Memory foam mattresses
by Chris Woodford. Last updated: June 7, 2011.
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 molds 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, claims its scientists have spent millions of dollars and a full decade turning TEMPUR into a much-improved material.
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. Simple unzip it, throw it in the washing machine, and your mattress looks as good as new. I've found that putting extra layers on top of a mattress like this can make it a little more comfortable but, at the same time, will reduce its ability to mold to my body shape. You need to experiment to find the most comfortable solution for your own body.
