A 2 and 6 split would work too.
Im just trying to maximize the daylight.
I’ll check out that book.
Nothing, which is why we should rely on modern sleep studies and what the science says is best now to optimize sleep…not what people may or may not have done hundreds to millions of years ago.
And what does the science say about two sleeps within a 24 hour period? Does it say you have to sleep continuous for 8 hours or 2 x 4 hours works just fine as well?
The second part of a continuous 8hr sleep (or a 2x4hr sleep that’s only broken to pee or a random waking) has a greater percentage of REM sleep as compared to the first which has more deep sleep. So I suspect if one were to try 2x4hrs with a significant gap between the two they’d eventually end up short on REM sleep and suffer the consequences of that, which would be similar to short sleeping every night. Fatigue, memory loss, greater risk of dimentia, poor body composition…etc. I don’t know if there’s been studies done on this exact idea though.
Given the body’s natural circadian rhythm, I think overall sleep would suffer in at least one of those stints too…because your body’s not at the right temperature and it’s too near a daylight hour and you wouldn’t have developed enough adenosine to feel sleepy…etc
Got the research links for it?
4 hours on, 4 hours off was the standard watch schedule for centuriess on sailing ships and well on into modern times That’s where “8 bells” comes from (one bell for every half hour, change the watch at 8 then start over).
Those guys were not training but life was pretty hard on a sailing ship back in the day. It must have worked out OK if the world’s navies stuck with it so long.
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In the modern electric light era we don’t go to bed when it gets dark, nor get up when it gets light. The blue light from your tv, tablet, computer screen are already messing with your body clock and brain activity and ability to fall asleep.
https://www.sciencedirect.com/science/article/abs/pii/S1389945707000810?via%3Dihub
https://www.nature.com/articles/s41539-019-0055-z
https://jcsm.aasm.org/doi/10.5664/jcsm.7668#:~:text=Short%20sleep%20(defined%20as%20≤,05).
We change at the margins through light use…but we generally don’t upend the whole concept of circadian rhythm. And those who do by doing shift work or working graveyard shifts generally have worse health outcomes.
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It’s dark at 4pm this time of year, how many are still awake 6 hours later at 10pm. It’s a lot more than margins.
Yes.
But for those of us who are stuck working overnight, like the poster in this thread and myself, biphasic/segmented sleep is sometimes still the best option to maximize total sleep time and quality.
I don’t think anyone is suggesting that people who work 9-5 should be pursuing these weird-ass sleep strategies. We only do them because sleeping the preferred way isn’t an option due to work.
This is disingenuous. If it gets dark at 4, then it gets light at 7am, so from 10pm you still have a 9hr window to sleep where your eyes and room aren’t interrupted by light.
In the summer it stays light to 9pm+ depending on where you live. We don’t all come mentally and physically undone in the summer because of lack of sleep.
So yes, our artificial light does allow us to create summer circadian rhythms all the time, but it’s also unhealthy if you overdo it.
None of those studies are looking at two sleep vs one sleep where the total duration of sleep is the same.
One is about obesity and its affect on sleep. Not sure what that has to do with sleeping in two shifts. Another is about temperature which again not sure what they has to two with a two shift sleep strategy?
You asked for sources on me referencing poor body composition as a result of bad sleep, how the bodys temperature regulation throughout the day is tied to sleep cycles, how the REM cycles differ throughout the night and how short sleeping leads to memory loss/dimentia. Those were relevant studies.
I already said as far as I know there’s no studies on specifically breaking sleep into two distinct parts throughout the day and night as it relates to training adaptations and/or health/longevity, but if you can find them…then please share. I’m simply hypothesizing based on what I do know about sleep (and my own experiences working mid shifts and trying to split up sleep times…or doing split sleeps during ultra races) that the subject would have a nearly impossible time getting a good second sleep, and thus their entire sleep volume would be shortened and they’d see the the same negative effects that people who do get poor sleep see.
I’ve already wasted too much of my time on this. Take care.
The biological drive for sleep is consequently greatest at night and lowest during the daytime in humans, with a secondary peak of sleep propensity in the mid-afternoon.29,32 Scheduling sleep during the daytime, therefore, may result in less actual sleep (eg, from increased time to fall asleep and more time spent awake) during the sleep episode (ie, lower sleep efficiency), although sleep deficiency may raise sleep efficiency even during times of low circadian drive for sleep.11,33 Furthermore, an endogenous circadian rhythm of REM sleep propensity promotes REM sleep in the early morning hours.8 Therefore, allocating an insufficient amount of time for sleep and then attempting to distribute that limited amount of time available for sleep across the day and night, both of which are features of the most popular polyphasic sleep schedules (as described below), will result in less sleep obtained because of the influence of circadian rhythmicity on sleep, and may disproportionately deprive individuals of REM sleep.
https://www.sciencedirect.com/science/article/pii/S2352721821000309#bib0011
You asked for sources on me referencing poor body composition as a result of bad sleep, how the bodys temperature regulation throughout the day is tied to sleep cycles, how the REM cycles differ throughout the night and how short sleeping leads to memory loss/dimentia. Those were relevant studies.
I already said as far as I know there’s no studies on specifically breaking sleep into two distinct parts throughout the day and night as it relates to training adaptations and/or health/longevity, but if you can find them…then please share. The one above explores polyphasic sleeping, which is different but I’d imagine would have similar results to 2x4hr schedule because of the underlying sleep principles. I’m simply hypothesizing based on what I do know about sleep (and my own experiences working mid shifts and trying to split up sleep times…or doing split sleeps during ultra races) that the subject would have a nearly impossible time getting a good second sleep, and thus their entire sleep volume would be shortened and they’d see the the same negative effects that people who do get poor sleep see.
I’ve already wasted too much of my time on this. Take care.
No such request, body composition was just one in a long list of possible outcomes you listed, almost as an aside not central. But I didn’t specifically reference it.
I am specifically asking for the research into two sleeps vs one where the total amount of sleep every 24 hours remains the same. What do you hsve on that?