Comment by hadoukenio | Hacker News Reader

Comment by hadoukenio | Hacker News Reader

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Ctrl-F sleep debt. Zero results found.

If you're reading an article on sleep studies and it doesn't mention sleep debt, it's not giving the whole picture. Look up William Dement for more info.

Now just for a bit of info so it may help others... for years I had the problem of going to bed around 10pm and then lying there awake for hours. Sometimes almost to 1am. Classic insomnia, until I read a book on sleep by William Dement, it all started to make a bit more sense - I was going to bed too early for my body and not accumulating enough sleep debt...

So the solution was easy! Stay up later. Instead, I started going to bed at around 11pm. I started falling asleep easier (within the recommend 20 minutes) and didn't have the issue of insomnia any longer. However this did lead onto another issue - headaches. After years of suffering from insomnia I had found the solution but then it lead to headaches. I chose headaches. But then I A/B tested some more. I now go to sleep between 12am and 12:30am. Headaches gone. Counter-intuitive, I completely agree. But headaches begone!

So IANAD (I am not a doctor), but if you're suffering from insomnia, try staying up an hour later each night to accumulate a bit of sleep debt. And if it's working but you're then getting headaches, try staying up another hour. If you do experiment with this, shoot me an email (see my profile). I would be interested to see if it works for more people or completely backfires.

(For the curious, I get out of bed at 5:05am every morning for work. So under 5 clean hours each night, no insomnia, no headaches)

Edit: I should have put more info on William Dement, otherwise people may think he's just another fly-by-night "expert" - Dr. William C. Dement, M.D., Ph.D., the world's leading authority on sleep, sleep disorders, and the dangers of sleep deprivation. He is the director and founder of the Stanford University Sleep Disorders Clinic and Research Center, the world's first sleep disorders center.

The evidence for medium- to long-term sleep debt is sketchy at best. Certainly in the short term (1-3 days) if you are deprived of sleep, or if you're chronically short on sleep, there's all sorts of cognitive and physiological effects.

But after over longer terms of a week or more, after returning to a normal sleep schedule, it's more complicated. Much of the 'overtired' feeling and cognitive effects come from being deprived of slow-wave sleep (SWS), which you get in the deepest phases of sleep. It's in this phase of sleep that motor skills are consolidated, and it seems to be the 'physically restorative' part of sleep. This is opposed to REM sleep, which you get in the lighter phases of sleep and is where you dream and where memories are consolidated. Unlike SWS, there are very few side effects to being deprived of REM sleep. In a typical eight-hour sleep there will be several cycles of sleep, totalling about four to five hours out of eight spent in SWS, and the remainder in REM and in transition between states.

As for sleep debt and why it doesn't really exist beyond the short term, it comes down to what sleep researchers call sleep architecture, or how the cycles and phases of sleep are arranged through a night's sleep. For example, there's typically a bias towards getting more SWS in the first half of the night, and more REM sleep in the second. Here's what a typical night's sleep looks like (Stages 3 and 4 are SWS sleep):

http://en.wikipedia.org/wiki/Sleep_architecture#mediaviewer/...

Your sleep architecture changes under sleep deprivation. If you are selectively deprived of SWS one night (e.g. by an evil sleep researcher waking you up any time you enter SWS), you will spend more of the next night in SWS to compensate. If your sleep is reduced gradually over time, your body will sacrifice REM sleep to maintain the same amount of SWS -- about four to five hours a night. As I said before, not getting much REM sleep has few side effects.

This is why you are able to sleep only five hours a night and still feel fine: your body simply adjusted to spend very little time in SWS. If I could guess, I'd say you probably have very few dreams anymore, maybe just one occasionally, shortly before waking up? I can't explain why this helped your insomnia or headaches, because I don't know much about how an insomniac differs from a typical person. But it's not to do with sleep debt.

Thanks, I've never heard of sleep architecture before.

> If I could guess, I'd say you probably have very few dreams anymore, maybe just one occasionally, shortly before waking up?

Wow, that is spot on. I've been doing under five hours of sleep for the past six months now, and I made an comment the other week to my wife that I no longer dream. Given what you said above, it agrees with what I'm experiencing.

Glad to help. I wouldn't worry about any of this, by the way. If you feel better on this schedule and don't notice any cognitive effects (e.g. forgetfulness of things that happened in the last two weeks or so), then do what works for you. There's some evidence that sleep restriction, which is the term in the literature for what you're doing (as opposed to sleep deprivation), can actually lengthen your lifespan. If you're a mouse, anyway.

But you're at about the limit: the number I recall is 5.5 hours of sleep being the minimum, but there's probably some individual variation there of +/- 0.5h or something.

> can actually lengthen your lifespan. If you're a mouse, anyway.

Interesting. But I would add that because I'm already winning since it's "time awake" vs "time alive". If sleeping 15 hours a day let me live 10 more years, what's the point if most of them aren't awake :)

I went into the opposite direction: my sleep schedule now wants to be 2am or later and yet I still have to be up by 7:30 to make it to work on time.

I will agree though that I have to be in a state where my body just can no longer stay awake before I fall asleep. I can't lay in bed. I can't read, I have to literally go until I can't any longer. I'm currently in a month or so of terrible sleep by it being broken up into 2 intervals where I wake up in the middle of the night and stay up for a few hours until my body wants to shut back down again.

Insomnia is an insufferable bitch for the most part. I will say YMMV on anything you change regarding sleep habits. I personally need to be in a massive amount of slept debt to properly fall asleep but it can easily backfire quite easily if I'm not careful.

for years I had the problem of going to bed around 10pm and then lying there awake for hours

Do you do any sports? Running or swimming for an hour (or cycling for two) works well for me.

Yeah, I'm actually very active. Gym, basketball, martial arts. Sorry to say that sport never made a difference with my sleep.

Edit: see above - I realised that sport actually kept me awake (tossing and turning, not falling asleep within 20 minutes).

I lift most nights but by the time I get home from work and to the gym it's like 7pm. Workout for 1-2 hours and it's nine. Trying to come down from that before midnight doesn't work. Then it's up at 6ish again.

I run, lift, and do heavy Colorado trails at high heartrate levels. I find exercise makes it generally more difficult to sleep. Has been a problem for years, only get real sleep on my rest days.

Thinking about this more, I'd agree with this too. That and mediation. Back in my insomnia years, I got so bored of lying there awake that I took up meditation. I found that when I meditated (sometimes up to an hour) I found that I needed even less sleep.

Given what we now know about chronic cardio and it's incredibly damaging effects on the body and the terrible consequences of losing sleep and the fact that it's been a problem for you for years you sure sound resigned to it all. I hope you don't suffer the typical consequences of such a dangerous lifestyle. Consider reading this: http://www.marksdailyapple.com/the-evidence-continues-to-mou...

Given what we now know about chronic cardio and it's incredibly damaging effects on the body

That looks like FUD from somebody who's living depends on blogging FUD. Of course, it's possible to train too hard, but this is very bad advice for the average (slightly overweight, not very active) person. If you worry about training too much, go talk to a sports physician and take a cardiac stress test. Or just run so slowly that you can breathe through your nose only.

Nope, science. FUD is pretty much what you replied with! :)

I only have this issue when I run at night. It seems like intense cardio in the morning is a better idea with regards to lessening sleep disruption.

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