> with no deleterious health effects

Is that actually the case? do we have long term data on these people? or are we just going off of "I feel fine on 5 hours of sleep" stories? Or are you only referring to day to day health effects?

It's a fairly well studied phenomenon known as short sleeper syndrome.

https://www.nih.gov/news-events/nih-research-matters/gene-id...

There are no known health problems caused by this syndrome, according to a Cleveland Clinic overview page: https://my.clevelandclinic.org/health/diseases/short-sleeper...

> There are no known health problems caused by this syndrome

Presumably they mean there's no evidence of this syndrome causing health issues (presumably the "known" part is redundant). Trying to position a causal hypothesis as a matter-of-fact-finding is crazy.

EDIT: that article is insanely poorly written and even worse cited. How are these websites giving super-sketchy medical advice even legal. There's no author to hold accountable, no way to remediate the quality of the article, no sources cited, and it's making statements that wouldn't hold up in a court of law.

I don't understand what you are objecting to. What would the causal hypothesis be, "this syndrome causes no diseases"? It's just an ordinary claim that if the syndrome is harmful, it's not as immediately apparent as something like sniffing glue. It's saying "this is harmless" can't be ruled out.

> There are no known health problems caused by this syndrome

This is a causal hypothesis framed as a statement. The rhetorics indicate an authoritative statement of fact regarding what the syndrome does cause, which is fundamentally an impossible conclusion to draw empirically.

The only hedge in the sentence is "known", which is tautological.

Of course, it's impossible to eliminate all variables, making authoritative claims about lack of causal relation impossible. But at least they could make the effort to frame this uncertainty in reasonable terms.

> What would the causal hypothesis be, "this syndrome causes no diseases"?

EDIT: but c'mon, just read the article. It's extremely bold in its claims with no evidence. "If you have short sleeper syndrome, you don’t need as much sleep as others. You can expect this to continue throughout your life." "Natural short sleepers don’t experience the same health risks as people who don’t get enough sleep." etc. I don't see any semantic difference between this and "this syndrome causes no known diseases". (or "SSS doesn’t pose any known health risks." as the actual quotation states.)

There's been research on it, although not as much as I wish. I'm one of those people who simply needs more sleep than the average, as does my dad... meanwhile, my mother chugs away just fine on 5 hours or so, and is in better health than either of we men are.

People who accomplish a great deal are often one of these "short sleepers" who can subsist on 5 or even 4 hours of sleep a night; think top-of-their-field salesmen, CEOs, and so on. They simply have more time to get things done, and don't have the problem longer sleepers do that getting 4-5 hours on a regular basis would start to affect their performance in every area of life, not to mention their health.

My wife needs 8-9 hours, whereas I can get by just fine with 5-6. She is a very light sleeper who will wake up 3-4 times every night; I can sleep through almost any noise, and never get up in the middle of the night. My son takes after me -- he seems to need significantly less sleep than other kids his age, but he's an extraordinarily deep sleeper.

Anecdotal, but I think that sleep depth might have something to do with it.

I used to get by fine with 5-6 hours, too, until I started getting 7-8 and realized how much better I feel.

I have spent months at a time getting 7-8 (amid years of 5-6). I never notice any difference and am actually surprised my body can do 7-8 to no purpose.

From the perspective of evolution there's a purpose... burn fewer calories in the dark when there's nothing else to do.

The question is whether it still matters in the modern era.

I think this is pretty common! More sleep makes everything better -- attention, immune system (getting colds less often), mood, etc.

I feel like a different person sometimes. And going to bed even 1hr earlier makes it generally much higher quality.

Anecdotal also but I sometimes sleep alone in my office (have a futon) where it is very quiet. I usually feel fully rested after 6 hours in there versus 8 hours in bed with wife, dog and the cat occasionally coming through.

I wish culturally it was standard for houses to have something like `sleep` rooms that are optimized for that purpose.

They're called a bedroom.

Obviously he means a room for one person to sleep. It’s called a bedroom too but he knows that and so do you.

That's called a divorce

Obviously he wants sleeping in different rooms normalized without a divorce. But you knew that.

I stopped sleeping with my wife in the same bedroom some years ago and it was great for our sleep quality.

It's very funny how people conflate that with other aspects of couples relationships.

Yes, I'm one of the people that needs a solid 7-8 of sleep or else I easily become agitated, and anxiety and OCD kick in quickly ... Would love for this to not be the case, if there was a way for me to need less sleep I would be very interested

Really? I thought I was the only one. Everyone around me seem to do fine with a good 3-5 hours of sleep. Before I lost weight, even if I had a good 7 hours of sleep, I'd still fall asleep at work. Now, even if I do get sleepy, a little moving around fixes things.

One thing to note, I have ADHD and have similar issues getting sleepy when understimulated no matter how much sleep I get at night. Getting up and moving around for stimulation helps.

3-5 hours a night??

There are a very small minority that seem to have a genetic component requiring less sleep for them (4-6hr).

https://www.ucsf.edu/news/2018/03/410051/scientists-discover...

A subsequent study has not found any link between the ADRB1/DEC2/other gene mutations and various sleep conditions:

- https://pmc.ncbi.nlm.nih.gov/articles/PMC9499244/

I am incapable of sleeping more than about 5.5 hours (unless I'm severely sleep deprived). So to me it seems likely that FNSS (familial natural short sleep) is a thing, but more research is needed I guess.

I sleep 5-6 hours a night. I also seem to be bi-phasic...on the weekends if I wake up after 5 hours, hang around for an hour and successfully go back to sleep, the second cycle is the sleep of the dead. Like, I don't move. Wake up with limbs fallen asleep, a deep divot in the memory foam...and a lot more rested.

(as an aside: have CPAP, apnea is not a factor.)

iirc, biphasic sleep is the “usual way” people sleep without the advent of electricity, yes? “the waking hour”, and all that.

I wonder if there was an increase in dementia-related disorders once lightbulbs kept people up longer.

> iirc, biphasic sleep is the “usual way” people sleep without the advent of electricity, yes? “the waking hour”, and all that.

I honestly believe that this is not "natural", but rather an adaptation to the absurdly long European winter nights. Note that we didn't evolve there, so it seems unlikely that bi-phasic sleep is the most primal way.

Some of us have partially evolved for that environment. My ancestors eyes turned blue to see in the dim light and their hair and skin changed from Ethiopian Black to pale and blonde af.

Seems reasonable to expect some degree of genetic drift in sleep regulation as well, but I know of no data on this.

A bigger pupil would work better for dim light vision. Light through the iris would sacrifice daylight vision. The light skin on the other hand does have an obvious benefit in that climate for Vitamin D.

Everything is an adaptation to something. The one 8 hours sleep a night is also an adaptation for the life style we adapted for in the last 100+ plus years.

A CPAP had a severe negative effect on my sleep even after two years of getting used to it. I had severe apnea measured in a sleep study, but even so I've done better without it.

It helps for me...of course if I dropped 40 lbs, it probably wouldn't be needed...but then there's the whole GLP-1/Weight thing.

I haven't used an alarm clock in 20 years and wake up within the same 5-10 minute window almost every day.

I have a friend that will just sleep through multiple alarms. But he can also just fall asleep in 10 minutes on an airplane and I can't sleep at all on a plane. He also takes lots of naps and I never take a nap unless I'm sick.

The worst feeling to me is waking up from some external noise. I just feel so groggy afterword. My body will feel better after 5 hours of sleep and I just wake up naturally compared to 5 hours, go back to sleep for 2 hours, and get woken up during the wrong time (middle of REM cycle?) and then I feel tired for the whole day even though I got more sleep.

Your friend could benefit from a sleep study. I'm not saying they have sleep apnea or UARS, but people with those disorders often have those symptoms.

Wasn't there supposed to be a smart watch out there you could set a window of time you wanted to wake up like "between 6:30 and 7:00" where it would use the sleep tracking to pick the optimal time to wake you up like at the end of a REM cycle? I feel like I must have hallucinated this because I'm wearing a smart watch (fitbit) now and no such feature exists.

I'm wearing a fitbit (charge 6) now, and I still have this feature. It's called "Smart wake" https://gadgetsandwearables.com/2021/07/09/fitbit-smart-wake...

A-ha that answers my question

>while the new Inspire 2 gives insights into sleep stages, the Smart Wake feature is absent. We’re not sure why this is. Hopefully it will come via a software update.

It's an app that uses data from your watch, the name is something like sleep cycle.

Apple Watch does this.

Not ootb-separate app needed?

There's an Android app called "Sleep" that does this without the watch. You put your phone on the corner of your bed and it figures out how awake you are with the accelerometer.

Quick edit, I guess the name changed slightly: https://play.google.com/store/apps/details?id=com.urbandroid...

my dad typically gets 3-4 hours sleep a night. when he was a kid he fractured his skull riding his bike and has a hard time getting comfortable laying on a pillow for very long. despite that he's been able to maintain a high performance lifestyle for most of his life. i've also been very interested to know how he's been able to do it.