This week is Sleep Awareness Week, so why is sleep so important?
Most of us will spend a third of our lives sleeping and our bodies put this time to excellent use.
While we are asleep our bodies undergo certain important processes – from repair and renewal to energy restoration.
Some people can function perfectly well with five to six hours sleep, while others need at least eight hours sleep every night.
This is because some people have a better ability to enter into a deep sleep – the stage of sleep needed to recharge the brain so we can function effectively during the day.
Over time, those nights of missed sleep (whether they’re caused by a sleep disorder or simply not scheduling enough time for the necessary ZZZs) can build into a sleep deficit. People with a sleep deficit are unable to concentrate, study, and work effectively. They can also experience emotional problems, like depression.
What Happens During Sleep?
You don’t notice it, of course, but while you’re asleep, your brain is still active. As people sleep, their brains pass through five stages of sleep. Together, stages 1, 2, 3, 4, and REM (rapid eye movement) sleep make up a sleep cycle. One complete sleep cycle lasts about 90 to 100 minutes. So during an average night’s sleep, a person will experience about four or five cycles of sleep.
Stages 1 and 2 are periods of light sleep from which a person can easily be awakened. During these stages, eye movements slow down and eventually stop, heart and breathing rates slow down, and body temperature decreases. Stages 3 and 4 are deep sleep stages. It’s more difficult to awaken someone during these stages, and when awakened, a person will often feel groggy and disoriented for a few minutes. Stages 3 and 4 are the most refreshing of the sleep stages — it is this type of sleep that we crave when we are very tired.
The final stage of the sleep cycle is known as REM sleep because of the rapid eye movements that occur during this stage. During REM sleep, other physical changes take place — breathing becomes rapid, the heart beats faster, and the limb muscles don’t move. This is the stage of sleep when a person has the most vivid dreams.
What your body does while you are asleep
The skin: Skin renewal and skin repair activity happens at its greatest at around 1am when we are in deepest sleep. This is when cell division – responsible for regenerating our skin, blood and brain cells – rises by up to 300 per cent.
Cell division is stimulated by the growth hormone which is produced at its maximum at this time of the morning.
If you want your beauty sleep, it is important to sleep at night. Day-time sleeping does not compare to night-time sleeping because the body’s clock is programmed with other tasks such as brain function and energy, rather than skin repair.
The immune system: Sleep is important for our immune system – the part of the body that is responsible for fighting infection.
Some scientists believe that during sleep we secrete higher levels of cortisol – the hormone secreted by the pituitary gland that protects the immune system – than during the day.
Hormones: At around 2am in the morning, cortisol – one of many hormones released into the bloodstream – is secreted at a higher level during the night. Cortisol is released during times of stress, but its main job is to activate sugars that are stored in the body, making energy available in the body. Because of this, if we experience a healthy deep sleep, we will feel rested and revitalised ready for the day ahead.
During the night the pituitary gland – the control centre of the brain that is responsible for releasing hormones – secretes its highest levels of sex hormones.
Among others these include testosterone – the hormone that produces sperm in the testes, oestrogen – the hormone secreted by the ovary, and prolactin – essential for milk production in nursing mothers.
Because of this, doctors claim if we suffer from sleep problems the levels of sex hormones secreted may diminish, which can lower our sex drive and affect our fertility.
The brain: There are 100 billion nerve cells, or neurons, in the brain which control our bodies.
Until recently, scientists believed that they did not work while we slept. It is now known that when we dream, the brain is working to the same level as it does during waking hours.
During deep sleep the nerve cells in the brain charge up billions of tiny electrical circuits needed for our brain’s concentration and memory skills. If we suffer from fragmented sleep, where we don’t enter a deep sleep stage, or sleep deprivation – this can lead to memory loss.
We can see why sleep is so vitally important so ensure you get the best nights sleep possible with a comfortable bed and fresh, clean, breathable bed linen.