The science of sleep: a guide to the stages

Looking after your physical, mental, and emotional wellbeing should be a daily commitment everyone makes, which is why self-care has been something of a hot topic in recent years.

While making the smaller lifestyle changes that make us feel good are what self-care is all about, getting back to basics is a must for mastering the art from day-to-day and feeling the real impact of a mindful routine.

Staying active, enjoying a balanced diet and connecting with others are the self-care basics that we shouldn’t forget. But it’s prioritising sleep that can reveal the most impactful health benefits.

Due to our busy lifestyles, it can be so easy to underestimate the value of sleep. Without enough it, your body can struggle to function on the most basic level.

Your mind will struggle through lack of sleep too as DNAFit details:

“Tiredness is a big contributor to reduced mental health. This is due to your brain not being able to function properly which can lead to you being unmotivated and stressed as, for instance, work piles up and the pressures of life increase. In turn, all of the aforementioned results of a poor sleep cycle will contribute to an overall decrease in your wellbeing.”

As you can see, there’s so much more to sleep than meets the eye. Let us talk you through the stages of sleep so you can really understand what your body goes through during this crucial resting period.

Stage 1

There are five stages of sleep and they’re either categorised as REM or non-REM. REM, which stands for ‘rapid eye movement’, is one stage, while the non-REM stages consist of multiple phases.

The first stage that you’ll enter when drifting off to sleep is non-REM, and it only lasts for between 1 and 5 minutes. During this stage, your heart and breathing rate will slow dramatically as your muscles relax.

You’ll produce high amplitude alpha brain waves and theta waves, electrical pulses that have to slow to induce a deeper sleep. During this first stage as the brain is still active, you can easily be woken.

Stage 2

The second stage is also non-REM and constitutes a light sleep. It occurs just before falling into the deepest sleep stages, and lasts between 10 and 60 minutes (the average duration being 25 minutes).

During stage 2, it’s the brain’s theta waves that take over causing bursts of rapid and rhythmic brain activity, known as ‘sleep spindles’.

Despite the brain being particularly active during stage 2, your heart and breathing rate will further decrease and so too will your body temperature. Eyes movements also stop.

 Stages 3 & 4

Stages 3 and 4 are often grouped together thanks to their non-REM, slow-wave nature. It’s during these phases of deeper sleep that your body will reap the most rewards. The body is busy repairing, regenerating and growing as well as bolstering that immune system.

Your body may be hard at work fulfilling its preserving, health-boosting roles, but it’s also at its most relaxed. The slowest heart and breathing rates occur during stages 3 and 4, and you’ll experience zero eye movement.

Stage 5

The only stage of REM sleep is also the dreaming phase. During stage 5, eye movements resume becoming more and more rapid, and your heartbeat and breathing will also increase. Brain activity increases too but your muscles can become temporarily paralysed.

Stage 5 lasts between 10 and 60 minutes, with the first instance of Stage 5 REM sleep the shortest. The duration subsequently increases as the wider sleep cycle repeats.

It takes approximately 90 minutes for all five stages of sleep to play out, so your body will experience the full cycle multiple times throughout the night.

Completing this sleep cycle and recharging your batteries is the only way to be the best version of yourself. Make sure you look after number one by prioritising sleep hygiene every day.