Health & Fitness

What Is Core Sleep And Why Is It Important?

A good night’s sleep is essential for our physical and mental well-being, but achieving truly restorative rest goes beyond simply clocking in the recommended 7-9 ...

by Kendra Reed

What Is Core Sleep And Why Is It Important?

A good night’s sleep is essential for our physical and mental well-being, but achieving truly restorative rest goes beyond simply clocking in the recommended 7-9 hours. The quality and type of sleep we experience play a critical role in determining how rejuvenated we feel upon waking.

At the heart of this lies the concept of core sleep – a term that has gained increasing attention in recent years. But what exactly is core sleep, and how does it differ from the deep sleep stage we’re more familiar with? In this comprehensive guide, we’ll unravel the mysteries of core and deep sleep, exploring their differences, importance, and how you can optimize both for a truly revitalizing slumber.

Can You Dream In Core Sleep?

Can You Dream In Core Sleep

Core sleep refers to the most restorative and essential stages of the sleep cycle, encompassing both deep sleep (also known as slow-wave sleep) and rapid eye movement (REM) sleep. These two stages are considered the backbone of a healthy, rejuvenating sleep experience, as they facilitate critical processes essential for physical and cognitive restoration.

While deep sleep is characterized by slow brain wave activity and physical regeneration, REM sleep is the stage during which we experience vivid dreaming. During REM sleep, our brain activity mirrors that of wakefulness, allowing us to process emotions, consolidate memories, and engage in imaginative mental exploration. Therefore, while dreaming does not occur during the deep sleep stage, it is an integral part of the core sleep experience, occurring during the REM portion.

How Much Core Sleep Do You Need?

The recommended amount of core sleep can vary based on age and individual needs, but generally, adults should aim for at least 4-6 hours of core sleep per night. This typically translates to approximately 1.5-2 hours of deep sleep and 1.5-2 hours of REM sleep, with the remaining time spent in lighter stages of non-REM sleep.

It’s important to note that these recommendations are not set in stone, as individual sleep requirements can vary. However, consistently failing to obtain sufficient core sleep can have detrimental effects on physical and cognitive function.

What Is Core Sleep vs REM Sleep?

While core sleep encompasses both deep sleep and REM sleep, REM sleep is a distinct stage within the core sleep experience. During REM sleep, our brains exhibit heightened activity, facilitating processes such as memory consolidation, emotional regulation, and creative problem-solving.

REM sleep is often referred to as the “dream state,” as it is during this stage that we experience the most vivid and memorable dreams. Additionally, REM sleep plays a crucial role in learning and memory formation, as well as supporting healthy brain development in children and adolescents.

Which Is Better: Core Sleep or REM Sleep?

Neither core sleep nor REM sleep can be deemed “better” than the other, as both play vital roles in maintaining overall health and well-being. Core sleep, which includes both deep sleep and REM sleep, is essential for physical restoration, cognitive function, and emotional regulation.

However, REM sleep, as a specific stage within core sleep, is particularly important for processes such as memory consolidation, emotional processing, and creative thinking. Ultimately, a healthy sleep cycle requires a balance of both core sleep and REM sleep, as they work in tandem to support various aspects of our physical and mental health.

Why Is Core Sleep Important?

Core sleep is crucial for several reasons, including:

  1. Physical Restoration: During deep sleep, our bodies engage in repair and regeneration processes, including tissue growth, muscle recovery, and the release of essential hormones like growth hormones.
  2. Cognitive Function: Both deep sleep and REM sleep contribute to cognitive processes such as memory consolidation, learning, and problem-solving abilities. Insufficient core sleep can lead to impaired focus, attention, and decision-making skills.
  3. Emotional Regulation: REM sleep, in particular, plays a significant role in processing and regulating emotions. Disruptions in REM sleep have been linked to emotional dysregulation and conditions like depression and anxiety.
  4. Immune System Support: Deep sleep is associated with the release of cytokines, which are proteins that help regulate immune function and inflammation. Adequate core sleep can strengthen the immune system’s ability to fight off infections and diseases.
  5. Energy Conservation: During deep sleep, our bodies conserve energy by slowing down various physiological processes, such as heart rate and respiration. This energy conservation allows for more efficient restoration and rejuvenation.

Why Is My Core Sleep So High?

While most people aim to increase their core sleep, some may find that their sleep-tracking devices or apps report unusually high levels of core sleep. There could be several reasons for this:

  1. Inaccurate Sleep Tracking: Sleep tracking technologies, while helpful, are not always perfectly accurate in distinguishing between different sleep stages. Factors like movement, heart rate, and breathing patterns can sometimes lead to inaccurate classifications.
  2. Age and Individual Differences: As we age, our sleep patterns change, and we may naturally experience more core sleep (particularly deep sleep) than younger individuals. Additionally, individual differences in sleep architecture can contribute to variations in core sleep duration.
  3. Sleep Disorders: Certain sleep disorders, such as sleep apnea or periodic limb movement disorder, can disrupt sleep quality and lead to inaccurate sleep stage tracking.
  4. Medication or Substance Use: Some medications, supplements, or substances (such as alcohol) can influence sleep patterns and potentially skew core sleep measurements.

If you consistently experience unusually high levels of core sleep and feel unrested or fatigued during the day, it’s essential to consult with a sleep specialist or healthcare professional to identify and address any underlying issues.


In the quest for a truly restorative night’s sleep, understanding the intricacies of core sleep and its relationship with deep sleep and REM sleep is crucial. Core sleep, encompassing both deep sleep and REM sleep, is the foundation upon which our physical and cognitive restoration is built. By prioritizing core sleep and implementing strategies to optimize it, we can unlock the full potential of our sleep experience.

From establishing consistent sleep routines and creating a sleep-conducive environment to exploring sleep-promoting accessories like weighted blankets or infrared sauna blankets, there are numerous avenues to enhance our core sleep quality. By embracing the importance of core sleep and taking proactive steps to nurture it, we can awaken each day feeling truly rejuvenated, energized, and ready to tackle life’s challenges with renewed vigor.


  • Kendra Reed

    Dr. Kendra Reed is a dedicated general medicine physician with 7 years of clinical experience. After graduating from medical school, she completed her residency in internal medicine, developing a well-rounded skillset in diagnosing and treating a diverse range of conditions. Patients appreciate Dr. Reed's warm bedside manner and commitment to providing comprehensive, personalized care. In addition to her clinical work, she is actively involved in community outreach programs, educating the public on important health topics. Dr. Reed is known for her ability to establish trusting relationships with her patients and help them achieve their wellness goals.

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