05/01/2011 16:50 GMT | Updated 22/05/2015 10:12 BST

The Power Of Sleep

From lettuce sandwiches to avoiding cheese before bedtime, there are a whole host of facts and myths surrounding the mysterious world of sleep. But thankfully scientists work tirelessly to advise us on making the best of our slumber.

So, armed with the latest research, here are our top ten strange-but-true sleep facts.,feedConfig,localizationConfig,entry&id=964528&pid=964527&uts=1292394491

Surprising sleep facts

The idea that we need less sleep as we get older is a myth, according to research.

In fact, older adults need just as much rest as the young but, because they often find it harder to sleep soundly, they can misinterpret this as a sign that they don't need so much.

But US research has revealed that this lack of sleep could damage health and brain ability.

Though the quality of sleep may suffer as we age, it is important to maintain the quantity in order to avoid cognitive decline.

Surprising sleep facts

Having an afternoon nap might seem like a guilty pleasure, but a recent study resulted in the surprising revelation that you might just wake up smarter.

According to new US research, getting forty winks after lunch improves the brain's ability to absorb new information.

The theory goes that the hippocampus, which stores our short-term memory, gets full up during the morning's work.

But a short siesta enables the brain to clear the facts that we've already processed, thereby making way for new memories.

Surprising sleep facts

If you are a parent with teenage children the morning wake-up call probably isn't your favourite part of the day.

But it turns out that your teens aren't just being lazy – they really do need more sleep.

All the hormonal upheaval of puberty means teenagers find it tough to get up in the morning, but it is during sleep that they release a hormone essential for the inevitable growth spurt.

This means that they need more sleep than both children and adults.

Surprising sleep facts

What with the school run, the housework and the nine-to-five job, getting enough sleep often seems like an impossible task.

But if you're not getting your eight hours, you might find it difficult to shift those excess pounds.

A recent UK study found that those who get less than four hours shut-eye each night are 73 per cent more likely to gain weight – and too little sleep could lead to some serious calorie cravings.

Surprising sleep facts

Most of us wake up to a screeching alarm tone and a general sense of grogginess.

But if you're looking for a perfect night's sleep, there is now an iPhone app that can tell you exactly when you should be waking up.

Sleep Cycle records the varying phases of our sleep and provides you with an optimal wake up time.

And there's no rude awakening, since the app gently brings you to life with soothing music.

Surprising sleep facts

If it's been a tough week at work and a series of hard-partying evenings, it can be all too tempting to bed down for the weekend.

But a weekend sleep marathon will do nothing to help you 'catch up'.

Scientists investigating the effects of short-term and long-term sleep deprivation found that an accumulated lack of sleep is not repaired by a day under the duvet.

In fact, people suffering from chronic sleep loss were unable to "bank" their sleep and sadly that rested feeling from a long lie-in is largely psychosomatic.

Surprising sleep facts

As comforting as it is to cuddle up with your loved one as you drift off to sleep, sharing a bed causes problems for men.

An Austrian study revealed that men were less able to sleep deeply with their partner than women.

This resulted in rising stress hormone levels and the boys' ability to perform a simple cognitive test suffered.

It also explains why your man is less than chirpy in the morning.

Surprising sleep facts

Your parents might have drummed it into you from an early age, but it turns out that making your bed can actually damage your health.

While you may have enjoyed a cosy night's sleep, the warm damp conditions are perfect for that nasty little critter, the dust mite – and that can cause asthma and other allergies.

But leave your bed scruffy and unmade and the dry conditions mean they won't survive.

Surprising sleep facts

It sounds obvious – lack of sleep equals grumpy morning.

But according to US research, young people who don't get an early night are running the risk of triggering depression.

A study of the habits of more than 15,000 college and high-school students, revealed that those who stayed up after midnight had a 24 per cent higher risk of depression.

The American Academy of Sleep Medicine recommends at least nine hours a night for young people.

Surprising sleep facts

If it seems like your wife or girlfriend is always tired, it's probably because she is.

Research at Loughborough University has revealed that women work their brains harder than men – and that means they need more sleep.

Specifically that multi-tasking the ladies are renowned for means the part of the brain known as the cerebral cortex is worked harder and it needs deep sleep to recover.

An extra 20 minutes a night more than men should do the trick.

Surprising sleep facts