Are you an Early Bird or a Night Owl? Know your inner clock.

The body has a natural time-keeping system that it uses to manage various systems. Biological rhythm is a term often used interchangeably with circadian rhythm.  These rhythms control cycles like sleep, wakefulness, body temperature, hormone secretions and more.  Our bodies maintain their biological rhythms through chemicals at the molecular level in response to their environment, how much exercise we get, and what medications we take.  They do not like to be disrupted and if they are, the disruption can lead to serious health issues.

Biological rhythms are determined by 20,000 nerve cells in the part of the brain called the suprachiasmatic nucleus that is housed in the hypothalamus. They run on 24-hour cycles.  Most living things have biological rhythms. For example, bio-rhythms keep nocturnal animals in their shelters during the daytime, they help flowers open and close at the right time, and even some germs have them.  The rhythms coordinate many mental and physical systems like the digestive system, and the endocrine system. They help our bodies maintain healthy temperatures and regulate our hormonal activity.

Our inner clock helps regulate and affect functions that include:

  • Sleep schedule
  • appetite
  • body temperature
  • hormone levels
  • alertness
  • daily performance and productivity
  • blood pressure
  • reaction times


The light/dark cycle of the sun has an important effect on our internal clock, our sleep, and our productivity when we are awake. Light plays an important role in setting our “clock”.  We should increase the amount of light exposure during the day and darken our bedrooms at night to sleep better.  Body temperature starts to rise in the last hours of sleep, maybe to encourage alertness for when we wake.  Body temperature decreases at night when we are going to sleep and melatonin, a hormone that makes us sleepy, is released.  We also experience a small drop in temperature between 2 – 4 PM which is why many people feel sleepy in the afternoon.  When the sun rises again, the brain is signaled by the light to turn down the melatonin.

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Early Birds:  These people wake up easily in the morning and have the most energy and are most productive early in the day. If you are an early bird, don’t schedule work or tasks that require focus for the afternoon.

Night Owls: These people find it more difficult to wake up in the mornings and feel alert.  They have the most energy quite late in the day and evening.  If you are a night owl, don’t try to accomplish tasks or work challenges before you are fully awake.

Biological rhythms change as we age. For example, our body clock shifts during adolescence and teens want to go to bed later and sleep later than younger children.

How to get in touch with your biological rhythms:

To really be able to experience your body’s biological rhythms, devote three or more days to listening to your body.  Do not use an alarm clock, so you can see when your body naturally wakes up, and when you feel sleepy in the evening.

Rhythm Disorders

Here are some results of rhythm disorders:
Problems falling asleep
Daytime drowsiness
Depression and mood disorders
Lower productivity at work
Being more accident prone
Decreased cognitive performance
Increased risk of diabetes and obesity

If we are fighting with our biological rhythms, it becomes difficult to be productive. Try a few lifestyle changes such as getting more exercise, and limit naps.  Here are specific ways to keep our biological rhythms operating efficiently:

  • Sleep – Stick to a sleep schedule. Try to go to sleep and wake up within a half hour of the same time each day, even on the weekends.
  • Jet Lag – When you change time zones, your body will try to function on the time it is at home. That is jet lag.  Your body will adjust in a few days, but you might not be at your best until then.
  • Screen time – You should unplug from all your devices at least two hours before bed because any amount of light signals your brain that it should wake up and be alert. Artificial light and even alarm clock light can have the same wakefulness effect.
  • Eating habits – Having late dinners or large snacks too close to your bedtime can send signals to the brain to rev up digestion and stay awake.
  • Time of exercise – The time of day you exercise can affect the signals being sent to the brain. If you exercise after work or in the evening and have trouble falling asleep, try different exercise times to see if your biological rhythms are happier.
  • Check the drugs you ingest – Caffeine, alcohol, melatonin, marijuana, and other drugs might be impacting your inner clock.

If problems persist and you feel out of sync with your inner clock, consult your healthcare provider.