Understanding the stages of sleep

Discover what goes on in your body and brain while you slumber – and why it’s so important.

Whether you love lounging beneath your doona all day or live by the ‘early bird gets the worm’ philosophy, quality sleep shouldn’t be a luxury. We all know that sleep and wellbeing are closely connected – but what actually happens when we drift off, and why does it matter? 

The stages of sleep explained

It may seem like there’s little going on once we doze off, but the truth is many processes take place while we sleep – we just aren’t aware of them.

There are two main stages of sleep: rapid eye movement (REM) stage and non-rapid eye movement (NREM). NREM sleep is further divided into different sub-stages. As adults, we cycle through these stages several times every night, with each cycle lasting approximately 90 minutes. The sleep cycles of children are slightly different and change as they get older. 

Here’s what happens during the different sleep stages (for adults) and how you can make the most of them. 

NREM 1: light sleep

When you first start to drift off, there’s a brief period of time where you hover between wakefulness and sleep. You still have some awareness of your surroundings, but your muscles are relaxed and your body is preparing for sleep. This phase typically only lasts for a few minutes and is believed to make up roughly five per cent of adults’ overall sleep time.

NREM stage 1 is the lightest stage of sleep, so you’re easily woken. It’s important to make sure your sleep environment is as dark and quiet as possible. A soft, comfortable mattress – such as the Forty Winks Crown Posture Bedding Premiere Divine Plush Mattress – will also help lull you into the next phase of sleep. 

NREM 2: moderate sleep

As you enter NREM 2, your heart rate and breathing slow down and your body temperature drops. Though you lose awareness of your surroundings, you can still be woken up fairly easily. Experts believe that your brain is working to consolidate memories and keep you asleep during this stage.

Breathable bedding can help support the natural changes in body temperature that occur during NREM sleep. The Moonshadow Pure Balance Sheet Set provides excellent thermoregulating properties and helps control bacteria, keeping you comfortable throughout the night as you progress through your sleep cycle. Similarly, the SensICE™ Cover in mattresses like the Forty Winks Crown Posture Bedding PostureAdvance Mattress, uses advanced technology to help you find your temperature ‘sweet spot’.  

Some people will also experience tossing and turning during NREM sleep, but the right mattress can help minimise these disturbances. The Forty Winks King Koil Chiro Enlighten Mattress, for example, is equipped with FlexGel Infused Memory Foam, which conforms to your body shape and relieves pressure that can cause tossing and turning. The added advantage of cool-to-touch gel helps with temperature regulation, too. 

Estimates vary, but NREM 2 typically lasts for about 25 minutes in the first sleep cycle and gets progressively longer with each successive cycle – accounting for almost half of the total time we spend asleep.  

NREM 3 and 4: deep sleep

During the final stages of NREM – also known as slow-wave sleep – your body continues to relax. You’re not easily woken, so you probably won’t be bothered by any loud noises. If someone (or something) does manage to wake you, you’ll feel quite groggy, and it can take anywhere between 30 minutes to an hour to get your game face back on.

You spend about one quarter of your total sleep time in slow-wave sleep (although this

 tends to lessen as you get older). Experts believe this is when your body repairs damaged tissues, builds bone and muscle and strengthens immune functions.

REM: dream state

Finally, we enter REM sleep, which – surprise, surprise – is marked by rapid eye movements. While your body stops moving and becomes temporarily paralysed, your brain activity and heart rate increase, and breathing becomes irregular. REM is also when dreaming occurs and is thought to make up around 20-25 per cent of our total sleep time (though again, estimates vary).

REM sleep typically occurs every 90-120 minutes, with each REM cycle getting longer throughout the night. While researchers are still exploring why we need REM sleep, it’s believed to be important for learning, brain development and making memories.

During this stage of sleep, support is key. A soft and comfortable mattress can help you drift off, but it takes the right amount of postural support to ensure you stay asleep. Mattresses like the Forty Winks Crown Posture Bedding Flowt Opulence Mattress, for example, can help you set the scene for optimal REM. The FLOWT® anti-gravity gel provides superior cushioning and support, while an additional layer of Belgian Black Diamond Foam creates a cloud-like feel that’ll help you drift into a deeper and more restorative sleep. Still not sure which is the best mattress for you? bedMATCH®, our patented diagnostic system, can help you find a personalised sleep solution to meet your unique needs. Plus, our helpful Sleep Specialists can offer plenty of advice to help make bedtime your favourite time.

Ready to sleep soundly throughout the night? Explore our mattresses here.