“As the term ‘core sleep’ refers to a combination of phases of sleep that happen at the middle and end of sleep cycles, people who find their sleep very interrupted will not be getting the opportunity to reap its healing benefits,” warns Moore.
This can mean your body doesn’t heal itself. “Denying your body and mind the opportunity to heal can lead to a massive range of physical and mental health issues,” she says. “Initially you may notice you look less refreshed, with dark circles, sallow tones and more inflammatory skin conditions being a visible indicator of the lack of time your body has to repair.”
She adds, “If this continues the range of symptoms is phenomenal, ranging from low mood, difficulty concentrating and low libido, to weight gain, diabetes, poor immunity and hormonal issues.”
How many hours of core sleep do we need?
In the first cycle, deep sleep is usually shorter—around 10-25 minutes. However, with each cycle, the amount of time we spend in deep sleep gets longer and longer. Over the course of a healthy 7-9 hour sleep, core sleep should account for around 3-4 hours.
Of course, this is just a guideline. “Depending on how long your sleep cycle is, the amount you need to feel refreshed can vary,” Moore says. “Initially, as you fall asleep you will notice you are likely to potentially wake easier, and as you slip into deeper sleep, this lessens. When uninterrupted is the time that your body has the opportunity to repair from the physical wear and tear of the day. As you then progress into REM sleep, your mind has the chance to consolidate memories and sort through mental stresses.”
How to optimise your core sleep?
If you’re struggling to get the right amount of core sleep each night, it”s important to make sure your body and mind are optimised for this essential sleep stage. In general, practising good sleep hygiene is a great way to encourage the body to settle into the core sleep stage.
“All the things that classically set you up for a good night’s sleep will give you the best chance of achieving core sleep,” says Moore. “From the moment you wake, you should be mindful of how your lifestyle impacts your sleep quality as well as duration.”