Busy and Burnt-Out or Rested and Rejuvenated?

In recent years, society has equated busyness with a badge of honor. Now, we are waking up to the truth that this type of distinction was just an illusion.

When one strives for getting things done over sleep, the promise for prestige comes at a high cost that is not worth the trade-off.

Thanks to the dedication of many sleep scientists, we now know that sleep is as vital to health as nutrition, movement, self-care, relationships, and socio-economic factors.

As I noted in my previous article, swapping slumber for work negatively impacts job performance, brain health, cognitive function, emotional balance, relationships, and overall wellness.

In this article, we will continue with our sleep series that reviews all the nuances of sleep. Specifically, we will explore why sleep is essential, theories on why humans need sleep, and the many benefits of slumber.

In an upcoming article we’ll look further into the phases of sleep, sleep cycles, chronotypes, and 11 tips for enhancing slumber according to an expert sleep neuroscientist.


Why Sleep is Essential?

Sleep is an essential function needed to maintain health. It assists the body and mind to recharge and optimally function. Without enough sleep, neurons in the brain become overworked and thinking, memory, and concentration is impaired. Even an acute lack of sleep slows physical reactions, increases emotional reactivity, and disrupts the brain’s metabolic processes of neuronal pruning and clearing out waste.1-8 Chronically, sleep deprivation has been linked to an increased risk for many diseases that effect immune, metabolic, cardiovascular, brain, and mental health.1-15

Most adults need between seven to nine hours of sleep a night; whereas children and teenagers need substantially more to support growth and development.

So, we know that without the proper amount of sleep, we suffer.

Yet, why is it that we have to dial down every evening to achieve ideal health?1-15


Theories on Why We Sleep

There are several dominant theories which have explored the brain to identify the specific purposes of sleep. They include the inactivity theory, energy conservation theory, restoration theory, and the brain plasticity theory.9-15

These ideas are not exclusive. Many experts believe that it is likely a combination of them that serve to frame a broad view on why we need sleep. It is these hypotheses, as well as other discernments yet to be discovered, that can unlock the insights on why we require so much of our life to be spent in slumber, and why we struggle when we don’t unplug.

Below is an overview of these main theories.9-15

  1. The inactivity theory is related to the evolutionary and reproductive benefits of the protection gained from sleeping in the dark. With inactivity at night, mammals are prevented from being harmed from predators and the injuries that can occur from moving around without light.
  2. The energy conservation theory is based on the fact that we have a 10% drop in metabolism when we sleep. This decrease in energy demand occurs during times of the day that are least efficient to hunt for food, sparing it for when it is needed most.
  3. The restorative theory focuses on the restoration and repletion of cellular components that take place during shut-eye. This is supported by evidence of the physiological rejuvenation that occurs during slumber. Specifically, muscle repair, tissue growth, protein synthesis, and the release of important hormones for development all happen when we are asleep.
  4. The brain plasticity theory is based on the neural reorganization, brain growth, and functional changes that takes place during slumber. Studies that report on the impact of sleep on memory, cognition, and the removal of debris from the brain for optimal brain processing provide convincing evidence for this concept. This position also explains why infants require upwards of 14 hours per day of slumber.9-15

Recently, Mathew Walker, PhD, a neuroscientist who studies sleep has popularized the vital role that it plays on health. His book, “Why We Sleep,” explores all the roles sleep plays on our biology, physiology, and psychology and is genius in weaving together all the theories.


The Many Benefits of Sleep on the Body

Knowing the reasons why we sleep is important to understand some of its functions. Below is an overview of more of slumber’s benefits based on various body systems.18-32


1. Heart and circulatory system

During sleep, various hormones are released that support heart and blood vessel health. Sleep also plays a role in blood pressure regulation. Getting adequate sleep has been associated with lower risk of stroke, cardiovascular disease, and hypertension (high blood pressure).18-23


2. Hormones

Hormones are on a 24-hour cycle that is impacted by sleep and wake times. 20,24-27 Below is an overview of several of them and how they interact with our slumber.

Cortisol and Melatonin: The balance of cortisol and melatonin influence our sleep-wake cycle. They are mediated by light and darkness. Melatonin levels rise in the evenings to enhance drowsiness and cortisol fuels us to wake up in the mornings. These alterations impact various bodily processes as well as other hormones.

Growth Hormone: Growth hormone (GH) rises in the evening and signals the release of testosterone, estrogen, and progesterone.20,24

Estrogen: Estradiol, the most potent estrogen, interacts with our circadian rhythm. It enhances deeper sleep when one has gone through a time of deprivation. It also reduces sleepiness during the wake phase. 24-27

Testosterone: Levels of testosterone are highest in the middle of the sleep cycle, around the REM stage of sleep. (We will learn more about sleep stages in a follow up article.) Too little or fragmented sleep could impact this testosterone peak. There is also some suggestion that testosterone could modulate the brain’s response to light, enhancing circadian rhythm balance.24

Thyroid: Thyroid-stimulating hormone (TSH) suppresses sleep. Furthermore, after sleep deprivation, TSH levels dip lower than normal.24, 28 This would result in less thyroid hormone production with sleep loss.


3. Metabolism

Metabolism is also based on the sleep-wake cycle. Sleep affects the hormones that control hunger (leptin and ghrelin), insulin response (blood sugar), cravings, and digestion and assimilation. 18-20


4. Respiratory and Immune Systems

Your immune system depends on sleep to enhance immune response. During sleep, the body makes proteins that fight infection and inflammation (cytokines) as well as antibodies and immune cells. Studies show that lack of sleep can inhibit immunity and increase susceptibility to germs.


5. Brain Functioning and Processing (such as thinking, cognition, and memory)

As already noted, without proper sleep the brain cannot consolidate memories or perform its regenerative functions for cleanup and pruning.


6. The Stress Response and Emotional Reactivity

When one is underslept, the amygdala (the emotional center of the brain) goes on hyperalert. This results in heightened emotional reactivity and poor perception of emotional cues, leading to an increase in stress and relationship misunderstandings.


Summary on Why We Sleep

When we get the proper amount of sleep, our brain, hormones, and whole body is optimized. When we are sleep deprived, our mental health and physical prowess suffers. The reasons why we need to sleep for these benefits to occur are complex and still being discovered.

What we do know now is that with all that sleep does for wellness, it is silly to skimp on sleep for busyness. The trade-off is too detrimental to brain, physical, psychological, and relational health.

Are you getting enough sleep?

If not, you can always get support for better slumber with a professional. A naturopathic and functional medicine doctor can help you find and correct the underlying reasons why you can’t get some shut-eye.

Please share your thoughts and comments below.

In the conclusion of this sleep series, I’ll discuss the different phases of sleep, chronotypes (night owls vs. early birds), and provide 11 tips for better sleep.

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  1. https://www.sleepfoundation.org/how-sleep-works/benefits-of-sleep
  2. https://www.verywellhealth.com/top-health-benefits-of-a-good-nights-sleep-2223766
  3. https://www.nhlbi.nih.gov/health/sleep/why-sleep-important
  4. https://www.sleepfoundation.org/how-sleep-works/why-do-we-need-sleep
  5. http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/why-do-we-sleep
  6. https://www.nhlbi.nih.gov/health/sleep/why-sleep-important
  7. https://www.nhlbi.nih.gov/health/sleep-deprivation
  8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3768102/
  9. https://pubmed.ncbi.nlm.nih.gov/29494118/
  10. https://www.jneurosci.org/content/37/3/464
  11. https://www.healthline.com/health/why-do-we-sleep
  12. https://www.verywellmind.com/theories-of-sleep-2795929#citation-2
  13. https://link.springer.com/article/10.1007/s00426-011-0335-6
  14. https://www.science.org/doi/10.1126/science.1241224
  15. https://www.amazon.com/Why-We-Sleep-Unlocking-Dreams/dp/1501144316
  16. https://www.medicalnewstoday.com/articles/sleep-cycle-stages#influences
  17. https://www.verywellhealth.com/the-four-stages-of-sleep-2795920
  18. https://www.sleepfoundation.org/how-sleep-works/benefits-of-sleep
  19. https://www.verywellhealth.com/top-health-benefits-of-a-good-nights-sleep-2223766
  20. https://www.nhlbi.nih.gov/health/sleep/why-sleep-important
  21. https://pubmed.ncbi.nlm.nih.gov/15133379/
  22. https://www.heart.org/en/health-topics/sleep-disorders/sleep-and-heart-health
  23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7071844/
  24. https://www.news-medical.net/health/Sleep-and-Hormones.aspx
  25. https://www.yalemedicine.org/news/women-are-your-hormones-keeping-you-up-at-night
  26. https://www.webmd.com/sleep-disorders/features/women-hormones-sleep-problems
  27. https://bywinona.com/journal/estrogen-and-sleep-disturbances
  28. https://www.sleepfoundation.org/physical-health/thyroid-issues-and-sleep
  29. https://www.sleepfoundation.org/how-sleep-works/chronotypes
  30. https://medicalxpress.com/news/2023-03-genetic-predisposition-night-shift-workers.html
  31. https://www.masterclass.com/articles/matthew-walker-on-improving-sleep-quality
  32. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5768894/

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Disclaimer: This material is for information purposes only and is not intended to diagnose, treat, or prescribe for any illness. You should check with your doctor regarding implementing any new strategies into your wellness regime. These statements have not been evaluated by the FDA. (Affiliation link.)

This information is applicable ONLY for therapeutic quality essential oils. This information DOES NOT apply to essential oils that have not been tested for purity and standardized constituents. There is no quality control in the United States, and oils labeled as “100% pure” need only to contain 5% of the actual oil. The rest of the bottle can be filled with fillers and sometimes toxic ingredients that can irritate the skin. The studies are not based solely on a specific brand of an essential oil, unless stated. Please read the full study for more information.

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