Honoring Our Circadian Rhythm – For Peak Performance

sunrise and circadian rhythm

Sleep is of utmost importance in order for us to feel and perform our best. We all have a natural internal rhythm, known as our circadian rhythm or clock. This internal clock dictates the best times for us to fall asleep at night, how much sleep we get, and when we wake up. This rhythm is connected to our every being, including our microbiome, which we now know is affected by changes in our natural rhythm.  Many things impact our sleep cycle, and thus affect how we are feeling, our energy level, our performance with exercise, and work, and even our mood and behavior. Some of these include blue light emission from screens (especially before bed), artificial light and not enough sunlight during the day, frequent travel throwing our cycles off, and staying up too late at night.

‘Disruptions of the circadian rhythms in shift workers are known risk factors for psychiatric disorders, gastrointestinal alterations, sleep and cognitive impairments, and breast cancer’

As a culture, we do not place a high enough value on sleep. Sleep is a foundation to health that is just as important as nutrition and movement. Sleep is when we produce growth hormones, heal, and regenerate. What are some ways in which we can honor our natural sleep cycle? First and foremost we need to expose ourselves to sunlight during the day, especially in the morning.

Getting Morning Sunshine

It is important that we get sunlight on the face, especially first thing in the morning. This helps us to produce melatonin, a hormone that improves sleep latency  and staying asleep at night. When we are exposed to dim or artificial lights in the morning, we do not get the signals to produce sufficient melatonin. Sunlight during the day corresponds to better sleep at night! This is especially true in climates where it gets very cold, and we aren’t outside as much. It’s still imperative to bundle up, and get outside, especially in the morning. This morning light sets the tone for our sleep at night!


Wear blue light blockers

Blue light blocking glasses do just what it says, they block blue light. What is blue light? Blue light is part of the light spectrum that has a very short wavelength, and produces a high amount of energy. Blue light comes from the sun, as well as televisions, cell phones, laptops, and tablets. Blue light from the sun peaks during the daytime. Our ancestors would be in sync with the sun, and go to sleep when the sun sets. However, our blue light use, with artificial lighting and electronics, now extends into the evening. Blue light before bed disrupts our circadian rhythms, and can make it difficult for us to fall asleep and stay asleep. Being on a device just before bedtime induces circadian phase delay and melatonin suppression, alters sleep quality, and reduces cognitive performance the next day. Exposure to natural light from the sun during the daytime, can help to counteract using a device with artificial light before bed.

Get to Sleep Early

We get the deepest most restorative sleep earlier in the night. This is when our body releases growth hormones, repairing and rejuvenating. Cortisol (the stress hormone), peaks in the morning and tapers at night. However, when we are not getting enough sunlight during the day, or are overexposed to blue light at night, this can increase our cortisol at night and keep us up later, thus affecting our natural sleep cycles.

In order to feel our very best, we need to honor our natural sleep cycles, just as the sun rises and sets. It’s time that we value sleep, and try to get to bed earlier in the night, when our body gets the most restorative sleep. Refrain from using electronic devices before bed, and if you need to be on them, wear blue light blocking glasses. Finally get out in the sunshine year round, especially during the morning hours. Your body responds to the sun, and produces adequate hormones to help you sleep better at night!



York A (2017). Rhythm and bacteria. Nature Reviews Microbiology, 15 (67). DOI: 10.1038/nrmicro.2016.192
Hatori M, Gronfier C, & Van Gelder RN et al. (2017). Global rise of potential health hazards caused by blue light-induced circadian disruption in modern aging societies. Aging and Mechanisms of Disease, 3 (9). DOI:  10.1038/s41514-017-0010-2
Kozaki T, Toda N, & Noguchi H et al. (2011). Effects of Different Light Intensities in the Morning on Dim Light Melatonin Onset. Journal of Physiological Anthropology, Vol 30, Number 3, pp 97-102. DOI: http://doi.org/10.2114/jpa2.30.97
Chang AM,  Aeschbach D, & Duffy JF et al. 2015. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A.;112(4):1232-7. DOI: 10.1073/pnas.1418490112.
Rångtell FH, Ekstrand E, & Rapp L et al. (2016). Two hours of evening reading on a self-luminous tablet vs. reading a physical book does not alter sleep after daytime bright light exposure. Sleep Med.;23:111-118. DOI: 10.1016/j.sleep.2016.06.016.

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