The Stages of Sleep

If sleep were easy, we would all do it, yes? But we don’t – not successfully. At least one third of Australians have difficulty sleeping to the extent it impacts their daily lives. There are many reasons this may be, although if you thought sleep was as simple as doing it or not, you would be wrong.  Sleep is a complex process. The human brain (not missing an opportunity to overcomplicate things) actually gives us 5 unique stages of sleep.  5! Honestly. Each with its own hallmarks and purpose. We cycle through these around 4 times per night so there’s plenty of space to derail.  

Despite having many steps to get right, we’re also conveniently sundials with anxiety.  Thanks to our Circadian Rhythm, the solar powered internal clock that triggers sleep hormone melatonin, we can actually decrease room for error in those 5 stages of sleep. So, let’s travel on a journey from Stage 1 to REM and in the interest of a good night’s rest, see some simple ways to get a-grade z’s by honouring our inner clock.

 

Stage 1:

Muscles are relaxing, brain activity is slowing, and you are getting very sleepy. Stage 1 is the lightest stage of sleep. It’s more of a drowsy state than anything, so is easily disrupted. If you wake up here, you may think you were never asleep. You may also have the sensation of having ‘fallen’ from a mentally fabricated Stage 1 mountain/building/pirate ship only to be rudely shocked awake. Muscle spasms are common in the drowsy phase which may shock you awake… we have a spray for that.)

Since our key sleepy hormone melatonin is kicking into gear from 9pm onwards, it’s a good idea to start your bed time rituals by then. You will be in sync with the flow of the day and more likely to reap the benefits of a short, sharp and shiny initial stage 1 to reach those juicy later stages more easily when you do hit the sack. Soaking in a magnesium bath gets that bod relaxing and helps to limit muscle spasms that may wake you. Cutting your screen time to avoid overstimulated brain activity after the 9pm mark is also advised.

 

Stage 2:

We are now officially asleep. Some slower eye movement happens here and your brain waves, body temperature and heart rate continue to drop. A couple of unique players called Sleep Spindles and K-Complexes get to shine in Stage 2. Researchers suspect these brain activations offer security, preventing external stimulus from entering da club and waking you up. Their motto: too much thinky thinky means less sleepy sleepy.

With brain bouncers on the job the daily guest list can indulge in some of the nerdiest party games I’ve ever heard of.  Memory consolidation and synaptic pruning sound less exciting than they should, they’re actually ruthless and the reason brain club guests today will not be guaranteed an invite tomorrow.  In stage 2, your brain cherry picks the pathways it plans to stay friends with, those that won’t get the call back and which besties to keep in the VIP section long term.

Melatonin production slows down towards morning which means we tend to spend more time in the lighter sleep stages the closer it gets to sunrise. Ensuring that your sleep space is darkened by black out blinds or wearing an eye mask to avoid unnecessary waking as well as limiting noise with ear plugs can prevent the body from waking up completely during the early hours.

 

Stage 3 + 4 (Deep Sleep):

Welcome to the most restorative portion of non-REM sleep. Slow brain waves called Delta Waves make up less than 50% of the Stage 3 noggin activity and more than half in Stage 4. These mean we’re not likely to responds to external stimulus and we’re also not dreaming, so Delta is a pretty mysterious place to be. It’s where the magic happens: we’re healing, growing and the immune system is strengthened. Your brain refreshes itself for more learning tomorrow. In stage 3 Deep Sleep, memories made that day are distributed from the short-term pick-up que to the longer-term parking bay. So many crucial activities happening in deep sleep, which may explain why we need more time than usual here after a period of deprivation – it’s a priority.  

We’re also on the home ground of the funny, scary, inconvenient and downright dangerous.  Parasomnias such as sleep talking, night terrors, bed wetting or sleep walking will happen now if you’re prone to them. Fun fact: kids hang out in deep sleep much longer than adults, creating space for more of those nocturnal behaviours that terrify exhausted parents into googling ‘signs my child is possessed’.

The first few sleep cycles of the night tend to contain relatively longer Deep Sleep stages.  These decrease in duration or disappearing all together as the sleeper carries on. The average sleep cycle is around the 90 to 110-minute mark so we can actually time the first few Deep Sleep cycles to match our melatonin max out by getting to bed near the 11pm mark.  This leads to get better, more restorative sleep. Stress hormones may impact memory transfer too, so working on stress and anxiety is crucial if you wish to reap the full benefits of Deep Sleep memory work (check out this Roll On if you need a helping hand.)

 

REM:

Also known as Rapid Eye Movement, the dreamiest of sleep states is upon us.  Spoiler alert… this stage has some rapid eye movement associated with it, who would have thought it?  It’s all in the eyes though, your limbs tend to be paralysed at this point as a way of avoiding physically acting out the dreams which, whether you recall them or not, a French Study found we all do approximately 4-6 times per night.

The lowest body temperatures occur at approximately 4:30am. Temperature regulation is not on the menu during REM sleep, so ensuring your space isn’t too hot or cold overnight will help to prevent rude awakenings in the early hours. Research suggests that waking during REM will tamper with the flow next time you’re asleep, skewing the scales towards more REM time till you catch up.  This means less Deep Sleep healing, so it really is important to make sure your sleep space is perfection on the temperature gauge.

 

And that’s a wrap! For the full sundial experience, you can explore the Circadian Rhythm chart… we’ll just leave this one here for you.

Read more about the science of Sleep in our Journal here

Tags: Science, Sleep