circadian rhythm
Sleep Health

Why Maintaining Your Body’s Circadian Rhythm is Important

Circadian rhythms are physical, mental and behavior changes that follow a 24-hour cycle within our bodies. This internal clock is controlled by the hypothalamus in our brains, in response to light and darkness, as well as other external cues such as temperature. Nearly every hormone in the human body is released in response to our body’s circadian clock.

Light in the morning hits the optic nerve, transmitting a message of “awake” to the hypothalamus. That translates to an elevation of body temperature and heart rate, as well as other biological changes such as an increase in hormones (including cortisol) and a decrease in sleep-related hormones.

When our eyes are not being hit by light, that signals it is nighttime. The body then produces melatonin and serotonin, two hormones which help us to get drowsy and fall to sleep, and the body temperature drops. Restorative biological processes such as cell regeneration occur, along with many “clean-up and maintenance” processes in the brain and body.

Before electricity, people went to bed when the sun went down and got up early, when the sun came up. Artificial lighting, late-night technology use and our whacky schedules have somewhat detached us from a natural 24 hour cycle, resulting in many of us not getting enough healthy, restorative sleep. Sleep disorders may occur, and insomnia may get addressed with sleep aids, which can further confuse your body’s natural rhythms. Abnormal circadian rhythms have been associated with obesity, depression, diabetes, psychological disorders and seasonal affective disorders.

Circadian Rhythms and Sleep

Teens in particular suffer from sleep deprivation due to disrupting their circadian rhythms. They stay up too late staring into their brightly lit technology, and then have to get up too early for school (likely when their sleep hormones have just kicked in). They drink caffeine throughout the day, and many take melatonin at night. This same unhealthy pattern is seen in many self-proclaimed “night owls” as well.

To further compound the issue, night owls may sleep late on the weekends, thinking they are “catching up”. This further disrupts their natural rhythms, which can lead to mood disorders, irritability, and even a compromised immune system.

Interestingly, high school schedules are not designed to support a teen’s natural behavior and healthy circadian cycle. And many jobs also do not fit well with natural circadian cycles. People tend to be at their peak performance only in very late morning and around dinnertime! How do those peak performance times coincide with your day?

Circadian Rhythm’s Impact to Workers’ Health and Safety

Imagine all the emergency physicians and other night shift workers (long-haul truck drivers, police, and more) who routinely hold life-affecting decisions and activities in their hands – and imagine how fatigued they are.