AIBU to choose to only have 5 hours sleep each night?

[Summergarden]

Everything I read about sleep emphasises how important it is to get 7-8 hours a night and that having less has a negative impact on your body.

So I’ve really tried to get in the habit of doing so, but feel so groggy if I sleep that long, both when I first wake and even further into the morning.

After some experimentation, it seems that 5-6 hours is the optimal sleep length for me in terms of feeling good, but I worry a bit about the negative effect of insufficient sleep on my body in the long term.

I do always sleep well, never wake up for the toilet etc.

Anyone else similar?

There is no universal amount of good sleep. Some people do well on 5h, some people need 10h. It's highly individual and I am not aware of any specific research which definitively shows certain number of hours is crucial.

The advised hours are an average.

So e people manage perfectly well on less.
Others need more.

I need more.

Listen to your body not averages.

It will also change as you get older and./or life circumstances change. Three years ago I was absolutely fine on 6 hours sleep - asleep by 10.30pm able to spring up out of bed and go to the gym at 4.30am, work a full day then go out on my bike for an hour in the evenings and sleep really well. Now I struggle to get up at 5.45am before leaving the house at 6.30am to walk the dog on the way to work. I don't sleep well and often toss and turn until the early hours not awake enough to get up and do anything but not sleeping either. Same thing happens at the other end of the night if I wake at 3am - not awake enough to get up but not sleeping either. I struggle on 7 hours these days.

Enjoy it while you can!!

There is a very interesting systematic review which shows that sleeping for one hour more than optimal shows much higher absolute risks than sleeping one hour less.
https://doi.org/10.1139/apnm-2020-0034

I only get about 5-6 hours sleep per night. I’m not a good sleeper. I do sometimes wonder what doing damage I’m to myself and whether I’m reducing my life expectancy or something. Sometimes I get about 3-4 hours.

As long as you can sleep easily and comfortably whenever you want or need to then you're alright.

I feel like ideally I'd be happiest with 12 hours! That's probably as I sleep so poorly and keep waking up. But if I had only 5 hours I'd be puking and having a really bad migraine all day!
Each to their own.

The "8 hours" guideline was most probably calculated for an adult male as well. As most things are.

6.5 hrs is my sweet spot for sleep.

I'm the same as you, I feel like dog shit if I sleep for more than 6 hours. It's just how I'm built, I've even had a sleep study done because my "solid 9 hours a night" husband thought I must have something wrong with me. They confirmed my sleep was healthy and I was getting plenty of REM and not waking at all, my body just doesn't seem to want more than 6 hours. I can sleep for more but it leaves me feeling lethargic and I often want to nap mid afternoon. 6 hours or less and I'm bright and energetic.

It's just an average, and an average likely based on the requirements of an adult male at that. There will always be people who fall outside those parameters, some needing a lot more sleep and some needing less.

This is true but recent research shows women need more, not less.