If you're like me who's read enough from enough sources, you'll have likely arrived at the same conclusion.
To be healthy (which can have many implications,including and not limited to better memory, thinking skills, lifespan etc.), You need to master a few basic principles in life.
Those basic principles seem to be
Body - adequate rest (sleep), regular exercise (activity) etc. & Mind - less stress/destress, positive mind, happiness etc.
I recently discovered the "holy trinity" of human energy and metabolism: regular sleep, regular meals and regular exercise. My previous chaotic approach caused chaotic (and very sub-optimal) energy levels.
I realized instead of working on my productivity directly, I need to work on stabilizing my energy level, because everything else ultimately depends on that.
Regular sleep, meals and exercise, practiced consistently, get your body into a pattern, where at each time of day it knows whether it should be releasing energy or resting, so it gets easier over time as the metabolism begins to work with your plans rather than against them.
I wonder if intermittent fasting has a place here. It has many health benefits; what is the optimum regularity of meals?
To expand - I generally fast from 7pm in the evening until 2pm the next day. This helps me with appetite/weight control, discipline, and I overall feel better this way. That said, I'm also a lot more productive later in the day. I chalk it up to not being a morning person, but maybe IF is working against me here. However, I notice when I eat in the morning, I feel off the rest of the day. Figuring out the right balance here is harrd, man.
Do you do this on certain days of the week, or every day?
I'd like to expand on the Holy Trinity by saying not only does chaotic sleep/meals/exercise lead to crap energy levels, but also chronic anxiety, because the body never knows what to expect, so it has to be ready for anything.
I think it's based on your body. Mine is very explicit: if I sleep less than 8 hours my stomach burns. If I sleep less than 7 my brain is useless. So, 8 for me (my wife needs 9!).
My general suggestion is that you should naturally wake up before the alarm rings. I set it to 9 hours and naturally wake up between 8 and 8:30 hours.
If I "naturally" wake up after 6/6.5 hours, does that mean that my body needs less sleep, or I should control more variables to sleep 8 hours (light, temperature, melatonin..) ?
(I do feel great some days when I sleep for longer..)
Experiment by going to bed sooner. Personally I figured out there's a certain time in the morning when I'll wake up which does not depend on the time spent sleeping. After some trials, I figured that less than ~7 hours of sleep will leave me in a bad mood, but only in the afternoon -- I seem to function quite well in the morning.
Do you feel well rested after that? Or do you feel run down? If the former, that's how much is required for you. Myself, I need nearly exactly 8 hours. More is fine, but anything less and I will feel like garbage for the whole day.
6-8 hours, depending on your body, unless people who say they're fine on 6 hours are just lying to themselves and others.
From what I've experienced, I think the time of day you go to bed matters as well, meaning even with a full fresh perfect feeling 8 hours, your body doesn't enter REM the same or produce the same amount of growth hormone or clean out the brain properly if you go to sleep everyday at say 6am vs sometime shortly after sun down. I guess it has to do with the light levels you experience.
As people have pointed out, it completely depends on your body. However, a good measure to see whether you're fully rested is to be aware of your energy levels after you wake up, and to be aware whether you feel sleepy/sleep deprived (not the I ate too much sleepy) during the middle of the day.
I've found them to be good indicators to whether i need to catch up on my sleep.
If you need more detail about healthy lifestyle, you're better off doing your own basic research than asking someone on HN to give you a few more words.
To be healthy (which can have many implications,including and not limited to better memory, thinking skills, lifespan etc.), You need to master a few basic principles in life.
Those basic principles seem to be
Body - adequate rest (sleep), regular exercise (activity) etc. & Mind - less stress/destress, positive mind, happiness etc.
Huh. Rocket science?