Here´s why your circadian rhythm matters

February 28, 2022
Reading time: 5min

A circadian rhythm or circadian cycle is the process that regulates your sleep and your being awake cycle. This rhythm is something your body process naturally and it´s running in the background. Usually, circadian rhythm repeats itself in every 24 hours.


A circadian rhythm or circadian cycle is the process that regulates your sleep and your being awake cycle. This rhythm is something your body process naturally and it´s running in the background. Usually, circadian rhythm repeats itself in every 24 hours.

Circadian rhythm affects all aspects of your life – your sleep and daily life and energy levels. There is no strict circadian rhythm carved in stone. Still, naturally our bodies respond to the light. Also, it is affected by temperature.

Circadian rhythm can have an enormous impact on our sleep. Messed-up circadian rhythm can totally mess up your sleep. Irregular or disrupted day and night rhythm may lead to some serious sleeping disorders.

Circadian rhythm is common to all organisms, even plants. For humans, circadian rhythm plays a significant role in our mental and physical health. Circadian rhythm is mostly controlled by our brains. Throughout the day, when there is light, our brain is giving us a signal, that it´s time to keep ourselves busy with daily activities. Somewhere around sunset, our bodies will start to wind down and gradually produce the hormone called melatonin. This prepares our bodies to restorative sleep.

If you happen to be a night-owl and your body can´t get enough sleep at night, the odds of depression or other mental illnesses rise significantly. Getting enough sleep may also affect our immune system. Lack of quality sleep makes you more responsive to seasonal illnesses.

3 habits that ruin your circadian rhythm

  1. Night Owl syndrome i.e. staying awake at night – probably we all know someone, who enjoys being awake late at night. But this can lead to significant productivity problems in the daytime, also messing up your circadian rhythm.
  2. Late-night worker – when there are busy times at work, the rare work shift at night is not something you should be concerned about. But if you are practicing it for months, it can soon become a problem.
  3. Taking a nap in the evening – 10 minutes of light phase sleep in the evening can lead you to tossing and turning all night. If this is common for you, then you should review your daily routine and schedule.

In addition, circadian rhythm can be disrupted by jetlags, while you are traveling. That´s why it is important to plan some extra time to take some rest while you arrive to your destination, to let your body to adapt local time.

Our natural circadian rhythm

Natural and healthy circadian rhythm is achieved by a routine, is related to day and night, and starts with acknowledging the processes in our body and brain. This includes sleeping, waking up, working hours, exercising, and winding down.


  • With sunrise, the melatonin release in our bodies gradually stops. This gives our brains a signal, that it´s time to wake up and to start with your day.
  • Somewhere around 7-8 AM it´s time to get some light. Open the curtains to let the sunlight in. Also, it´s a good idea to take a walk to the office or school, to maximize the effect of light exposure.
  • A healthy breakfast is the foundation of your productive day. Eat food that´s full of healthy fats, proteins, and carbohydrates.
  • Between 9 AM and 11 AM our alertness is usually highest. This is a good time to perform tasks that need your full attention.


  • At noon, it´s time to nurture your body with some nutrients. Eating your lunch is important, so don´t skip it.
  • In the afternoon, you will have the best coordination and fastest reaction time. Attend a training session or call a meeting in Teams or real-time.
  • Do not consume caffeine before 3 PM.


  • Evening is the right time to enjoy dinner and talks with your friends and family, and also to wind down.
  • When the sun is down, our body naturally starts to feel more relaxed. Also, you can dim your lights at home to feel more cozy and to wind down.
  • Limit your screens at least 2 hours before bedtime. Be sure this rule is applied also to your kids, as their brains are even more sensitive to bluelight.


  • Somewhere around 11 PM, melatonin release starts and your body is feeling sleepy. It´s time to go to bed!
  • At 2 AM, our bodies will have the deepest sleep of the night, followed by the valuable REM sleep phase.
  • Just before waking up, our bodies usually have the lowest temperature. Starting from there, the whole process starts again.

Tips for adjusting circadian rhythm

If you have some issues in your day-and-night cycle or your energy is low during the day, then you probably need to redesign your circadian rhythm. Here are some tips:

  1. Set up a routine – try to set your own schedule, when you will go to sleep and when you wake up. Be sure to stick to that routine even on weekends.
  2. Work out – exercising helps your body to stick with natural circadian rhythm and melatonin production. Some people may gain benefits from and early yoga session, while others need hard gym work in the afternoon. Either way, don´t schedule your workout right before bedtime.
  3. Avoid beverages in the evening, especially coffee and wine – consuming caffeine in the evening might keep you awake at night. Wine might make you feel fuzzy, but decreases your chances to get a good quality sleep at night. Alcohol may affect your whole circadian rhythm, especially when consumed right before bedtime.
  4. When your circadian rhythm is out of pace, train your brain and body with 0,5 h pace – for example, if you currently go to sleep at 1 AM. and wake up at 8 AM, try going to bed at 12:30 AM and waking up at 7:30 AM. Practice this new schedule for a week. If your body has accepted this shift, then shift those times back another half-hour the following week, and so on.