What You Need to Know About the Circadian Rhythm
If you need persuading that all living beings are part of a greater natural design and living cosmos look no further than the circadian rhythm. Circadian rhythms are found in most living organisms including animals, plants, fungi and tiny microbes.
What is the circadian rhythm? In a nutshell, it is the physical, mental and behavioural changes that occurs as the result of a daily (24 hours) cycle of light and darkness. Humans, in particular, have a collection of 20,000 neurons (nerve cells) that form a complex structure called the suprachiasmatic nucleus (SCN). Think of the SCN as our internal master clock, which is located in the anterior part of the hypothalamus and situated above the optic chiasm in the brain. The SCN and the process of modulating stimulus from the eyes is what produces a person’s circadian rhythm.
The SCN works in tandem with other bodily systems and, more broadly, one’s surrounding environment. As a physiological system one’s circadian rhythm is affected by light and darkness, which explains why certain external cues can either speed up or slow down the cyclically pattern. This is why jet lag can hit us so hard. When you’re passing through different time zones your biological clock will be at a different time from your destination. For instance, if you fly from Hong Kong to New York City you “gain” 13 hours (or 12 hours accounting for Daylight Saving Time). When you wake up at 7:00 am in NYC your biological clock is still functioning on Hong Kong time, which would be 8:00 pm (or 7:00 pm at DST). This discrepancy in time and change in natural light is what makes you feel out of sorts. It often takes a few days to reset our biological clocks.
The circadian rhythm influences a host of physical and behavioural routines like sleep-wake cycles, hormone release, appetite, digestion, and body temperature. To be sure, life’s challenges can easily disrupt the circadian rhythm, but we can typically restore equilibrium quickly. If, however, you experience a fitful circadian rhythm that is difficult to shake off it’s best to seek professional help. Irregular rhythms have been linked to chronic health conditions like diabetes, depression, obesity, sleep disorders, and seasonal affective disorder (SAD).
Undoubtedly, modern life has impacted people’s circadian rhythms. Technological devices like smartphones and overall screen time affect bodily functioning. “Sleep hygiene” denotes the habits that promote a good night’s rest. Some changes that we can adopt to improve sleep hygiene and, therefore, regulate our circadian rhythm are the following: go to bed at the same time each night; turn off all lights; turn off all smart devices; cut off-screen time half an hour before going to bed, and make your bed a sanctuary by reserving it for only sleep and sex. Similarly, adopting certain practices during the daytime help maintain one’s circadian rhythm at peak performance. For example, 15-30 minutes of exposure to natural daylight lifts one’s mood and improves concentration.
While changing personal habits and sticking to them will improve one’s circadian rhythm, drastic improvement in sleep and overall energy is often attributed to regular exercise or sports. Our bodies, as biological organisms, are perpetually seeking homeostatic balance. Exercise releases endorphins that can get the body revved-up or turned-down. Because exercise and the circadian rhythm work in conjunction with each other, certain forms of exercise are better done during different parts of the day. For instance, it’s best to do cardio early in the morning to get the body started for the day and strength training in the afternoon. Likewise, yoga in the evening helps the mind and body to unwind helping you get ready for a good night’s sleep.
The old adage, “early to bed and early to rise makes a man healthy, wealthy and wise” is an obvious truism. It’s worth looking to people of bygone times to give us pause and reflect on our present circumstances. This doesn’t mean that we should feel a sense of anxiety or apathy because we cannot fully recover those conditions in our current times. Rather, the point is that insight is what helps us ask relevant questions and encourages positive behavioural changes. Human beings are creatures and we function best in harmony, not opposition, to Nature.