Your Circadian Rhythm and How to Adjust It
While many people have heard the term "circadian rhythm" and know that it has to do with the body's sleep cycle, few understand just how this sleep rhythm gets established — or disrupted. However, understanding the circadian rhythm, sleep and how to adjust it is important for an overall healthy lifestyle.
What is Circadian Rhythm?
Most bodily processes occur in rhythms or cycles. However, those that take roughly 24 hours to complete are called circadian rhythms, according to UCLA Health. While we often refer to it as a single circadian rhythm, there are actually several circadian rhythms in the body, and they affect important functions like temperature, blood pressure, mental alertness and hormone levels. One of the essential circadian rhythms is the sleep-wake cycle.
The National Institute of General Medical Sciences (NIGMS) notes that circadian rhythms are governed by a group of about 20,000 nerve cells that form a structure known as the suprachiasmatic nucleus (SCN) located in the hypothalamus in the middle of the brain. The SCN is responsive to daylight and uses information it receives from the eyes about incoming light to speed up, slow down or reset your body's clock by controlling levels of melatonin, a hormone needed for healthy sleep. As it gets dark at night, the SCN tells the brain to produce more melatonin to induce sleepiness, and in the morning, when light increases, the SCN tells the brain to slow production of melatonin so you can wake up more easily.
Circadian Rhythm Sleep Disorders
However, according to UCLA Health, work, school and social commitments may interrupt sleep routines. One such example is jet lag, a common circadian rhythm disorder. It often occurs when an individual travels across several time zones and their sleep cycle has trouble adjusting. This type of disruption can cause insomnia, daytime drowsiness, irritability and difficulty concentrating, and it can take up to a week to adjust to the new schedule.
Another common disruption is the shift work disorder, which affects people who work night shifts or rotating shifts. They are awake when the body naturally wants to sleep, and sleeping (or attempting to sleep) during the day when the brain is programmed to be awake. Because of our natural disposition and the SCN's ability to signal melatonin production during daylight hours, those affected by the shift work disorder get less sleep than those who sleep at night, and their sleep is fragmented.
Adjusting Circadian Rhythms
While circadian rhythm disruptions can affect the body's health and well-being, there are few natural ways to adjust your body's internal clock. According to Sleep.org, factors like light exposure, exercise and mealtime schedule all affect the circadian rhythm and can be used to get your body back in sync. For example, if someone needs to get up at an earlier hour, light is the most effective tool to help them feel less tired and get the sleep they need. Turn the lights down an hour before the desired bedtime to signal to the brain that it is time to sleep, and in the morning, turn on as many lights as possible to promote wakefulness.
Mealtimes can also affect circadian rhythm. For instance, if someone wants a later bedtime, they should try eating at a later hour. This moves the internal clock back and signals to the brain to go to sleep later. Physical activity in the evening rather than in the morning can have the same effect. However, it is a good idea to make these changes gradually and give the body time to adjust to your new schedule rather than making these changes overnight — literally.
Overall, the circadian rhythm is a vital part of the body's sleep cycle — which is why disrupting it can lead to a number of health problems. However, there are simple ways to reset the body's sleep habits even when there are issues like jet lag or shift work disorder to overcome. Try resetting your circadian rhythm for a better night's sleep and a better morning every day!