The circadian rhythm is a natural cycle of sleep and wakefulness. When you’re aligned with your internal clock, it helps you get quality sleep, leading to better health, productivity, and well-being. But what is the circadian rhythm? And how do we keep it on track? We’ll explain all that and more in this blog post!
What are circadian rhythms?
The internal clock that regulates our sleep and wakefulness is known as the circadian rhythm. It’s called a “circadian” clock because it follows a roughly 24-hour cycle, the same length as one full rotation of Earth around the sun.
The circadian rhythm is controlled by an area of your brain called the hypothalamus, which responds to light and darkness by sending signals to other parts of your body. These signals help determine when you feel tired or energized, what time you go to bed at night, and when you wake up in the morning.
The hypothalamus is one of several areas of your brain that regulate essential functions like body temperature, moods, hormone levels and blood pressure — all of which are affected by how well (or not) you sleep at night.
How does circadian rhythm affect sleep?
The circadian rhythm is driven by sunlight, which affects the production of melatonin and other hormones in our brains.
When you sleep, your body produces melatonin, making you sleepy. When it gets dark outside (or if you’re in the dark), your body produces more melatonin. This is why we tend to get sleepy when the sun goes down.
The timing of melatonin release depends on how long it’s been since you last saw sunlight — longer periods of darkness mean more melatonin is released into your system, making you tired.
Circadian rhythms are crucial for healthy functioning because they help us stay awake during the daytime and asleep at night. While we have some control over our circadian rhythm through light exposure or caffeine intake, we cannot override it completely.
However, your circadian rhythm can change with age and lifestyle choices such as diet and exercise. They can also be thrown off by jet lag or shift work.
What else does your circadian rhythm affect besides sleep?
You may be wondering how the circadian rhythm affects more than sleep. Well, it’s essential to understand that your body and mind work together. When you get quality sleep, you’ll find that your energy levels increase and your mood improves. Your metabolism also gets a boost from getting enough restful sleep at night, as it’s easier for the body to burn calories when well-rested!
Not only does getting enough shut-eye help with losing weight or maintaining a healthy weight (which makes it easier for people with Type 2 Diabetes), but research has shown that getting plenty of Zzz’s can improve immune function as well as cognitive performance (i.e., how well we think).
Why you don’t want to mess up your circadian rhythm?
When your circadian rhythm is messed up, your body’s systems won’t function optimally.
A disturbed sleep-wake circadian rhythm can give rise to serious sleeping problems.
Without the proper signalling from the body’s internal clock, a person can struggle to fall asleep, wake up during the night, or be unable to sleep as long as they want into the morning.
Poor sleep is associated with several chronic health conditions, including obesity, diabetes, cardiovascular disease and mental health problems.
The consequences of poor sleep are far-reaching, contributing to increased risk for:
- Cardiovascular disease – Poor sleep has been linked to increased stroke and heart attack risk.
- Obesity – Research shows that people who do not get enough sleep are more likely to be overweight or obese than those who get enough sleep.
- Diabetes – Several studies suggest that getting too little sleep can increase your risk for type 2 diabetes by impairing the body’s ability to regulate blood glucose levels.
- Depression and anxiety – People who don’t get enough sleep are more likely to experience symptoms of depression and anxiety than those who get enough rest.
- Driving accidents – People who have slept less than six hours in the previous 24 hours may experience difficulty concentrating and reaction time while driving.
What can disrupt your circadian rhythm?
- Jet lag. Jet lag is a temporary condition when your internal clock becomes out of sync with external time. When you travel across time zones, your circadian rhythm can be disrupted.
- Shift work and other disruptions to sleep schedules. If you work nights or other odd hours, it can be difficult to get enough sleep during the day and stay awake during the night, especially if you’re trying to do this every day for weeks or months at a time. This causes fatigue, irritability, increased risk for accidents and errors in judgment at work, poor performance on tests/exams/job evaluations/etc.
- Advanced Sleep Phase Disorder: People with this type of disruption find themselves tired by early evening and awake very early in the morning. Even if they want to be up later at night or sleep later in the morning, people with an advanced sleep phase disorder usually can’t do so. This disorder is relatively rare, affecting around 1% of people in middle and older age.
- Delayed Sleep Phase Disorder: This type of circadian rhythm disruption is associated with “night owls” who stay up late at night and sleep in late in the morning. It is rare among the general population — affecting just 1 or 2 people out of every 1,000 — but impacts up to 16% of teenagers. The exact cause is unknown but may be related to genetics, underlying physical conditions, and a person’s behaviour.
How to maintain a healthy circadian rhythm
To maintain a healthy circadian rhythm, you should focus on practising good “sleep hygiene”.
Sleep hygiene includes:
- Establish a regular bedtime routine, such as reading and relaxing before sleep.
- Reduce the amount of artificial light you’re exposed to in the hours before bedtime and keep electronic devices out of your bedroom at night.
- Avoiding caffeine, nicotine and alcohol in the hours before bedtime.
- Exercising regularly but not too close to bedtime.
- Avoiding heavy meals shortly before bedtime.
- Ensuring comfortable sleeping conditions, such as keeping your bedroom cool and dark with a comfortable mattress and pillow.
- Keep naps short and early in the afternoon if you want to sleep well at night. Naps longer than 60 minutes can push back your bedtime, making it more difficult for you to fall asleep when nighttime rolls around.
Conclusion
Having your circadian rhythm in check is important for how you feel each day, not to mention your overall health. You can take simple steps to keep your circadian rhythm in check by practising sleep hygiene.
However, If you’re still having trouble sleeping, complete Harley’s free online sleep assessment. One of our doctors can guide you in improving your sleep quality and overall health.
