Memory foam mattresses
Last updated: September 23, 2008.
Did you sleep well last night? Maybe you're of the same mind as
Benjamin Franklin, who famously said: "There will be sleeping
enough in the grave." But if you're like most people and you
believe the key to a good day's work is a good night's rest, the best place
to start is with your bed. You're going to spend about 8 hours a
night sleeping for your entire life—roughly 25-30 years of snoozing
in all. With all that lying about doing nothing, doesn't it make
sense to find the most comfortable bed you possibly can? Many people
are switching from traditional, sprung beds to mattresses made of
"memory foam" that mold exactly to your body shape. Let's take a
look at high-density foam mattresses and find out how they work!
Photo: Visco-elastic foam sinks in where you press it, so it
molds exactly to your body shape.
The trouble with sleeping...
...is that your bones get in the way. Without bones, sleeping
would be easy: if you were just a big blob of muscle and fat, imagine
how comfortably you'd sleep! Unfortunately, though, all that body
tissue is wrapped around a hard structure—your skeleton—that feels
about as comfortable as the frame of a bicycle. A traditional bed has
a mattress of soft material supported by coiled metal springs inside.
It gives when you lean on it, but unless there are dozens of springs
arranged in small pockets, it won't respond exactly to your body
shape. If you lie on your back, your bottom will press further than
the rest of your body leaving parts of your spine
unsupported—potentially giving you backache the next day. If you lie
on your side, your hips and shoulders will tend to press down
more—supporting more than their fare share of your bodyweight and
making you feel uncomfortable.
Photo: "Sleeping enough in the grave"—Benjamin Franklin might have been less than enthusiastic about memory foam mattresses.
Picture courtesy of US Library of Congress.
How foam mattresses are different
The idea of memory foam is incredibly simple. Instead of sleeping
on springs, you sleep on very thick foam that gives way where you
press on it. Technically, it's called visco-elastic: visco (from
viscous) means it moves when you apply a force; elastic means it
returns to its original shape when you remove the force. The foam is
temperature sensitive, so it tends to sink more as your body
temperature warms it up. Very quickly, it molds to your unique contours.
If you sleep on your side, the foam sinks in much more at your
shoulders and hips so—in theory—your entire body is always
perfectly supported and your spine remains straight. Your weight is
spread more evenly and the pressure is relieved on places like your
shoulders and hips. That's why many people find memory foam
mattresses help to reduce the symptoms of problems such as backpain
and arthritis. If you change position or turn over, the mattress
immediately remolds to your new shape.
High-density foam mattresses are also claimed to be more hygienic
because bed bugs apparently don't like living in the foam. In
reality, bugs can lurk in your bedding, on your carpet, on your
walls, and in plenty of other places in your bedroom—so this claim
is a bit of an exaggeration. It may be true that memory foam beds
reduce the problem of bed bugs, but scrupulous hygiene is
really the only solution to that particular problem, not just a
change in your mattress.
Space tales
Photo: Blastoff: Are you sitting comfortably? Then we'll begin.
Memory foam was designed for exciting moments like this. Picture courtesy of Great
Images in NASA.
The original memory foam was invented in the early 1970s by NASA
scientists. Their mission? To develop a pressure-relieving material that would cushion astronauts
in rocket cockpits against extreme forces during
blastoff. The foam mattresses sold commercially are a much-improved version of NASA's technology. Speaking about
its TEMPUR® products, the leading manufacturer, Tempur-Pedic,
says:
"Our Swedish scientists, realizing the enormous potential of
the pressure-relieving material, spent nearly a decade and millions
of research dollars perfecting TEMPUR material as the ultimate sleep
surface for consumers."
Buying tips
Although TEMPUR is the best known brand, there are many other
companies selling memory foam mattresses, mattress toppers, and pillows.
Some of them are vastly inferior products and you need to be very wary when you buy something
described as "memory foam" that you're getting the real deal. You
need to compare the density measurements of the products you are offered
to ensure you're getting proper, heavy, memory foam. Having said that, it's important
to make sure the foam you get feels comfortable as well:
if the foam is too dense for your bodyweight, it won't sink in
enough to be properly comfortable (so, in practice, different people need different thicknesses of foam).
Also make sure the foam complies with all appropriate fire and safety regulations.
Crucially, you should only buy a memory foam bed if it's offered to you on a no-quibble, money-back
trial. Your body will take some time to get used to the bed, so
you'll need to try it for a couple of weeks at least.
Photo: This mattress has a washable cellular cover to keep it cool
and clean.
Further reading
