A cow is an animal, but not all animals are cows. Likewise, a biological clock regulates the circadian rhythm, yet not all biological clocks are circadian.
In a nutshell that answers the question “What is the difference between circadian rhythm and biological clock?” There is more to it, which I will explain in this article.
Your circadian rhythm and your biological clock influence how you feel, your general condition, weight, and sleep. And since no one is exactly the same, it is important to know what your circadian rhythm is, how your biological clock and external factors affect it.
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Table of contents
- 1 What biological clocks do we have?
- 2 How about the circadian rhythm?
- 3 What is your type?
- 4 External factors that interfere with our circadian rhythm
- 5 What is the difference between circadian rhythm and biological clock?
What biological clocks do we have?
Every living thing is regulated by biological clocks. Here I am talking exclusively about the biological clocks that control us, humans.
- The circadian rhythms last about 24 hours, like the sleep-wake rhythm (the sun);
- The monthly rhythms last for about 28 to 30 days (the moon), like the female menstrual cycle;
- We know seasonal rhythms and annual rhythms. We feel different in summer than in winter;
- Finally, there are perennial rhythms. Some of your cells are renewed every 7 years.
How about the circadian rhythm?
The circadian rhythm is endogenously controlled and functions largely independent of environmental factors such as light and temperature.
External factors may influence, but first of all your genes determine your optimal circadian rhythm.
The body functions with a circadian rhythm are our temperature, heart rhythm, sleep pattern, the secretion of certain hormones, the volume of the urinary bladder, and our need for food and drink.
It is not a myth that some people function better in the morning and others in the evening. The division is approximately 40% early birds, 30% night owls, and the rest somewhere in between.
Although we can make some adjustments, we can’t change our type entirely. Age also matters. Teenagers have a hard time getting out of bed in the morning for a reason. Their circadian rhythm has shifted to later, while children and older people get up early and go to bed early.
What is your type?
We function optimally when we live according to our personal circadian rhythm. External factors, such as fixed office hours or shift work, can negatively influence this.
This not only affects your sleep pattern but also your weight and the way you function.
But how do you find out what your type is?
There are 2 ways to do this: either you live a time without an alarm clock or you go live in a cave without daylight for a few days.
Research into resilience
The coronavirus has had a lot of influence on our functioning and our social life. As part of an experiment to test how we can adapt to changing circumstances, 15 French citizens had themselves locked up in a dark cave for 40 days.
They had no clocks or access to social media or telephones. They ate when they were hungry and slept when they were tired.
Once out of the cave, it turned out that a few thought they had been underground for 23 days. Most assumed 30 days.
This showed that the assumption that the circadian rhythm lasts 24 hours is incorrect. This is partly determined by society and by the way we live.
Optimal functioning within our society
We cannot pretend that a day is 26 or 28 hours. So we have to make the most of the 24-hour rhythm.
I wear an Oura Ring. A gadget that monitors my sleep and movement pattern. Many top athletes use the Oura to determine their optimal time of performance.
When I first got the ring, I tried out different times to go to sleep. I woke up without an alarm when my body saw fit. I have always slept badly and my goal was to find out my ideal sleep and wake time.
Computer data or pen and paper
The data of the ring made it easier to discover my patterns, but you can also do that without a ring of course. Keep track of when you go to sleep. Try out a few different times and find out when you wake up on your own. The ideal pattern:
- Fall asleep within about 15 minutes;
- 7-9 hours of sleep without feeling restless;
- 20-25% REM sleep;
- 15-20% Deep Sleep;
- Wake up energized and rested.
Once you’ve discovered your ideal pattern, try to stick to it daily. Also on weekends. Our body thrives with regular patterns. This applies not only to sleep but also to meals.
External factors that interfere with our circadian rhythm
It is good to be in natural (sun)light as much as possible. This can be a challenge in wintertime, depending on where you live. If you suffer from the winter blues or even depression, consider using a special daylight lamp.
When my mother got older and sicker, I bought her a lamp like this. The nurses put them on for half an hour while they were getting her dressed and preparing breakfast.
We usually have too blue and too bright light at night. Current smartphones have a ‘night shift’ setting, which filters the blue light from the screen. It is also advisable not to look at screens some 2 hours before we go to sleep.
A loud alarm early in the morning suddenly startles you. See if you can set nature sounds or, better yet, try to wake up on time without an alarm clock.
The temperature should be comfortable during the day and a little too cold at night. Start your day with a cold shower, then your body warms up faster afterward. You can end the day with a warm shower to let your body cool down.
Your body temperature fluctuates during the day. In the morning it’s usually a bit lower than in the afternoon.
Avoid a heavy meal just before going to sleep. Stop eating in time to allow your body to enter a natural fast. Whether you eat breakfast or not, at least drink one or more glasses of water when you get up.
Movement can also have a positive or negative effect on your circadian rhythm. Ideally, you walk and stand more during the day and you sit mainly in the evening. (Silly, don’t you think, to let our kids sit still in school all day).
Meeting people is important, we noticed this recently. People are social beings. But if our friends have a later circadian rhythm than we, it can interfere with our bedtime. The so-called social jet lag.
We can either meet them earlier or try to be strong and leave earlier. I wasn’t surprised to read in the newspaper the other day that Spanish people sleep fewer hours than the Dutch or the Belgians. They are notorious for going to bed really late although their office hours are in sync with the rest of Europe.
Stress is one of the worst ailments of our time. We are too busy, we act too busy. It won’t be long before stress is the #1 killer.
Office hours and school schedules
Night owls will have a hard time getting to the office in time. Early birds will have their midday dip early in the afternoon, night owls will have it 2 to 3 hours later.
Time zones and night shifts
Different time zones are a major disruption to our circadian rhythm when flying from east to west or vice versa. And that also applies to shift work.
Having to go to work at different times and changing sleep patterns not only have a bad effect on the quality of our sleep but are also considered to be a cause of dementia.
What is the difference between circadian rhythm and biological clock?
Our biological clock plays a huge part in our circadian rhythm as an internal factor. Yet, external factors can have a positive or negative effect on this rhythm. Establish your ideal circadian rhythm and fold your life around it as much as you can.
Are you an early bird or a night owl? Tell us in the comment box below.