Do you know your circadian rhythm?

Do you know your circadian rhythm?

June 21, 2020 0 By Rick

Are you a night owl or an early bird? Are you more productive in the morning or much later in the day? Hopefully, by now, you have identified your type. But have you ever wondered how this can affect you aside from going to bed at night and getting up in the morning? You might be surprised to find that your body contains “clocks” that help keep everything running smoothly. But there’s one “biggie” the drives your circadian rhythm, which controls things like your body temperature, hunger and sleep. And that internal clock is connected directly to your eyes, so light has a significant effect on it. It’s called the circadian clock.

A biological clock
This is the biological clock we have, which controls our sleep-wake cycle, the release of hormones at necessary intervals, body temperature, blood pressure, and other critical mechanisms to maintain homeostasis or balance. It seems that all life has this internal clock that falls in line with the Earth’s rotation and helps us adapt to changing aspects of the day and environment. All life, as well as plant and animal behavior, responds to the sun, i.e., is determined by the light-dark cycle. You might call us “slaves” to the sun. The circadian clock is a core feature for understanding life. So, let’s take a closer look at this all-important clock and how it affects us.

As soon as you open your eyes in the morning, light makes your brain turn specific genes on and certain genes off to fire you up for the day. Light also signals your brain to stop producing melatonin – the “sleepy” hormone. As day gradually turns to night, your melatonin production commences again to get you ready for sleep. Although our clocks seem to run on the same schedule for most of us, there are outliers that sometimes baffle us. You know, the people that jump out of bed, fully alert and primed for action and the people that you literally must drag out of bed. 

“Larks and night owls”
The former are often called “larks” and the latter “night owls.” Each of these types has its own pros and cons. Early birds are super productive until around mid-afternoon and then seem to crash. They often turn in early at night. Night owls get increasingly more productive as the day goes on and are really rolling as evening approaches. They seem to be able to party all night. If you’re wondering why, scientists think it has to do with the “speed” of your internal circadian clock – larks have slightly faster clocks while owls have slower ones. It really doesn’t matter what the speed of your clock is, the trick is to work with your clock and not against it.

Clocks out of sync
Our body clock changes its speed as we get older. Babies seem to sleep the better part of the day (except in the middle of the right when you need your sleep most no matter what type you are). Teenagers like to stay up later at night and sleep longer in the morning. Adults, on the other hand, usually (but not always) end up sleeping somewhere between seven to nine hours. Pensioners (+65) sometimes move in the other direction by going to bed early and getting up earlier. This may seem quite natural, but what happens when we throw our clocks out of sync? 

Our bodies need routine
Remember your university days when you pulled several all-nighters to make up for the studying you should have done instead of partying? If you were like me, you thought you could make up any sleep you lost on the weekend. How did that work out for you? Not only did I “lose” a weekend, but I felt like crap when I did get up. That’s because our bodies need routine, and the best way to get that is to get up and go to bed at the same time every day. There’s a reason sleep deprivation is used in military training (and other areas, interrogations, for example) to push people to and sometimes past their limits. Ask me, I know. During Hell Week in BUD/S, we got 4 hours of sleep in 5 ½ days. And we didn’t get it all at once, either! Talk about zombies.

Body clocks gone wild
Another excellent example of body clocks “gone wild” is jet lag. When you fly across several time zones, your body clock really goes out of sync. And the more time zones you cross, the worse it gets. It usually takes a few days for your internal clock to adjust. And changing our clocks twice a year for daylight saving time is like jet lag without leaving the ground (although in the EU, that might end soon). But wait, there’s more. Messing up your clock can affect you in other ways you might not have thought of (whoops! Ended a sentence with a preposition. My old English teacher is probably turning in her grave). Naps can help you out, of course, especially in the mid-afternoon. But anything longer than this could make it harder for you to fall asleep at night.

Front-loading food
Our circadian rhythm even affects our eating habits and weight loss, according to nutritionist and author Tamara Duker Freuman, who has developed a meal-timing based plan she describes as the “circadian-synced diet.” Research has shown that you have a much better chance of making those unwanted kilos disappear when you front-load your calories (eating most of your calories early in the day). “What we’ve seen is that people on diets with the same number of calories who front-load calories to the earlier part of the day fare better in terms of subjective and objective measures of satiety,” Freuman says. “They feel more satiated in the evening, and there are actually differences in their hunger and satiety hormones … and this seems to contribute to weight loss success.” But wait, there’s more.

Healthy cellular function
Researchers at the University of Zürich discovered in a study that our circadian rhythm regulates protein transcription. “When you’re feeling tired and head off to bed, the proteins necessary for healthy cellular functioning are produced, peaking at two points in the day: right before bed and upon waking up. Sleep sets into motion the transcripts for protein-building, while waking up promotes synapse-firing, the communications device that allows neurons to speak,” according to the researchers. What can we take away from this? Honoring our circadian rhythm (getting seven-to-nine hours of sleep works for most people) promotes the optimal building of proteins and communication between neurons. If you deprive yourself of sleep, you’ll not only be tired, your mental health will end up paying a steep price over time.

Circadian rhythm and disease
We’re becoming increasingly aware that the more we get divorced from our circadian rhythm, the more we run the risk of getting sick. That’s right, your immune system can be affected, too. Some studies have demonstrated a link between messed-up circadian rhythms and cancer, diabetes, bipolar disorder and even obesity. Researchers have found that circadian rhythms can influence the treatment of disease. Apparently, even the time of day you have surgery or take a medication plays a role. Moreover, some scientists believe that our circadian rhythms may also influence the treatment of disease.

Sleep tips
If you’re having a hard time falling asleep, try these tips. Turn off the TV and dim the lights at least an hour before bedtime. Put away any screen that gives off a blue light as that glow signals your brain to stop producing melatonin. Take a bath, listen to some soft music and read a good book. Don’t fight your circadian rhythm, work with it instead! Remember, well over 90% of the repair work done on our bodies takes place at night. That’s what sleep is for. Getting eight hours of sleep is a means of preparing us for tomorrow. And for most of us, if we don’t get enough sleep, we still have to do tomorrow. Sleep on that!