How much sleep do our bodies really need?

Not really, you can do fine with less or more sleep.

I'm more interested about why my waking time is synced to some particular hours. Irrelevant of when I go to sleep, I always can wake up only in some times of day. I don't use clock alarm, and I can wake up on my own only around 2:30, 13:00, 17:00 and 20:00. Why is that so?

>>8451016
Probably got something to do with light in your house.
I believe that you should be able to replace an alarm clock with a light that slowly turns on about half an hour bwfore you need to wake up. If anyone has experience with that it would be lovely if you could share.

Needed sleep depends on roughly 3 things. Height, mental exertion, and physical exertion. You can also include injuries should you have any that are still healing. Diet will play a part in you being tired, but it's not exactly related in the same way.

Average 6' college students need 8 hours of sleep
5'6" needed 7.5 (students were studying sciences, engineering, or computer science degrees at a pace of 6 school hours a week. Homework was not quantified.)
All sleep was standard sleep with no deprivation cycles or supplements used. As close as you're probably going to get to a control group.

Sleep deprivation cycles (more commonly known as poly-phasic sleep) increases sleep efficiency dramatically at the cost of rigid sleep schedules.

Waking up without an alarm is bullshit. Every single claim and attempts to create this is found with the subject waking up 5-6 (some cases more than 15 ) times prior to actual desired wake-up time. "But I don't remember waking up" no shit. Each sleep cycle, you wake up. No one is an exception barring any medical issue (which if you had, you wouldn't be touting it around like a trophy.) You don't remember because your brain activity doesn't increase to the point of consciousness until roughly 30 seconds later. If your checking the clock, your bringing your brain to hurry levels of activity which is in turn fucking your sleep efficiency.

The constant wake ups towards the desired wake up time reduce sleep quality to the point you may not get to any restful stages of sleep at all for the time you could have had one or two cycles.

Sleep is kinda my forte, ama.

>>8451031
Is probably right. Had a patient who would wake up every time his sprinklers came on and one specific sprinkler struck a stop sign outside his home. The noise was barely audible, but it was enough.

Melatonin plays off light, however you don't suffer from light exposure as much as media tells you you do. Nor does your bed actually matter that much.

>>8451033
Isn't a big part of sleep just to save energy though? Couldn't you just eat 4 times a day and sleep 3-6 h?

>>8451033
Give me a sleeping plan polyphasic.

>>8451033
is it wrong to sleep 12 hours a day as a 6' college student?

>>8451100
Yes it is.

>>8451033
when i get sleep deprived my efficiency decreases alot. I'm short but still need tons of sleep. I need 3 days a week where I sleep 12 hours a day

>>8451058
No, on both accounts. Does sleeping save energy? Yeah. Does some arbitrary number of times eaten in a day matter? No.
I'm gonna assume you're smarter than most who say that and interpret "just add energy". There's no explicit answer for that.

Needed sleep correlates really well with tdee. Restful sleep can definitely happen in less time, if all sleep was restful sleep ( and both types, not just one or the other) you'd only need be sleep for 3 hours give or take an hour depending on physical/mental exertion and body composition

>>8451072
Why? Google polyphasic sleep and you'll find a wealth of information. Caveat to that, the less delta sleep you get, the slower you're going to heal/repair. On an ubermensch sleep schedule, damage that would take a day to heal normally, could take a week. You definitely won't be building any muscle at 2 hours of delta-less sleep.

>>8450985
>the only part of sleep that we need is REM sleep,
[citation needed]

>when i get sleep deprived my efficiency decreases alot. I'm short but still need tons of sleep. I need 3 days a week where I sleep 12 hours a day

What are you doing? Physical/mental stressors specifically.

>>8451127
just college stuff.
I suppose the social interaction stresses me out.

>>8451111
I thought that humans slept based on day/night cycles and that's why it's said that you need ~8 h of sleep. If you slept naturally about 8 h every day and then added artificial light a few hours before having to wake up, wouldn't you start to wake up earlier?

>>8451126
Hah, I completely ignored this. You definitely need more than rem, and rem certainly isn't "shortly" after falling asleep. Of any given sleep cycle, it's quite solidly in the second half until a few consecutive cycles occur.

You want nothing but REM? If you have a sedentary life style, that's doable. Active at all? You'll die of a lot of different things failing. Body needs time to repair damage, you're either sleeping or meditating in delta states (basically just sleeping in a different position). Either way, that's functionally sleep.

>>8451133
Natural human sleep was to sleep 4-6 hours, get up before the sun rose, do some shit, go back to bed for 2 or 3 hours. I don't know what infomercial you've been listening to (there's a lot of them saying exactly what you just said) but that's marketing, not peer reviewed study.

I've been testing this for like 2 years, You can function normally on 4-5 hours but you will get tired/drowsy as soon as you come home from school or work. Optimum amount is 6 or 7 hours that I found, the key is to keep your sleep times consistent rather than the amount of time you actually sleep, at least in my case.

Has anyone tested staying up more than 18 h and sleeping 6< h, together more than 24 h?

>>8451145
>>8451162
Yes, these are sleep deprivation cycles.
You very much can function, the "drowsiness" you experience is the sleep deprivation part. If you can ignore that and set yourself to a schedule, you're going to find it fairly successful at reducing total sleep needed.

Trade off is that you get some hours of sub optimum mental performance, which some argue is superior since you get more total hours.

Caffeine will help reduce drowsiness, however you need to stay properly hydrated and purge the caffeine from your system if you don't want your sleep quality to plummet.

Rutaecarpine is what we generally used to play with caffeine and when to start purging our lab rats (college students) of caffeine.

Also regular correlations of grape consumption and increased caffeine tolerance. This was never thoroughly tested, but it was ruled out as allowable diet during periods of study.

Anyone have experience with alternate (biphasic/polyphasic) sleep cycles? Would be interested in your experiences with this sort of stuff.

>>8451033
Could i convert to a 6 day week consisting of 28 hour days?

how do i get back to schedule after a sleep deprivation cycle?

>>8451221
>>8451145
this doesn't really work that well for me because I have to do stuff all day. I have college from 8am to 2/4pm and then advanced language classes from 4pm to 7pm.
I drop in performance by about 2 grades. I write essays that get 60% if im sleep deprived and 80% if I get enough sleep

>>8451033
I have never seen something that shows poly phasic sleep cycles work whatsoever. Plus to say that only REM sleep is needed seems ridiculous considering how much is unknown about sleep. Non REM sleep does seem highly important when you look at those who do use these poly sleep schedules. They may get as much REM but they all report feeling worse and not being able to think as well.

Also, there is research showing how csf helps clean the brain of debre such as those beta amyloids found in Alzheimers during sleep and this does not only happen during REM. By limiting your sleep using these schedules you're limiting how much waste is removed and could be greatly increasing your risk for disorders like Alzheimer's.

>>8451444
bump

Hey sleep guy

I'm a math major college student, also a competitive powerlifter with heavy weight training 4x a week. 25 years old, 5'10, 194lbs

How much sleep should I be getting per night to succeed in both maths and lifting? What's the best way to organize myself if I train from 8pm-10pm and have classes/studying at 10am in the morning until 6:30pm

I realized recently that I can force myself to wake up in the middle of the at night at specific times with decent accuracy. Let me explain, sometimes I want to watch a streamed event that occurs during the night due to timezones. I then imagine myself waking up at that time, like at 2:30 am or 4:00 am, etc. About 95% of the time I will actually wake up very close to the time I imagined. Is there an explanation for this?

>>8450985
Sleep consists of 8-9 cycles of sleep per night, each cycle consisting of three stages, only one of which is R.E.M. sleep.
>>8451016
Because you wake up easiest between stages, see above
>>8451058
Sleep has a lot to do with the chemical workings of the brain and nothing to do with food

>>8452520
Well, food has a lot to do with the "chemical workings of the brain", reductionist you.

I usually sleep around 12-15 hours during a good portion of the week, and then 4-6 hours during the rest of it. I seem to be pretty comfortable with it but I'm wondering how fucked it is to sleep for so long, it just feels right to sleep in that long. I feel very rejuvenated after doing so much of the time.

>>8452373
Idk but I can do it too as I grow older. Always needed an alarm as a kid

>>8451607
From 1st hand experience (uberman which is 6 20 min naps and no main block of sleep)- it works but you can't skip naps or oversleep otherwise you're pretty much fucked.

>>8451963

I guarantee you're not gonna be this guy, but I gotta try:

Hey Maverick lifting bro. Keep taking your time on those deadlifts

>>8451033
>>8451607
>Making all these claims without citing a single paper.
t. Med school students

>>8451963
Nights you lift, probably another hour. I haven't studied anyone with such a schedule.

What could happen: Your sleep simply gets more efficient and you dip down faster, where you get more time in delta sleep and don't need an overall increase.

Or

You'll simply just need that time for muscle repair, so whether you get more efficient or not, until your muscles have repaired the damage, it's going to try and get additional time.

My best guess is 8 - 9 hours, closer to 9.5 on days you lift heavy. If you're using workout aids, I strongly recommend to dump caffeine and maybe even just to sleep. If you find yourself crashing hard on weekends, definitely not getting enough and my second guess is pretty likely. Is it bad that you catch up on weekends? Not really if you're functioning fine otherwise.

As to the guy whining about citations... Lol whatever. I'm not asking you to believe me, and I'm not going to beg you to.

The guy claiming he's never seen polyphasic work... LMFAO. I've never personally watched an experiment at the fusion labs in Germany that claim to be working with hydrogen now, ergo that can't work at all either!

>>8451963
>5'10, 194lbs

So how small is it anon?