Questions of sleep are often on the tip of tongues — from how much you or your loved ones need, to how to break bad sleep habits, to managing disorders such as sleepwalking or snoring.
It’s understandable given that our relationship to sleep is often personal and can reflect our daily lives and habits, from late-night cram sessions while studying, to disrupted nights with new babies, to falling into bed as the sun rises due to shift work or an all-night party for a mate’s 18th, 21st or 40th.
We lead busy lives, and sleep can often be the first thing to stop feeling like a priority.
In fact, recent studies have shown that up to 4 in 10 Australians don’t get enough good quality sleep [2], and the impact of that is being felt collectively across our health and wellbeing. After all, sleep, particularly deep sleep, is essential for everyone.
Crucial in refreshing the mind and repairing the body [1], deep sleep is really what keeps us going, but to understand its importance (and how to get more of it), it’s first necessary to understand when and how deep sleep happens.
Understanding your sleep cycle
As with many things, sleep is not monolithic, rather, it’s a cycle made up of 4 distinct sleep stages over approximately 90-120 minutes. This cycle is then repeated between 4 and 6 times a night to create the experience of sleep overall [3].
These stages are:
The transition
Stage 1 is all about moving your body from consciousness or wake to slumber. In other words, it's the stage where you fall asleep. This phase doesn't often last long and is characterised by your breathing slowing and your heart rate dropping.
Light sleep
Stage 2 is the first phase of actual sleep and while your breathing and heart rate continue to slow, it's further characterised by your temperature dropping and your muscles relaxing [3].
It’s generally understood to mark a change in brain waves too, coaxing your body into a phase called slow-wave sleep [4].
Slow-wave sleep
Also known as deep sleep, slow-wave sleep is the third stage of your sleep cycle and your final non-rapid eye movement phase. It's marked by low-frequency, high-amplitude brain activity [4]. In other words, your brain waves slow down and your body truly rests.
REM sleep
Finally, your body experiences REM sleep, which is a very active period of sleep marked by rapid eye movement and increased brain activity.
It's generally understood to have important metabolic consequences due to an increase in metabolic rate and glucose utilisation and is usually the phase where we experience dreams. REM sleep ends with us waking up and the sleep cycle begins again.
But why is deep sleep so important?
All these different phases of sleep serve different purposes, and deep sleep is understood to be the part of your sleep cycle where your body focuses on repairing itself and other restorative functions.
During this phase, your body releases a growth hormone and works to build and repair muscles, bones and tissue. Deep sleep also promotes immune system functioning, and recent studies have found that this slow-wave sleep phase may also be important for regulating glucose metabolism and replenishing energy stores [3].
On top of that, research shows that deep sleep is important for cognitive function and memory, and it’s even thought to play a role in language learning, motor skills, and the developing brain, making it crucial for development.
How much deep sleep do you need?
As deep sleep is a part of your broader sleep cycle and is initiated by your body’s natural circadian clock, it’s impossible to trim out and get on its own.
That said, medical professionals and specialists recommend adults get 8 hours of sleep a night, and it’s thought that up to 20% of that is going to be deep sleep [2]. Unfortunately, 6 hours of sleep a night is just not enough.
In other words, roughly 1.6 hours of sleep a night will hopefully be slow-wave sleep.
What happens if you don't get enough deep sleep?
Insufficient deep sleep can impact your health and well-being in a range of ways, from the symptoms you probably know, such as fatigue, to many you may not, such as high blood pressure.
As deep sleep is a period of your sleep cycle devoted to repairing and rebuilding many of the parts of your body that help you to function, studies indicate that a lack of slow-wave sleep can cause more than just exhaustion, poor concentration and memory.
In fact, it can cause mood disturbances, impaired judgement and reaction time, and poor physical coordination [1]. It can also seriously impact your immunity, leaving you more susceptible to infection and putting you at risk for health conditions such as heart disease and diabetes [3][2].
How to increase deep sleep naturally
Getting enough sleep and improving sleep quality can be a bit of a journey. There's a lot to factor in as parts of our lives can impact our ability to stick to a consistent sleep schedule and stay asleep through the night.
So much of how we sleep depends not just on our commitments and routines, but on our own bodies and contexts. That said, in answering the question of how to increase deep sleep, there are a number of things we can do to ensure better sleep quality and an easier time falling asleep.
Exercise
Exercising regularly has been shown to greatly combat difficulty sleeping. Even just 30 minutes of aerobic exercise a day can have you sleeping for longer and falling asleep faster while also helping to improve your sleep hygiene [5].
Sleep patterns
Maintaining regular sleep patterns and a bedtime routine has also been shown to encourage more deep sleep and improve overall sleep quality.
Monitor time in bed
Staying in bed for longer portions of the day can interrupt your bedtime routine and create a subconscious association that limits your ability to get more deep sleep.
Keeping your bed for bedtime will help your body and mind to maintain the connection with falling asleep.
Avoid certain substances
Avoid alcohol, caffeine and cigarettes which are stimulants that can cause disrupted sleep.
Say no to naps
No matter how tired you are, try to avoid napping during the day as it could make it harder for you to fall asleep come nighttime.
Clinical sleep treatment
If your sleep is quite disrupted, don't be afraid to talk to a doctor about treatment plans, particularly if you have sleep disorders such as sleep apnoea.
If you're unsure where to start, Pilot offers a clinical sleep treatment customised to help you fall asleep and stay asleep.
Simply take our online consultation with an Aussie practitioner and they'll be able to create a treatment plan based on your experiences with sleep so you can say goodbye to counting sheep each night. Plus, your treatment will be delivered discreetly to your door and you'll receive automatic refills every 2 months so you never run out.
Image credit: Getty Images
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