Waking up feeling groggy and irritable? There’s a good chance you’re missing out on REM sleep. We look at what’s happening in our brain during the night and share some game-changing tips for acing this crucial sleep stage.

There are some dream days where the alarm goes off and you feel like you could run back-to-back marathons. Then there are others where you can barely prize your eyes open without the help of a good pep talk and a strong coffee. So what separates a good night’s sleep from a disastrous one?

Aside from getting the obvious seven hours (or more) of sleep recommended by the Sleep Foundation, experts say that it’s the quality of our kip that’s the real clincher, not just the time spent under the duvet.

Given that 1 in 3 of us struggle to get enough good sleep, it’s hardly a surprise that there’s mounting interest in this previously overlooked area of health. Just look at the explosion of sleep trackers, that measure how much kip we’re getting in granular detail, for proof.

But despite high-tech wearables like Fitbit opening our eyes to the importance of REM sleep, most of us still have no freaking clue what’s happening to our bodies when we’re at rest - let alone how to fix it. So what exactly is going on during this sleep stage, why is it so important, and is there anything we can do to optimize it?

REM sleep, explained

REM, also known as ‘Rapid Eye Movement’ sleep, is one of five key sleep stages that occur in a cyclic pattern every night. Unlike the other four stages, it’s the most active type of sleep.  During this time of the night, we’re dreaming, making sense of the day’s memories and solving tricky subconscious problems.

In non-REM sleep, our brain waves slow down and we maintain some form of muscle movement. “During REM sleep, our brain activity increases and starts to resemble a waking state,” says Carlie Gasia, a Spencer Institute–Certified Sleep Science Coach and spokesperson for Sleepopolis.

“Typically your eyes also move rapidly behind your closed lids and your heart rate jumps up too.”

It’s during this stage of sleep that you’re most likely to have a vivid dream about an ex-flame or a nightmare about sitting an exam unprepared. But as the body is in a temporary state of paralysis, it prevents you from acting out the images and emotions you're experiencing.

“REM sleep first occurs about 90 minutes after falling asleep, and happens roughly every 90 minutes thereafter,” says Dr. Chester Wu, sleep psychiatrist and Rise Science medical reviewer. It ramps up as the night progresses, with the first REM episode typically lasting around 10 minutes and subsequent episodes getting longer, with the final one potentially lasting up to an hour. 

Why is REM Sleep important?

When it comes to our wellbeing, every stage of the sleep cycle matters, but REM has a particularly hefty job. If you’ve ever gone to bed seething about an argument and woken up surprisingly unbothered, it’s probably because you got enough REM sleep. “Research has found that REM is key to consolidating our memories, regulating our moods, and maintaining our cognitive function,” says Gasia.

When we’re in this restorative sleep stage, our industrious brains begin the administrative process of filing away our memories, separating them from painful associated feelings. As we spend time sitting in this place of sleeping wakefulness, researchers have concluded that we learn to process our emotions and get a better handle on them. 

A study conducted by the Department of Neurology of the University of Bern, found that during REM sleep, the brain actively ‘stores’ positive memories and ‘dampens’ the consolidation of negative emotions - helping us to feel more indifferent about the things that irk us.

It makes sense then, that if we’re deprived of this vital dream sleep, we can feel cranky and more short-tempered than usual. Studies have found that REM sleep also has a knock-on effect on our cognitive performance, so we may also be unable to focus on a simple work task or deliver a sparkling presentation after just one bad night.

Plus, there’s a negative effect on our physical health too. While a lack of sleep in general can increase the risk of an earlier death, a 2020 study of over 4,000 adults found that a 5% decrease in REM sleep was linked with a 13% greater risk of dying from any cause over the following two decades.

As Dr Wu explains: “Chronic REM deprivation could potentially contribute to more serious health issues like obesity, diabetes, and cardiovascular disease.”

Can we do anything about REM sleep?

Experts advise that we spend 20-25% of our time asleep in the REM stage, around 90 minutes per evening. If you’re tracking your slumber, it can be panic-inducing to see a consistently low REM score, even after a decent stretch of sleep. So what can be done? 

“Unfortunately, you can't directly control or influence how much time you spend in REM sleep - it's a complex process controlled by the brain, based on its needs,” says Dr Wu. In other words, it’s a homeostasis process, meaning the body adjusts how much time it spends in REM sleep depending on our changing external conditions.

That said, some underlying health conditions can affect the length and quality of REM sleep. Scientists have observed that people with depression tend to have bouts of REM sleep earlier in the night, while sleep apnea, taking antidepressants, and insomnia, can all reduce the amount of REM sleep we get. If you’re worried about your sleep, it’s always worth chatting to your GP who can look into potential causes and treatments.

Other than getting a full night’s sleep, Wu says that consistent timing matters. “Waking up a couple of hours earlier than usual may only seem like a minimal amount of sleep loss, but it could mean you've missed out on most of your REM sleep.” As we mentioned earlier, the duration of REM stages increases as the night progresses, so most of your REM sleep happens in the final hours of the morning. Stacking your sleep at the weekend might feel like it’s working for you, but Wu says it’s always better to stick to a consistent sleep schedule throughout the entire week.

Our top 3 REM sleep tips

We’ve all heard the standard sleep tips (avoid your phone, don’t drink coffee after noon), but what else can we do to supercharge our REM sleep? Try one or all of the following…

Break up with your sleep tracker

Your sleep tracker may be feeding you valuable insights, but all that scary data could be negatively impacting your mental health. Studies have found that an excessive preoccupation with sleep, dubbed ‘orthosomnia’, can trigger anxiety - leading to further sleeplessness. Slip off your tracker at night and you won’t be fixated on dwindling sleep scores.

Channel Marie Kondo

When it comes to getting those necessary ZZZs, the clutter in your room could be keeping you awake. Research has found that having a busy and messy bedroom contributes to alertness and stress, making it hard to relax enough to get to sleep. Make your space a clean and cool palace of calm, and use blackout curtains or an eye mask to block out light if you need to.

Bulk up on beans

Studies have linked fiber intake with deeper, more restorative sleep, so load up on plant-based goodness. All beans are fiber-packed, but white and navy varieties are the most potent, so opt for tins of garbanzo, kidney, lima, or pinto beans. Chuck them in casseroles, stir them in chili or spoon them on toast for a savory breakfast option.

Finally, if you’ve tried everything from journaling to cold water therapy and you’re still struggling to drift off, it’s probably a good idea to chat with your GP. They can offer guidance on healthy sleep habits and lifestyle changes that can improve sleep, or refer you to specialist treatment if it’s needed.