What is REM sleep and how much do I need?

When it comes to shut-eye time, not all sleep is equal. Turns out, there are different types of sleep, with REM (Rapid Eye Movement) sleep in particular having an important role in brain health and memory function.

Consider nib your health partner when it comes to looking after your body and mind – and when it comes to getting good quality shut-eye, we spoke with associate professor Dr Aliza Werner-Seidler, clinical psychologist at the Black Dog Institute to explain what REM sleep is – and how we can get more of it.

Sleep can be divided into two main types – REM sleep and non-REM sleep. REM sleep happens about every 90 minutes during sleep. It’s the time of sleep when you dream more, and your blood pressure and heart rate go up.

REM sleep was first discovered back in the 1950s, when scientists studying sleeping infants noticed that there were distinct periods when their eyes moved rapidly from side to side (hence the name).

Meanwhile, non-REM sleep has four stages. The first stage is when you transition between being awake and asleep and can be easily woken up. During the next three phases of non-REM sleep, your eye movements stop, your body temperature drops and you go into a much deeper sleep.

REM sleep is important because it’s when mental restoration takes place, says Aliza.

It’s essential for keeping your brain in shape and converting short-term memories into long-term ones

With four in 10 Australians reporting they do not get enough sleep, how can we know if our REM sleep is being impacted?

Ideally most adults would spend about 20-25% of their total asleep time in REM, says Aliza. “So, if you rest for seven to eight hours per night, the total comes to about 90 minutes of REM sleep,” she explains.

However, infants and young children need more REM sleep because their brains are learning and developing more. Newborn babies, for example, need to spend about half of their sleep time in REM.

Not getting enough REM sleep could impact daytime functioning, and learning that’s facilitated by memory, Aliza says.

“REM sleep is thought to be helpful for the consolidation of procedural memory,” she explains. “This is the type of memory you use when you learn a new skill, like how to ride a bike. It differs from factual or semantic memory, which you use for something like dates or a list of facts.”

REM sleep may also help with problem-solving and your long-term memory, Aliza adds. 

Whether you are getting enough REM sleep is linked to your overall sleep. So, if you’re not getting enough good-quality sleep in general, then chances are your REM sleep is being impacted, Aliza says.

“Since REM sleep occurs mostly during the second half of the sleep period, sleeping for too short a period may not allow time to complete all the REM sleep cycles,” she explains.

Therefore, the best and most simple way to improve your REM sleep is to improve your overall sleep.

Aliza’s top four recommendations for improving overall sleep are:

• Develop a regular sleep schedule. Try to go to bed and wake up at the same times each day

• Address sleep problems. If you suffer from conditions that interrupt your sleep, such as obstructive sleep apnoea, there are treatments to help

• Avoid or cut down on alcohol, caffeine and tobacco. Alcohol can delay when you first enter REM sleep and means you spend less time in REM sleep, Aliza advises. Caffeine and tobacco can also interfere with normal progression through the sleep stages

• Develop good sleep hygiene. This means setting your bedroom and your daily routines up in a way that promotes restful sleep, including by:

• Exercising regularly

• Maintaining a cool, dark and quiet bedroom environment

• Establishing a regular bedtime routine with soothing activities, such as reading or taking a warm bath

• Avoiding gadgets and screens for around an hour before bedtime

• Taking a break from trying to sleep – If you can’t get to sleep after 20 minutes or so, leave your bed and do something else in another room until you feel sleepy enough to return to bed

Please note: The tips throughout this article serve as broad information and should not replace any advice you have been given by your medical practitioner. 

The Black Dog Institute is one of our nib foundation partners. We’re helping the Black Dog Institute fund the Sleep Ninja app – an evidence-based intervention programs to help young people adopt healthy sleep behaviours and improve their wellbeing.

Please note: The information throughout this article serves as broad information and should not replace any advice you have been given by your medical practitioner.