# Can sleep “count less” under nonextreme circumstances? **URL:** \ **Category:** Factual Questions\ **Created:** [September 4, 2024, 7:52am UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725 "2024-09-04T07:52:18Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [September 4, 2024, 7:52am UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/1 "2024-09-04T07:52:18Z")
Something I’ve always wondered: if I came home from work, fell asleep on the couch for three hours, woke up for four, then got seven hours of sleep overnight, does that fully count as having had ten hours of sleep that day? I’ve wondered this because, for example, I know extreme numbers of interruptions in sleep can severely lessen its effects (eg new parents), but I don’t know how far that goes. And personally, I’ve always known that my natural sleep tendencies aren’t ideal, but I didn’t know the extent to which it affects me. ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [September 4, 2024, 12:06pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/2 "2024-09-04T12:06:42Z")
It’s my understanding that the number ,length and timing of interruptions matters. For example, the pattern you describe is not going to have the same effect as someone with sleep apnea who wakes up 15 or 20 times an hour for a couple of seconds but aren’t even aware they are waking up. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [September 4, 2024, 12:15pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/3 "2024-09-04T12:15:53Z")
I agree with Doreen, but I also believe that the effects of sleep vary with individuals. As I understand it, Thomas Edison never slept more that 4 hours a night and tended to rely on “cat naps” to keep himself energized. Personally, I can be totally exhausted after a very rough day, nap for 40 minutes, and then be energized until I go to bed at 10:30 or 11:00. ---
**Author:** ![CoolHandCox](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/coolhandcox/32/16233_2.png) [@CoolHandCox](https://boards.straightdope.com/u/CoolHandCox)\ **Post date:** [September 4, 2024, 12:34pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/4 "2024-09-04T12:34:50Z")
The answer is in this book: [Why We Sleep](https://www.grahammann.net/book-notes/why-we-sleep-matthew-walker). I don’t remember the answer, but it might. I did take away that good sleep was extremely important: > The shorter your sleep, the shorter your life span. ---
**Author:** ![burpo\_the\_wonder\_mutt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/burpo_the_wonder_mutt/32/365_2.png) [@burpo\_the\_wonder\_mutt](https://boards.straightdope.com/u/burpo_the_wonder_mutt)\ **Post date:** [September 4, 2024, 1:31pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/5 "2024-09-04T13:31:21Z")
Funny, I’d always heard the longer you sleep, the shorter your life span, as well, because it’s less time being active. Probably the same people that buggered the Food Pyramid after all those years. ---
**Author:** ![thorny\_locust](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thorny_locust/32/431_2.png) [@thorny\_locust](https://boards.straightdope.com/u/thorny_locust)\ **Post date:** [September 4, 2024, 2:35pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/6 "2024-09-04T14:35:56Z")
There’s evidence that sleeping straight through the night may not be the natural pattern for a whole lot of people. (The wedmd site appears to class it as a disorder and at one point implies it might not be safe – but all the rest of their article effectively disagrees with that.) Bottom line is probably: if it works for you, then it works for you. > **[Biphasic Sleep: What It Is And How It Works](https://www.sleepfoundation.org/how-sleep-works/biphasic-sleep)** > > Biphasic sleep describes sleeping in two segments per day. Learn about potential benefits and how to try this kind of schedule. > **[What Is Segmented Sleep?](https://www.webmd.com/sleep-disorders/features/what-is-segmented-sleep)** > > Find out whether it's a good idea to break up your nighttime slumber into two shifts. ---
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [September 4, 2024, 4:18pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/7 "2024-09-04T16:18:29Z")
This raises an interesting question: If sleep extends life spans, it does so by increasing the gross life span, i.e. the number of years between birth and death. But suppose I’m only interested in net time awake, the time that I have to do stuff. Does more sleep increase the gross life span at the same rate as it increases the share of my time that I spend asleep? In other words, does it also increase my net time awake aggregated over the course of my life? I suppose it doesn’t, and that sleeping more is still a net loss in terms of time awake. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [September 4, 2024, 4:46pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/8 "2024-09-04T16:46:48Z")
> [@Schnitte](#): > > But suppose I’m only interested in net time awake, the time that I have to do stuff. But you have to balance against the consequences of the opposite end as well; sleep deprivation may give you more lifetime hours available to potentially “do stuff” but also degrade or destroy the actual utility of those hours, so that those hours can’t actually be used to “do stuff”. It’s a balance. ---
**Author:** ![CoolHandCox](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/coolhandcox/32/16233_2.png) [@CoolHandCox](https://boards.straightdope.com/u/CoolHandCox)\ **Post date:** [September 4, 2024, 5:30pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/9 "2024-09-04T17:30:30Z")
> [@Schnitte](#): > > This raises an interesting question: If sleep extends life spans, it does so by increasing the gross life span, i.e. the number of years between birth and death…does it also increase my net time awake aggregated over the course of my life? I can’t say that this is known. Certainly not on an individual level. I would say, as **gnoitall** stated, that you should also consider your quality of life. Sleeping the correct amount will make you a healthier individual (lack of sleep can lead to Alzheimer’s, diabetes, heart issues, etc). Also, it can lead to things we probably don’t notice - difficulty with memory, learning, etc. Again, that book I linked above is extremely eye-opening about sleep/lack of sleep. But to answer your question directly, I saw that people who get proper sleep live on average 5 years longer. If we say proper sleep is 8 hours a day; and you want to only sleep 6 hours per day to have more awake time…_I think_ that’s enough to do some math to determine if you’d have more awake time in lieu of a longer lifespan. But I’m not good at math and you’d have to make some assumptions and pick arbitrary starting/ending points. ---
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [September 4, 2024, 7:25pm UTC](https://boards.straightdope.com/t/can-sleep-count-less-under-nonextreme-circumstances/1006725/10 "2024-09-04T19:25:06Z")
In terms of the math: Life expectancy in the US is about 76 years. Suppose this is for someone who spends 8 hours a day sleeping. Then this person will have 50.7 years awake in their life (two thirds of 76 years). If sleeping for only six hours a day cuts life expectancy down by five years, then such a person will have 53.25 waking years (three fourths of 71 years). So still a net gain, if we disregard quality.