Mattress Myth: Firmer is better

It's a common misconception that a firmer mattress is a better mattress. Orthopedists once recommended sleeping on an extremely firm mattress, but there's little evidence to support that view. The optimal surface is purely subjective, says Clete Kushida, M.D., Ph.D., director of the Stanford University Center for Human Sleep Research.

So the best mattress for you is the one that's most comfortable. A study published in 2003 in the British medical journal The Lancet suggested that individuals who suffer from lower back pain would benefit from a medium-firm sleeping surface. That conclusion makes sense to several experts we interviewed. If a mattress is too firm, it won't support all body parts evenly and may cause discomfort at the heaviest points (hips and shoulders). Too soft, and you could sink into the surface and have a hard time moving, which could cause tingling, numbness, or aches.

Alan Hedge, Ph.D., a professor of ergonomics at Cornell University, noted that the best mattress supports your spine at all points while allowing it to maintain its natural curve. By age 40, according to  Hedge, skin loses elasticity and becomes more sensitive to pressure points, which argues for a softer, more cushiony surface as you age. "Slightly softer works better because there's less compression on the skin," he said.

When shopping for a new mattress, keep these tips in mind:

• Don't rely on product names. Each maker describes its products differently. One company's ultraplush might be another's supersoft.
• Wear loose clothes and shoes you can slip off. Spend at least five minutes on each side and your back (your stomach, too, if that's a preferred position).
• Don't be embarrassed to lie on many mattresses at the store. Salespeople expect it. Our panelists who took beds home for a monthlong trial rarely changed the opinion they formed after the first night. On the whole, their opinions also tracked with those of our 15-minute testers.

Essential information: Read "Mattress myths" to learn how to be a savvy shopper. Check out our buying guide for more advice on getting the perfect bed. And find out how to get a really good night's sleep.