by Sophia Pollalis ATC, LAT, CSCS

A circadian rhythm, not to be confused with the cicada rhythm of late summer, is the natural wake-sleep cycle your body follows. Not the one that you force your body into, but the one you experience when you go camping on a non-electric site. It’s a step back in time, a look at what our primitive ancestors did without a reliable source of artificial light. The sun rules your world. You wake with it, you wind down without it. It provides stimulus to wake up and stay awake. I was thinking recently of how much I related to Wall-E when he rolls out of his home rather ragged, pulls out his solar panel, and sits in the sun until he’s ready. As more of a night owl, I need this exposure to sunlight to really wake up. My circadian clock runs a little slow and it charges on sunlight. What does this look like?

Here is an example of a circadian rhythm. It’s just a simple sine wave of equal height and width that represents our wakeful drive. It’s highest a little after you wake up and decreases through the day. It rises while you’re asleep so when it’s time to wake up, your body has the drive to do it. This rhythm doesn’t change and it shifts only with the sun. When you travel halfway around the world or just to the next time zone, your circadian rhythm can be affected. Your body wants to adjust to the natural sun cycle, even when we can’t see it’s warm glow. It doesn’t matter if you hole up in your basement and don’t see the light of day for two weeks while you quarantine; your body still experiences this rhythm. Plants do this too. They raise their leaves to greet the sun, their flowers bloom in daylight so pollinators can do their work. Even when kept in a dark room, they still move in time with their internal clock. Unlike plants, though, we humans have jobs and those jobs don’t always match up with our personal circadian rhythms.


For example, during the school year my typical schedule is 12pm to 7pm. This allows me to wake a little later, get some sunshine in, take my time with getting ready, and naturally stay up a little later when I get home. I sleep wonderfully on this schedule. In the summer and weekends, my schedule shifts a little. Right now, I have to be at the school by 7am so I have to wake up at 5:15am. This is way to early for me personally. I can do it, but I don’t perform as well and it takes me quite a while to be fully awake and present. The same goes for early risers. They wouldn’t do as well with my late schedule during the school year but would thrive on my summer hours. Unfortunately companies can’t accommodate everyone, and most don’t think to do so in the first place.

The second simple part of sleep is our sleep drive. While our wake drive doesn’t change, our sleep drive does. When we wake up first thing in the morning after a good night’s rest, it’s at its lowest. It slowly builds throughout the day. If we’re on a regular schedule, it peaks at a time that the circadian rhythm is lowest. This makes the perfect combination of low wake drive and high sleep drive. We can of course fight the urge to sleep with stimulants like caffeine and artificial light or reduce our sleep drive by taking a nap.


Have you ever pulled an all-nighter working on a big project? That feeling of dragging from 12 to 4am? Needing a cup of coffee and all the lights on, maybe some loud music? Your sleep drive is continuing to climb and your wake drive is still pretty low but climbing. Like magic, when it comes time for you to normally wake up, you aren’t so tired, you might call it a second wind. Your wake drive is now at its peak. Voila! You made it through the night. The sun is out and you can probably make it through the day. It’s certainly not recommended to go without sleep for that long, but there is a science behind how you made it.

Blue light has become a very popular term in regard to eye strain and sleep. Specifically, blue light is a specific frequency of light that stimulates our brain into staying awake. The sun gives off tons of it which, according to our primitive ancestors, told us time of day and when we should be doing things. Because we now have technology at our fingertips at all hours of the day, we are receiving an excess of blue light at times that we wouldn’t normally have any light at all. I’m talking about your before bed Facebook scrolling, tv watching, email checking (which is another talking point on its own). Even after-dinner screen time, depending on what time you eat dinner and go to bed. Experts say you should reduce or eliminate screen time within two hours of sleep. Use this time to read a book or listen to music. Allow your natural sleep and wake drives take their place. While these are very generalized tips and points of learning, they apply to everyone.


From my personal experience when I give myself a rest from the screen, I sleep better and perform better the next day. I feel more refreshed, more myself. We live in a world that never sleeps and currently in unknown times. We can help ourselves by taking control of the things we can change, and understanding the natural processes that take place within us.