why is sleep so important? the benefits of sleep

Sleep is an essential function that allows your body and mind to recharge, so when you wake up each morning you feel refreshed, alert and ready to go about your day with a spring in your step. Getting enough quality sleep each night is vital to your health and wellbeing, and is just as important as eating a nutritious diet and exercising. Read on to discover all you need to know about sleep, including what it is, the benefits, the science behind it and what happens if you don’t get enough.

what exactly is sleep? 

Sleep is an altered state of consciousness, in which you have limited interactions with your surroundings. Although you are relatively still and quiet during sleep, the brain remains active and carries out important functions. Sleep is essential to every process within your body and affects both your physical and mental functioning the next day. It also gives you the ability to fight disease and develop immunity, and without enough sleep, your brain simply can’t function properly.

the benefits of quality sleep

From improving concentration to keeping your emotions in check, getting plenty of quality sleep each night has many benefits for both mind and body. Sleep does vary from person to person, but most adults should aim to get around 7-9 hours worth every night, so you can function at your best each day.

Improves concentration and productivity - a good night’s sleep helps to maintain your energy levels and allows you to remain focused throughout the day, A lack of sleep has a negative impact on attention span, concentration, risk assessment and reaction times, so if you have an important decision to make or your job involves operating heavy machinery, you are more likely to make a mistake or have an accident, so getting the sleep you need helps you to stay sharp and alert each day.

Helps to maintain a healthy weight - a lack of quality sleep means your body is using up more energy, which can lead to eating more and choosing food that’s higher in calories later in the day. Being sleep-deprived could also change the level of hormones within your body that signal hunger and fullness, leading to an increase in appetite and if you feel tired, you don’t usually feel like exercising, so getting enough sleep aids with maintaining a healthy weight.

Supports a healthy immune system - sleep is highly beneficial for your immune system and keeps it functioning at its best. Quality sleep supports the proteins and cells of  your immune system to help detect and destroy any foreign invaders your body may come into contact with, so when you’re not feeling well, it’s important to give your body the time it needs to rest and repair.

Keeps your emotions in check - sleep not only maintains good physical health, it has a positive impact on your mental health too. Depression or anxiety can lead to difficulty sleeping and not getting enough sleep may increase your risk of developing poor mental health. If you’ve got a lot on your mind, you may find yourself wide awake at night feeling anxious or worried, whilst not being able to sleep just adds to your list of concerns and you may find you’re feeling down or irritable. Ensuring you get enough sleep really can make all the difference to your overall mood and wellbeing.

Helps you to learn and make memories - during sleep, your brain organises and processes all the information you’ve taken in throughout the day and converts short-term memories into longer-term ones. This helps with better learning and means that when you wake up, things are often clearer in your mind and easier to understand.

the science of sleep

Your internal 24-hour body clock, also known as the circadian rhythm, regulates your sleep cycle and controls when you feel tired, so you’re ready for bed, and when you feel fresh and alert when you wake in the morning. This sleep-wake drive may be connected to adenosine, which is an organic compound produced in the brain. The levels rise as the day goes on and so you become more tired, and then during sleep, your body breaks down this compound.

Light also has an influence on your circadian rhythm. So, in your brain there’s an area of nerve cells known as the hypothalamus and within this region there’s a cluster of cells called the suprachiasmatic nucleus - this is responsible for processing signals when your eyes are exposed to natural or artificial light, and it’s these signals that help your brain determine if it’s day or night.

Light hits the photo receptive retinal ganglion cells at the back of the eye, this signal is passed down the optic nerve and into the brain to the suprachiasmatic nucleus. Not all light has the same effect. We need bright light particularly in the morning to help set our circadian rhythm. Bright light means getting outside or close to a window, artificial light has much lower lux levels - Hannah Shore - Sleep Expert at Silentnight.

As the natural light fades away, and day turns to night, your body releases melatonin - a hormone that promotes drowsiness. And when the sun comes up, your body releases cortisol, which is a hormone that promotes energy and alertness.

the stages of sleep

So that's the science behind sleep explained, but what happens after you’ve drifted off to sleep? When you fall asleep, your body follows a sleep cycle that’s split into four stages, which repeat throughout the night until you wake up, with the duration of each cycle lasting around 90-120 minutes. Achieving the right amount of each as you sleep will leave you feeling more refreshed.

Non-rapid eye-movement sleep stage 1 - lasting several minutes, the first stage is light sleep and is where you transition between wakefulness and sleep. Your muscles will relax and your heart rate, breathing and eye movements slow down.

Deeper non-rapid eye-movement sleep stage 2 - this is the longest stage and is when deep sleep happens, with your heart rate and breathing continuing to slow. Your eye movements will stop and body temperature lowers too.

Non-rapid eye-movement sleep stage 3 - Your heartbeat, breathing and brain wave activity are all at their lowest levels and your muscles are as relaxed as they can be. At first, this stage is longer and then decreases as the night goes on. On average about 12-20% of your sleep is spent in this stage.

Rapid eye movement sleep - this happens around 90 minutes after you’ve fallen asleep and is when your eyes quickly move back and forth under your eyelids. Your heart rate, breathing and blood pressure begin to increase and dreaming is at it’s most vivid. As the night progresses, the duration of this stage becomes longer.

what happens if you don’t sleep? 

As you’ve discovered, it’s clear to see why sleep is so important and a lot can happen to your body if you don’t get enough sleep.. Sleep deprivation can put your health at risk and is linked to depression and increased inflammation. A lack of quality sleep can also weaken your immune system, lead to weight gain and poor decision making, and can even make you more accident prone, not to mention those feelings of irritability and a low mood. 

If you’re struggling to get enough shut-eye, creating a good sleep environment can aid with a blissful night’s sleep. Sticking to a bedtime routine, making sure your bedroom is cool and ensuring that you have the most comfortable mattress, will help you drift off into a peaceful slumber.