The Circadian Rhythm and Stages of Sleep

Stages of sleep - Guy Yawning

What is Circadian Rhythm?

Studies have proven that there is a 24-hour circadian rhythm governing when we are asleep and when we experience wakefulness. No matter if a person considers themselves a night owl or they work the night shift, the human body, as well as those of animals and plants, are regulated by an internal biological clock called “The Circadian Rhythm”.

The Circadian Rhythm has its influence when we sleep and when we are awake -this is otherwise known as our sleep-wake cycle. They also govern hormonal release, such as that of growth hormone which occurs mostly when we are amidst the deepest cycle of sleep, as well as our body temperature. When our circadian rhythm has been disrupted or is abnormal, we find there is a strong association with an aftermath that creates obesity, depression, bipolar disorders and diabetes.

When a person has been awake for an extended period, their sleep/wake cycle alerts them that there is a need for sleep, and one consequently becomes drowsy. Ordinarily, the circadian rhythm regulates the timing of sleep and wakefulness at differing times during a 24-hour span.

Between the hours of 2-4am, most adults experience the highest drive to sleep.

Interesting alongside this information is that we are also driven to sleep between the hours of 1 – 3 pm. Those with sleeplessness requiring an insomnia treatment will suffer most at these times of the day according to our natural circadian rhythm.

Brain Waves and Sleep Cycles

Gamma is considered the “Insight” brain wave and has the fastest frequency of all brain waves and is associated with high-level information processing.

Beta is the “Waking Consciousness” and the brain wave responsible for reasoning.

Alpha brain waves are more often present in deep relaxation. When we are awake, it is Alpha that may slip us into a daydream and also assists in light meditation. Alpha helps focus us through this quiet balancing of the mind. Alpha brain waves are present when our intuitive facilities are optimised.

Theta is the light meditation and sleeping brain wave. It includes REM dream state.

Delta is our deep sleep brain wave. It is the realm of our unconscious mind and is linked to the regeneration that occurs during deep sleep. It is called delta sleep because of the presence of high-amplitude, low-frequency delta waves that are seen to occur in the EEG. People are difficult to rouse once they are in Deep Sleep. Deep sleep is extremely effective in decreasing the sleep drive that builds steadily over the course of the day. Human growth hormone is released in pulses during deep sleep.

Brain waves and sleep

The Stages of Sleep

When we are getting ready to fall asleep, our brain goes through Alpha and Theta, where we experience periods of dreaminess. We experience the same dreaminess during the day yet we don’t usually fall asleep due to our circadian cycle. Many people who practice mediation will gain control over their brain waves essentially “hanging out” in Alpha which is a very restful / peaceful state.
Once our brains begin to enter Theta we are slightly awake and yet in a light state of sleep. Therefore we can be woken easily if disturbed in a Theta state. If undisturbed within 5-7 minutes most people will reach the 2nd stage of sleep.
The second stage of sleep usually lasts 20 minutes and at this time our body temperature begins to drop, along with a slowing of our heart rate.
At stage three we are in the transition from light sleep into the deep slower frequency brain wave of Delta.
Lasting approximately 30 minutes this is the Delta regenerative stage of deep sleep.
When we dream, regardless of whether we remember dreaming or not – it occurs at stage five known as the REM sleep stage. In REM our brain experiences an increase in activity whilst other body systems such as our muscles become relaxed. We experience rapid eye movement (REM) and this is typically the dream state. Sleep does not always follow suite with each sleep stage one after the other. Most often our brains go back and forth after reaching Stage 4 back into stages, 3 and 2 before falling into a deep REM sleep. Once REM is over, we usually return to Stage Two sleep. Sleep cycles through these stages approximately 4 or 5 times throughout the night.
When we dream, regardless of whether we remember dreaming or not – it occurs at stage five known as the REM sleep stage. In REM our brain experiences an increase in activity whilst other body systems such as our muscles become relaxed. We experience rapid eye movement (REM) and this is typically the dream state. Sleep does not always follow suite with each sleep stage one after the other. Most often our brains go back and forth after reaching Stage 4 back into stages, 3 and 2 before falling into a deep REM sleep. Once REM is over, we usually return to Stage Two sleep. Sleep cycles through these stages approximately 4 or 5 times throughout the night.
Understanding your sleep cycle and optimising your sleep sanctuary are great moves towards improving the regeneration and repair of your body. Our specialist dr has put together a helpful Sleeping Guide with tips on how to get to sleep. Register to find out about our Sleep Peptides, available here at Peptide Clinics Australia.
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