A few weeks ago, we posted a piece on the new Hours of Service Regulations for drivers of Commercial Motor Vehicles (CMVs). The rules continue to change, due to accidents on our roadways which continue to occur and research being conducted which helps us to understand what factors, exactly, are causing these accidents. One theory which researchers have been studying for years is the concept of Circadian Rhythms.
Circadian Rhythms are related to our biological clocks. Our biological clocks regulate our bodies throughout our lifetimes, and, on a smaller scale, our Circadian Rhythms regulate and affect each day of our lives. Each of us has our own, individualized Circadian Rhythm, which is based on each individual’s lifestyle. Specifically, the term “Circadian Rhythm” refers to a person’s 24-hour clock. The concept is based on the idea that our bodies have internal clocks, which operate like…clock-work. Most of us operate on a 24-hour clock. During our 24-hour days, our bodies go through various processes, depending on what we are doing–waking up, eating, going to sleep, etc. The processes include sleeping patterns and digestion patterns. At what time bodily processes occur determine at which times throughout the day we are naturally inclined to be most alert or drowsy.
Many environmental factors can affect a person’s Circadian Rhythms, including exercise, stress, and meal schedules. The factor found to be the strongest at affecting a person’s Circadian Rhythm is daylight. Basically, the human Circadian Rhythm is based on responses to light and dark. Every organism on this planet has some sort of Circadian Rhythm, a pattern of wakefulness and sleeping which that organism is naturally predisposed to act out. Humans have been trained to have our wakefulness triggered by daylight. Traditionally, daylight causes us to be more awake and more alert, because the daylight sends signals to our eyes, which send signals to our brains, to release certain hormones which wake our bodies up. Like daylight, darkness does the same thing. Darkness has been known to trigger the release of melatonin, the “sleepy hormone.” Some people who suffer from insomnia take melatonin supplements, to help them sleep.
In addition to hormone release, Circadian Rhythms affect “body temperature and other important bodily functions,” according to the National Institute of General Medical Sciences’s website. Chronic disruption of a person’s Circadian Rhythm has been linked to heart disease, weigh gain, anxiety, and depression. This is due to the fact that a person’s Circadian Rhythm, which tells a body when to sleep, when to wake, and when to eat, determines at what times the body releases certain chemicals which aid in digestion and regulate a person’s heart rate. If you are eating at an irregular time, when your body is not programmed to release chemicals which help your body digest food, this can disturb your metabolism and confuse other processes in your body which are related to your metabolism. If you are unable to sleep when you want to, due to an erratic schedule, this could lead to problems with fatigue and insomnia. Disruption of the Circadian Rhythm can also affect a person’s sensitivity to certain drugs, such as caffeine and alcohol.
This phenomenon is usually studied as it relates to jet lag, the issue that many travelers face when they travel from one time zone to another. But, it affects many other people, in various other walks of life, as well. Other people who often suffer from disruptions in their Circadian Rhythms are airplane pilots, truck drivers, business men and women who frequently travel from one time zone to another (e.g., someone who works out of New York City AND Los Angeles), people who do shift-work, and even teenagers, whose bodies are dramatically changing day to day.
Though a person’s Circadian Rhythm may be altered somewhat, this takes time and consistency. Even then, our natural clock will still want to be in control. The problem arises when a person has no consistency in his/her sleep patterns – or even with a consistent lifestyle, fails to get the proper sleep and rest to “reset” our clock on a daily basis. If your sleep pattern is changing day-to-day, with no coherent pattern, your body is unable to predict when it must start settling into sleep or waking up. As many of us know, it is oftentimes difficult to sleep when we want to sleep or when we need to sleep. For most of us, being able to sleep, or telling our bodies to go to sleep is not as easy as turning a light switch on or off. And an “unnatural pattern” (working nights, etc.) can be made more difficult if we try to stay awake longer than we should, in order to get things done during the day before heading back to work at night, and deny our body the rest it needs.
Failing to heed our natural Circadian Rhythm can lead to a lack of concentration, lack of ability to react to circumstances, and an overall malaise that can affect our health and safety – and that of those around us.