What is the sleep cycle and why do we need to understand it?

Apr 26,2021 | Dan Holman

When you think about getting the sleep you need, it's understandable that you might focus on how many hours of sleep you get. While duration of sleep is undoubtedly important, it's only part of the equation.

To ensure your time spent sleeping has the maximum restorative benefits it's imperative to ensure the quality of sleep is optimised. Ensuring the highest restorative levels for your body you must complete the full sleep cycle which is composed of four sleep stages.

Completing each stage in the cycle multiple times allows your mind and body to gain the rest required resulting in waking up rejuvenated. By understanding the sleep cycle we can review how different sleep disorders such as insomnia and sleep apnea can impact your health.

The cycles of sleep

Sleep is variable. On an average night, a person goes through 4 to 6 sleep cycles. Each cycle is composed of four individual stages of sleep. Sleep cycles will change throughout the night.

The first sleep cycle ranges from 70-100 minutes, while cycles later in the night tend to last 90-120 minutes. Also, how much time is spent in each sleep stage will change as the night progresses.


Image Source: BBC 

The stages of sleep

There are four states of sleep. Rapid eye movement (REM) and three others that are non-REM (NREM) sleep. These stages are characterised by patterns of brain activity during sleep.

Image Source: The Sleep Council

Sleep Patterns

NREM sleep is made up of three different stages. It becomes harder to wake up from your sleep, the higher state of NREM sleep you are in.

Stage 1 (N1)

Starting with stage 1, this is the "dozing off" stage and is usually only lasts 1 to 5 minutes. Your body is just starting to relax and you may have periods of brief twitches. The changes in your brain are quite light and it's quite easy to wake up during this stage. If you aren't disturbed you can move quickly into stage 2. If uninterrupted you may not spend much more time in stage 1.

Stage 2 (N2)

Stage 2 can last for 10-25 minutes during the first sleep cycle but will stretch during the night.

In stage 2 your body enters a more relaxed state including a lower temperature, slowed breathing and heart rate. During this time your brain enters a new pattern and eye movement stops. Brain activity slows but there are short bursts of activity which help resist being woken up by external stimuli. Usually you will spend about half of your sleep time in N2 sleep.

Stage 3 (N3)

N3 sleep is a regenerative period where your body heals and repairs itself. The first stage of N3 lasts from 45-90 minutes. As you progress through the night, further episodes of N3 become shorter and shorter. N3 sleep decreases with age. Elderly people may have no measured N3 sleep at night, this is normal and occurs in healthy sleepers.

When you reach Stage 3 or "deep sleep" you become harder to wake up. Your heart and breathing rates reduce in frequency and your muscles are at their most relaxed. Your brain activity during this stage has an identifiable pattern of what are known as delta waves. This stage is critical to restorative sleep, allowing for your body to recover and grow. This is the stage of sleep where you strengthen your immune system and other key bodily functions.

Stage 4 (R)

REM sleep is essential for restoration of your cognitive functions like memory, learning, and creativity.

The first REM sleep episode generally occurs after 90-110 minutes of sleep. During this state of sleep the brain activity is at levels nearing when you're awake. REM sleep periods tend to be longer later in the night. Our heart and breathing rates increase and become irregular. It is during REM sleep that we dream. 

During this time your body experiences atonia which is a temporary paralysis of the majority of your muscles excluding your eyes and the muscles that control breathing.

As the night progresses REM stages lengthen, especially in the second half of the night. In total, REM constitutes 25% of sleep in adults.

Why are the sleep stages important?

Sleep stages matter because they allow your body and brain to rest and develop. If you fail to obtain enough of both N3 and REM sleep it is likely to have negative consequences on your ability to think clearly, have balanced emotions and maintain physical health.

If you are woken frequently during earlier stages of sleep you may struggle to fully reach and maintain the deeper sleep stages. People with insomnia may not have enough total sleep to accumulate the nightly time needed in each stage.

How can you have a better sleep cycle?

While you cannot control fully your sleep cycle, you can improve your chances of a deeper and more restful sleep. If you are struggling to get the rest you need it is vital for you to focus on improving sleep environment and sleep routine. This starts with your day time activity.

Release pent up tension and stress through exercise, it's well known that those whom exercise regularly sleep better.

Be mindful and aware what you consume before bedtime. Avoid stimulants and large meals.

Consistency is key. Be sure to go to bed and rise at approximately the same time every day. Create a wind-down routine for at least 30 minutes before bed. Our Sleep sprays are perfect for encouraging your mind to wind down and settle into a restful sleep.

Improve your bedroom environment by keeping it tidy, cool, dark and quiet.

According to Sleep Foundation, keeping your bedroom temperature between 15.6-19.4 degrees Celsius will help get you the most comfortable sleep.

Eliminating noise and light disruptions can help you create your own sleep sanctuary. Blackout curtains or a quality sleep mask can help keep the sunshine from disturbing your sleep. 

Keeping pets out of your bedroom and wearing ear plugs can help eliminate noise distractions. 

Addressing underlying health issues might be the key to achieving restorative sleep cycles. If you suspect that you might have a sleep disorder such as sleep apnea it is important to talk with a doctor who can appropriately guide you with care.

We here at Masters of Mayfair have a passion for relaxation, healthy living & adventure in equal measure. Finding the perfect balance is a journey. So be sure to trial many different strategies to find one that works for you. We wish you all the best with achieving a more restful sleep and unlocking the energy needed for the adventure that lies ahead in the following day.


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Photo by bruce mars on Unsplash