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The Science of Sleep: What really happens when you’re snoozing!

Updated: Sep 30, 2023

Have you ever wondered what is going on in your body and mind when you drift off to sleep every night? You spend an estimated 1/3 of your life asleep (or attempting to get to sleep!), and yet many of us are still in the dark about what actually goes on.

This year ‘World Sleep Day’ falls on the 17th of March and the topic is: sleep is essential for health. You probably know that a healthy diet and exercise are essential for good health, but did you know that sleep is just as important? Not getting enough Z’s can impact your physical, mental and emotional well-being.

In this article, we’ll delve into the fascinating world of sleep cycles, exploring the different stages of sleep and what happens in our minds and bodies in those stages. We’ll also look at some of the key processes that occur while you’re asleep. Keep reading to the end, where you’ll find some handy tips to help you get better shut-eye tonight!

The sleep cycle

Our body has a 24-hour internal clock that regulates the sleep/wake cycle known as the circadian rhythm. According to the Centre for Disease Control and Prevention (CDC), women should aim for 7-9 hours of sleep per night. Getting enough sleep is essential, but the quality of sleep is even more important.

A sleep cycle lasts around 90 minutes, and you need to smoothly progress through 4-6 of these cycles each night. Each cycle contains two main stages known as non-rapid eye movement (non-REM) and rapid eye movement (REM). Non-REM is made up of individual stages as well.

So what happens during these sleep stages?

Stage 1 Non-REM (Non-Rapid Eye Movement): Drifting off to sleep

  • Lasts less than 10 minutes

  • Brain, breathing, heartbeat, and eye movements slow down

  • Muscles relax with occasional twitching

Stage 2 Non-REM (Non-Rapid Eye Movement): Light sleep

  • Lasts around 25 minutes

  • Heart rate and breathing slow even more

  • Temperature drops

  • Brain activity slows down with occasional bursts of activity that are responsible for shutting down your senses to ensure an interrupted sleep

Stage 3 Non-REM (Non-Rapid Eye Movement): Deep sleep

  • Lasts around 30-40 minutes

  • Body relaxes even further

  • Muscles are fully at rest

REM (Rapid Eye Movement)

  • Brain is highly active

  • Lasts about 10 minutes

  • Eyes move rapidly

  • Heart rate gets faster and breathing becomes irregular

  • Dreams take place

  • Most muscles are temporarily paralyzed, apart from those responsible for eye movements and breathing

Why is sleep important?

Sleep is vital for your overall health and well-being. A good night’s sleep helps you to recharge and wake up feeling rested and refreshed. More importantly, sleep plays a role in a variety of biological processes that are essential for your body to function properly.

  • Immune function Sleep plays a role in strengthening your immune system. While you are asleep, proteins known as cytokines are produced which help your body fight off foreign invaders such as bacteria and viruses. Good quality sleep means you will be less susceptible to infections and have better resistance against disease.

  • Metabolism This is the process by which your body converts food into energy. During sleep your metabolism slows down, allowing your body to conserve and store energy. Sleep also regulates the hormones involved in metabolic processes, such as cortisol and insulin.

  • Mood Your brain processes and consolidates emotions associated with your mood. The body also regulates chemical messengers and hormones that are involved in controlling your moods such as serotonin and cortisol.

  • Memory function Your brain sorts, processes, and stores new information so that you can retrieve it in the future. It also reactivates and strengthens memories formed while you were awake so that you will remember them.

  • Hormone balance Sleep is important for regulating the production of hormones such as estrogen and progesterone, which are involved in your menstrual cycle (you might recognize these if you use a method of birth control that contains hormones!). However, it is also just as important for hormone balance later in life too. When you reach menopause, your body goes through significant hormonal changes. Adequate sleep can help to minimize adverse effects, such as hot flashes and mood swings.

  • Cell renewal and repair - During sleep your body is busy carrying out healing and restoration processes. At night, growth hormone is produced which repairs and regenerates damaged cells and tissues. Your body also cleans out toxins and waste products and produces antioxidants to prevent cell damage.

6 simple tips to improve your sleep

Establishing healthy sleep habits, otherwise known as ‘sleep hygiene,’ is important to ensure you get a restful night under the covers. Check out these helpful tips from sleep experts to improve the quality of your Z’s!

1. Keep a consistent sleep schedule – Go to bed at the same time every night, and get up at the same time every morning. This will help to regulate your body’s internal clock so that you fall asleep faster and wake up refreshed.

2. Create a relaxing bedtime routine – Read a book or take a warm bath to signal your body to wind down and get ready for sleep. Try this relaxing and stress-relieving bath soak from Germie’s top self-care picks.

3. Make your sleep environment comfortable – Invest in good quality bed linen and keep your room cool, dark and quiet. Try a sleep mask, like this one, another Germie top self-care pick.

4. Avoid caffeine and alcoholBoth of these can lead to disrupted sleep. It's not always possible to avoid caffeine or alcohol, whether it be a tight deadline you need a caffeine boost for, or a night out with the girls and espresso martinis. However when it is possible, opt for herbal teas or decaf instead.

5. Limit screen time before bed – The blue light emitted by screens such as smartphones can suppress the production of melatonin, a hormone that helps to regulate your sleep. Exposure to the blue can trick your brain into thinking that it is still day time which can disrupt your natural sleep/wake cycle. Screen time is also mentally stimulating and prevents you from entering the relaxed state necessary for sleep.

6. Practice relaxation techniques – Deep breathing and guided meditation can help to calm your mind and prepare you for sleep.

Hopefully, you have gained a better understanding of why sleep is so important for your health. Remember sleep is not a luxury, but a necessity. Take care of your body and prioritize those Z’s! What happens while you are asleep will shape the person you are while awake.

Do you want to keep up to date with the latest news, tips and advice on all things related to female healthcare? Join the Germie community by subscribing here and take control of your health today.




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