The term “circadian clock” refers to the internal timekeeping system used by the human body. A natural “circadian rhythm” governs the body’s daily cycles of sleep and wakefulness, appetite and digestion, hormone activity, and other biological activities. This internal clock is responsible for regulating the body’s circadian rhythm. Circadian is derived from the Latin term “circa diem,” which means “about a day,” and refers to the fact that most circadian rhythms reset themselves every 24 hours. Rhythms are influenced by natural cues such as light exposure, engagement with others, and scheduled meal times. However, once a circadian rhythm has been established, it is difficult to modify it, even if it is not exposed to the regular cues that are used to set the rhythm.
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What Is Circadian Rhythm?
The suprachiasmatic nucleus (SCN) is a group of around 20,000 neurons that make up the circadian clock (SCN). Located near the base of the brain, the cluster is called the hypothalamic nucleus. An eye-activated signal is sent to the SCN, telling the brain it’s time to get up when the eyes detect light during daylight hours. To ensure that you’re awake and alert, the SCN produces a variety of chemicals including cortisol.
For example, circadian rhythms are regulated by light and other signals known as “zeitgebers,” which are German for “time giver” or “synchronizer.” These signals help the body determine whether it is day or night. The circadian rhythm is thought to be most strongly influenced by light as a zeitgeber. While our eyes are closed, we still get signals from the SCN because our eyes are still able to detect light. Physical activity, food consumption, body temperature, and social engagement are all examples of zeitgebers.
The 24-hour cycle of hormone production is regulated by circadian rhythms. A hormone called cortisol is secreted by the body as soon as the sun comes up in the morning, causing us to feel energized and awake. When you first get up, a healthy person’s energy levels will gradually decrease throughout the day, peaking in the evening when the sun has set. Melatonin, a sleep-inducing hormone, is released by the pineal gland as the sun sets.
Additionally, circadian rhythms play a crucial role in regulating appetite and digestion, body temperature, mood, and fluid balance. Every 24 hours, the circadian clock resets for most healthy humans. Throughout the day, people’s levels of alertness and fatigue can fluctuate. “Early risers,” who go to bed early and rise early, and “night owls,” who stay up late and sleep in, are two such instances.
As you become older, your sleep patterns will change as well. Babies, on the other hand, sleep at various stages throughout the day and night, but older individuals tend to go to bed and wake up earlier.
Circadian Rhythm Sleep Disorders
Healthy humans’ master circadian clocks function on a 24-hour cycle. When the body’s natural circadian rhythms are out of whack, sleep disorders can result. Symptoms of these diseases can vary widely, but for the most part, sleep disturbances and excessive daytime sleepiness are the most frequent.
Some of these occurrences can be traced back to a problem with the individual’s own timekeeping system. For example, a disorder known as delayed or advanced sleep-wake phase disorder occurs when a person’s sleep-wake cycle slips at least two hours out of sync with standard circadian schedules. When a person is unable to fall asleep or wakes up feeling groggy, they have an irregular sleep-wake rhythm disorder, which is another example of irregular sleep-wake rhythms. It is common in persons with dementia such as Alzheimer’s disease, Parkinson’s disease, and others.
Another cause of irregular circadian rhythms is a misalignment of the circadian clock with the external surroundings of the individual.
People who work nights or early morning shifts are more likely to suffer from shift work disorder, which can lead to excessive daytime sleepiness and make it difficult to fall asleep at the time you set for bed. People who travel across many time zones in a short period of time are at risk for jet lag, a disorder that affects those who experience it. Temporary weariness and sleep disturbances are common side effects of long-haul flights, as the body tries to acclimate to the new time zone.
There are several conditions that can only be diagnosed after a three-month period of symptoms. However, sleep specialists can treat many of the conditions above with the measures we’ve described above, such as light exposure therapy and melatonin supplements, which can be prescribed by them. It’s possible that establishing a regular nighttime routine and improving sleep hygiene will also have an impact. If left untreated, these diseases can have a detrimental influence on your physical, cognitive, professional, and social functioning.
What Causes Circadian Misalignment?
Both sleep deprivation and circadian misalignment can increase your chance of developing Type 2 diabetes, obesity, cardiovascular disease, and cancer in the long term. In the short run, you’ll be groggy when you wake up and sleepy throughout day. Additionally, you’ll feel more anxious and stressed, and your judgment and focus will deteriorate. Any and all of your concerns will be addressed in some way.
The following are examples of factors that can mess with your circadian rhythm and have an impact on your ability to sleep and function:
- The largest influence on your circadian rhythm is caused by improperly timed light exposure. Avoid light at night and expose yourself to light as soon as possible after waking up to keep it functioning like clockwork.
- The natural production of the sleep-inducing hormone melatonin in your body is disrupted when you are exposed to light (especially bright light and the blue light emitted by electronic gadgets) 90 minutes before bedtime. This might make it harder to fall asleep and stay asleep.
- Travel jet lag and social jet lag can cause daytime sleepiness and/or overnight wakefulness because they disrupt your circadian rhythm, which affects your ability to sleep and wake during the day and night.
- Work in shifts: Sleeping during daylight hours and staying up during the night is the primary cause of shift workers’ circadian disturbance.
- Substances that interfere with sleep: Having a drink, a cup of coffee, or a cigarette too close to bedtime might make it harder to get to sleep and remain asleep because these substances are recognized sleep disruptors. There is often a disruption of the circadian rhythm and an increase in sleep debt.
- When it comes to optimal circadian functioning, consistency is key, and this is especially true when it comes to sleep habits. You put yourself at risk for circadian misalignment and all of its health and energy consequences if you don’t go to bed and wake up at nearly the same time every day due of stress, child rearing, health difficulties, bedtime procrastination, etc. Taking a late-afternoon nap might also interfere with your body’s circadian rhythm.
You need to figure out which of these variables may be interfering with your body clock in order to bring it back on track. The second stage is to reestablish circadian synchronization by practicing proper sleep hygiene. We’ll go into this further in the future, but for now, we thought you would be interested in learning more about the research that supports these suggestions. It may be easier to perform a reset if you are aware of what causes your internal body clock to run.
Understanding What Makes Your Master Clock Tick
In addition to light and dark, there are a number of other influences on your circadian rhythm, some of them internal and some of them external. The first step in delving into this fascinating world of interconnected brain and body functions is to establish some basic definitions and connections.
Suprachiasmatic Nucleus (SCN)
In the hypothalamus of the brain, a collection of neurons (the SCN) is tuned to the Earth’s 24-hour rotation around the sun.
Also known as the brain’s master clock, the SCN influences light and other environmental stimuli, and it maintains the body clock through hormonal, neurological, and nutritional signals. The SCN, for example, responds to darkness by triggering the pineal gland to produce melatonin, which helps your body prepare for sleep.
Secondary circadian clocks, known as peripheral clocks, can be found in virtually all of the body’s tissues and organ systems.
As a result of near-constant communication with the SCN, peripheral clocks operate in your immune system, metabolism, digestion, and thermogenesis/body heat systems, as well as in the liver, pancreas, and gut (in the heart and brown fat tissue). Additionally, even a brief period of circadian misalignment can have detrimental effects on the body, including the development of pre-diabetic diseases.
The underlying circadian rhythm is your chronotype. If you’re a “evening chronotype,” you’re more likely to wake up earlier in the morning, go to bed later at night, or anything in between.
Your chronotype is defined by your age and genetics, and the length of your circadian rhythm is regulated by your sleep schedule and exposure to light. Due to the fact that their bedtimes tend to get later and later, night owls are more prone to circadian misalignment.
Entrainment is the establishment or resetting of one’s circadian rhythms through synchronization. An internal biological clock is synchronized with nature’s light-dark cycle or other external time cues, such as the time of day.
It’s not always easy to keep your circadian rhythms in sync. The timing of light exposure and other zeitgebers can be adjusted to restore your circadian rhythm if your early bird or night owl sleep routine has gotten so extreme that it has caused considerable circadian misalignment.
An environmental or social cue that influences and helps synchronize biological rhythms is known as a Zeitgeber (German for “time giver”). It acts as a trigger to either set or reset the biological clock.
Although natural sunshine is the most essential zeitgeber, the RISE app’s advice for food/meal times, temperature and activity all play an important role in our sleep hygiene guides. Zeitgebers, such as alarm clocks and school or work schedules that keep us on a regular schedule, can also be categorized as zeitgebers.
A circadian rhythm that’s out of whack can be brought back into balance by adjusting the timing of your light exposure and other zeitgebers. Also, excellent sleep hygiene practices are critical to the process.
Can you reset your circadian rhythm?
Your circadian rhythm can be reset, yes. But first, you need to know your personal circadian rhythm.
As Dr. Roth puts it, “I tell a lot of patients that they’re attempting to squeeze a square peg into a round hole. Some people are natural night owls, and their bodies naturally prefer to sleep at midnight, but they are forcing their bodies to sleep at nine p.m.
Because your body isn’t accustomed to going to bed so early, you may have a difficult time falling asleep and getting up at the time you prefer.
There are certain times of the day when you will be most alert and productive if you know your circadian rhythm, which is what Dr. Roth stresses. In the later hours of the night, people who are night owls are most productive. A morning person is one who is most productive in the morning. ”
Your circadian rhythm is affected by factors like as light, temperature, and when you eat. External cues that affect your internal clock are known as zeitgebers.
According to Dr. Roth, “So the sun is a zeitgeber.” “Zeitgebers include everything from our school timetable to our employment schedule to our workout routine. We can alter our circadian rhythms by varying the stimuli we are exposed to.
How to reset your circadian rhythm
He says that “resetting the timing of when you sleep and when you get up” is what he means by “resetting your circadian rhythm.” This has more to do with your sleep pattern than how well you fall asleep, according to “it has more to do with.”
Resetting your circadian rhythm can be done by following the following guidelines:
Have a routine
It’s a good idea to make a bedtime schedule if you’ve been waking up at all hours of the night. You’ll have an easier time getting to sleep and getting out of bed if you’ve established a pattern.
Even on days off or weekends, it’s critical to keep to the same schedule.
In general, exercise aids in the generation of melatonin, which in turn aids in sleep. Your body’s other systems can also help your circadian rhythm by working out.
Every person’s experience with exercise and how they feel afterward is unique.
Exercise in the morning might boost your energy, according to Dr. Roth. “It exhausts some people, so they wait until after work to enjoy it,” says one.
Avoid alcohol and caffeine in the evening
Keep track of how long it’s been since you’ve had a cup of coffee. It’s best to avoid coffee in the evening because it can keep you up well into the night.
Even if you enjoy a glass of wine or a glass of beer in the evening, you might want to rethink that practice. Despite the fact that alcohol may temporarily put you to sleep, it can have a long-term impact on your circadian rhythm.
Limit screen time
Put an end to your nightly ritual of perusing social media before turning in.
A disruption in your circadian cycle occurs as a result of the blue light emitted by cell phones and tablets.
For at least 30 minutes before you go to sleep, turn off all displays.
Even while you may enjoy a long afternoon nap, it can disrupt your circadian cycle and make it more difficult to sleep at night.
If you must nap, keep it brief (no more than 30 minutes) and schedule it for before 3 p.m.
Gradually move your bedtime
Don’t expect your circadian cycle to be fixed or reset overnight. Dr. Roth advises a gradual shift in your nighttime schedule to achieve the best results. In half-hour shifts, this can be accomplished.
Try going to bed and waking up half an hour earlier for one week, and then another half an hour later for the next week to see whether it helps you get a better night’s sleep or if you need to get up earlier in the morning.
Why your circadian rhythm matters
Dr. Roth explains that your circadian rhythm has an impact on every element of your life.
This can include your appetite as well as the times you eat. Dr. Roth explains this more. As a result of sleep deprivation, people’s appetite can fluctuate, either rising or falling, and the timing of when they’re hungry can also shift.
How to tell it’s time for a reset
If you’re experiencing any of the following symptoms:
- I’m having a hard time getting to sleep at night.
- You have problems winding down at night.
- It is difficult for me to rise in the morning.
- Do not have the ability to focus on my everyday duties and obligations.
Circadian rhythm disorders can be diagnosed by a sleep medicine specialist or behavioral sleep medicine psychologist, who can help you restore your circadian rhythm.
If your preferred sleep schedule isn’t matched with what you want it to be, you have a circadian rhythm issue, according to Dr Roth. It is possible for your doctor to identify these problems and then examine and treat them.
According to Dr. Roth, therapeutic options include modifying sleep schedules and habits, utilizing light therapy, and supplementing with melatonin.
Dr. Roth explains that “our circadian rhythms change throughout time.” It is a fact of life that as we get older, our circadian rhythms shift. People in their fifties, sixties, and seventies may find that going to bed and waking up early is a need. “If you were an insomniac in high school, you could become a morning person later in life.”
Tips for Resetting Your Sleep Schedule
In the event that your sleep routine isn’t working for you anymore due to difficulty waking up in the morning or staying up later than desired, what are your options? Try the following actions to get your sleep schedule back on track:
- However, be patient and adjust your bedtime. If you want to get to sleep earlier, you can gradually reduce your bedtime until you reach your target time. A doctor may be necessary in some cases. According to Rafael Pelayo of the Stanford Sleep Disorders Clinic at Stanford University, “as a general rule, it’s simpler to push away sleep than to advance sleep.” While it is possible to extend your nighttime hours by a few minutes, getting to bed earlier is more difficult. Dr. Pelayo recommends gradually increasing the amount of time you spend in bed by no more than 15 minutes every two or three days.
- Don’t take a nap, even if you’re feeling sluggish. Sleeping at night can be disrupted if you take a nap during the day.
- Pelayo encourages exercising when you’re in the mood for a snooze. “Exercise will wake you up and keep you alert. Then you can put off going to sleep till later,” he explains.
- Getting up at the same time every day will help you stay on top of your schedule. Consistency is essential for a healthy sleep routine. You need a good alarm clock, so don’t hit the snooze. Pelayo claims that “the clock in your head requires instructions.” The brain expects people to get up at roughly the same time each day, and if they do or don’t, it serves up those instructions. A person’s brain does not understand the concept of weekends or traveling between time zones. He claims that’s what’s wrong.
- Stick to your regular bed and wake times as much as possible once you’ve found a routine that works for you. Pelayo warns that even one late night can undo all your hard work. Avoid exposing yourself to light before bedtime. Exposure to dusk light has been shown in studies to cause your biological clock to advance. Remember that light tells the brain that it’s time to get up and go about your day. Avoid bright and outside light near to bedtime (including light from cell phone, laptop, and TV screens) and keep your surroundings dim at night if you’re attempting to go to sleep early.
- Avoid working out right before going to bed. A workout too close to bedtime can keep the brain and body active (by increasing heart rate and body temperature) and make it more difficult to fall asleep.
- Although some studies have found that exercising in the evening can help you sleep better if you don’t do it within an hour of going to bed, it all depends on the individual and how their body responds to exercise.
- Choose low- to moderate-intensity workouts if you want to exercise later in the day because they will be less stimulating, and make sure to finish your workout with a cool down.
- Make sure you don’t eat anything too close to bedtime. You should steer clear of foods high in sugar and stimulants, such as caffeine and nicotine, which can trigger a surge in blood sugar. Acidic and spicy foods can also cause heartburn. Eat some sour cherries or kiwis if you’re hungry, as these fruits have been proved to help you sleep better.
- Set the tone for a peaceful night’s sleep by creating a bedtime ritual. Do something you enjoy, such as taking a hot bath and listening to soothing music. Keep the room dark and the temperature moderate, and make sure that your mattress and pillows are at least as comfy as possible. Getting some shut-eye is something you look forward to. Sleeping shouldn’t be a chore, says Pelayo. Pelayo agrees.
- Take use of the sun’s rays. Exposure to bright light (such as sunshine) in the morning helps your body know it’s time to wake up and sets your circadian rhythm for the day, so that you feel sleepy when it’s time to go to bed.
- For those times when the sun isn’t out and you don’t have the opportunity to get outside, there are unique indoor lighting options.
- Make an appointment with your doctor or other medical professional. Consult your physician if your sleep schedule is interfering with your work and other obligations, if any of the aforementioned measures fail to help, or if you’re having trouble sleeping for any reason.
- Our ability to operate and stay healthy today and in the future are both impacted by the quality of our sleep. A lack of sleep can have a negative impact on your health, but there are healthcare specialists who can assist. If your primary care physician lacks sleep expertise, they may be able to direct you to a sleep specialist.
The amount of time it will take to get your clock back on track will be determined on the reason for your time being off. Pelayo advises that “the rule of thumb is that it normally takes one day each time zone” when readjusting to a new time zone. If it’s a long travel, some people need two weeks to become used to the new environment.
Getting back on track might take a long time for those with DSPS because of how deeply ingrained the pattern is. Pelayo says, “We tell people to wait one or two months.”. People are startled when they begin to sleep better after a long period of poor sleep.” It also wakes you up when you’re shocked that your sleep is getting better because you’re not sure if it will continue to work. The allure of a good night’s sleep wears off after about two months.”
Changes to your sleep schedule (especially if you suffer from delayed sleep phase syndrome) aren’t easy, but they can be achieved with the right amount of self-discipline This will just make things worse,” Pelayo advises. Be confident that you’ll get some shut-eye eventually.