Circadian rhythms, commonly known as the “body clock”, are 24-hour cycles that are part of the body’s internal clock, running in the background to carry out essential functions and processes. One of the most important and well-known circadian rhythms is the sleep-wake cycle.
When properly aligned, a circadian rhythm can promote consistent and restorative sleep. But when this circadian rhythm is thrown off, it can create significant sleeping problems, including insomnia. Research is also revealing that circadian rhythms play an integral role in diverse aspects of physical and mental health.
How does it work?
The circadian rhythms throughout the body are connected to a master clock, sometimes referred to as the circadian pacemaker, located in the brain. Specifically, it is found in the suprachiasmatic nucleus (SCN).
The SCN is highly sensitive to light, which serves as an critical external cue that influences the signals sent by the SCN to coordinate internal clocks in the body. For this reason, circadian rhythms are closely connected to day and night. While other cues, like exercise, social activity, and temperature, can affect the master clock, light is the most powerful influence on circadian rhythms.
Hormones also play a role in your circadian rhythms. The hormones melatonin and cortisol may increase or decrease according to your circadian rhythm. Other factors like metabolism and body temperature can also affect your circadian rhythm.
What affects your circadian rhythm?
There are many factors that affect your circadian rhythm. Some of them are:
- Shift work: Work obligations can cause major disruptions in a person’s circadian rhythm. Shift work, which requires having to work through the night and sleep during the day, puts a person’s sleep schedule directly at odds with the local daylight hours.
- Unhealthy sleeping habits: Having unhealthful sleep habits may disrupt the circadian clock across the day. This may include issues such as going out late and waking up early, consuming caffeine at night, having no set sleep time, not having a comfortable sleeping space etc.
- Travel: People who travel frequently may experience disruptions in sleep and their circadian rhythms, especially if they often move between time zones. This is known as jet lag, the groggy or tired feeling as the body tries to catch up with time changes and the new rhythms of the day.
- Stress and mental health conditions: Having a stressful lifestyle and various mental health conditions like insomnia, depression and anxiety can also have an impact on the circadian rhythm.
How to maintain a healthful circadian rhythm
There are several important factors to consider when maintaining a healthful circadian rhythm.
If possible, go to bed and wake up at the same time each day. Setting a regular time may help the body set its rhythms around these times. Some choose to set a morning alarm to wake up at the same time each day. This may help the body adjust and encourage tiredness when they need to sleep to wake up on time.
Here are some tips that may help promote a healthful circadian rhythm:
- going outside or in bright light in the morning
- avoiding caffeine late in the day
- taking small naps in the early afternoon if a person needs to nap
- avoiding long naps or napping later in the day
- avoiding heavy meals
- performing calming activities before bed, such as reading or doing gentle stretches