When you want to improve your sleep,
“No smartphone before bed,”
“Cut back on caffeine at night,”
“Take a long, relaxing bath”
are the kinds of habits many people focus on.
Of course, these habits matter.
But there is one more thing worth reviewing: the bedding you rest your body on for hours every night.
Is a firm mattress better, or a soft one? Is a high pillow better, or a low one?
In fact, a range of studies has looked at bedding, and they suggest it is not as simple as “firmer is better for your body” or “the more expensive, the better you sleep.”
Mattresses and Sleep: What 47 Studies Show
A systematic review published in 2026 examined 47 studies published between 1999 and 2023 to assess how mattress characteristics affect sleep and the body.
It looked at more than just sleep quality.
Mattresses were evaluated from several angles, including pressure on the body, the alignment of the spine and the effects on the lower back.
The option that received relatively strong support was
a medium-firm
mattress.
In other words, a mattress is not better the harder it is, nor is one so soft that your body sinks deeply into it ideal.
A Firm Mattress Is Not Always Best for Your Back
“If you have back trouble, a firm futon or mattress is better.”
You may have heard this advice.
However, a well-known study found somewhat different results.
A randomized controlled trial published in the medical journal The Lancet compared firm and medium-firm mattresses in 313 people with chronic non-specific low back pain.
The group using medium-firm mattresses showed better results than the firm-mattress group for pain in bed, pain on rising and physical function.
The idea that “the firmer, the better for your back” is not necessarily right.
Choose Bedding With Turning Over in Mind
We do not sleep in the same position all night.
We turn over many times while we sleep.
That is why bedding needs not only to support the body but also to avoid concentrating strain on any one part and let you change position naturally.
If it is so soft that your body sinks in deeply, you may find it harder to change position.
If it is too firm, on the other hand, some people feel pressure on specific areas such as the shoulders or hips.
So when choosing a mattress, rather than judging only by firm or soft, it is important to consider how well it suits your build and the way you usually sleep.
Pillow Height Matters Too
The pillow is just as much a part of daily life as the mattress.
Pillows have been studied as well, and a systematic review reported that the height and shape of a pillow may change the alignment of the cervical spine.
Here too, there is no single height that suits everyone.
Do you mostly sleep on your back, or on your side?
What are your shoulder width and build like?
And how far does your body sink into the mattress?
Rather than looking at the pillow alone, you need to think of your body, pillow and mattress as a set.
Expensive Bedding Does Not Guarantee Good Sleep
Bedding ranges from a few thousand yen to several hundred thousand yen or more.
Of course, materials, construction and durability differ, but from the point of view of sleep,
being expensive does not mean it will suit you.
What matters is whether it suits your body.
The bedding that feels comfortable varies with your build, sleeping position and preferences.
Because it has great reviews.
Because a celebrity uses it.
Because a luxury hotel uses it.
Rather than deciding on those grounds alone, it is important, if you can, to actually lie down and check how far you sink, how easy it is to turn over and how well it works with your pillow.
You Use It Every Day, So Take Another Look
If you sleep seven hours a day, you spend about 30% of each day on your bedding.
Seen that way, a mattress and pillow are not just furniture but key parts of your everyday sleep environment.
When we want better sleep, we tend to focus on adding new habits or sleep products.
But before that, it may be worth asking yourself,
“Does the bedding I use now really suit my body?”
Take a moment to consider it.
You notice discomfort somewhere in your body when you wake up.
It is hard to turn over.
Your pillow height never feels quite right.
You have used the same mattress for many years.
If any of these sound familiar, reviewing the bedding you use every day is one way to improve your sleep environment.
At La HEAD, we will continue to share research-based information on sleep and rest that is easy to bring into daily life.