Restorative Sleep

The most critical phases of sleep to focus on for recovery are the restorative sleep stages (Deep Sleep + Rapid Eye Movement Sleep). These two sleep stages help our body and brain to recover.

Typically, the proportion of Rapid Eye Movement (REM) sleep in adults is normally 20%-25%, and deep sleep accounts for 13-23%.

Restorative sleep is an important criterion for assessing sleep quality. A low percentage of restorative sleep usually indicates that our body and brain have not achieved full recovery.

Rapid Eye Movement Sleep

Many apps misleadingly describe Rapid Eye Movement sleep as light sleep, implying that REM sleep is not important. However, the opposite is true; REM sleep is crucial for our brain's repair.

Characteristics of REM sleep include rapid eye movement, increased brain activity, and almost complete muscle relaxation. During REM, we often dream. REM sleep typically begins about 90 minutes after falling asleep, recurring every 90 minutes, with longer durations in the later sleep cycles.

REM sleep plays a key role in the recovery and renewal of the brain, including:

  • Enhancing cognition, regulating emotions and stress: During REM sleep, the brain is highly active, processing and consolidating memories, emotions, and learning. Studies show that REM sleep is vital for emotional health, helping regulate emotional responses and reduce stress and anxiety.

  • Increasing creativity: The REM sleep stage is when dreams are most frequent and vivid, which is thought to benefit creativity and problem-solving. By processing and reorganizing information in dreams, REM sleep may promote the formation of innovative thinking and insights.

  • Consolidating memory: REM sleep is crucial for memory formation, especially for processing complex emotional memories and enhancing creative thinking. The brain replays experiences from the day during this stage, helping consolidate memory and learning.

Deep Sleep

Also known as Slow Wave Sleep (SWS), it is characterized by the slowest brainwave activity during the sleep cycle. It is a key period for restorative sleep, during which heart rate, breathing rate, and brain activity all slow down, allowing the body to enter its deepest state of rest.

Deep sleep usually occupies a larger proportion in the early part of the night and gradually decreases later.

Deep sleep plays a key role in physical recovery, including:

  • Physical repair and growth: During deep sleep, the body releases growth hormones, promoting cell and tissue repair, regeneration, and growth. This stage is especially important for the growth and development of children and adolescents.

  • Enhancing the immune system: Deep sleep is crucial for enhancing immune system function, helping the body resist diseases and infections. Sufficient deep sleep helps maintain health and defend against external threats.

  • Brain cleaning and recovery: During deep sleep, the brain undergoes a cleaning and detoxification process, clearing metabolic waste through cerebrospinal fluid. This process is vital for preventing neurodegenerative diseases and maintaining brain health.

  • Cognitive function and emotional stability: Although deep sleep is more closely associated with physical recovery, it also has important impacts on cognitive functions and emotional stability. Lack of deep sleep affects emotional regulation, increasing the risk of depression and anxiety.

By ensuring adequate REM sleep and deep sleep, we can promote overall physical and mental health and effectively reduce stress.