Rikza Abdullah Contributor Jakarta

As adequate sleep is essential to health and wellbeing, mattress manufacturers compete with each other by designing new products and claiming their goods are the best to sleep on.

However, we must be very careful in selecting mattresses that are most suitable for us because the quality of sleep is also determined by the ways we sleep, apart from psychological factors.

Psychologists, as quoted by the National Sleep Foundation of the United States on its website, said that sleep was essential to our mental and physical performance. Not getting enough sleep might weaken our immune system and may be a risk factor for diabetes, hypertension and obesity.

During sleep, the body secretes a number of necessary hormones that affect growth, regulate energy and affect metabolic and endocrine functions. For example, near the end of the sleep period, the body secretes the stress hormone, cortisol, which stimulates alertness. Sleep is also the time when growth hormone is secreted, which drives childhood growth and plays an important part in regulating muscle mass in adults. Further, the sleep cycle affects secretion of the hormone, leptin. This hormone tells the body when it should feel full and thus, has a direct influence on appetite and weight.

Thus, good quality sleep should be uninterrupted by inconveniences that may be caused by anything, including the use of unsuitable mattresses and the wrong position of our bodies.

Unsuitable mattresses, for example, may cause us to toss and turn on them and not to sleep well at night.

The number one reason we toss and turn is pressure points. Innerspring mattresses, whose comfort layers are not thick enough, for example, may put pressure on different areas of our bodies, causing blood circulation to be restricted to those areas and when it becomes uncomfortable, our bodies turn to a new position.

The rigid, non-conforming surface of a hard mattress also forces our bodies to adapt to its flat shape, bending our spines into an unnatural position and creating pressure points at the shoulders, hips and feet, which can cause us to toss and turn trying to find a more comfortable position.

Another reason is improper spinal alignment. Since a traditional mattress is flat and our bodies are curved, the traditional mattress fails to offer enough support in the lumbar region, often allowing our lower backs and hips to sink below the rest of our bodies. This causes pressure and discomfort in that area which in turn causes our bodies to turn to a new position.

To help reduce such inconvenience, manufacturers have introduced various kinds of mattresses, such as those filled in with springs, latex, foam, water or air. Some of them are made adjustable to our needs when sleeping on them.

Rob Nijkrake, marketing manager of PT King Koil International Indonesia, said here Wednesday that spring-mattresses were the most popular throughout the world, followed by mattresses made of latex and Talalay latex -- latex manufactured with a process invented by Dr. Talalay of the United States.

"Spring-mattresses a large capacity for ventilation," he said.

"If a mattress has no adequate ventilation, our body, during our sleep, will produce too much liquid that will be absorbed by the mattress."

Some manufacturers and dealers claim that latex mattresses dynamically conform to our bodies, providing support and pressure relief. Relieving pressure reduces the tossing and turning that interrupts sleep and brings needed oxygen and nutrients to tired, aching muscles. Latex is also antimicrobial and dust mite resistant, according to them.

Nijkrake said Talalay latex was better than general latex because the former had open round cells and thousands of ventilating ducts, thereby offering better air circulation and moisture control, as well as reducing the chance of fungal and bacterial growth.

Foam mattresses, when designed with adequate thickness and density, will be temperature sensitive. In normal temperatures it is firm. But when we lay down to sleep, they react to our bodies' temperature and mold themselves to our shapes.

An airbed mattress provides total body support and proper spinal alignment that is expected to reduce pressure points and reduce tossing and turning.

Advanced Comfort, a U.S. mattress manufacturer, says on its website that an airbed with adjustable firmness allows a sleeper to customize the sleeping area to his/her exact liking. Whether they like it softer or firmer, they, just with a single cordless, hand-held, remote control, can select the comfort level that suits them best or independently adjusts the firmness level on either side of the bed with the push of a button.

Some manufacturers have introduced waterbeds, equipped with tubes that are adjustable to wanted levels of support and can be filled with heated water. On such waterbeds, sleepers' bodies are supported in a posture perfect position, where their heads, shoulders, hips and feet are kept in a straight line.

Out of those various mattresses, the good ones are those which protect our backs during the our sleep. And the most important thing needed for finding a correct mattress to support the back involves knowing what position we sleep in. Some of us sleep on our backs, some on our sides and some on our stomachs.

For a back sleeper -- someone who sleeps on his/her back -- a mattress that is firm but not too hard is the most suitable. It will hold the spine in check without irritating the muscles and joints. A firm mattress works better in this case than a softer type because the spine needs to be kept straight when the sleeper is on his/her back.

The best kind of mattress for a side sleeper is the one with a supportive density, which has enough give to conform to the bumps and curves of the body, and with a softer overlay to provide more comfort for the muscles and joints. Such a mattress is also suitable for a stomach sleeper because a softer overlay is needed to substitute for the lack of a pillow and provides more comfort for muscles and joints. However, sleeping on the stomach is not recommended as it will irritate the neck and back due to the complete rotation of the neck to one side.

Nijkrake said mattresses, from whatever materials they were made, would be most convenient if they are designed with different zones, each of which would give more or less support, depending on the heaviness and lightness of our body zones, so that they would provide the right level of support for natural body curves.