While we may hear a lot of chatter on the ideal amount of sleep we need each night, we often overlook the importance of the quality of sleep we get.
For example, if you’re getting between 7-9 hours of sleep every night, then you’re naturally spending about one third of your life asleep; and while that may seem like a lot of sleep time, it is very important that our body get that sleep as it allows both our body and mind to recharge and rehabilitate so that we can perform at your best for the rest of the day.
Going deeper into the importance of deep sleep, sleep is divided into 4 stages which repeats between 1 rapid eye movement (REM) and 3 non-rapid eye movement (NREM) phases. These phases are also known as light sleep and deep sleep. It usually takes between 90-120 minutes to cycle through all 4stages and every adult typically experiences 4-6 of such cycles every night.
What Is Slow Wave Sleep?
Deep sleep which is often referred to as slow wave sleep is an important stage in the sleep cycle that enables proper brain function and memory. Deep sleep which occurs in the third stage of the non-rapid eye movement (NREM) sleep sees essential bodily functions like our breathing and heart rate slow down, and muscles are relaxed.
Typically, we fall into deep sleep within the first hour of falling off to sleep. But as your sleep progresses, deep sleep wears out and progressively gets shorter. However it gets very difficult for anyone to wake up while in deep sleep.
So Why Is Deep Sleep So Important?
While all the stages of sleep are important, deep sleep is particularly crucial for physical and mental benefits. During deep sleep, our bodies release growth hormones and work to build and repair our muscles, bones, tissues and our immune system. Deep sleep is also essential for cognitive function, memory skills and has been proven to play a role in effectively learning new languages and motor skills.
Information inputs that we gather while awake, are unable to be stored without proper deep sleep. In fact researchers say that deep sleep strengthens our brain synapses and preserves the most relevant ones in our memory.
Deep sleep also comes with a lot of other benefits which include energy restoration, cell regeneration, increased blood supply to muscles, strengthening of our immune system and a better and happier mood the next day.
It is with no doubt that the evidence of deep sleep is beneficial to our daily functions. Therefore, it is crucial to focus on the quality of your sleep on top of just counting the amount of hours you get to sleep.
Drifting Into Deep Sleep
In order to get more deep sleep, we need to focus on getting at least 8 hours of sleep nightly. Within that time, at least about 23% of our sleep would be spent in deep sleep.
So here are the stages of sleep that we go through on a nightly basis:
Stage 1: We drift from being awake to being asleep. This is known as non-rapid eye movement sleep which doesn’t last very long. While we may start to relax and dream, you may find yourself twitch involuntarily as you transition into stage 2.
Stage 2: This too is still a light sleep phase. While you may be drifting into steadier sleep, your heart rate and breathing will start to slow down while your tense muscles start to relax. Here your body temperature will also decrease and your brain waves are less active too.
Stage 3 & 4: In stage 3, we move into deep sleep and stage 4 is your deepest sleep stage.
While you’re in deep sleep, your breathing, heartbeat, body temperature, and brain waves reach their lowest levels. Your muscles are now extremely relaxed, and you are most difficult to rouse. It is here where you have reached the stage of proper deep sleep. This lasts anywhere between 45 – 90minutes with longer periods in the first half of the night and gets shorter with every sleep cycle.
REM Stage: As the name suggests, this is when our eyes move quickly beneath our eyelids. REM sleep usually occurs for about 90 minutes and it is during this stage when we experience dreams as our brain activity increases. When our heart rate increases to its near wakeful state, our breathing becomes faster and our limbs may feel a little paralyzed to prevent us from physically acting out our dreams.
The REM stage happens several times a night and each time we’re in this sleep stage, we spend less time in the deeper stage of sleep.
Getting quality deep sleep is essential for our well being. Not getting enough quality sleep can contribute to heart disease, obesity, hypertension, and even the risk of death.
If you’re sleeping 8 hours regularly but spend most of it tossing and turning, then you may not be getting enough sleep. So work on increasing the amount of deep sleep that you get and you can try these to help you along the way:
- Create a relaxing routine to wind down before bed
- Have a warm shower
- Avoid caffeinated drinks
- Use an eye mask to block out the light
- Sleep in a cool and conducive room
- Live a healthy lifestyle – exercise and eat healthy
- Listen to white noise
- Avoid going to sleep when you’re very stressed
While scientists agree that stages 1 to 4 and REM sleep are all important, deep sleep is the most essential of all for us to feel well rested and stay healthy.
If you’re waking up tired on a regular basis and not getting the right amount of deep sleep, then it’s about time to talk to a healthcare provider.