[robertlf]

I find that if I get eight hours of sleep at night, I can move mountains. But if I only get 7.75 hours of sleep or less, my eyes feel tired all day and I'm only half as productive. I've never understood why there is such a marked difference between eight hours of sleep and almost anything less than eight hours. There's something chemically going on inside that I don't understand. The problem I'm having now is that I can get a good five or six hours but I wake up after that fifth or sixth hour and can't get back to sleep long enough to get that ideal eight. This problem is seriously affecting my career and I don't know what to do. I do do moderate to vigorous exercise five times a week but that doesn't always help.

[dopylitty]

I have a theory that there are two variables that impact my subjective feeling of having a good night’s sleep.

The first is whether I wake up at the right part of the sleep cycle. For you that might mean 7.75 is when you’re deeply asleep while 7.5 or 8 might be a better time to wake up. Crucially for me it also means even if I get more than eight hours I still feel like garbage if I wake up and get out of bed at the wrong part of the cycle.

The second variable is how much sleep I get. I might wake up in the right part of the cycle but if I got 6.5 hours of sleep I start to drag, especially in the afternoon. That’s where avoiding activities like eating before bed or drinking alcohol helps. That’s also where doing a 4-5 mile run during the day (not too close to bedtime) helps because I’m more likely to maintain sleep for a full eight hours.

[robertlf]

That's interesting. I definitely think there's a cyclical aspect to it because my fatigue usually goes away in the evening around 6 p.m. or later.

[sizzle]

Second this, waking up in REM makes me groggy with brain fog all morning. I use a sleep cycle calculator every night.

[nradov]

Waking up in REM has zero effect on me. This might be an individual thing.

[GeneralMaximus]

I had sleep issues for years until I discovered that I'm allergic to dust and pollen. Washing my sheets every few days, vacuuming them with a small hand-held vacuum cleaner before sleeping, and using an air filter in my room dramatically improved my sleep.

Other things that have interfered with my sleep in some form or another are vitamin deficiencies, exercising way too much at once, caffeine late in the evening, alcohol, and anxiety.

Despite all the research, I haven't found screen time to have any impact at all on my sleep. I sometimes play the Switch in bed right before I crash, and it doesn't seem to affect anything.

Edit: oh, another thing. A bit of music or a podcast really helps me fall asleep faster. They help me turn off all the work-related thoughts in my head and focus on something entirely different.

[esperent]

Similar issue here except for damp. I live in a very humid country and the increase in my sleep quality once I started to run a dehumidifier in my room at night is crazy.

I used to wake up sneezing at 4am regularly and now I never do.

[sizzle]

I had the opposite issue with low humidity, dry nasal passages and bloody noses, sore throat, can’t sleep etc. until >~25% humidity is restored

[vocram]

You sounds like me. I’m seasonally suffering of the same problem. And AFAICS it doesn’t correlate with my sleep hygiene.

What’s worse, I feel tired the whole day, but not that much anymore towards night.

[hornd]

This is very much me to a T, even including waking up far too early and having difficulty getting back to sleep. It's absolutely bizarre how it seems like difference in 15-30 minutes can have such a negative effect. Hope you can solve your sleep issues!

[bytemilk]

Get analytical with you sleep. Did you drink caffeine after 12pm? Make a log of foods you eat? Are you practicing good sleep hygiene? Cortisol levels can cause issues with sleep cycles.

[Tenoke]

6 hours of sleep are enough for most people physically and the rest is more tiredness than any reduced ability. It's possible the other negative effects you are experiencing are mostly placebo.

E.g. look at the studies discussed here https://guzey.com/theses-on-sleep/

I used to be in the same position and am now better by just not worrying about sleeping less or feeling tired when I do.

[joconde]

That site is half hypotheses made up by the author, and half irrelevant things like "this study proves that you won't die sooner if you cut 2 hours of sleep". Nothing in there indicates that sleeping less won't lead to less physical ability.

I only skimmed for references after the comparison with junk food, hunger, and cavemen. It truly sounds like they are making this up as they go along.

[Tenoke]

For example all-cause mortality in the linked there biggest meta-analysis is actually lower at 6 than 8 hours (graph[0]) and only slightly higher than at the optimal point. This isn't the same as general ability but it's likely correlated and all the evidence seems to point in the same direction.

0. https://guzey.com/files/books/why-we-sleep/shen2016.jpg

[joconde]

How do we know that shorter sleep causes lower mortality, instead of, say, that better health or some genes cause both?

Even if we assume that correlation is causation, I haven’t seen much of that evidence.

[laurent92]

But beauty is essential for a lot of people in the workplace in 2022, and you can’t get beauty when you wake up naturally after only 6hrs. It’s sad but it’s a reality, as a manager in IT.

[mupuff1234]

What's your sleeping environment like?

I find that making sure the room is still fairly dark in the morning makes it much easier for me to fall back asleep in case i've woken up "too early".

I also started sleeping with earplugs in the last 2 years or so to make sure morning city traffic noises don't wake me up.

And lastly, don't reach to the phone to look at the time, better have a regular clock which doesn't have all that extra stimuli.

[tsol]

I find sleep masks help me to get the full 8 hours. Without being able to sense light, I guess my body assumes it should still be asleep and I usually don't wake up early. It doesn't work every time, but it works often enough for me to try to stick to it.

[hubridnoxx]

Just chiming in with a hearty +1. My numbers are slightly different though. If I get 7.25 hours of sleep or more, I'm feeling great. If I get 7 or less - depending on how much less - tired eyes, headaches, trouble focusing, worse strength/endurance, etc. And the hilarious thing is my brain seems hell-bent on getting exactly 7. It's hard for me to get that extra 0.25 hours. :|

[doitLP]

There are a number of things you can do to help your sleep and a quick search will turn up the list. No doubt you’ve looked at this before but I found it was helpful to go for blood on that list and really try to do everything fully (in addition to the exercise.

There was a recent article about vit D and sleep that is worth checking out. Supplementing with D seems to have helped me quite a bit. https://news.ycombinator.com/item?id=28770869

I would also check out a few other potential things that could be affecting your sleep that might not show up in a sleep hygiene listicle, like prostate problems, metabolism changes, CO2 concentration in your sleeping room, sunlight exposure and undetected sleep apnea.

[yowlingcat]

I've found that as I get older if I ingest any remotely psychoactive substances (caffeine, alcohol), I'll have difficulty getting a full 8 hours of sleep. Same applies with stress. The problem is compounded if I'm not exercising regularly or if there are any gaps with my nutrition.

[cjcampbell]

I've struggled with sleep for various reasons for most of my life, and I've put a lot of energy into diagnosing the disruptions. Have you made any observations about the pattern of waking that could provide clues about why it's happening? I'm happy to share a few of the discoveries I've made for myself over the years in case one of them leads you down a productive path.

I had a horrible bout of insomnia early in my career. I'd never given much thought to depression, but it turned out to be the culprit. In my experience, even low grade depression or anxiety (including seasonal affective disorder) can have a major impact on sleep.

I have chronically tight hip flexors due to a spinal injury and years of desk work. At some point I discovered that a quick hip flexor stretch plus sitting in a deep squat for 30 - 60 seconds right before bed is really helpful for me falling asleep and staying asleep.

In the last two years I noticed that my sleep quality really tanked. At some point, I decided to start monitoring my oxygen levels with a continuous monitor (from Wellue) even though I don't have much of an issue snoring or other signs associated with sleep apnea. After observing increasingly frequent dips into the 75 - 85% range, my doctor ordered a sleep study and we confirmed a central sleep apnea diagnosis.

The CPAP definitely wasn't an immediate boon to my sleep, but I have noticed the difference now that I'm maintaining a healthy oxygen level through the night. Even with that improvement, my overall sleep quality is still pretty crap and that can still take a toll on my mental acuity during the day. I did make one more useful observation in the past month when I noticed that I was waking up more and more frequently from shoulder pain. I think that this problem has been building for awhile, and I've had some luck already rearranging pillows to reduce the pressure (plus exercises and stretches).

Whether or not any of these are familiar, I hope you can get to the bottom of the issue quickly. Hang in there, and don't forget to be patient with yourself as you work through it.

[sizzle]

Try sleeping with a partner that ends up going diagonal and kicking you in the night haha have not solved this one yet…

[rramadass]

You might find the book The Circadian Code by Dr. Satchin Panda useful. Previous comment here - https://news.ycombinator.com/item?id=30504022#30512208

[rg111]

I have found that it is not the time duration of sleep, but the waking up time that is important in my productivity.

If I wake up at 11 in the morning after 4 hours of sleep, I am much more energetic than after 7 hours of sleep if I wake up at 5 or 6 in the morning.

If I sleep less, of course I feel sleepy sooner in the evening. But never have had energy issues.

OTOH, 8-8.5 hours of sleep anytime is optimal for my energy.

I have seen that I am outright miserable after 6 hours of sleep and waking up at 6 although I am fully productive after 4 hours and waking up at 11.

[exo-pla-net]

Consider CBD. It knocks me out if I'm restless. You'll likely want pure CBD, which doesn't get you high. Just chilled out. Worrying about your perfect 8 is probably making things worse, so finding place of peace regarding sleep will also help. But CBD is probably the quick and dirty solution.

[mettamage]

I don't get why this was downvoted. CBD, unlike THC is not even an illegal substance in The Netherlands. Weed needs to be sold via coffee shops, but CBD pills are simply findable in pharmacies.

There are quite a few studies about it (e.g. [1]). And while I haven't researched it enough to verify any claim at all, the fact that it has been research does mean it's not all that odd that some people suggest a link between CBD and sleep. So there is some merit to exo-pla-net's suggestion.

[1] https://doi.apa.org/doiLanding?doi=10.1037%2Fpha0000285

[pcc]

Wondering if anyone on this thread who’s felt this way has been able to try out biphasic sleep and can report if it made a difference? The idea of a “second sleep” after an hour or so awake seems to be gaining prevalence in popular media as something humans used to do naturally.

[syspec]

You literally just described me, the needing 8 hours and not any less. The waking after 5/6 and not falling back to sleep.

The only thing that worked for me is Trazadone

[baby]

This is me, except it's 9hours of sleep and if I get a bit less I just feel tired all day. My current theory is sleep apnea.

[wnolens]

Same, 8.5-9 is the thing. I did a sleep study and technically have very mild sleep apnea (<5 apnea events per night).

[kvhdude]

did you check your thyroid levels.

[throwaway5848]

It's the exact same for me. It's like at eight hours exactly something "clicks" and you're fresh, but anything before that is a weird uncompleted process where I feel like garbage all day yet I can't go back to sleep. I can even feel the weight of my eye bags. Then, I take a short (20 min) nap at some point in the day and I'm completely recovered.

It's frustrating because just 15 more minutes would have prevented all that suffering.