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Sleep Wake Cycle: What Is It & Why It's Important

Our sleep-wake cycle is the ratio between how much time we spend awake and how much time we spend asleep in every 24 hour period. The pattern that develops from our average sleep-wake cycle is just one of the body’s circadian rhythms. Following the recommended sleep guidance of eight hours each night, a good sleep-wake cycle is approximately eight hours of sleep to 16 hours awake.

Our circadian rhythms, including our sleep-wake cycle, exist to help us regulate our bodily functions to ensure they rise and fall as we move through a 24-hour day. Some of our bodily functions that help to regulate are the production of hormones, our core body temperature, appetite, and our energy levels.


Our circadian rhythms are attuned to our homeostatic sleep pressure. We know our homeostatic sleep pressure simply as the need to sleep. Our homeostatic sleep pressure is low upon waking after a restful night’s sleep. The pressure builds as we go about our day. Things like strenuous physical labor, concentrated mental activity like studying, staying awake for long periods of time, and even a compromised immune system can all contribute to the increase of our homeostatic sleep pressure.

When our homeostatic sleep pressure and our body’s circadian rhythm are in sync, we have achieved a healthy and balanced sleep-wake cycle. So, other than unlocking an achievement in life, why is it important to have a healthy sleep-wake cycle?


The Importance of a Healthy Sleep Wake Cycle


Do you ever feel like every cell in your body is telling you it’s time to go to sleep? The truth is they just might be. Every cell in our bodies has its own biological clock. Each biological clock is synchronized by the suprachiasmatic nucleus, or the SCN, that is located in the brain. 


Changes in proteins that our genes produce can increase overnight and fade as the day goes on, and as these changes occur they activate the feelings of alert wakefulness and, in turn, sleepiness. Because our bodies are all different, you may experience different levels of wakefulness and sleepiness in comparison to others. 


One of the biggest contributing factors to the body’s establishment of an internal clock or consistent rhythm is sunlight. The transmission of sunlight through the optic nerve starts a process that first tells the SCN to release information through chemical messages that tell the body to release hormones like cortisol and neurotransmitters like norepinephrine and serotonin. 


In addition to helping keep you alert, the brain chemicals like norepinephrine and serotonin help soothe the mind and relieve stress. These can contribute to your emotional wellness, and that’s why it is sometimes recommended that you increase your sunlight exposure.


Because of the optic nerve’s role in this process, visually impaired individuals with no perception of light experience a desynchronization in their circadian rhythms. This can make it necessary to take extra steps to establish a healthy sleep-wake cycle for those individuals.


If you’ve ever experienced an afternoon slump in your energy levels, you can thank your internal clock. As the day goes along, the chemical adenosine collects in the bloodstream and causes you to feel tired, and between two in the afternoon and 5 p.m., we experience a strong dip in our wakefulness that makes us long for a nap. 


As the sunshine fades, our brains take this as a signal to begin releasing the hormone melatonin to prepare us for sleeping. As we age, we produce less melatonin, and it may help aging individuals to add a supplement to help them fall asleep at night. 


Sleep is an essential process for the brain’s health. Once our brain enters into sleep, the brain’s cleaning process can begin. The glymphatic system cleans out waste, like proteins, that’s present in the brain. This is part of why prolonged episodes of sleeplessness can have negative impacts on the brain. 


If you’ve ever pulled an all-nighter and had brain fog the next day, you can relate, but extremely long periods of going without sleep can lead to sleep deprivation psychosis. Although these represent different extremes of the effects of sleep deprivation on the brain, they speak to the brain’s need for sleep. 


Further proof of the healing powers of sleep on the brain is found in the way sleep helps heal damage in patients that have suffered a stroke or traumatic brain injury. This could be due to the increased activity of the glymphatic system during periods of sleep.

What Factors Can Impact The Sleep Wake Cycle?

 

Developing a synchronized and stable circadian rhythm can help promote a healthy and balanced sleep-wake cycle, but different factors can have an impact on your body’s circadian rhythms. Some of these factors are:


    • Age - This is why we need different amounts of sleep at different ages. Adults should aim for seven to nine hours, but children need between ten to sixteen hours depending on their age.

    • Blue light exposure - Fluorescent lights, LED lights, and electronic screens cast out blue light waves, and if exposure to these light waves isn’t regulated, the process of releasing melatonin can be inadvertently halted. It may be helpful to supplement melatonin if you stayed at the computer for a bit too long.

    • Shift work - Working at night instead of sleeping goes against the body’s natural daylight cycle, and shift work can require conditioning. This irregularity can disrupt the body’s circadian rhythms. 

    • Caffeine - Most of us are huge fans of the most common stimulant in the world, caffeine. Most consumers of caffeine don’t realize that it blocks adenosine receptors in the brain. We just enjoy the feelings of alertness and skipping the afternoon slump.

    • Daylight Saving Time - Not only do we have to remember to change our clocks around the house and adjust to new hours of daylight, daylight saving time causes a disruption in our sleep-wake cycles that can throw us off during an adjustment period. The alarm clock comes just a bit too early, and some people even struggle with changes in mood and health concerns. 

    • Jet Lag - Crossing more than one or two time zones can interrupt an established sleep-wake cycle until the body adjusts to the new time zone and location. 

What Can You Do To Establish A Healthy Sleep Wake Cycle?

One of the best ways to establish a healthy sleep-wake cycle is to practice good sleeping habits. For example, establishing a peaceful sleep environment at a comfortably cool temperature with enough darkness to help alert your body that it’s time to rest can do a lot to help your sleep habits.


If you find that you struggle to fall asleep at the end of the day, consider a natural supplement that contains melatonin to communicate to your body that it’s time for rest. Complete Calm Sleep Gummies contain natural extracts that help promote healthy sleep. Within a half hour to an hour, one gummy can help to calm your mind, promote the release of tensions, and help you feel ready to sleep. 


Natural supplements that are well formulated like Complete Calm Sleep Gummies can help improve your sleep health, and you can avoid the groggy feelings the next morning.

Conclusion


A healthy sleep-wake cycle for most adults will allow for about one hour of sleep for every two hours of being awake in a 24 hour day. Establishing a good sleep-wake cycle is important for the body’s functions, and it is especially important for the brain’s health. Practicing good sleep hygiene can help establish healthy circadian rhythms, even if you need a little help getting to sleep. 


Sources:

Visual impairment and circadian rhythm disorders | NCBI 

Sleep Deprivations Stages: The 5 Stages and What They Mean | healthline.com 

Module 2. Sleep Pressure: Homeostatic Sleep Drive | NIOSH

Meet our Experts

This article has been reviewed by members of our Scientific Advisory Board.

  • Dr. Jay Cowin, Nutrition Expert

    Founder of Functional U, a Nutrition, Performance & Optimal Health practice.