How much sleep do we really need?

Do we really need 8 hours of sleep a day? I’ve always wished I could sleep less so I have more time for everything else.

I’ve checked out many sleep research sites. OK, some people need less sleep. OK, some people can get by sleeping very little. But then my question is: Can average 8-hour-sleeping people adjust to very little sleep? Do we really sleep 8 hours because our bodies need it, or is it that we’re just conditioned to it?

I’ve seen a documentary a while back, about an experiment where a man was conditioned to sleep just 3 hours a day. It took 3 months and a lot of suffering on his part, but after those three months he went by OK. I just couldn’t find any reference to this study online. Any idea? Anyone?

I’ve heard that Leonardo da Vinci managed to survive by taking a fifteen minute nap every four hours. I don’t remember where I read this, so take it with a grain of salt. They said that someone tried it and it worked, but he got bored so he went back to a normal sleep schedule.

I’ve read repeatedly that 6.5 to 7 hours a day is perfectly sufficient. Of course, some people need more, some less, but I think one will sooner or later notice if one is not getting enogh sleep, so no need to worry.
Maybe this link is of help.

I was discussing this with some friends, including a doctor, over the weekend.

I get by on 4-5 hrs a night, plus maybe 1 afternoon nap a month and 1 8-hr night a month. I never use an alarm clock - just wake up naturally. Another of us is on 8 hrs a night, always.

The doctor said, basically, people should just take what they feel they need - a classic example of letting your body decide what you should do.

He made an interesting point: If you need an alarm clock to wake up every morning, you are - by definition - not getting enough sleep.

Margaret Thatcher famously run Britain on 4 hrs sleep per night for 10 years. Or so the rumour goes…

People do have individual sleep needs. Usually, 3 circadian cycles a night. To feel refreshed when you wake up, try to wake up at the end of a cycle. Sometimes you’re better off getting 3 hours of sleep (one cycle) than getting 4.5.

Likewise, take naps that are 10 - 20 minutes long, so the cycle doesn’t get to a deeper stage. If you nap too long and get deep into sleep, you will feel groggy when you wake up.

You can NOT die from lack of sleep. You will have impaired functioning, though. Sleep has been associated with good health. Epidemiological data shows that getting 7-8 hours a night is highly positively correlated with health, but this can be confounded with variables such as SES and age.

Recent media (/.) claimed that a longitudinal study showing that people who sleep less live longer may have really misinterpreted the data that we’ve known for a long time: that old people sleep less.

I apologize for not having citations.

Hemlock, while the mention of the alarm clock certainly sounds intuitively correct, that would mean that I need between 10-12 hours of sleep a night.


Or it could mean that you have accumulated sleep debt. You could test that by going to bed really early and seeing if you eventually catch up on your sleep and start waking up earlier. Although I must admit I don’t have any kind of cite. Just sounds plausible based on what little I know about sleep behavior.

I sort of recall hearing something to the contrary of this in a psych class in college.

Something to the effect of a form of torture being keeping a person awake until they actually died from lack of sleep.

For some reason I recall the figure being something like 11 days…

Can anyone shed more light on this?

I’m getting by with five hours right now, though I usually prefer 6-7. A little caffeine helps, natch. :wink:

I’m not sure it is possible to die from lack of sleep except in a torture situation. Your body releases chemicals into your system to get you to go to sleep. You will eventually just drop.

Im on about three hours, and I woke up feeling fine.

I seem to remember hearing, though I’m not sure from where, that it is possible to be “too tired to sleep.” As in, so exhausted that you are unable to fall asleep. Is this possible?

You folks might be interested in the Uberman’s sleep schedule:

[Ed Norton]
But I’m in pain! Can’t you just give me something?
[/Ed Norton]

Ah, college. Sometimes 12 hours is 3 days’ worth of sleep, some times it’s a nap.

I used to think I needed 8 hours of sleep to get by but I started spending a lot of time with a friend who didn’t sleep much and pretty soon I had adopted her sleep habits. I’ve found that 3 or 4 hours a day is about all I NEED - I will get drowsy sometimes during the day but it passes, and usually by the time I’m ready for bed again I’m not sleepy anymore. I’ve gone extended periods of time with less than 4 hours of sleep a day, every day.

I have a close friend who sleeps 4 hours a night on average between work and the fire academy. Me, I get to sleep 14 hours if I want to (I’m a college student) but I always feel groggy. He’s always complaining about how he doesn’t get enough sleep, but I don’t feel like I’m even starting to sleep until 6 or 7 in the morning (after 4 hours of unconsiousness). Wake me up after 7 hours and I won’t be able to function properly (I couldn’t pass a police DWI test)

Actually I think that many of my grades have suffered because I’ve gotten too much sleep. The more sleep you get the less you use it and the more you need it. I heard a quote somewhere that according to the Nave SEAL program, the human body only needs 2 hours of sleep a week. I have no sites but my personal experience seems to indicate that the less sleep I get, the grumpier I am in the moning, and the more aware I am during the day.

It’s all about training your body. You tell it how much sleep it’s gonna get, it’s gonna complain for a while and you’re gonna feel like crap, but in the end it’s gonna make the best use of what you can give it!

No one really knows how much sleep we need, or for that matter, why we sleep at all.

There are numerous approaches to sleep reduction, and while most of the posts here refer to polyphasic sleep (sleeping in many short intervals through out the day instead of one prolonged nightly chunk), some people do well with, say, one 4-hour period of “anchor” sleep at night and 2 half-hour naps during the day.

The best reference I’ve seen is “Why we nap” by Dr. Claudio Stampi. It’s written for academia (and it’s god-awfully expensive… you might be able to get a copy via interlibrary loan) and is an impressive compilation covering years of cross-disciplinary research, including the military’s investigation into sleep reduction in sustained/emergency operations.

About a year ago I reduced my sleep to 6 hours per night, and I feel at least as alert and rejuvenated as I did on 8. I plan to try a further reduction to 5 hours per night later this summer. Curious: when I was sleeping 8 hours per night I would, on occasion, take naps - usually lasting 30-45 minutes. But these days, if I take a nap, I fall asleep immediately and wake up in 10 minutes feeling quite refreshed. Pretty cool.

The “tricks” that worked best for me when I was reducing my sleep time were to turn on very bright reading lights as soon as I got up, keeping them on until the sunlight took over, and to reduce my sleep gradually, no more than 15 minutes per week.

Here’s a link to the transcript of a “Scientific American Frontiers” episode done 10 years ago. It follows one of Dr. Stampi’s experiments recreating Leonardo’s 15-mins-round-the-clock sleep schedule
This link is to an article by Stampi that references his work with around the world solo sailors. It’s chatty, without much “how-to” info, but interesting, nonetheless

In my neurosci class last semester, my professor outlined an experiment in which two mice would be put on the same revolving platform (with a divider separating them). What would happen is that both of their brain/sleep waves were monitered and the platform would move whenever the experimental mouse would slip into (non-rem) sleep, waking it up on every attempt. The control mouse, if sleeping, would be woken up as well, but otherwise can catch naps before the rotations, so the experimental setup didn’t compromise the following results:

The results seemed to be that the experimental mouse, well, would eventually die. He would consume more food, but lose more weight. Poor mouse.

More than I got last night…ZZZZZZZZZ…