What is deep sleep?
Did you know there are actually five stages of sleep? Each stage can be easily distinguished from each other: two are light sleep, the following two are deep sleep and the fifth is a short, 15-minute burst of rapid eye movement, or REM sleep.
Our sleep expert, Dr Nerina shares her thoughts on deep sleep versus REM sleep.
What does deep sleep mean?
In deep, non-dreamless sleep, there is virtually no body movement and it is likely that this is where our deepest restoration comes from. Deep sleep phases vary in duration throughout the night with the first 90 minute cycle of sleep made up mostly of deep sleep with 7-10 minutes of REM sleep.
What is REM sleep?
REM sleep is the result of the brain trying to scan the events in the dream world. In other words, if you look left and right in your dream, then your eyes will follow the dream and move left and right under your eyelids.
In this stage, your body goes into a state of paralysis or otherwise, we might start acting out our dreams!
REM sleep varies in duration throughout the night with the first stage lasting around 7-10 minutes. As sleep progresses throughout the night the REM stages become longer, to around 45 minutes.
Which is more important?
While deep sleep is vital, so is REM sleep. In laboratory studies, rats who usually live for two or three years, if deprived of REM sleep live only three weeks on average. REM sleep stimulates the brain regions used in learning, particularly for normal brain development during infancy – this could explain why babies spend much more time in REM sleep than adults.
How much deep sleep should you have a night?
Whilst there is a lot of focus on the quantity of sleep that we should be getting, when looking into the benefits of sleep, it seems that quality also plays an important role.
Dr Nerina Ramlakhan, Silentnight’s resident sleep expert, has spent her career looking into our sleep patterns and finding ways we can improve them.
Dr Nerina found that we sleep in cycles of roughly 90 minutes called the ultradian cycle. This cycle consists of 5 stages with one and two being ‘light sleep’, three and four ‘deep sleep’ and the fifth being a burst of ‘REM’ (rapid eye movement) sleep.
During these deep stages of sleep, glucose metabolism in the brain improves our short and long term memory capability and supports our overall learning ability. It is also when we restore the most energy and major cell repair occurs. These benefits of deep sleep highlight just how important it is to ensure we allow our bodies to get enough sleep.
How do you fall into a deep sleep?
As we can’t fall directly into deep sleep, the only way we can help encourage us to clock up the hours is to ensure we get enough sleep, at the right times. This includes preparing ourselves for sleep correctly and earlier than many people currently do.
With stage four accounting for 13-23% of our sleep, people may find themselves experiencing a lot less of this essential regenerative rest. To ensure you prepare yourself for as much as possible it is essential to head to bed early. Dr Nerina highlights that even if you’re getting 7-9 hours sleep, heading to bed late you could be depriving you of this regenerative rest.
The hours between 1-3am are where we enter deep restorative sleep, and adequate rest before these hours is essential to allow our bodies to rest fully. Between 9-11pm it’s advised that we start relaxing and preparing for bed. To help drift of during these hours, restricting the use of technology and taking extra steps such as a bicarbonate of soda bath or yoga can help those who struggle getting to sleep.