The sleep cycle affects and involves several body systems, organs, and hormones that all work together to regulate the entire cycle. The nervous system , which includes the brain, helps to regulate the sleep-wake cycle through the circadian rhythm . The hypothalamus controls sleep and wake signals, and the pineal gland produces melatonin . The autonomic nervous system regulates the transition between wakefulness and sleep and promotes relaxation. There are many hormones involved in the process. Melatonin helps to regulate the sleep-wake cycle; cortisol, when dysregulated, can affect sleep quality; growth hormone is secreted during deep sleep and plays a role in tissue repair, muscle growth, and cell regeneration; and adenosine is a neurotransmitter that helps keep you awake and alert, promote sleep drive, interact with caffeine, and integrate light signals. The endocrine system is also involved. The thyroid gland influences energy levels, which can affect sleep quality and duration. The pancreas regulates blood sugar and insulin , which support healthy sleep or can disrupt rest when not balanced. Sleep affects the cardiovascular system, lowering blood pressure and heart rate . Deep sleep also affects heart rate variability ; a higher HRV during sleep is associated with better recovery and overall health. During sleep, particularly REM, breathing patterns change, helping the body enter a more relaxed state. Rest and digest! Sleep plays a key role in digestion , and disruptions to your sleep cycle can negatively affect your digestive system. Likewise, when your body is focused on digestion, it may struggle to relax and enter a restful sleep fully. Both processes rely on balance for optimal health. Sleep is crucial for maintaining immune function . During sleep, the body produces cytokines, proteins that help to regulate immune responses. During sleep, especially deep sleep, the body focuses on muscle repair and growth in the musculoskeletal system . Skin, or the integumentary system , is also repaired and regenerated during sleep. The body repairs damage produces collagen, and fights free radicals. The eye’s retina helps regulate the body’s circadian rhythm by responding to light exposure. Light exposure in the morning helps to reset the body’s internal clock, and darkness in the evening helps to trigger melatonin release. In summary, sleep affects virtually every organ system in the body, and its quality and quantity are essential for optimal functioning across multiple systems. Disruptions to the sleep cycle can have wide-reaching effects on physical, mental, and emotional health.

1 lemon balm tea bag 4 oz boiling water 4 oz tart cherry juice 2 tsp honey 8 oz favorite milk

Large mug or cup Saucepan Frother (optional)

The Sleep Cycle

Jan 3, 2025

By Shae Brackett, LMT Customer Service & Social Media

01

Meet The Sleep Cycle

We spend about 1/3rd of our lives sleeping, it is an important and normal body process that allows the body and brain to rest and recharge. When we sleep, our body, body systems, and processes all slow down, entering a state of rest. Did you know that certain essential processes occur during sleep? While we rest, our cells work to replenish and restore energy for the day ahead. The body focuses on healing injuries and repairing tissues. Meanwhile, the brain reorganizes, processes memories, and consolidates information that we have learned. This time is not a passive state; it’s an active time for our bodies and minds to recover and prepare.

Stages of Sleep

While sleeping, the brain does not become totally inactive. Brain activity goes through predictable patterns or stages of sleep. These stages fall into two broad categories. Rapid eye movement or REM sleep and non-REM or NREM sleep. NREM sleep consists of deep restorative stages called slow-wave sleep or SWS. This is where physical repair and growth occur. REM sleep is where the brain processes and stores information, consolidates memory, regulates emotions, and regulates brain function.

In each of these stages are cycles. There are three stages to NREM sleep. When we fall asleep, we enter NREM stage 1 and cycle between NREM stage 2 and 3. Stage 1 of NREM is the lightest stage of sleep and lasts only a few minutes. Stage 2 accounts for about 45% of sleep time and is slightly deeper than stage 1 but still considered light. This is where brain waves slow, and there are noticeable pauses in the brain’s electrical activity. We go through multiple rounds of NREM stage 2, each longer than the last. Stage 3 is the deepest stage of NREM and accounts for about 25% of sleep for adults. The brain is slow and strong in this stage, and the body uses it to repair injuries and reinforce the immune system. In stages 2 and 3, the brain has bursts of activity, and the brain waves in stage 3 regulate them. Stage 3 helps us to wake up feeling rested.

After stage 3, the next is stage 2 NREM, the doorway to REM. REM sleep accounts for 25% of sleep and is where dreams happen, and eyes tend to move behind the eyelids. Brain activity in this stage is similar to when we are awake! The first REM cycle is usually the shortest at about ten minutes. After the first REM cycle, you go into a new cycle and go back into stage 1 or 2, and then the cycle starts over. A cycle typically lasts between 90 and 120 minutes before another begins. Usually, people go through four to five cycles per night.

The sleep cycle is complex and important. When we don’t get enough sleep in all the cycles, we go into a sleep debt, which is when the amount of quality sleep we get is not enough for what we need. When we don’t get enough sleep over long periods, we can’t catch up on the sleep we missed out on, which can lead to issues.

02

Anatomy & Function

How Much Sleep

So, what is enough sleep? How much sleep do we actually need? This varies from person to person and changes throughout our lifetime. Some people need less, and some people need more. Genetic, health, and environmental factors can all impact how much sleep we need. Due to hormones, females typically need more sleep than males, and that need can change throughout the menstrual cycle and pregnancy.

Sleep doesn’t have to happen all at once! Sleep customs vary by culture and even time period. In some cultures, sleep is split into two periods during the night, and many cultures take napping seriously.

The following is what is recommended and includes naptimes:

Age/Amount Needed

Birth to 3 months / 14-17 hours

4 months to 12 months / 12-16 hours

1 year to 5 years / 10-14 hours

6 years to 12 years / 9-12 hours

13 years to 18 years / 8-10 hours

19 years to 64 years / 7-9 hours

65 years and older / 7-8 hours

The Circadian Rhythm

The circadian rhythm is our body's internal natural clock. This helps to regulate our natural and healthy sleep-wake cycle. This automatic process affects many processes in the body, ensuring they operate efficiently within 24 hours. This pattern or rhythm communicates to the body when it should sleep and when it should wake while also affecting hormones, digestion, and body temperature. This rhythm is set naturally and is controlled by the brain, specifically by a tiny cluster of cells called the suprachiasmatic nucleus or SCN located in the hypothalamus. The SCN is highly sensitive to light: when light enters the eyes, it signals the brain to stop producing melatonin, the hormone responsible for promoting sleep. While light plays a key role in regulating this rhythm, other factors such as food, stress, physical activity, temperature changes, changes to routine, travel, medication, mental health conditions, and poor sleep habits can all disrupt it. Disruptions in the circadian rhythm can negatively impact sleep quality and hinder the body's processes.

01

Meet The Sleep Cycle

We spend about 1/3rd of our lives sleeping, it is an important and normal body process that allows the body and brain to rest and recharge. When we sleep, our body, body systems, and processes all slow down, entering a state of rest. Did you know that certain essential processes occur during sleep? While we rest, our cells work to replenish and restore energy for the day ahead. The body focuses on healing injuries and repairing tissues. Meanwhile, the brain reorganizes, processes memories, and consolidates information that we have learned. This time is not a passive state; it’s an active time for our bodies and minds to recover and prepare.

Stages of Sleep

While sleeping, the brain does not become totally inactive. Brain activity goes through predictable patterns or stages of sleep. These stages fall into two broad categories. Rapid eye movement or REM sleep and non-REM or NREM sleep. NREM sleep consists of deep restorative stages called slow-wave sleep or SWS. This is where physical repair and growth occur. REM sleep is where the brain processes and stores information, consolidates memory, regulates emotions, and regulates brain function.

In each of these stages are cycles. There are three stages to NREM sleep. When we fall asleep, we enter NREM stage 1 and cycle between NREM stage 2 and 3. Stage 1 of NREM is the lightest stage of sleep and lasts only a few minutes. Stage 2 accounts for about 45% of sleep time and is slightly deeper than stage 1 but still considered light. This is where brain waves slow, and there are noticeable pauses in the brain’s electrical activity. We go through multiple rounds of NREM stage 2, each longer than the last. Stage 3 is the deepest stage of NREM and accounts for about 25% of sleep for adults. The brain is slow and strong in this stage, and the body uses it to repair injuries and reinforce the immune system. In stages 2 and 3, the brain has bursts of activity, and the brain waves in stage 3 regulate them. Stage 3 helps us to wake up feeling rested.

After stage 3, the next is stage 2 NREM, the doorway to REM. REM sleep accounts for 25% of sleep and is where dreams happen, and eyes tend to move behind the eyelids. Brain activity in this stage is similar to when we are awake! The first REM cycle is usually the shortest at about ten minutes. After the first REM cycle, you go into a new cycle and go back into stage 1 or 2, and then the cycle starts over. A cycle typically lasts between 90 and 120 minutes before another begins. Usually, people go through four to five cycles per night.

The sleep cycle is complex and important. When we don’t get enough sleep in all the cycles, we go into a sleep debt, which is when the amount of quality sleep we get is not enough for what we need. When we don’t get enough sleep over long periods, we can’t catch up on the sleep we missed out on, which can lead to issues.

02

Anatomy & Function

How Much Sleep

So, what is enough sleep? How much sleep do we actually need? This varies from person to person and changes throughout our lifetime. Some people need less, and some people need more. Genetic, health, and environmental factors can all impact how much sleep we need. Due to hormones, females typically need more sleep than males, and that need can change throughout the menstrual cycle and pregnancy.

Sleep doesn’t have to happen all at once! Sleep customs vary by culture and even time period. In some cultures, sleep is split into two periods during the night, and many cultures take napping seriously.

The following is what is recommended and includes naptimes:

Age/Amount Needed

Birth to 3 months / 14-17 hours

4 months to 12 months / 12-16 hours

1 year to 5 years / 10-14 hours

6 years to 12 years / 9-12 hours

13 years to 18 years / 8-10 hours

19 years to 64 years / 7-9 hours

65 years and older / 7-8 hours

The Circadian Rhythm

The circadian rhythm is our body's internal natural clock. This helps to regulate our natural and healthy sleep-wake cycle. This automatic process affects many processes in the body, ensuring they operate efficiently within 24 hours. This pattern or rhythm communicates to the body when it should sleep and when it should wake while also affecting hormones, digestion, and body temperature. This rhythm is set naturally and is controlled by the brain, specifically by a tiny cluster of cells called the suprachiasmatic nucleus or SCN located in the hypothalamus. The SCN is highly sensitive to light: when light enters the eyes, it signals the brain to stop producing melatonin, the hormone responsible for promoting sleep. While light plays a key role in regulating this rhythm, other factors such as food, stress, physical activity, temperature changes, changes to routine, travel, medication, mental health conditions, and poor sleep habits can all disrupt it. Disruptions in the circadian rhythm can negatively impact sleep quality and hinder the body's processes.

Supporting Systems and Interactions

The human body is a marvel of interconnected systems, each playing a vital role in maintaining balance, health, and vitality. While we often think of the body's organs and processes in isolation, the truth is that no part functions alone. Every system relies on and influences others in a delicate dance of cooperation.

When one system is compromised, others often compensate or respond, illustrating how deeply intertwined all functions are. The body, then, is not just a collection of parts, but an integrated whole, where every aspect plays a crucial role in maintaining the flow of life, energy, and healing. Understanding this interconnectedness allows us to approach health holistically, nurturing not just individual parts, but the whole person.

Supporting Systems

Quality sleep is essential for physical recovery and repair, mental clarity, emotional balance, and immune function. A well-regulated sleep cycle supports optimal brain function, enhances mood stability, and improves the body's ability to handle stress. Additionally, it positively impacts metabolism, cardiovascular health, and hormonal balance. Good sleep is intricately connected to nearly every aspect of a healthy life. By prioritizing sleep, we give our bodies and minds the resources to thrive, ensuring long-term health and vitality.

Hormones

The sleep cycle affects and involves several body systems, organs, and hormones that all work together to regulate the entire cycle.

The nervous system, which includes the brain, helps to regulate the sleep-wake cycle through the circadian rhythm. The hypothalamus controls sleep and wake signals, and the pineal gland produces melatonin. The autonomic nervous system regulates the transition between wakefulness and sleep and promotes relaxation.
There are many hormones involved in the process. Melatonin helps to regulate the sleep-wake cycle; cortisol, when dysregulated, can affect sleep quality; growth hormone is secreted during deep sleep and plays a role in tissue repair, muscle growth, and cell regeneration; and adenosine is a neurotransmitter that helps keep you awake and alert, promote sleep drive, interact with caffeine, and integrate light signals.
The endocrine system is also involved. The thyroid gland influences energy levels, which can affect sleep quality and duration. The pancreas regulates blood sugar and insulin, which support healthy sleep or can disrupt rest when not balanced.
Sleep affects the cardiovascular system, lowering blood pressure and heart rate. Deep sleep also affects heart rate variability; a higher HRV during sleep is associated with better recovery and overall health.
During sleep, particularly REM, breathing patterns change, helping the body enter a more relaxed state.
Rest and digest! Sleep plays a key role in digestion, and disruptions to your sleep cycle can negatively affect your digestive system. Likewise, when your body is focused on digestion, it may struggle to relax and enter a restful sleep fully. Both processes rely on balance for optimal health.
Sleep is crucial for maintaining immune function. During sleep, the body produces cytokines, proteins that help to regulate immune responses.
During sleep, especially deep sleep, the body focuses on muscle repair and growth in the musculoskeletal system. Skin, or the integumentary system, is also repaired and regenerated during sleep. The body repairs damage produces collagen, and fights free radicals.
The eye’s retina helps regulate the body’s circadian rhythm by responding to light exposure. Light exposure in the morning helps to reset the body’s internal clock, and darkness in the evening helps to trigger melatonin release.

In summary, sleep affects virtually every organ system in the body, and its quality and quantity are essential for optimal functioning across multiple systems. Disruptions to the sleep cycle can have wide-reaching effects on physical, mental, and emotional health.

Sleep Comes Easily & Quickly To Me

Fun & Interesting Facts

Sleep is crucial for overall health and essential for learning memory, body repair, hormones, and brain function. It is as important as food, water, and air for survival
People can survive longer without food than they can without sleep
According to the CDC, staying awake for 24 hours has similar cognitive effects to a blood alcohol concentration of 0.10%, higher than the legal driving limit
Sleep deprivation is common, with about 40% of US adults and 70% of adolescents experiencing it
Humans are the only mammals that willingly delay sleep
Bright screens and artificial light can affect sleep cycles
Not everyone dreams in color, today 75% of people dream in color, but before color television, only 15% of people did
Sleepwalking affects about 6.9% of the population
Kids need more sleep than adults, and females need more sleep than males
Oneirophobia is the fear of nightmares or dreams, somniphobia is the fear of falling asleep, clinomania is the urge to stay cozy in bed all day, and dysania is when you wake up and don’t want to get out of bed.

What is necessary for the optimal health of this system?

Achieving and maintaining a balanced, healthy life requires a holistic approach that recognizes the complex interplay between nutrition, lifestyle, the use of herbs and supplements. Each of these elements plays a unique yet interconnected role in supporting the body's intricate systems.

Together, nutrition, lifestyle, and herbal support create a synergistic approach to health. They nurture the body as a whole, and support the body’s natural ability to heal, adapt, and flourish. Understanding the role each of these elements plays allows us to make more informed choices that contribute to lasting well-being.

Nutrition

Fruits & Vegetables

Avocado
Bananas
Broccoli
Goji Berries
Grapes
Kale
Kiwi
Leafy Greens
Tart Cherries

Specific Foods

Almonds
Chamomile Tea
Chia Seeds
Chicken
Chickpeas
Dark Chocolate
Eggs
Fatty Fish (salmon, mackerel, tuna)
Fiber
Flaxseeds
Herbal Teas
Honey
Milk
Nuts & Seeds
Oatmeal
Pumpkin Seeds
Rice
Sesame Seeds
Sunflower Seeds
Turkey
Walnuts

MicroNutrients

Vitamins: B6, D
Calcium
Iron
Manganese
Magnesium
Omega-3 Fatty Acids
Tryptophan

Lifestyle

Before Bed:

Avoid caffeine
Limit artificial light
Meditate
Read
Journal
Practice Deep Breathing Exercises
Stick to a Routine
Limit eating
Practice gratitude
Avoid work
Avoid Social media
Wind down

Tips:

Eat magnesium-rich foods
Make your bedroom a sanctuary
Make your room cool and dark
Use dim, warm, low lights after the sun goes down
Prioritize sleep and sleep routine
Get bright, natural light, first thing in the mourning
Manage stress
Use calming essential oils
Wake up gradually
Hydrate and move upon in the morning

Herbal Friends

Ashwagandha
Black Cohosh
Blue Vervain
California Poppy
Catnip
Chamomile
Eleuthero (Siberian Ginseng)
Ginseng
Hibiscus
Holy Basil (Tulsi)
Hops
Jujube Fruit
Kava Kava
Lavender
Lemon Balm
L-Theanine (from Green Tea)
Magnolia Bark
Milky Oats
Motherwort
Mugwort
Passionflower
Rhodiola
Schisandra Berry
Skullcap
St. John’s Wort
Sweet Marjoram
Valerian
Wood Betony

Supporting Supplements

Melatonin
Tryptophan
Tart Cherry
5-HTP
Trace Minerals
L-Theanine

Supporting Recipe

Cherry Lemon Balm Moon Milk

End your day on a calm and cozy note with this comforting bedtime beverage. Each ingredient in this recipe is thoughtfully chosen to help you relax and prepare for a good night’s sleep.

Lemon balm tea, known for its calming properties, helps ease stress and quiet the mind. Tart cherry juice provides a natural source of melatonin, supporting your body’s sleep-wake cycle. A touch of honey adds gentle sweetness, while warm milk creates a creamy, soothing base that feels like a hug in a mug.

This simple, delicious drink is the perfect way to wind down and transition into a restful night.

Ingredients

1 lemon balm tea bag
4 oz boiling water
4 oz tart cherry juice
2 tsp honey
8 oz favorite milk

Supplies

Large mug or cup
Saucepan
Frother (optional)

Directions

Place the tea bag in a large (16oz+) cup or mug. Pour boiling water over the tea bag and let steep for 10 minutes. Remove Bag.

Heat cherry juice, honey, and milk to a soft simmer. Remove and pour over prepared tea; top with additional frothed milk if desired.

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About The Author

Shae Brackett our Customer Service Director and Social Media Manager, has been with RidgeCrest since 2016. Shae is a licensed massage therapist, and guides the customer care team, is our culture caretaker, and serves as our creative oracle across social media, blogs, and meditations. She describes herself as creative, thoughtful, nature-loving, compassionate, and nurturing. Her favorite herbs are Ginger and Lavender, and she proudly recommends SereniZen® (formerly Anxiety Free), PhysiQOL™, SinusClear®, and Belly Be Happy®.

Click to meet the team.

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Land Acknowledgement

We acknowledge that we operate on the ancestral lands of the Shoshone, Goshute, and Ute peoples. We recognize their deep connection to this land and honor their history, culture, and ongoing presence. We are committed to learning from and respecting the Indigenous communities who have stewarded this land for generations.