The NASA Studies on Napping | Hacker News Reader

The NASA Studies on Napping

priceonomics.com

86 pointspriyadarshy31 comments

But what data is this conclusion based on? One important study by NASA for the most part.

This is bollocks, for the most part. There have been plenty of studies done on naps, powernaps, short term sleeps. When I was going through uni in the 90s, the motor vehicle registry agency in my state was doing a lot of research in the area of powernaps. Later on I spent some time in sleep medicine myself, and studies here and there would filter through. This is not a notion reliant on one study with a small n.

I would have thought that a startup founder who bases his company on the premise of napping would have read more on the topic.

> This is bollocks, for the most part. There have been plenty of studies... my state was doing a lot of research... studies here and there would filter through... this is not reliant on a single study with a small n.

There is a missing piece of information in your comment. Does this mean the studies you've seen were contradictory? You mention there have been a lot of studies done about the subject but not the results. Can you elaborate on why you reached this conclusion?

I'm genuinely curious about what makes you think so -- the research I've been able to find all seem to corroborate the benefits of napping [1], and I've always been under the impression power naps were effective myself.

I wrote another comment here about how a small n can still produce surprisingly statistically significant results, but besides that it also looks like there are many more than one study on the topic.

> I would have thought that a startup founder who bases his company on the premise of napping would have read more on the topic.

There is no reason to assume this article contains the entirety of the founder's knowledge about the topic. I for one think this write-up makes a much more compelling read than a comprehensive review of the academic literature. Of course, none of this prevents him from selling and marketing his product anyway...

[1] http://en.wikipedia.org/wiki/Power_nap#Benefits

The author is making it sound like the entire notion of the benefit of power naps is based on a single NASA study. This is what I am railing against - it's not one 'landmark' study which suggests the benefits of power naps.

There's also been crossover study of naps and shift workers. The world of scientific napping is not underpinned by one NASA study, not even 'for the most part'.

There is no reason to assume this article contains the entirety of the founder's knowledge about the topic.

Having had minor formal training and then employment in the sleep industry, both as a medical technician and later as an equipment supplier working with in-house clinical specialists in the field, I find it hard to fathom that someone who had a ton of relevant knowledge would characterise the conclusion that 'napping is good for you' as 'coming from one NASA study for the most part'.

But is it, or is not?

I don't understand what you're asking. Are you asking if the studies I've seen are contradictory, like pyduan first said? I thought it was relatively clear when I was saying that the science of napping isn't underpinned by one NASA study that there's more support than one 'landmark' study.

Part of the problem with most other studies are that it is very had to metricize on-the-job performance and sleepiness. Some of the cool things about this study are: 1) very clear metrics to measure performance (reaction time) 2) very consistent testing (repeated trials over an actual 9 hour flight, then over 4 days of additional flights) 3) additional non-subjective metrics for sleepiness (the teams strapped an EEG on the pilots while they were flying to monitor brain activity!!!)

It's frustrating, but most health and wellness magazines are a bit like an echo chamber with no clear references to source data.

This is interesting, but I wouldn't consider it a conclusive study. According to the original paper, the sample size is only 21 (12 napping pilots, 9 no-rest pilots).

Are pilots representative of the population? You could have 1000 pilots and it still wouldn't be conclusive...

True, but this isn't necessarily a showstopper. Unless you think pilots react to sleep differently or are grossly more/less sleep-deprived than everyone else, it's not implausible to assume it generalizes. Every study has flaws, but rarely are they so awful the entire result should be discarded.

This is a comment that often comes up when the sample size doesn't seem very big, but keep in mind that the required sample sizes to draw statistically significant conclusions can be surprisingly small especially when the effect size is large.

According to Figure 14 it seems to be the case, with the difference between the two group means being large enough to be significant at p < 0.002 (according to their numbers). A good threshold is usually considered to be < 0.05, so this is a pretty strong result. (The p-value is the probability this difference is simply a statistical fluke and not actually meaningful.)

Here [1] is a discussion on how to pick a good sample size for an experiment. As you can see in the table to the right, if the effect is strong a sample size of just a few dozens can be perfectly acceptable!

Here the biggest threat to the validity of these results is not the sample size, but whether one can generalize the case of the pilots in-flight (a very specific task performed by a very specific type of individuals). As trentmb says it's not clear whether pilots are very representative of the general population in this situation, although it also looks like there have been multiple studies done on the subject [2] which seem to confirm the benefits of napping as well. For what it's worth it definitely corroborates by own experience as well so I'm actually quite curious to see where Napwell will go.

[1] http://en.wikipedia.org/wiki/Sample_size_determination#Requi...

[2] http://en.wikipedia.org/wiki/Power_nap#Benefits

It's not a drug trial or a voting poll. You don't need that many samples when the statistical effects are large enough.

The unit of performance in these studies is reaction time, which isn't a useful measure in a field like programming or design.

That is incorrect. There are also metrics regarding "microevents", which are points in time during which brainwaves momentarily exhibit the characteristics of the first stages of sleep. This is effectively a measure of how often the subject is starting to "nod off". The napping group showed far fewer of these events.

Does anyone find it surprising that the napping group had performance improvements BEFORE they took their nap?

What's going on here?

http://s3.amazonaws.com/pix-media/blog/539/Untitled.png

Maybe because they knew they were going to rest soon, they could be more prone to be fully alert, a bit like the sprint runners do during the final lap, because they know they'll rest soon.

The easy way to avoid nap grogginess is to limit then to under twenty minutes.

At some point I read that Edison used to hold a spoon in his hand and have a platter on the floor. When going into deeper the hand relaxes, dropping the spoon, hitting the platter, creating noise to wake him up.

I did this once, but I don't really have a problem with sleep inertia, so I just set an alarm, usually for 15 minutes.

From this perspective the device on kickstarter seems problematic: the goal should be to avoid deep sleep rather than just focus on a gentle wakeup.

I am sure the device will help some people out though and their approach is a lot easier than sleep monitoring.

There are two ways to nap: a quick 20 min nap doesn't take you into deep sleep (characterized by delta wave patterns--google SWS) and let's you wake with much less sleep inertia. It's refreshes, but doesn't consolidate memory. A longer nap (60-90 min) typically takes you into deep sleep, and is harder to wake from. However, a long nap will give you memory consolidation and recovery on par with a full nights sleep.

I thought that was Dali and then he would paint right after waking up from the nap. Maybe both.

How do you guys time this? Whether napping or sleeping it often takes me at least 30 mins to even fall asleep lol (sometimes longer). I will say though that I do get a good 9 hours sleep 95% of nights, so I haven't often felt a need to nap.

I was thinking the same. It takes me 30-40 minutes to fall asleep. When they are referring to a nap in these studies, does it mean full-blown sleep?

This post has a good explanation and some advises:

http://danieltenner.com/post/32895447025/0017-how-to-nap-htm...

I assume I will start napping (sometimes it doesn't seem well defined when a nap truly starts) pretty immediately. After 3 minutes I am going to give up.

Napping is a skill that takes practice, you need to get your body accustomed to falling asleep quickly and consider giving up after 5 minutes. Probably only try it on days when you don't get 9 hours of sleep. Consider intentionally getting less sleep on a weekend day and trying to nap then. Timing a nap after eating a large meal helps me a lot, along with a caffeine let-down.

I wrote a bash script (and somewhat later, a Javascript version) where you press a key and when you release it the timer starts, effectively getting you to sleep just 15 (or whatever) minutes. Also prevented taking more than a set amount of minutes between falling asleep and sleeping. It works pretty well, as long as you sleep close enough to a real keyboard (for Bash) or an iOS device (haven't tested the JS solution in other than Mobile Safari)

Me too. 30 mins minimum, unless I'm very, very tired. The comments below seem to indicate this can be trained though. I hope it's true and I hope I'll have the discipline to train myself. Falling asleep fast would be great. Usually I listen to some boring audio lecture at night and it helps.

kozlovsky has better advice in a link, but I learned during a period of intense sleep deprivation. Enlisted military personnel are famous for their ability to nap anytime anywhere; this is a skill that is trained into them through sleep deprivation during boot camp. Edit: I didn't mean to imply that I'm a soldier, I'm not.

Try breathing like a sleeping person does for five minutes.

Interesting article. Cheers for sharing! A brain reset (power nap) should today be accepted / common knowledge as eating healthy food to stay healthy.

For power naps stay within your REM sleep. The duration varies from person to person tho. You don't need any sophisticated monitoring device whatsoever. When the down slope hits, do a Caffeine Nap - a cup of tea/coffee right before your powernap and in 20 or so mins when the caffeine hits you will be wide awake.

But what about those of us who doesn't know where we are and what year it is, when we wake up from a nap? Does the results still hold for us? I am so disoriented after a nap that I am borderline deranged for several minutes.

I've found that often when I feel groggy during the day. Taking time out to do 5 to 10 minutes of deep twisting back stretches will revive me almost as well as a power nap.

That's pretty interesting. These pilots, and I suspect most of us, spend almost all of their working time seated in a chair. I'd be curious to see a study of people whose jobs require a lot of physical activity, or even just standing and walking. Would a nap be as beneficial or as necessary? (I'm guessing yes, but that their alertness doesn't get as low to begin with.)

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