The Importance of Sleep: Why 8 Hours Of Sleep Is So Important

the importance of sleep

In today’s busy world, it seems that the importance of sleep often gets sidetracked for productivity. Sleep is one of the most natural and vital requirements for our body. You would be surprised to find out then, that one third of the population reports at least 1 symptom of insomnia1 and 50 to 70 million Americans suffer from sleep disorders2. I’m sure you or someone you know has suffered from a lack of sleep. You know the feelings: drowsiness, brain fog, fatigue, irritability, low motivation, on and on. The physical and mental effects of sleep deprivation are quite profound. Driving tired has even been compared with driving under the influence3,4. A lack of sleep has been associated with various conditions like obesity, diabetes, psychological disorders, heart disease and even cancer5,6,7,8. The importance of sleep can’t be denied, yet so many people trying to achieve health don’t place enough priority on it. If you’re dieting and exercising but not sleeping properly, you are setting yourself up for failure. No matter how good your diet or exercise regimen, you NEED to address sleep to achieve complete health.

So why is sleep so important? Let’s look at the various roles that sleep plays.


1. Recovery

The primary reason that we and other animals sleep is to recover. We still don’t know why exactly we need to sleep, but we know that without it, our bodies suffer. During sleep the autonomic nervous system shifts more into parasympathetic tone, our breathing slows, muscles relax, heart rate slows, and blood flow to the brain increases2,9. Levels of growth hormone also peak while we sleep, helping our bodies repair themselves9.10


2. Regulation of Our Circadian Rhythm

Our circadian rhythm is our internal clock that is closely linked to our physiology. This rhythm controls many of our hormonal patterns, such as growth hormone mentioned above, as well as our sex hormones, cortisol, thyroid and more11. If our hormones become out of balance, we can quickly end up with metabolic problems or disease.


the importance of sleep


3. Memory Consolidation

When we sleep, our short-term memories from the day are stored and consolidated into long term memories12. This occurs for not only cognitive processes but motor and perceptual skills as well. Those who suffer from sleep deprivation often have symptoms of poor cognitive performance and “brain fog”.


4. Immune Support

As we sleep, our immune system goes to work fighting any pathogens that may be lurking in our body. The state of rest allows our body to focus its energy on this task since we are not exposed to the amount of stressors or toxins we usually are during wakefulness. Conversely, a lack of sleep can create an overactive immune system leading to inflammation13

When we look at the many important roles of sleep, it’s clear to see why it’s so important and why a lack of sleep can have such profound effects on our body. If you want to be healthy you have to make sleep a priority. It can be difficult in such a fast-paced life where we feel like we always need to be doing something, but giving your body the sleep it needs is one of the easiest and best things you can do for your health.


  1. Roth T. Insomnia: Definition, Prevalence, Etiology, and Consequences. Journal of Clinical Sleep Medicine: JCSM: Official Publication of the American Academy of Sleep Medicine. 2007;3(5 Suppl): S7-S10.
  2. Institute of Medicine.Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Washington, DC: The National Academies Press; 2006.
  3. Blazejewski S, Girodet P, Orriols L, Capelli A, Moore N, f CG. Factors associated with serious traffic crashes: A prospective study in southwest France. Archives of Internal Medicine. 2012;172(13):1039-41.
  4. National Sleep Foundation. Drowsy Driving Facts and Stats. Retrieved 15 Nov 2016 from
  5. Kecklund G, Axelsson J. Health consequences of shift work and insufficient sleep. BMJ (Clinical research ed). 2016;355:i5210.
  6. Tobaldini E, Costantino G, Solbiati M, Cogliati C, Kara T, Nobili L, et al. Sleep, sleep deprivation, autonomic nervous system and cardiovascular diseases. Neuroscience and biobehavioral reviews. 2016.
  7. Tobaldini E, Pecis M, Montano N. Effects of acute and chronic sleep deprivation on cardiovascular regulation. Archives italiennes de biologie. 2014;152(2-3):103-10.
  8. Grandner MA, Seixas A, Shetty S, Shenoy S. Sleep Duration and Diabetes Risk: Population Trends and Potential Mechanisms. Current diabetes reports. 2016;16(11):106.
  9. Schupp M, Hanning CD. Physiology of sleep. BJA CEPD Reviews. 2003;3(3):69-74
  10. Gunawardane K, Krarup Hansen T, Sandahl Christiansen J, Lunde Jorgensen JO. Normal Physiology of Growth Hormone in Adults. In: De Groot LJ, Chrousos G, Dungan K, Feingold KR, Grossman A, Hershman JM, et al., editors. South Dartmouth (MA):2000.
  11. Morris CJ, Aeschbach D, Scheer FAJL. Circadian System, Sleep and Endocrinology. Molecular and cellular endocrinology. 2012;349(1):91-104.
  12. Diekelmann S, Wilhelm I, Born J. The whats and whens of sleep-dependent memory consolidation. Sleep medicine reviews. 2009;13(5):309-21.
  13. Zielinski MR, Krueger JM. Sleep and innate immunity. Frontiers in bioscience (Scholar edition). 2011;3:632-42.{Roth, 2007 #144}{Roth, 2007 #144}

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