REM sleep: what it is and how to improve it

The key points

• REM (Rapid Eye Movement) sleep is the phase in which we dream. It plays a crucial role in processing experiences and consolidating memories.

• In adults, REM sleep makes up around 20 to 25% of total sleep. With eight hours of sleep, that equals roughly 90 to 120 minutes.

• A consistent sleep rhythm, stress reduction and a comfortable sleep environment are the most effective ways to increase and stabilise REM sleep.

What is REM sleep?

REM sleep is not a uniform state but part of a structured sequence of sleep cycles. Each night, your body moves through several cycles of around 90 minutes, and each cycle includes light sleep, deep sleep and REM sleep.

The term REM stands for Rapid Eye Movement — the quick eye movements that can even be observed from the outside as the eyes shift rapidly beneath closed eyelids.

During REM sleep, brain activity is almost as high as when you’re awake, while muscle tone is strongly reduced. This natural muscle paralysis prevents your body from physically acting out your dreams.

REM sleep is also the phase in which we experience the most vivid and emotional dreams, the ones we often remember in the morning. Today, we know that this intense dreaming is essential for processing both emotional and physical experiences.

How REM sleep differs from deep sleep

Deep sleep and REM sleep are often confused, but they serve completely different purposes.

• Deep sleep is the phase of physical recovery: tissues regenerate, the immune system strengthens and growth hormones are released.

• REM sleep, on the other hand, is responsible for mental and emotional processing, memory consolidation and integrating experiences.

Both phases are essential — and they complement each other within the nightly sleep cycle.

Why is REM sleep so important?

The importance of REM sleep goes far beyond dreaming. It influences key physical and mental functions that directly affect performance, wellbeing and long‑term health.

Memory and cognition

During REM sleep and memory, your brain links new information with existing knowledge. Learned content is strengthened, while irrelevant impressions are filtered out. This process is essential for memory formation and cognitive performance. Researchers even assume that consistently low REM sleep can lead to concentration difficulties and reduced mental flexibility.

Emotions and stress processing

In the REM phase, your brain processes not only experiences but also the emotions associated with them. The nervous system uses this stage to correctly categorise emotionally stressful — but also positive — events.

During this process, the hormonal balance also regulates itself: melatonin supports a stable sleep rhythm, while healthy sleep helps reduce the stress hormone cortisol. People who chronically sleep poorly often react more irritably and are more susceptible to stress — a direct consequence of disrupted sleep cycles.

Regeneration and physical performance

Even though physical recovery takes place primarily during deep sleep, REM sleep plays a crucial role in regenerating the nervous system. For anyone exposed to high physical or mental demands, a sufficient REM proportion is essential to maintain performance and continue improving.

How much REM sleep do we need?

REM sleep varies from person to person, so only general guidelines exist. In healthy adults, REM sleep makes up around 20 to 25% of total sleep time. With eight hours of sleep, this equals roughly 90 to 120 minutes.

REM sleep occurs throughout the night

REM cycles appear in every sleep cycle, not just once per night. However, the proportion of REM sleep increases significantly in the early morning hours. This explains why dreams feel most vivid just before waking — and why early alarms or stress‑related awakenings can cut off a large portion of your REM sleep.

Individual differences are normal

How much REM sleep you need depends on several factors, including age, health, lifestyle and current physical or emotional demands.

Children and teenagers have a much higher REM proportion than adults — a sign of how essential this phase is for development and growth. With age, the REM share tends to decrease gradually.

5 practical tips to improve REM sleep

Anyone who frequently feels inner restlessness or struggles with daytime concentration should take a closer look at their sleep hygiene. Supporting healthy sleep cycles with clearly defined sleep phases contributes noticeably to both physical and mental balance.

The following measures help you improve both deep sleep and REM sleep.

Tip 1: Keep a consistent sleep rhythm

Your body thrives on routine and predictability. Going to bed and waking up at the same time each day supports your natural circadian rhythm and makes it easier for the nervous system to transition into deep, restorative sleep phases. It’s worth keeping your schedule stable even on weekends.

Tip 2: Reduce stress and evening cortisol

Cortisol is one of the biggest disruptors of emotion‑processing dream phases. If your body is still tense in the evening, it takes longer to reach restorative sleep depth. Evening rituals such as gentle stretching, breathing exercises, a warm tea or a soothing bath help calm the nervous system — creating ideal conditions for restful, uninterrupted sleep.

Tip 3: Avoid alcohol and caffeine

Alcohol and caffeine significantly influence sleep architecture:

• Caffeine delays sleep onset,

• Alcohol suppresses early‑night REM phases, even if you feel like you slept well.

If you want to increase your REM proportion, avoid caffeine after early afternoon and reduce alcohol as much as possible.

Tip 4: Optimise your sleep environment

A cool, dark and quiet bedroom fundamentally improves sleep quality. The ideal temperature is 16–18°C, and both noise and light should be minimised before bed. Darkness supports melatonin production, helping your body transition smoothly into deeper sleep stages. Your smartphone should ideally be switched off or set to flight mode.

Tip 5: Choose breathable nightwear

What you wear in bed has a major impact on your thermal comfort. Overly warm or synthetic materials can disrupt temperature regulation, causing discomfort or even awakenings — often at the expense of REM‑rich dream phases.

Breathable nightwear made from natural fibres such as cotton or TENCEL™ supports a stable body temperature and helps your body relax. CALIDA’s DEEPSLEEPWEAR collection is designed specifically for restorative sleep, using skin‑friendly materials that create optimal conditions for all sleep stages.

Conclusion

REM sleep is far more than the dream stage — it is a crucial period in which your brain processes experiences, regulates emotions and strengthens memory pathways. This makes it essential for improving your stress resilience, mental clarity and overall cognitive performance.

With a consistent sleep rhythm, targeted evening relaxation, avoiding caffeine and alcohol, and creating a comfortable sleep environment, you can noticeably increase the quality and duration of your REM phases. Choosing breathable, skin‑friendly nightwear further supports stable temperature regulation and helps your body make the most of every sleep stage.