July 22, 2014

Scientists struggle to determine whether you should sleep 8 hours...

... or only 7.

Lots of correlation/causation issues there. People sleeping lengthily may be trying to catch up, sleeping something off, or just plain ill. Why would they do well on brain tests?

And why assume that there is one right answer for human beings or even for one individual, year 'round, in different light conditions? I think it's amazing that our need to sleep fits with the day-to-night cycles of the earth. But then I lived through the great "biorhythms" pseudo-science outbreak of the 1970s:
Most biorhythm models use three cycles: a 23-day physical cycle, a 28-day emotional cycle, and a 33-day intellectual cycle. Although the 28-day cycle is the same length as the average woman's menstrual cycle and was originally described as a "female" cycle, the two are not necessarily in any particular synchronization. Each of these cycles varies between high and low extremes sinusoidally, with days where the cycle crosses the zero line described as "critical days" of greater risk or uncertainty.
Fortunately, that's total nonsense, and we are pretty well attuned to day and night. Night is for sleeping. How long? Why is that question even needed? I think it's because people are waking up to alarm clocks or other intrusive noises and jostlings. Too bad! I think you'd know how long you need to sleep if you'd just go to bed when you're tired and wake up when you wake up, but I guess that's some kind of luxury these days... or in any day. 

18 comments:

Nonapod said...

I find that if I don't get about 7 and a half hours (about 5 complete sleep cycles) I feel kinda off. If I get less than 4 hours I'm barely functional. I know lots of people who claim that they don't need more than 6 hours.

Anonymous said...

The studies I've read about, where people are isolated from natural light cycles and clocks and allowed to set their own schedules, seem to show that the normal human cycle is something like 26 hours. Under natural conditions we are woken up by the sun and our circadian rhythm is reentrained to the 24-hour cycle, over and over.

Eleanor said...

It's one of the benefits of being retired.

campy said...

"And why assume that there is one right answer for human beings "

Because Stop denying Science You H8R!!

Michael K said...

I spent years having sleep interrupted every hour or so by phone calls. I could go right back to sleep and was able to give orders to the nurse calling that were appropriate in retrospect. Now, I can't do that since I retired.

I do have to have a clock in the room because I wake up every two hours or so and look at it. Without a clock, I can't get back to sleep.

William said...

"I wake to sleep and take my waking slow.".......The most luxurious feeling on earth is to wake up, realize there's no great need to get out of bed, and then roll over for another hour.

SJ said...

I discovered while camping in a tent that dependence on the light cycle of the sun makes sleep and wakefulness much easier. I didn't need an alarm to arise early. And I didn't need a clock to tell me it was late, because the sun had gone down.

However, living in a house with artificial light makes it easier to attempt a sleep-cycle that isn't as closely connected to the Sun. And easier to slip into patterns that involve short sleeping cycles, tiredness, dependence on alarms, etc.

Original Mike said...

"Night is for sleeping."

You're obviously not a star gazer.

SJ said...

Addendum: I suspect that sleep cycles, like diets or exercise regimes, are not one-size-fits-all.

Nor even one-plan-for-one-person-for-life.

@Ann, weren't you writing about a segmented sleep pattern some time back? Something like two periods of sleep per night, with an hour of wakefulness in the middle of the night?

I wonder how that would connect to studies of modern sleep patterns.

The Crack Emcee said...

"You'd know how long you need to sleep if you'd just go to bed when you're tired and wake up when you wake up,…"

Yeah, but the scientists are white - nothing can be THAT simple.

It's like slavery - as long as that original sin is there, I know, whatever phony "logic" comes down the pike, starting from slavery will winnow out the merits:

Can a white person do so-and-so and a black person can't? No. Why? Slavery.

Can a black person do so-and-so and a white person can't? Yes. Why? Slavery.

Slavery's our country's conversational equivalent to the sleeping mind telling the body it's time to wake up.

Whites saying "We don't even THINK about race" (usually after being racist) are languishing in bed staring at the ceiling, long after they should've risen.

Oh yeah, I forgot - they, alone, don't really have to:

Because of all that slavery.

Hundreds and hundreds of years of it. Back-breaking work from sun up to sun down, blood, sweat, violence that was off-the-chain (and a regular feature of life) all followed by dancing for white's entertainment and, maybe, even a midnight visit from the master-in-the-mood, who don't know nothing in the morning but all you "lazy niggers" getting the crops in.

I hear - on this blog, from totally-unaffected-by-racist-culture types, like Gahrie - that we're still "lazy".

Which is worse - being called "lazy" because you'll only do other's work under threat of force?

Or using cruelty to build a society where whites can admire themselves - but only by telling lies, about themselves, being good people?

It's MLK's "dream" in 2014.

God, I hate this place,...

The Crack Emcee said...

BTW - I'm a 4-hour guy, when I've got a project going (like now) but I crash - HARD - when it's over. Out for at leastt 10-to-12 hours.

BTW - smoking lots of pot now, while working, but still put in 18 hours yesterday.

BTW - I'M AWESOME!!!

Ambrose said...

I wonder if the scientists are working late nights on these studies?

Unknown said...

Has anyone ever claimed that humans were nocturnal? even half a million years ago? I don't think so. There are nocturnal creatures but that's not us so… for at least a million years people had a pretty obvious guide to sleep times. Maybe 7-8 hrs in the summer and 10-12 in the winter. Could get wired into the brain I would think.

Sydney said...

I do best on 9 to 10 hours, but unfortunately my life doesn't allow that except on vacation.

Ann Althouse said...

"@Ann, weren't you writing about a segmented sleep pattern some time back? Something like two periods of sleep per night, with an hour of wakefulness in the middle of the night?"

Yes, first sleep & second sleep. The topic of several old posts.

Ann Althouse said...

"Lazy" is a negative way of putting something that has a positive aspect, like resistance to overwork or skepticism about what work really needs to be done and for whose benefit.

If we were a culture of worker bees and overachievers it would be… well, what would it be? Not America.

Obviously, the propaganda is: Work hard. But the part of you that says no — just say no — has some good purposes and deserves some respect.

Freedom, play, rest, love… these are important things that can get overshadowed by too much work and this absurd drive to achieve.

For what?

campy said...

"If we were a culture of worker bees and overachievers it would be… well, what would it be? Not America. "

Barack Obama (and his unending line of democrat successors) will require you to work.

David said...

I think you'd know how long you need to sleep if you'd just go to bed when you're tired and wake up when you wake up, but I guess that's some kind of luxury these days... or in any day.

That's my mode a good part of the time. Easy to do because I'm retired. Today, though, I had to get up quite early to catch a plane to go to a meeting. (Not completely retired.) Had slept about five hours. But I feel fine, and I generally do these days when I'm on shorter sleep than usual.

I have no idea why, but it's quite nice.