Which is better REM or deep sleep?

Quick Answers

REM and deep sleep are both important stages of sleep that serve different purposes. REM sleep is vital for memory consolidation and learning, while deep sleep is important for restoration and rejuvenation. Experts recommend getting both REM and deep sleep each night for optimal health and functioning. There is no definitive answer as to which is “better” – both are essential.

Sleep is crucial for many aspects of health and wellbeing. During sleep, the body and brain go through various stages that allow us to restore, recharge, and process information from the day. Two of the most important stages of sleep are rapid eye movement (REM) sleep and deep, or slow wave, sleep. But which of these two stages is more beneficial? Should we aim to get more REM or deep sleep? Or are both equally vital? This article will examine the difference between REM and deep sleep, the benefits of each stage, and whether one is “better” than the other.

What is REM Sleep?

REM sleep first occurs about 90 minutes after falling asleep and recurs about every 90 minutes throughout the night. REM sleep is characterized by rapid eye movements, increased brain activity, faster breathing, and muscle paralysis. This is the stage of sleep when we dream the most vividly.

Some key features and functions of REM sleep include:

  • Brain activity spikes – the brain becomes very active during REM similar to when we are awake.
  • Vivid dreaming – our most intense and memorable dreams occur during REM sleep.
  • Memory consolidation – REM helps strengthen and enhance memories and learned skills.
  • Emotional processing – REM assists in processing emotions, stress, and experiences from the day.
  • Muscle paralysis – muscles are immobilized during REM to prevent acting out dreams.
  • Circadian rhythm alignment – The timing of REM cycles helps align the body’s 24-hour circadian rhythms.

Overall, REM sleep is vital for proper cognitive function and mental health. It allows the brain to process information from the day for long-term storage and supports learning and memory retention.

What is Deep Sleep?

Deep sleep, also called slow wave sleep, progresses through three stages characterized by slow brain waves, reduced muscle activity, and slow breathing and heartbeat. Deep sleep occurs mostly in the first half of the night.

Some key features and functions of deep sleep include:

  • Brain waves slow – Large, slow brain waves called delta waves occur.
  • Body restoration – Growth and repair of tissues and muscles occurs.
  • Hormone regulation – Deep sleep triggers the release of growth hormone and supports hormone balance.
  • Immune support – The body produces cytokines that support immune system function.
  • Energy conservation – Metabolic rate and energy usage decrease, conserving energy.
  • Memory consolidation – The transfer of memories from short-term to long-term storage occurs.

In summary, deep sleep allows the body to rejuvenate at a cellular level, regulating growth, repair, and immunity. It also conserves energy and supports memory consolidation.

Key Differences Between REM and Deep Sleep

Although both are necessary stages of healthy sleep, REM and deep sleep have distinct differences:

Brain Activity

  • REM – very high brain activity, similar to wakefulness
  • Deep sleep – low brain wave frequency and activity

Breathing and Heart Rate

  • REM – increased breathing rate and variability in heart rate
  • Deep sleep – slow, steady breathing and heart rate

Muscle Activity

  • REM – muscle paralysis
  • Deep sleep – decreased muscle activity

Hormone Secretion

  • REM – no major hormone activity
  • Deep sleep – growth hormone release

Memory and Learning

  • REM – consolidates memories and learning
  • Deep sleep – transfers memories from short to long-term


  • REM – minimal physical restoration
  • Deep sleep – significant cellular repair and restoration

So in summary, REM and deep sleep affect the body quite differently and serve unique purposes that are both important to health.

Benefits of REM Sleep

Getting adequate REM sleep (about 20-25% of total sleep in adults) is vital for the following reasons:


REM sleep helps consolidate procedural and declarative memories so they can be stored long-term. Studies show getting REM enhances recall and knowledge retention. Lack of REM disrupts this memory processing.


By consolidating memories, REM also enhances learning. REM assists with processing new skills and information so they can be mastered over time. Reduced REM impairs ability to learn and apply knowledge.


The vivid imagery, associations and heightened brain activity during REM spark creative thinking and problem solving. Getting sufficient REM facilitates innovative ideas.

Emotional Health

REM provides an opportunity to process emotions safely through dreaming. This leads to better mood, stress resilience, and emotional intelligence when awake.

Brain Development

REM is critical for developing brains in utero and during infancy and childhood. REM stimulates synapse formation and programs instinctive skills and behaviors.

In summary, REM sleep is indispensable for cognitive health, emotional regulation, and ongoing learning. Making REM a priority can enhance focus, productivity, creativity, and overall wellbeing.

Benefits of Deep Sleep

Getting 15-25% of sleep in the deep stages is also essential for:

Cellular Repair

Deep sleep triggers protein production needed for restoration of cells and tissues throughout the body, especially muscles, bones, and skin. This is when the most significant physical regeneration occurs.

Immune Function

The body produces antibodies and cytokines during deep sleep to bolster immune defenses. Deep sleep also fights inflammation which supports immune responses.

Metabolic Health

Deep sleep regulates appetite hormones like leptin and ghrelin. It also controls glucose metabolism by recharging insulin sensitivity in cells. These impacts promote healthy weight and blood sugar levels.

Growth & Development

Deep sleep stimulates the pituitary gland to release human growth hormone, essential for childhood development and muscle mass maintenance in adults.

Brain Detox

The brain’s glymphatic system clears away metabolic waste products that accumulate during wakefulness. This neuronal cleaning only occurs during deep non-REM sleep.

Overall, deep sleep allows the body to restore and renew itself at a foundational level. Prioritizing deep sleep enhances physical health and daytime performance.

REM vs Deep: Which Is More Important?

There is no definitive answer as to whether REM or deep sleep is more important or “better” overall. Both play indispensable yet different roles in health, wellbeing, and functioning. Like yin and yang, REM and deep sleep balance each other. The optimal sleep pattern involves cycling between REM, deep and light sleep several times throughout the night.

Some key points when comparing REM and deep sleep:

  • Both are vital – Don’t prioritize one at the expense of the other.
  • REM dominates early morning while deep sleep prevails in first half of night.
  • Aim for about 20-25% of total sleep time in both REM and deep stages.
  • Too much REM or deep sleep may be problematic.
  • Lack of REM most impacts learning, focus and emotional health.
  • Lack of deep sleep primarily disrupts cellular repair, immunity, metabolism.
  • Overall sleep time and quality is just as important as balance of stages.

In the end, strive to get sufficient overall high quality sleep with balanced REM and deep cycles tailored your individual needs. Don’t force one type of sleep over the other. Optimize sleep hygiene practices and allow your body to naturally regulate optimal REM-deep cycles.

Tips to Improve REM and Deep Sleep

Here are some evidence-based tips to enhance both REM and deep sleep:

For better REM sleep:

  • Don’t consume caffeine, alcohol or heavy meals before bedtime
  • Go to bed and wake at consistent times to sync circadian rhythm
  • Ensure room is completely dark
  • Get adequate overall sleep amount (7-9 hrs)
  • Take magnesium supplements which increase REM
  • Reduce stress and anxiety through relaxing activities before bed
  • Get morning sunlight exposure to set circadian rhythm

For better deep sleep:

  • Avoid electronics and screens before bed
  • Engage in moderate exercise during the day
  • Develop a relaxing pre-bed routine
  • Use blackout curtains to darken room
  • Take Calcium and Vitamin D supplements
  • Have a light carbohydrate snack before bed
  • Ensure comfortable mattress and pillow for ease
  • Consider white noise or sleep music

Optimizing sleep hygiene and your bedroom environment can go a long way in supporting both REM and deep sleep. But don’t hesitate to see a sleep specialist if you continue having issues.

Tracking REM and Deep Sleep

Tracking your REM and deep sleep stages can provide insight into your overall sleep quality. Here are some options for monitoring sleep cycles:


Polysomnography involves extensive monitoring in a sleep lab, using EEG of brain waves plus other body sensors. Considered the gold standard, but expensive and inconvenient.

Home Sleep Apnea Tests

Basic home tests like WatchPAT monitor pulse, oxygen, movement and breathing to estimate REM, light and deep sleep. Less extensive data than polysomnography.

Sleep Tracking Devices

Wearable devices like Fitbit, Apple Watch or Oura Ring use movement, heart rate and algorithms to estimate sleep stages and quality. Can lack accuracy but convenient.

Sleep Tracking Apps

Sleep tracking apps utilize only movement and sounds during sleep. Provide a rough breakdown of sleep stages based on limited data.

For those with sleep disorders or who want comprehensive sleep stage data, consider a home sleep apnea test or polysomnography. Otherwise, consumer sleep tracking can provide general insight into sleep quality over time.

The Takeaway

Both REM and deep sleep offer tremendous health and performance benefits that complement one another. Focus on optimizing overall sleep quality, rather than just one particular stage. Aim to get sufficient REM and deep sleep cycles each night by supporting your body’s natural sleep processes. Consistent, high-quality sleep with a balance of REM, light and deep stages is ideal for waking up feeling recharged and restored.

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