When did "eight hours of sleep per day" become an accepted guideline?

Stephen Tashi
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Main Question or Discussion Point

When was the notion that most people need eight hours of sleep per day popularized? Was it a rule of thumb before there was any scientific research to support it? Did the notion arise after the widespread use of electric lighting - when people acquired an alternative to going to sleep when it became dark and getting up at sunrise?

I gather modern research had more detailed guidelines. https://www.cdc.gov/sleep/about_sleep/how_much_sleep.html
 

Answers and Replies

jim mcnamara
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8 hours - There are biochemical reasons related to the removal of potentially damaging compounds that build up during the day. -Matthew Walker, "Why we sleep?"
See disccussion: https://www.physicsforums.com/threads/questions-about-the-book-why-we-sleep.978718/#post-6250372

The "8 hours" predates sleep research, started with the advent of Western timekeeping, I'm told. Correct time is essential for navigators to determine longitude. Per google, an ngrams search shows the saying must predate 1800, try doing your own search using ngrams
https://books.google.com/ngrams/
 
Stephen Tashi
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Per google, an ngrams search shows the saying must predate 1800, try doing your own search using ngrams
https://books.google.com/ngrams/
That's a neat tool. The specific guideline "eight hours of sleep" is found in a source from 1826: https://www.google.com/books/edition/the_monthly_gazette_of_health/66AEAAAAQAAJ?hl=en&gbpv=1&dq="eight+hours+of+sleep"&pg=PA322&printsec=frontcover I wonder if there was any scientific sleep research in those days.
 
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I just feel like doodoo if I haven't slept at least 7 hours. I usually don't even need an alarm clock, I'm mostly awake after 7.5 hours. As for why, I don't know. My guess is the "8 hours a day" is some kind of heuristic argument for as much as I've looked into the topic, it's not well understood why we need sleep.
 
f95toli
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This is pure speculation; but I would have thought quite a lot of indirect "research" would have been done by the military throughout history?
Commanders would presumably have known roughly how much sleep/rest their soldiers would have needed to be efficient, and how lack of sleep would affect them.
 
russ_watters
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[edit/rework]
This is pure speculation; but I would have thought quite a lot of indirect "research" would have been done by the military throughout history?
I would think so.
Commanders would presumably have known roughly how much sleep/rest their soldiers would have needed to be efficient, and how lack of sleep would affect them.
Yes, but not more with the goal of managing sleep deprivation than the goal of ensuring consistent, suefficient sleep. Soldiers/sailors don't get to decide when to get shot at. As a result, sleep deprivation is the norm in training and combat.
 
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Leading to the ancient military wisdom:
Never run when you can walk.
Never walk when you can stand.
Never stand when you can sit.
Never sit when you can lay down.
 
I wish more studies were done on sleep or at least easily available/accessible.

I think this is much like dietary requirements, each person has different needs. Yet we all need to eat/sleep.

Personally I think I do better on polyphasic sleep cycles. *Shugs*
 
WWGD
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I have trouble getting uninterrupted sleep. After 2-3 hrs of sleep , I am wide awake. Would be nice to enter into REM at will and hopefully cut down on the total amount needed.
 
I generally wake up before the eight hour mark or alarm clock and usually cannot fall back asleep once awake. Quality sleep is challenging, I’m a very light sleeper 💤
 

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