in the week on my 4am sleeps nights I do find myself getting tired around 4-6pm and usually have around a 1 hour nap (i work form home so can go to bed when i please ) which unlike the morning nightmares I find very refreshing and I get off to sleep very easily then. With the 8-11 one I find it really hard to get back to sleep but the afternoon naps Im asleep very quickly. Strange old body clock.