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Comment by crazygringo | Hacker News Reader

> “Sleeping 8.5 hr. might really be a little worse than sleeping 5 hr.”

How can people even take this kind of pseudo-science seriously?

If I sleep for 5 hrs, I'm a complete zombie during the day, unproductive and depressed.

If I sleep for 8.5 hrs (which is how long I sleep naturally), I feel great, productive, and happy. I get way more done.

There are all sorts of studies showing all the negative effects of not getting enough sleep -- that sleep-deprived doctors, for instance, are basically acting under an impairment equal to a few drinks of alcohol.

The idea that people in general are getting too much sleep is really quite preposterous.

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How is an expert on sleep saying something MIGHT be true now being classed as pseudo science and not to be taken seriously?

Your rebuttal of this "pseudo science" is that you perceive that you personally need 8.5 hours sleep - now that smacks of pseudo science to me.

People are very different. Just because 1 person in a 1000 (or 100 or million or whatever) benefits from 8.5 hours sleep does not necessarily mean that in general one might get more benefit from less than 8.5 hours sleep.

This is not hard science, I doubt it could ever be, but that does not mean it is pseudo science and certainly should not be dismissed out of hand because it does not fit into the model of the world that you have personally.

Because of statements like:

> people who sleep between 6.5 hr. and 7.5 hr. a night, live the longest, are happier and most productive

O RLY? Time for another basic primer on causation vs. correlation.

That was the result of a study (in other words, science). Where is your proof that the study is invalid?

Note that I am not saying that the result is fact, just that there is science to indicate that things are not as simple as they may appear to people that dismiss the whole thing as "pseudo science".

>>That was the result of a study (in other words, science). Where is your proof that the study is invalid?

I'm afraid "science" is quite a bit more complicated than you seem to believe.

One of its most basic tenets is that extraordinary claims require extraordinary evidence. One study is not enough to prove the assertion that people who sleep for 6.5 to 7.5 hours a night are the happiest.

That was a statement that really stuck out. I cannot believe these 'conclusions' from just one study.

Why? What you copy-pasted makes no claim of causation (e.g., it does not say anything like "if you sleep 6.5 to 7.5 hours a night, you will be happier"); you just chose to read it that way.

If people are very different, isn't the conclusion there to figure out how much sleep you need to function effectively and ignore all the people who tell you how much you should need to function effectively? This is something you can measure and experiment with directly, and your results will be a lot more personally relevant than a blog post on the Internet.

I need to point this out -- the question of how much sleep I need to function effectively, and how my functioning varies with differing amounts of sleep, is definitely something I can measure.

It is not at all something I can experiment with directly, unless you believe that sleep under the effects of sleep-inducing drugs is equivalent to natural sleep (it isn't, in my experience).

You can shorten the amount of sleep or wake up at different points in your sleep cycle - just use an alarm clock. You'll probably want to separate out these effects and control for each independently - I find I feel much more rested with 6.5 hours of sleep than with 7 (and perform better on tasks), because the latter interrupts me in the middle of a sleep cycle.

You can't really lengthen your natural sleep cycle without conflating things with drugs, but I've found that personally I can sleep up to 11 hours if I let myself (although there may be another conflating factor as I tend to sleep more when I'm learning something hard).

This article is worse than pseudo science. It is just a bunch of inaccuracies. One thing that caught my attention is how he quotes a study out of context:

"The sleep deprived person can in fact deliver the exact same results as someone who isn’t sleep deprived in any exercise. That is, given it is a non repeated exercise and they give it their best shot."

This phenomenon is called neuron tiring and he makes it sound like someone only carries out wrong judgements sparingly whereas it is more like when person is exhausted from running. The person's legs don't turn off, they are tired. They are still useable and could probably sprint for a very short distance but will eventually start shaking. If the person tries to sprint again, he can but still not for long. This is what being tired or sleep deprived does. You can go for very short sprints but you fail at endurance.

And the 8 hours thing is a mean and it is not pseudo science. Google actual medical sources and see for yourself.

If you take a look at the interview, Kripke is actually talking about the mortality effects of sleeping, NOT the functional effects. [1] I've seen many studies showing the detrimental effect of oversleeping (typically defined as >=9 hours) on mortality, obesity and cardiovascular risk. There's not a complete consensus on the whether this effect is true, though, nor on its neurobiological model. For review and meta-analysis, see [2].

On another note, even when we're talking about mortality, I don't think that sleeping 8.5 hours might be worse than 5. That seems to be an off-hand remark during the interview, to me.

[1] I don't recall any study looking specifically at task performance after oversleeping. The link to the study in the OP's post (http://www.sfn.org/index.aspx?pagename=news_052008&print...) is broken. [2] http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2869.2008....

In fairness, the OP treated the claim with some scepticism and quoted a contradictory view from another "sleep expert" that criticised the idea that levels of optimal sleep were the same for everyone.

What perplexes me is this notion that a person's optimum amount of sleep stays constant whatever they're doing (confounding factors like alcohol, illness and recent sleep-deprivation aside). Surely I'm not the only person in the world whose sleep requirement varies considerably according to the level of physical and mental exertion of the day before, climate, diet, ambient stress level etc.?

And whilst I believe naps probably are a good idea, I'm a bit perplexed to how one times a nap so it ends up being at least 20 mins and no more than 30 mins. Often it takes me that long simply to fall asleep, especially if it's a sunny mid-afternoon and I have plans for the rest of the day to be thinking about...

Perhaps, I have fallen victim to psuedo-science, as I can't readily produce any papers or reputable articles on the subject, but I thought there was something to getting certain amounts of sleep. Where, if you wake up in the midst of certain portions of the REM cycle, you would actually feel more tired for a length of time.

My own experiences seem to fall in line, but it may just be a placebo effect.

Yeah I have to hit a sleep cycle. 5 Hours is terrible, 3.75 is a good amount of sleep for me. If I oversleep and wake off a sleep cycle, e.g. 8.5 hours, I would have been better off getting up earlier and on a sleep cycle (7.5 hours or 3.75 hours). If I sleep 3.75 hours in a night, I will get tired later on in the day, but I won't find it difficult to get up. But I can top up with a nap during the day. My most efficient days have been sleeping in three, 3.75 hour sessions spread throughout the day and without daylight. I wrote my PhD thesis like that. Its not a good method for working with people though.

OK, your personal anecdote compared to mine:

If I sleep for 5 hrs, I'm completely fine. I can do that for days on end. If I sleep for 9 hrs, I'm completely fine as well.

The reality, and from what I've read by cognitive scientists (there are a few), there is no set number of hours of sleep a person needs. For the right person 5 hours is great. For others it isn't. Which is a whole lot better than the crap "common wisdom" of EVERYONE NEED 8 HOURS OF SLEEP that is thrown out for days on end.

Also, never take personal anecdote seriously. Anecdotes will only lead to worse science, not better.

I share your experience. I feel completely miserable on anything less than 6 hours, and I'm lucky to find myself getting anything done at all on those days.

If I sleep 9 to 10 hours, I do feel groggy/sleepy for several hours—it's not pleasant, but mellow grogginess/sleepiness is wonderful compared to the demoralizing mental and physical exhaustion I feel when I've not slept enough.

Thanks for the anecdote, and for comparing a 5-hr night of sleep to a 24-hour work shift.

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