let's talk core sleep

We all sleep differently. Some of us sprawl out like starfish and others cover themselves in a duvet to cocoon themselves. Some people are early birds with body clocks, perfectly in tune with the rising sun, while others find themselves saying “five more minutes” and hitting snooze on their alarm each morning. 

The “how” we sleep might be different, but the “why” always remains the same. We sleep to rest our bodies and rejuvenate our minds. That’s where core sleep comes in. Join our sleep experts at Silentnight as we explore what core sleep is, how much you need and the science behind it.  

We’ll also share our top tips to help you hit your core sleep goals, making sure you’re waking up feeling your best self every morning. 

what is core sleep? 

Core sleep is the most important stage of sleep; it’s a prolonged period of uninterrupted slumber which gives our bodies and minds time to rest and recover. During this period, your body focuses on replenishing its vitality, restoring any mental or physical energy used throughout the day. 

Sleep scientists usually categorise core sleep as the most important non-rapid eye movement (NREM) stages of sleep, including deep sleep. Core sleep also includes some essential elements of rapid eye movement sleep (REM). However, some sleep trackers categorise core sleep and deep sleep as two separate states of rest, with core sleep referring to the earlier, lighter stages of sleep. For this article, core sleep will refer to the later stages of NREM sleep and some of REM sleep, covering the most important stages of the sleep cycle. 

what’s the difference between core sleep and deep sleep? 

Core sleep acts as the essential foundation of our sleep cycle. Covering most important elements of a good night’s rest, the key elements of core sleep include the relaxation of muscles, a lower heart rate, and reduced brain activity.  

Deep sleep is simply one element of the sleep cycle and specifically refers to the heaviest period of core sleep. Sometimes referred to as slow-wave sleep, deep sleep is when the most intensive physical restoration takes place, and your mind is at its least responsive. During deep sleep, your body is repairing damaged tissue, releasing growth hormones and bolstering its immune system.

what about REM sleep?

REM sleep takes place separate from the rest of the sleep cycle. REM sleep is when your brain is at its most active and dreaming takes place. This is an important stage of the sleep cycle for processing information and memory consolidation.

why is core sleep important?

Core sleep is when the body gets to work restoring itself ready for the day ahead. Outside of making sure you wake up feeling well-rested, core sleep has numerous physical, mental, and emotional benefits. 

• Physical health: Core sleep restores the energy that the body needs to mentally and physically power itself. Core sleep also aids athleticism by improving endurance and recovery.   

• Emotional regulation: A lack of sleep can have a significant effect on how you behave, affecting stress levels and your mental health. Core sleep allows your mind to switch off and reset, processing the day’s events and allowing you to wake up with a clear head. 

• Cognitive function: Core sleep supports everyday cognitive functions by improving your ability to solve problems, process information and concentrate. It also facilitates further REM sleep, which is vital for memory consolidation. 

Over time, a lack of core sleep will result in your body being unable to properly recharge at the end of each day. This can lead to physical fatigue and a visibly tired appearance, as well as difficulty concentrating and irritability. 

how much core sleep should I be getting each night?

Typically, core sleep makes up about 5 hours of the sleep cycle, however the exact amount you should be getting varies depending on how old you are and how much sleep you get each night. Babies and toddlers will need more total hours of core sleep each night as they sleep for longer. However, adults will have fewer hours of core sleep, but it will make up a similar percentage of their sleep schedule. Generally, core sleep should make up around 50% of your sleep each night.

how do I know if I’m getting enough core sleep?

While you can use sleep trackers and smart devices to measure the amount of core sleep you’re getting each night, they aren’t always accurate. For example, Apple’s line of watches provides users with sleep metrics that define ‘core’ sleep as the earlier, lighter stages of the sleep cycle rather than the essential deep and REM sleep stages.  A simpler way to check is based on how you feel: if you’re waking up each morning feeling mentally and physically refreshed, you’re likely getting enough core sleep.

top tips to get more core sleep each night

Don’t worry if you don’t think you’re getting enough core sleep each night, we’ve collected some of our top tips to help you get the optimal amount.

keep a consistent sleep schedule 

Falling asleep and waking up at a similar time each day will help to regulate your internal body clock and maintain a consistent sleep schedule. Try to maintain this schedule even on weekends to maximise your core sleep. 

create a relaxing bedtime routine 

A regular bedtime routine of calming activities such as reading, relaxation techniques or a warm bath can help to reduce anxiety and stress before bed. You should also avoid blue light from electrical devices and opt for less stimulating activities which will help you to fall asleep easily each night. 

avoid caffeine or alcohol before bed

Drinking too much alcohol or consuming caffeine before bed can negatively impact the amount of time you spend in REM sleep, an essential part of core sleep, reducing the quality and duration of your sleep. You can check out our guide on the connection between sleep and your diet to learn more about the impact that food and drink have on how we sleep. 

make your room a sleep-friendly environment

Core sleep revolves around uninterrupted rest, giving your body the chance to properly recover. Creating a sleep-friendly environment by maintaining a cool temperature, reducing noise, and blocking out light will allow your body to enter the deeper stages of core sleep and fully recover.  

Core sleep is an essential part of making sure you’re waking up feeling rejuvenated and well-rested every morning. Getting the right amount of core sleep each night also gives your body and mind time to recover from the day’s events. And creating a relaxing bedtime routine with a consistent sleep schedule will ensure you’re getting enough core sleep each night. To learn more about getting the best night’s sleep possible, check out our full healthy sleep guide.