Muscle Memory And Rem Sleep: A Connection?

During REM sleep, the body's muscles are paralysed. This is known as muscle atonia, and it prevents sleepers from acting out their dreams. However, people with REM sleep behaviour disorder (RBD) do not experience this paralysis, and can physically act out their dreams, which can lead to injury.

REM sleep is characterised by relaxed muscles, quick eye movement, irregular breathing, an elevated heart rate, and increased brain activity

REM sleep is the fourth stage of sleep, characterised by relaxed muscles, quick eye movement, irregular breathing, an elevated heart rate, and increased brain activity.

During REM sleep, the muscles in the arms and legs become temporarily paralysed, a condition known as atonia. This prevents people from acting out their dreams and injuring themselves. However, the muscles required for breathing and eye movement remain active. The paralysis is caused by two powerful brain chemical systems, the neurotransmitters gamma-aminobutyric acid (GABA) and glycine, which "switch off" the specialised cells in the brain that allow muscles to be active.

REM sleep is also associated with vivid dreams, memory consolidation, emotional processing, and brain development. Most dreams occur during this stage of sleep, and the increased brain activity is similar to that of a waking brain.

In addition, REM sleep plays a crucial role in muscle recovery. During this stage, the body releases growth hormones and initiates protein synthesis, which repair and rebuild muscles, reducing soreness.

The first REM episode is usually short, lasting just a few minutes. However, with each subsequent sleep cycle, the duration of REM sleep increases, with the longest episodes occurring towards the end of the night.

During REM sleep, the muscles in your arms and legs become temporarily unable to move

REM sleep is the fourth and final stage of the sleep cycle, during which the eyes move rapidly, the heart rate and blood pressure rise, and brain activity increases. The first REM episode is short, lasting only a few minutes, but it lengthens during subsequent cycles. Most REM sleep occurs in the second half of the night.

During this stage, the body releases growth hormones and initiates protein synthesis, aiding in muscle recovery and repair. This is also when most dreams occur, and they tend to be more vivid than dreams experienced during non-REM sleep.

While the muscles in the arms and legs are paralysed during REM sleep, the respiratory and eye muscles remain active. This selective paralysis is caused by two powerful brain chemical systems, involving the neurotransmitters gamma-aminobutyric acid (GABA) and glycine, which work together to "switch off" the cells that allow muscles to be active.

REM sleep is associated with muscle recovery, as it promotes the release of growth hormones and supports protein synthesis

REM sleep is the fourth and final stage of the sleep cycle, characterised by rapid eye movements, increased brain activity, irregular breathing, and a temporary loss of muscle tone. During this stage, the body releases growth hormones and initiates protein synthesis, which are crucial for muscle recovery.

The growth hormones stimulate muscle growth and repair tissues, while protein synthesis is a vital step in repairing and building muscle tissues. Therefore, adequate REM sleep is essential for muscle recovery and building a stronger, more resilient body.

To maximise the benefits of muscle recovery, it is recommended to aim for 7-9 hours of quality sleep each night, with around 25% of that time spent in the REM stage. This equates to approximately 2 hours of REM sleep within an 8-hour sleep cycle. Getting sufficient REM sleep improves overall sleep quality, reducing muscle soreness and inflammation.

Additionally, the timing of sleep after exercise is crucial. The first two hours after a workout are critical for muscle recovery, as the body releases growth hormones and initiates protein synthesis during this window. Prioritising sleep during this period enhances muscle repair and growth, ensuring optimal results from physical training.

Furthermore, managing stress and adopting bedtime rituals are integral components of a holistic approach to maximising muscle recovery. High-stress levels can disrupt REM sleep, hindering the muscle recovery process. Incorporating stress-reducing activities, such as meditation or deep breathing, can create a conducive environment for optimal REM sleep and improved muscle recovery.

REM sleep behaviour disorder (RBD) is a condition in which people physically act out their dreams

People with RBD may shout, punch, kick, or jerk in their sleep, which can lead to injuries to themselves or their sleep partner. The condition can also cause poor sleep quality. RBD is associated with neurodegenerative diseases such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. It is also often an early sign of these diseases, and can present in otherwise healthy individuals as idiopathic or isolated RBD (iRBD). iRBD is associated with an 80-90% risk of progression to a neurodegenerative disease within 10 years of the first diagnosis.

RBD is usually diagnosed through a detailed sleep history, especially if the patient already has a diagnosis of an associated condition. An overnight sleep study in a laboratory setting, known as video polysomnography (vPSG), is also used to identify RBD. Management of the condition includes providing physical safeguards in the sleeping environment, such as padding near the bed and soft barriers at the sides of the bed, as well as medication.

RBD is caused by a lack of temporary paralysis during REM sleep, which is usually induced by muscle atonia

During REM sleep, the muscles in the arms and legs become temporarily paralysed. This condition is known as atonia, and it prevents sleepers from acting out their dreams. However, people with REM sleep behaviour disorder (RBD) do not experience this temporary paralysis, and can physically act out their dreams, sometimes injuring themselves or their bed partner.

Another cause of RBD is the lack of orexin, a brain chemical that regulates sleep, wakefulness, and appetite. This can lead to a failure to stabilise REM sleep, resulting in RBD. Additionally, certain antidepressants can cause RBD due to imbalances in the neurotransmitters dopamine and serotonin, which are involved in REM sleep.

RBD can be diagnosed through a physical exam, a neurological exam, and an in-lab video sleep study or polysomnogram (PSG). Treatment for RBD focuses on creating a safe sleeping environment, and may include medications such as melatonin, clonazepam, or pramipexole.

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