In a past life when I was young and fairly healthy I regularly would get ~5-6 hours of sleep for most of the week and try to get a nice solid 8 hours when I had a day off. I didn't really have any problems with performance that way either. Now days it's a totally different story.....
The last study I saw said around 7 is best for most people, as long as they are getting that every day. But it can vary with your lifestyle and body. If your body needs more time to recover, you may need longer. If your brain is worked very hard you may need longer. Less may suit you. I find that the brighter the room I sleep in, the less sleep I get by naturally waking earlier and it doesnt seem to affect me negatively. I also read that the less sleep you have, the more it shortens your overall life, but that maybe isnt per capita, but per person, so you may need to find your own optimal before knowing what is less. There was (supposedly) a drug developed that allowed people to stay awake indefinitely and when stopped, you could have one nights sleep and return to a normal lifestyle. This shortened your lifespan too. But after reading this report, I havent heard any more mention of it, perhaps it was a spoof?
3 hours and I can still do daily work just fine. At least 5 if I'm doing something that requires reflexes or cognitive function. Ideally, I try for at least 6-7.
I used to do manual labor on 4 hours a night, and I was great. Always fresh. Fast forward ~10 years. Somewhere around the 5 hours (and under) mark I feel physically ill when I wake up. Worse than having a fever. I basically need 6+ hours just to function. 7/8 To be approaching 'normal'. -scheherazade
I've always needed loads of sleep, 8 minimum. 12 optimum. Any less than 8 and I feel terrible all day.
Depends how active I've been through-out the day. 6-7 hours usually hits the spot though. Gotta' love it you wake up thinking it's almost time for work, then you check the time and you've still got 3/4 hours till that damn alarm goes off. Woop! On the flip side -
with me it really doesn't matter how many hours i sleep as long as i fall into deep sleep, will function properly and all will be well. if my sleep is disturbed and keep waking and sleeping all night then it makes no difference, even if i sleep 12 hours when i wake up i will become absolutely untreatable, i might break things, kick doors, get startled easily by anything, curse, blaspheme and once in while become a danger to everyone including myself, my mood really takes a beating. if my brain was a computer, i'd say i require a complete shutdown, not powersaving.
Recently did a 2 day stint which included working over a full day followed up with driving through the night then traveling for most of a day, then did some technical work. Had about 5 hours sleep the day before so about that much
5 hrs when I'm morning shift; 23:00 till 04:00, 8 hrs when I'm afternoon shift; 02:00 till 10:00 and 10 hrs when night shift 09:00 till 20:00 with 1 hr lunch during the day. one of the reasons why I hate morning shift cause I'm always sleepy and grumpy
I could never sleep more than 6-7, any more and it makes me lazy and doesn't have any physical or mental benefits, even if i'm working hard or exercising twice a day. Minimum seems to be about 3, sat up on my phone till 5 watching E3 and was up at 7 and while i got through the day i was starting to get a headache by 5pm, still managed to stay up till 1am last night though so i couldn't of been that tired.
Hmm I once wrote two consecutive college exams with 4hr of sleep. It was like my brains were on steroids, easy to remember, easy to recall etc... But then after..... needless to say.