{"id":3882,"date":"2019-12-23T13:10:18","date_gmt":"2019-12-23T12:10:18","guid":{"rendered":"https:\/\/disturbmenot.co\/?p=3882"},"modified":"2020-06-05T00:53:37","modified_gmt":"2020-06-04T22:53:37","slug":"what-is-the-circadian-rhythm","status":"publish","type":"post","link":"https:\/\/disturbmenot.co\/what-is-the-circadian-rhythm\/","title":{"rendered":"What Is the Circadian Rhythm and How Does It Affect Sleep?"},"content":{"rendered":"
Have you ever noticed that you feel amazing in the evenings, but lack energy in the mornings? Have you ever wondered about the scientific explanation for the difference between night owls and early birds? Well then, perhaps you should first be asking, <\/span>what is<\/span> the <\/span>circadian rhythm?\u00a0<\/span><\/p>\n Understanding this part of our biology, both in practicality and in the scientific sense, can help us get more control over our lives\u2014and our health. We can quickly define the circadian rhythm as a biological cycle that lasts for 24 hours every day. Within the 24-hour cycle, this rhythm influences our hormones, eating habits, and body temperatures, not to mention our sleep-wake cycles.<\/span><\/p>\n Know that the <\/span>circadian rhythm<\/span> is present <\/span>in plants<\/span>, animals, and fungi\u2014not just humans. It\u2019s absolutely central to our daily lives, our habits, and our health. In fact, the 2017 Nobel Prize in Physiology or Medicine was awarded to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young for their research and discoveries pertaining to these biological cycles.<\/span><\/p>\n Below, you can find more information on the circadian rhythm, its scientific basis, and how it influences our lives and habits.<\/span><\/p>\n Before continuing, you need to understand the difference between the circadian rhythm and our biological clock. Namely, the circadian rhythm, or rather rhythms, can also be defined another way: they are the physical, mental, and behavioral changes a person experiences within a 24-hour cycle.\u00a0<\/span><\/p>\n Meanwhile, our <\/span>biological clock<\/span> is something similar, but still a little different because it\u2019s a more inclusive term. Namely, a good definition of this process follows the fact that this is our innate timing device. Our biological clock actually leads to the occurrence of the circadian rhythm (as well as other biological rhythms) within the body.<\/span><\/p>\n A simple answer is that the <\/span>hypothalamus<\/span>, by <\/span>definition<\/span>, is in charge of the circadian rhythm. But to give a little more detail, the circadian rhythm is controlled by a cluster of nerves found within the hypothalamus, known as the suprachiasmatic nucleus (the SCN). This cluster of nerves basically makes up the biological clock we mentioned earlier. Now that you know <\/span>what regulates circadian rhythms<\/span>, how does all this actually work?<\/span><\/p>\n The purpose of the SCN is to respond to varied environmental cues (for example, they\u2019re the reason we feel tired once night falls). Some of these cues (also known as zeitgebers) are light levels, our eating habits, and our physical activity levels at certain points in time.<\/span><\/p>\n Once we experience some of these cues, they trigger the appropriate reactions within our bodies\u2014things like our metabolism, <\/span>sleep<\/span><\/a>, mood, and body temperature, as well as our <\/span>melatonin <\/span>secretion. And it\u2019s this melatonin secretion that leads to the common connection between <\/span>circadian rhythms <\/span>and sleep.<\/span><\/p>\n Namely, melatonin is known as the \u201csleep hormone.\u201d Produced by the pineal gland, it\u2019s activated by one of the aforementioned environmental cues, most often when our retina detects lower light levels (i.e., darkness falling outside). Melatonin then prepares our bodies for sleep.<\/span><\/p>\n Comprehensive <\/span>research<\/span><\/a> has shown that melatonin is vital for sleep, and many people take it in supplement form in order to improve their sleep quality. It also regulates blood pressure, our cortisol levels and immune functions, and also our body\u2019s antioxidant defenses.<\/span><\/p>\n A healthy circadian rhythm will lead to the production of melatonin several hours before one goes to bed and will peak somewhere around five hours after falling asleep.\u00a0\u00a0<\/span><\/p>\n <\/span><\/p>\n This is a common question that hinges more on semantics than it does on actual biology. Namely, on one level, you can understand that some examples include things like our sleep-wake cycles, hormone secretion cycles, and body-temperature cycles. However, these can also be seen as actions and processes within the body that are in fact merely governed by the circadian rhythm.\u00a0<\/span><\/p>\n Your circadian rhythm isn\u2019t just about you getting a good night\u2019s sleep. Rather, it has a substantial impact on your health and overall wellbeing. For example, a <\/span>study<\/span><\/a> that included over 8000 employees showed interesting results. Of these participants, some worked standard \u201cnine-to-five\u201d jobs, while others had shift-based employment. The shift employees tended to get sick more, often suffering from a range of infectious diseases.<\/span><\/p>\n The <\/span>human circadian rhythm<\/span> influences our hormones and metabolism. It can also help us regulate blood sugar levels. Namely, our insulin levels are higher during the day than they are at night\u2014and turning this on its head can mess up our blood sugar regulation. When these processes are functioning properly, you\u2019ll have more energy during the day, as well. After all, your <\/span>body clock <\/span>dictates when the mitochondria, the powerhouse of the cell, will release energy. Throwing this off-balance leads to disrupted sleep and low energy levels during the day.<\/span><\/p>\n In fact, disrupting our natural circadian rhythm by not sticking to a regular sleep schedule leads to <\/span>cardiovascular health<\/span><\/a> problems, an increase in weight gain, insomnia, mood changes, and so on. Nearly any issue that comes with disrupted hormones and a messed-up metabolism will be linked to a disrupted circadian rhythm.<\/span><\/p>\n No circadian rhythm is strictly set in stone. While there are of course certain fixed points\u2014like the fact that the circadian rhythm is greatly influenced by light\u2014people\u2019s rhythms generally vary.\u00a0<\/span><\/p>\n A <\/span>study<\/span><\/a> published in <\/span>Sports Medicine<\/span><\/i> shows that there are distinct differences in cognition for people based on the time of day. People defined as night owls have a tough time waking up in the mornings and have more energy later in the day. However, it seems that the <\/span>internal clock<\/span> works differently for early birds, who are full of pep earlier in the day.\u00a0<\/span><\/p>\n The reasoning behind these distinctions can be found in the actual name \u201ccircadian.\u201d Namely, it comes from <\/span>circa<\/span><\/i>, meaning \u201caround,\u201d and <\/span>diem<\/span><\/i>, meaning \u201cday.\u201d This \u201caround\u201d part is vital. First, it refers to the fact that these rhythms do, indeed, revolve around a single day. However, \u201caround\u201d can also mean approximately. The <\/span>circadian rhythm in humans<\/span> isn\u2019t completely fixed to 24 hours\u2014different rhythms can be a bit late or early. So you can expect that early birds have a faster rhythm, while night owls have a slower rhythm.<\/span><\/p>\n Essentially, the notion that there\u2019s such a thing as a standard circadian rhythm isn\u2019t completely true (but also not completely false). While the sleep schedule most appropriate for you revolves around you going to bed when night falls and rising when the sun does, there\u2019s also a chance that, based on your chronotype, doing precisely this can actually be harmful.<\/span><\/p>\n Now, there are several biological rhythms that govern certain processes in our bodies, all centered on a specific period of time. These four biological rhythms represent the natural cycle in which our body\u2019s chemicals or functions change with time:<\/span><\/p>\n Our <\/span>body\u2019s internal clock<\/span> (the SCN) regulates all of these.<\/span><\/p>\n Now, the diurnal rhythm is essentially the circadian rhythm when it\u2019s synced with the passing of day or night. Quite often this is equated with the circadian rhythm, but there are some differences. Namely, the latter also includes physiological rhythms like sleeping, for example. Furthermore, the diurnal rhythm is specifically tied to night and day, governed by the <\/span>diurnal clock,<\/span> while the <\/span>circadian rhythm<\/span> by <\/span>definition<\/span> includes the behaviors found within a 24-hour cycle.<\/span><\/p>\n Ultradian rhythms are rhythms that include much shorter periods of time. The periods are defined as lasting longer than one hour, but shorter than a day. However, these rhythms also include blood circulation, growth hormone secretion, arousal, and bowel activity. Infradian rhythms, however, are much longer. They include things like menstruation, for example, or seasonal rhythms.<\/span><\/p>\n This unfortunately shines a light on some less-than-fair aspects of our society. Namely, if you\u2019re asking <\/span>what is your circadian rhythm<\/span>, you need to experiment and go against the grain. For some people, the nine-to-five grind is perfect, since their rhythms are ok with getting up early in the mornings.<\/span><\/p>\n However, if you\u2019re a night owl, you won\u2019t enjoy this option at all. Getting up early will be unpleasant, and you won\u2019t really have enough energy in the mornings to accomplish what you need to. Put simply, your <\/span>internal body clock <\/span>dictates that you\u2019ll be much more productive later in the day.<\/span><\/p>\n However, all this in a sense helps you figure out what\u2019s natural for your body. First, you need to set a schedule, and then stick to it strictly. You go to bed at a set time and get up at a set time\u2014no exceptions. After a couple of weeks, you\u2019ll understand whether the fatigue you feel in the mornings is truly due to your circadian rhythm not being in line with other people\u2019s, or if you simply had bad sleep hygiene and habits (more on that below).<\/span><\/p>\n There isn\u2019t only one specific sleep disorder related to the circadian rhythm. Rather, there are several that fall within the same family. Now, a simple definition of this type of sleep disorder is that it affects the timing of sleep. People will have difficulty sleeping and waking at the times traditionally necessary for school, social engagements, and work, causing a great deal of <\/span>stress<\/span><\/a> and anguish.<\/span><\/p>\n A <\/span>circadian rhythm disorder<\/span> can be intrinsic or extrinsic. The former is caused by certain misalignments and issues within the body and our internal clocks. The latter occurs due to external events.\u00a0<\/span><\/p>\n DSPS is represented by people who have their sleep-wake times greatly delayed in comparison to people functioning normally. As a result, they have trouble waking up at what one would consider a regular time.\u00a0<\/span><\/p>\n ASPD is the opposite of the previous type of <\/span>circadian rhythm sleep disorder<\/span>. Here, people fall asleep sooner and wake up much earlier than what\u2019s considered typical.\u00a0<\/span><\/p>\n Irregular sleep-wake rhythm disorder (ISWRD) falls within a standard 24-hour cycle. However, people with this disorder have very irregular sleep patterns. They wake up often during the night, they have disorganized bouts of sleep, and they often must nap during the day.\u00a0<\/span><\/p>\n Finally, non-24-hour sleep-wake disorder (N24) mostly targets people who are blind, because they can\u2019t detect light. People suffering from this disorder have a delay in their sleep-wake cycles, and this can often become more serious and turn into DSPS.<\/span><\/p>\n Now, if your <\/span>internal sleep clock <\/span>is disrupted because of external events and obligations (most often these are associated with work), you can end up with extrinsic disorders like jet lag or shift work sleep disorder. Jet lag occurs when we have a misalignment between our internal circadian rhythm and the external world. Caused by switching between too many time zones too rapidly, our <\/span>internal clock<\/span> isn\u2019t immediately able to adjust to the new environmental cues.\u00a0<\/span><\/p>\n Shift work sleep disorder (SWSD) is also caused by a misalignment between our internal clocks and the environment. It primarily happens to people who work at night or who switch up their work schedule often.<\/span><\/p>\n <\/span><\/p>\n Now we have a better answer to the question, <\/span>What is <\/span>the<\/span> circadian rhythm<\/span>? But what can disrupt its normal processes? While we\u2019ve mentioned the most common intrinsic and extrinsic disorders tied to the circadian rhythm. However, there are other factors that can cause problems, like the following:<\/span><\/p>\n Some of these lead to intrinsic changes, while others are like <\/span>jet lag<\/span>, essentially environmental and extrinsic.<\/span><\/p>\n First and foremost, to maintain a healthy circadian rhythm, you\u2019ll need to make certain lifestyle changes and stick to good <\/span>sleep habits<\/span>. However, controlling your circadian rhythm, changing it in a way that\u2019s beneficial (i.e., without severe medication or an illness) is impossible. Rather, you can only revert back to your regular pattern, or actually develop what\u2019s most natural to you.\u00a0<\/span><\/p>\n Now, these methods fall into two categories. First, you need to figure out what your natural circadian rhythm is (see above). Next, you\u2019ll need to implement the best sleep hygiene and habits. So, as far as developing good habits is concerned, if you want to set your <\/span>internal alarm clock<\/span> to its most natural state, stick to the following:<\/span><\/p>\n Yes, they do. Namely, our bodies are continually changing, and our circadian rhythm will of course follow suit. Many older people have issues both falling asleep and staying awake. As time goes on, our internal rhythm loses consistency. For example, circadian clocks in seniors are a bit faster. They wake up early in the mornings and feel fatigued earlier in the evenings. They also tend to feel a decline in cognitive functions once evening comes.<\/span><\/p>\n The circadian rhythm is a part of life, of nearly all living things, and understanding it better than you did yesterday can prove useful. We hope this article has thoroughly answered the question, <\/span>What is<\/span> the <\/span>circadian rhythm?<\/span> Understanding why it\u2019s so important, what its underlying mechanisms are, and what we can do to make it fit our lives will have a major impact on our physical and mental health.\u00a0<\/span><\/p>\n Remember, your circadian rhythm isn\u2019t just about getting enough sleep. Rather, it regulates your metabolism and immune system, and it\u2019s vital for your health and overall wellbeing. So try to stick to a regular sleep schedule. But now that you have an answer to just <\/span>what is<\/span> the <\/span>circadian rhythm<\/span>, you also know that other healthy lifestyle habits are important too.\u00a0<\/span><\/p>\nWhat Is the Difference Between<\/b> One\u2019s <\/b>Circadian Rhythm and Biological Clock?<\/b><\/h2>\n
How Does the Circadian Rhythm Work?<\/b><\/h2>\n
What Are Examples of Circadian Rhythms?<\/b><\/h2>\n
Why Is the Circadian Rhythm Important?<\/b><\/h2>\n
What Is a Normal Circadian Rhythm?<\/b><\/h2>\n
What Are the 4 Types of Biological Rhythms?<\/b><\/h2>\n
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How to Figure out Your Own Natural Circadian Rhythm<\/b><\/h2>\n
What Is<\/b> a <\/b>Circadian Rhythm Sleep Disorder<\/b>?<\/b><\/h2>\n
Intrinsic Disorders<\/strong><\/h3>\n
Delayed Sleep Phase Syndrome\u00a0<\/strong><\/h4>\n
Advanced Sleep Phase Disorder\u00a0<\/strong><\/h4>\n
Irregular Sleep-Wake Rhythm Disorder\u00a0<\/strong><\/h4>\n
Non-24-Hour Sleep-Wake Disorder\u00a0<\/strong><\/h4>\n
Extrinsic Disorders<\/strong><\/h3>\n
Jet Lag<\/strong><\/h4>\n
Shift Work Sleep Disorder\u00a0<\/strong><\/h4>\n
What Can Disrupt Our Circadian Rhythm?<\/b><\/h2>\n
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How Do I Control My Circadian Rhythm?<\/b><\/h2>\n
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Do Circadian Rhythms Change with Age?<\/b><\/h2>\n
Conclusion<\/b><\/h2>\n