So I read this yesterday evening and I thought ... hey, why not? I normally sleep on a mattress on the floor but have been looking into a cheap japanese futon (because I have this crazy idea of fitting everything I need in my car so I can just pack it all and go).

But yesterday I just put down a pillow and had a blanket and slept on the floor. It was a bit awkward and I think it needs getting use to. I'll try it again tonight and see how that goes. My back feels a lot better than usual ... because it forced me to sleep on my back and side rather than my stomach.

EDIT: So day 2 of sleeping on the floor wasn't so awesome. I like a firm sleeping spot (awkward phrasing ...) but concrete-like floor + carpet + lack of any other cushion whatsoever was not too conducive to REM cycling. Also, if I was trying to mirror the sleep habits of early humans, they probably slept on dirt (which had a bit more give than concrete), maybe had some grass, perhaps animal hides and such. So really, I'd think they had at least something comparable to what the OP described (a futon). Since I'm not going to put a pile of dirt, grass, and animal hides in my bedroom- I'll stick to the mattress for now until I can afford a futon or think up some alternative.

A while back, before I went Paleo. I herniated a lumbar disc, and sleeping on soft surfaces caused me a fair bit of pain. I finally wound up cutting a slit into the side of my mattress, and sliding a 2x6' sheet of plywood over the springs, but under the foam top. So I sleep on a bed that's pretty darn firm by most people's standards, and I can always take the board out if I want to.

i have a thin 1.5" memory foam pad on the floor and i love it.

I have been sleeping on a layer of sheets/blankets on the floor for a decade and it has worked well. I currently roll three sheets: One for under my knee, one under my lumbar region, one under the neck. I believe this preserves sound posture. Anyone care to disagree or comment as to what the best posture for sleeping is(ie. ergonomically best posture)?

I used to sleep on an air mattress but it got a hole in it so I tried sleeping on the floor (with just a sheet underneath). There's a half-inch of carpet so it's not like sleeping right on hardwood, but compared to a mattress it's very, very hard. And incredibly comfortable, which is pretty funny; after seeing all those mattress commercials with such and such technology, the best sleep of my life has been without a mattress of any kind. First, when I lie down I get this "ahhhh" sensation, like I'm immediately relaxed. Second, THE night I switched to a hard surface my dreams became incredibly vivid, and have remained so to this day. There's definitely a connection; anyway I'm very satisfied with my choice. Only problem is explaining it to girls ;)

For a long time in my early and mid twenties, I slept on a firm, foam mattress pad, about 6 inches thick. No sagging, no springs or pressure points. I always slept really well.

Stephen-Aegis,

I couldn't agree more. Last summer I bought the minimalist dense high quality futon. Yes it's much better than anything else. And I like the red pill also. It's basically the same thing as with minimalist shoes which improved my sprinting and running technique and goes well with learning POSE running.

I stumbled upon a very interesting blogpost where a physiotherapist (Ronny Liebmann, Leipzig, Germany) explained why springy matressese irritate your nervous system and diminish sleep quality. You need contact to the ground- in sleeping and running. No blue pill. :-)

Floor is a bit too hard. I've done it and it is ok, but the dense futon is nice and a little bit softer.

As an outdoor guide, I frequently sleep on a thin mat (1.5" thick) on the ground. I spent two summers sleeping 5 nights a week on a thin mat on the ground. I don't know whether it was sleeping on the ground or the 6+ hours of exercise a day I got while guiding, but my back never hurt and I was never sore. I also gained the ability to sleep on just about any surface in any position, mostly because I was so exhausted all the time. Now, even after having slept on a traditional mattress for 5 months, I can still get a good nights sound sleep on the ground without a pad on the occasion I'm in the field overnight.

There's a great book called The Indian Tipi: It's History, Construction and Use by Gladis Laubin, who spent lots of time living with American Indians on the plains in the early 1900s. There is a section of the book talking about what they slept on and there views on back health.

Cheap, clearance foam mattress from IKEA on wood boards = heaven

When I travelled to Japan in my teens I slept on a thin futon on the floor with a small sack of wheat for a pillow. Best sleep of my life!

I spent a good amount of time homeless and got out of the 'mattress habit'.

As part of the process I had to learn a completely new way of sleeping and now find matresses to be uncomfortable and damaging.

I currently sleep on the floor (ideally with carpet under me, sandwiched between duvets or a simple mummy-bag) and have done so for years, but my best sleeps whether rough, bivouac, camp or at home have had several things in common.

For the best sleeps I'd recommend not only the dense foam mattresses on solid wooden surface mentioned above but also, odd as it may sound, sleeping with your head slightly lower than your feet.

I would recommend inclining the bed/board if possible, but you may get a similar effect from simply raising the feet on a pillow or folded bedding.

Ever since I joined the Army in 1992 (got out a few years later though), for a long time I was able to sleep pretty much anywhere. But for some reason my body will not tolerate it as well now. I cannot sleep on the floor or on a futon mattress without my back killing me after a few days of such abuse. I hope this changes someday, because it's not an advantage to only be able to sleep comfortably on something soft, even if I do prefer it.

I sleep on a 2" foam pad. On top of a big, fluffy mattress that's too deep for even "deep" sheets. My bed is so high an old boyfriend used to call it the Rock of Gibraltar. I could spend all day in there. Sometimes I do; just me and my Netflix.

I usually sleep in my boyfriend's bed which is a regular, if aged, mattress with boxspring. But I never notice much difference in how my body feels on waking no matter what I sleep on. When I used to live with my parents with no A/C I slept in the bathtub or on the wooden floor with just a pillow all summer. When I camp I put a sleeping bad on an area free of poky rocks and sticks. I have the ability to sleep like a log in any circumstances...

I keep trying to get my husband to go for a big king size matress and an additional twin on the floor complete with harem style pillows, southeast Asian fabrics and mosquito netting. It's not minimalist but I want the ridiculous hippie family bed setup. He's not biting... Yet.

For about nine months now I've been sleeping on a 5 mm yoga mat with a blanket and a sheet, and I sleep great. It took about a week to get used to, and then felt completely normal. I'm fairly nomadic, so its nice to have the same bed wherever I am. I'm also 6' 5" so I don't really fit on most mattresses anyway. I do sleep predominately on my back. Other positions would be less comfortable.

My wife and I have been sleeping on the floor since 2006. I play the drums and had to sound proof my studio and had a little bit of the material left over (http://goo.gl/lF6QU). It's about 20mm thick. I cover the pieces with a throw rug so they don't shift and lay a normal sheets over it. My wife still uses a pillow but I ditched those long ago. At one point we thought we might like to get a bed and we went to the store and tried some out. FAIL! I could never go back to a soft mattress.

Mattresses make me feel like my body is being swallowed!

I like sleeping in "hard" surfaces. After weeks of sleeping on the living room floor over an exercise mat and a blanket, my husband finally listened to my pleas and got rid of our mattress.

Now it's in the basement against the wall, and it's used as a punching bag :-) My cat likes to sit on top and watch with big eyes as you punch the mattress. "Yeah, yeah, kill it! Kill it good!", she says.

I bought 3 foamy exercise mats, laid them side by side on the bed and cut them to fit snug with the bed (the bed has a slightly raised border to hold a mattress in place). Then on top of the mats I put 2 not so thick blankets. And then one of those thick foamy mattress covers. Those are excellent, by the way.
Total height of the mattress is about 1 inch and a half.

I put "hard" in quotes because I actually find this makeshift mattress very soft and comfortable, but other people freak out when they see my bed.
Because my husband likes a softer bed, I put an extra foamy exercise mat on his side.

It's been about 3 or 4 years that we've used this bed, and it still feels comfortable. I flip and fluff the bed maybe every 4-6 months (but you're supposed to do that with normal mattresses too).

For infants and toddlers, look at "Montessori floor bed" on google images (though some examples make me cringe).
I'm thinking of sewing a couple blankets together to form a twin-size mattress, then leaving one part open (like a pillow case) so I can put a hard exercise mat inside. With a hard exercise mat it won't bunch up.