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In our fast-paced world, getting the deep, restorative sleep you need to feel happy and healthy can be difficult. Though your sleep can become disrupted for many reasons, the culprit is sometimes an issue with your circadian rhythms.
Disordered circadian rhythms can cause sleepless nights and drowsy days. Worse yet, they can set you up for chronic illness later in life. Fortunately, simple habits like establishing a bedtime routine or avoiding blue light before bed can help you reset your body’s clock.
Whether you’re wrestling with jet lag, suffering from insomnia, or simply feeling curious about how to optimize your sleep, this guide will help you understand how to fix circadian rhythm disruptions and get some much-needed rest.
Table of Contents:
- What are Circadian Rhythms?
- What Happens When Circadian Rhythms Are Disrupted?
- How to Fix and Reset Your Circadian Rhythm
- Maintaining a Healthy Circadian Rhythm
- Circadian Rhythm FAQs
What are Circadian Rhythms?
Circadian rhythms comprise all of the numerous changes an organism undergoes every 24 hours. In fact, the word “circadian” comes from the Latin words for “approximately” (circa) and “day” (diem).
Humans evolved circadian rhythms as an early survival strategy. Syncing periods of activity and rest with the 24-hour cycle of day and night made it easier for our ancestors to stay safe and healthy.
Circadian rhythms are sometimes called “sleep-wake cycles,” but they determine so much more than just when we get up and go to bed. Our hormones, digestion, blood pressure, body temperature, and blood sugar are all part of circadian rhythms' delicate balancing act.
How Do Circadian Rhythms Work?
Think of circadian rhythms as a “biological clock,” or better yet, a system of many biological clocks that all rely on each other. The body’s “master timekeeper” is the suprachiasmatic nucleus (SCN), part of the brain’s hypothalamus located near the optic nerve.
The SCN receives information about our environment from our sense organs. In response to changes in light, temperature, and other inputs, the SCN signals our glands to release hormones like melatonin and cortisol. Melatonin signals to the body that it’s time to rest, while cortisol signals that it’s time to be awake and active.
These hormones activate protein molecules that control a wide variety of cellular activity, triggering enormous cascades of changes in the body that affect everything from metabolism to immune function.
Everyone’s circadian rhythms are different. Most people like to be awake when the sun is up and asleep when it’s down, but there’s significant variation beyond that. Our circadian rhythms are affected not just by light and temperature, but by our genetics, ages, and lifestyles.
Common Circadian Rhythm Disruptors
What is circadian rhythm disruption? Many lifestyle and environmental factors can contribute to it. In the modern world, it’s impossible to avoid all of these disruptors all the time, but minimizing them can improve your health.
- Irregular Sleep Schedules: Maintaining consistent sleep and wake times is key to healthy circadian rhythms. Even sleeping in on weekends can throw your body’s clock out of whack.
- Poor Diet and Exercise Habits: Eating heavy meals and drinking caffeine or alcohol, especially late in the evening, can impact sleep. Exercising infrequently or late in the day can also leave you tossing and turning.
- Screens and Artificial Light: The light emitted by cell phones and computers is similar to sunlight, which confuses our circadian rhythms. Another great reason to avoid late-night doomscrolling!
- Jet Lag: Traveling across time zones and being forced to quickly adjust to a completely different time zone can wreak havoc on your sleep.
- Season Changes: We often struggle to adjust to seasonal shifts, especially far from the Equator where the sun may never seem to set in summer and winters pass in near-constant darkness.
- Shift Work: People who work night shifts or have irregular work schedules can experience circadian rhythm disruptions. Even shift workers who get enough hours of sleep but at irregular times often find themselves exhausted.
- Sleep Disorders: If your circadian rhythm has been disordered for a long period and making lifestyle adjustments has not helped, you may suffer from a sleep disorder that should be treated by a specialist.
What Happens When Circadian Rhythms Are Disrupted?
An out-of-sync circadian rhythm can be more than just uncomfortable and inconvenient. Because the circadian rhythm affects so many of your body’s most important processes, disrupted sleep can impact your health in many ways.
In the short term, a disrupted circadian rhythm can cause:
- Fatigue due to difficulty falling asleep or staying asleep
- Loss of coordination, which can lead to accidents
- Issues with focus, attention, and memory
- Weakened immune response
- Aches and pains
- Anxiety or irritability
Worse, researchers have discovered correlations between long-term circadian rhythm disruptions and chronic illness, including:
- Obesity
- Diabetes
- Cardiovascular disease
- High blood pressure
- Digestive issues
- Alzheimer's Disease
- Mental health conditions
- Cancer
Circadian Rhythm Sleep Disorders
If your circadian rhythm issues are severe, your doctor may diagnose you with a circadian rhythm sleep disorder. There are many types of sleep disorders, but there are three that are especially relevant to our discussion of circadian rhythms:
Advanced Sleep Phase Disorder causes patients to feel tired long before their desired bedtime and to wake up extremely early in the morning. Older adults are especially susceptible to the disorder.
Delayed Sleep Phase Disorder is the opposite problem: patients with this syndrome have a hard time falling asleep until very late at night and often struggle to get out of bed in the morning. Teenagers and young adults often have delayed circadian rhythms.
Irregular Sleep-Wake Rhythm Disorder involves a complete breakdown of circadian rhythms. Patients with this syndrome take short naps throughout the day and night because their bodies do not respond to the brain’s circadian signals.
Signs Your Circadian Rhythm is Off
Because so many of your body’s processes rely on your circadian rhythms, a disruption can affect you in many ways. The most common signs of circadian rhythm dysfunction include:
- Feeling unusually tired when waking up
- Experiencing fatigue throughout the day
- Having difficulty falling asleep at night
- Falling asleep or waking up very early or very late
- Short, unsatisfying periods of sleep
- Increased mental health issues
- Aches and pains (like headache or stomach upset)
How to Fix and Reset Your Circadian Rhythm
You now know that a disrupted circadian rhythm spells trouble for your short-term health and long-term well-being. Fortunately, there are many natural sleep aids you can use to help your body reset its circadian rhythms and return to peak form. Here are several ways to fix your circadian rhythm:
- Gradually Adjust Your Sleep Schedule
- Optimize your Sleep Hygiene
- Increase Daytime Light Exposure
- Take a Sauna or Hot Bath Before Bed
- Limit Screen Time Before Bed
- Limit Alcohol and Caffeine
- Try Melatonin Supplements
- Take a Cold Plunge First Thing in the Morning
Gradually Adjust Your Sleep Schedule
We tend to sleep best when our sleep patterns, our circadian rhythms, and the natural 24-hour cycle of light and dark are aligned. One of the best ways to reset the clock is to become more consistent in your sleep schedule, even on weekends and during vacations.
Anyone who’s battled jet lag knows that our bodies do not respond well to abrupt changes in our sleep schedules. To shift your sleep-wake cycle without shocking your system, adjust your alarm and/or bedtime by just 15 minutes each night until you reach your goal.
Optimize your Sleep Hygiene
Our ancestors sought shelter in cool, dark caves and other hiding places at night. Though we are now used to much cozier bedrooms, we still prefer to sleep in conditions that mimic our ancient sleeping quarters.
Doctors maintain that the optimal temperature for sleep is between 60-67° F. That might be difficult (and expensive!) to achieve in the summer months, but turning your thermostat down a degree or two when you go to bed might help you sleep.
Limit light in your sleeping environment with blackout curtains or sleep masks, and reduce noise with earplugs or a white noise machine. If your mattress or pillows leave something to be desired, consider replacing them.
Increase Daytime Light Exposure
Our brain’s master timekeeper, the SCN, is hardwired to our optic nerve. It should come as no surprise, then, that light exposure has a direct effect on our circadian rhythms.
Basking in the sun first thing in the morning — and throughout the day — can signal to your body that it’s time to be active. If you can’t get outside, sit near a window. If your home or office is gloomy, consider changing window treatments or rearranging furniture to take advantage of what light there is.
Finally, if you live in an area where there is little sun at certain times of year, consider light therapy. A light box, sun lamp, or smart light bulb can emit bright light that mimics sunlight.
Take a Sauna or Hot Bath Before Bed
Another great hack for your circadian rhythms is to use a sauna or hot bath before bed each night. The rapid cool-down your body experiences after a sauna session mimics the temperature dip your body naturally undergoes when you become drowsy at night. Heat therapy also relaxes your muscles and helps your body manage pain, which can help you get comfortable for sleep.
Limit Screen Time Before Bed
Too much light exposure at night can be just as destructive to your circadian rhythms as too little during the day. When you’re preparing for sleep, illuminate your bedroom with dim, warm light.
It is especially important to avoid blue light — the light that cell phones, TVs, and computers emit — before bed. Blue light can inhibit your body’s release of melatonin, the hormone that prepares us for sleep.
Some phones and computers have settings that limit the amount of blue light they produce, but it’s still best to put your phone down at least an hour before bed. Not only will it help you reset your circadian rhythms, but it will also reduce stress.
Limit Alcohol and Caffeine
We often think of alcohol and caffeine as producing opposite effects on our bodies: caffeine wakes us up, while alcohol calms us down. However, both harm sleep.
Studies suggest that both alcohol and caffeine suppress the REM phase of sleep, which can keep us from feeling rested even if we fall asleep and wake up on time. For best results, stop drinking caffeine about eight hours before bed, and consume your last alcoholic beverage three hours before bed.
Try Melatonin Supplements
Melatonin is critical to a healthy sleep-wake cycle because it helps your body understand when it’s time to wind down. If your circadian rhythm is out of whack, especially due to jet lag or a sleep disorder, you may want to support your body’s natural melatonin production with a supplement.
Melatonin supplements are widely available in stores, but it’s still best to talk to a doctor before trying them. They interact with some medications and are not suitable for long-term use.
Take a Cold Plunge First Thing in the Morning
Daily ice baths are becoming a popular way to manage circadian rhythm disruption. Cold plunging also helps the body manage stress, pain, and inflammation, all of which can indirectly help you sleep at night.
Because cold therapy wakes us up, it’s best to avoid ice baths before bed. However, even two or three minutes in ice-cold water first thing in the morning gives your body a shot of cortisol and epinephrine, hormones that increase alertness and energy. This can help your body understand that it’s time to start the day and get active.
Maintaining a Healthy Circadian Rhythm
Now that you know what circadian rhythms are and how to bring them back into equilibrium, it’s time to audit your daily habits to ensure that your circadian rhythm remains healthy.
- Maintain a consistent daily routine: Waking up and going to sleep at the same time each day is crucial for your circadian rhythms. Studies suggest that exercising and eating at the same time each day make a difference as well. All these activities help your body know where you are in the 24-hour cycle.
- Create a bedtime ritual that works for you: Following a consistent routine each night before bed can help you achieve more regular sleep. Put away screens, work assignments, and anything else that brings you stress an hour before lights out. Instead, stretch, meditate, or read.
- Monitor your sleep with health monitoring technologies: Many companies have designed wearable devices and apps that can provide you with valuable information about your health. You can use technology to track your movement, heart rate, blood pressure, and more while you sleep.
Circadian Rhythm: FAQs
How Does Jet Lag Disrupt Your Circadian Rhythm?
Jet lag disrupts your circadian rhythm by dramatically and abruptly changing your sleep and wake times. It is more severe the further you travel, especially when you are headed east. To avoid the worst effects of jet lag, adjust your sleep schedule by an hour per night in the days leading up to your trip. When you arrive at your location, try to force yourself to stay awake until dark.
When Do Babies Develop Circadian Rhythm?
Babies develop circadian rhythms about four months after birth. That’s because their bodies do not produce melatonin or cortisol right away. Any sleep-deprived parent can tell you that babies sleep very erratically, especially in the first nine months. Fortunately, most children settle into a regular sleep schedule once their circadian rhythms mature.
How Long Does it Take to Reset Your Circadian Rhythm?
The best way to know how to reset circadian rhythm disruptions is to understand their cause. Jet lag typically eases at a rate of one day for each hour you have shifted in transit, while sleep disorders may take longer to resolve. If you implement the tips above, you should feel a difference within several days.
How Plunge Tubs and Saunas Support Healthy Sleep Habits
Our circadian rhythms involve nearly every organ, system, and cell in our bodies. That’s why keeping your circadian rhythms healthy is one of the best ways to support your long-term mental and physical health. When your body’s clock is out of whack, saunas and cold plunges can be especially effective ways to reset it.
Medical Disclaimer: The information contained in this post is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions or before embarking on any new health or wellness routine, including saunas and cold plunging. Neither the author(s) nor the publisher of this content take responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any cold plunging routine or other health or wellness program.