[unparagoned]

That's a good list but I have to strongly disagree with the idea that 6 hours might be enough for most people. Sleep is so important that you really should be aiming to get as much as you can. We have models for the mechanism by which lack of sleep may contribute to stuff like dementia, along with animal autopsies, coupled with the fact that people who only get 6.30h sleep per night have a higher chance of getting dementia than someone getting 8h.(there may be some negative loop stuff there, but it is a negative loop). There may be some people that can function fine on 6.30h sleep at night, but that says nothing about it being healthy. Maybe every book, and sleep scientist I've herd is peddling this pseudo science about how you should aim for 8h plus, but I doubt it. I'm sure you have some random article supporting your position but what about any actual studies showing that people getting 6h sleep is safe both in theory and practise... in any case my tip for people is to throw away your alarm clock and wake up naturally once you've had enough sleep. If you are relying on your alarm clock to wake you up then almost by definition you aren't getting enough sleep.

[imustbeevil]

There was a recent post here [1] with graphs showing that anything more than 6.5-7 hours increases all cause mortality about the same, if not more, as sleeping less.

Here's the discussion part on long sleep:

> Proposed mechanisms for mortality associated with long sleep include: (I) long sleep is linked to increased sleep fragmentation that is associated with a number of negative health outcomes; (II) long sleep is associated with feelings of fatigue and lethargy that may decrease resistance to stress and disease; (III) changes in cytokine levels associated with long sleep increase mortality risk; (IV) long sleepers experience a shorter photoperiod that could increase the risk of death in mammalian species; (V) a lack of physiological challenge with long sleep decrease longevity; (VI) underlying disease processes mediate the relationship between long sleep and mortality.

[1] https://www.nature.com/articles/srep21480

[nicoburns]

This thread is about cognitive ability not mortality though. I definitely know people who function fine on 6 hours sleep, but I will become a zombie if I only get this much sleep over a period of say a couple of weeks (at least if I'm doing mental work, if I'm mostly doing physical things with my day this can different).

I need at least 8 and preferably 10 hours of sleep (as an average).

[coldtea]

>This thread is about cognitive ability not mortality though.

I'd expect the optimum for mortality and congnitide ability in this case would be about the same. Else we'd have the case of something worsening your health but making you smarter (whereas for food, exercize, etc. it's the inverse).

>I need at least 8 and preferably 10 hours of sleep (as an average).

While there is more or less sleep required by different people, note that what an individual "needs" might not be the optimum for them under all conditions, but be such because e.g. they are stressed, overworked, sleep badly, etc.

E.g. someone with apnea (e.g. due to weight) might need 10 hours of sleep to feel well, but that is because they have low quality sleep, and need the extra time to conpensate - not because their organism, if cured of its apnea, actually needs that amount of time optimally.

[unparagoned]

I think you are right that you'd expect them to be correlated. But I think we need to look deeper at mortality rates and the amount of sleep.

Its probably due to reverse causation. If you are ill then the best thing you can do is sleep, so ill people sleep more. Its not that sleep is bad. If those people only slept say 8h then their health outcomes would be much worse. Basically if you are sleeping 11h then you should be worried about an underlying medical condition, not from the actual amount of sleep itself

[unparagoned]

Thats usually due to reverse causation. If you are ill then the best thing you can do is sleep, so ill people sleep more. Its not that sleep is bad. If those people only slept say 8h then their health outcomes would be much worse. Basically if you are sleeping 11h then you should be worried about an underlying medical condition, not from the actual amount of sleep itself