Some days we have this feeling of unexplained tiredness as soon as we wake up. As we push ourselves through the day, this fatigue or lack of energy continues. Also our focus and productivity level goes down. One important reason why this happens is disturbed ‘biological clock’. Read this blog to find out how to reset biological clock of human body and function at your fullest ?

Introduction to ‘Biological clock’, ‘Circadian rhythm’ and ‘Sleep - Awake cycle’

Biological clock is an internal timing mechanism active inside all living beings. It sets a biological rhythm in our body over 24 hour period of a day. This rhythm is better termed as “circadian rhythm”.

It is because of this circadian rhythm we are able to maintain “sleep-awake cycle”. Which is why, we are most active during daytime and restful towards night.

But there are many factors that disrupt biological clock of human body. Once that happens it impacts our health, relationships and also job, adversely. Here we will unravel how to reset this physiological clock in body.

11 Ways How To Reset Biological Clock of Human Body

We are living a lifestyle that deranges natural biological clock of body. Which ultimately imbalances body metabolism. Detoxification process slows down and metabolites / toxins accumulates inside body. This disordered metabolism invites not only various physical ailments but also mental illnesses like depression and mood disorder.

Below we have mentioned 11 ways to reset our bodily clock. Few points stated here are obvious and probably you are aware of them. But you have not applied these fully yet. However, some pieces of information are so recent, I bet you did not know them before.

1. Expose to morning sunlight :

Out of all external factors ( zeitgeber ) the one that plays topmost role in maintaining sleep-awake cycle is solar light. When sunlight falls on retina of eyes, it signals brain that this is day time. This signal suppresses sleep hormone ‘melatonin’. As an effect, we wake up from sleep.

Hence the best thing to do as soon as you get up from bed is to expose yourself to morning sunlight. It resets body from sleep mode to alert mode and gears it up for the day.


2.Routine sleep-awake schedule :

There should be a regular schedule for going to bed and waking up daily for a person. The day to day variation in sleep time or awake time should not be greater than 30 minutes.

Also you should go to bed early and wake up timely to sync with physiological clock of body.

So what should you do if you are going to bed late ?

Reschedule your sleep time. Best way to motivate yourself is, to plan the next day morning routine in advance. Jot down the things you want to do very next morning and assign time to each task. For instance exercise at 6 am, journaling at 7 am etc. Once you write it down, it directs brain to manifest it.

Nevertheless do not do any drastic change in your schedule. For instance if you go to bed at 1 pm and wake up at 8 am customarily. And you intend to shift it to 10 pm and 6 am. How would you do that?

Science says do not make any extreme change in your routine. Shift the timing by 15 min at a time.

This is because biological clock is already set to previous routine. And it warrants some time to reset.

3.Avoid screen before bed time :

Scrolling through smart phone while going to sleep is quite mainstream. And then we wonder why we are so tired and exhausted the next morning or sometimes the entire day. The answer is here.

Modern devices like cell phones, tablets, laptops and televisions use LED ( Light Emiting Diode ) blue light. Natural blue ray present in solar light is beneficial for body. But artificial LED blue lights in screen devices suppress sleep hormone ( melatonin ) secretion in brain at night.


Melatonin is the most crucial hormone that gives us sound sleep. Blue LED light reduces it significantly by almost 5 times. This leads to sleep disturbance and hence over-tiredness the next day

What should you do then? Stay clear from screen devices at least 1-2 hours before going to bed. Practice this religiously and notice the difference in your energy level in body.


4.Switch off bright light in evening :

Our body is designed to stay active during day and rest during night. Light plays a crucial role here to signal our body if it is day or night.

Bright light at night gives a delusion of day. It tells brain to stay active and alert, instead of taking rest. Thereby it is desirable to dim the light in evening hours.

5.Meal time :

Pay attention to your meal time. At what time you should take breakfast or lunch or dinner is as important as what food you should choose to eat. Being said that, you ought to eat right food at right time.

Avoid late night food.

Now a days it is a common practice to grab some food from fridge and eat past midnight. But bear in mind that night time is the worst time to take food.

This is when body systems are supposed to relax, repair and revive. Our biological clock takes “EATING-FASTING” as external cues to detect day and night. For example, when we eat, it conveys the impression to brain that, it is day. Likewise when we fast it tells brain that it is night and hence time to relax.

Taking food at late night will engage all the bodily system to again work to digest and assimilate that food instead of relaxing. So this clashes against physiologic clock of body and messes it up.

Best possible time is to take food is 2-3 hours before going to sleep. So that by the time you sleep food is already digested. It also prevents acid reflux.

7.Cut down on caffeine:

Even I am guilty of doing this many times. That I too take caffeinated beverages at odd time of day. Coffee and tea and certain other beverages have caffeine in it. If you are habituated to these, then take in morning hours.

Moreover never take caffeine products like tea and coffee in late afternoon or evening. Doing so hampers biological rhythm of body. Hence make it a rule not to touch these products after 3pm to 4 pm.

8.Avoid long day-time nap :

How many of you had this uneasy feeling after taking a long day-time nap ? You sleep for hours in afternoon post lunch and when you wake up you feel lost. It is because long afternoon nap confuses our body rhythm.

Ideal is to take nap for 20-30 minutes maximum, that too in early afternoon. Refrain from taking nap in late afternoon

9.Weekend routine :

How does “Monday blue” feel like? Why is it so unpleasant to wake up on a Monday morning and go for work? The reason is our weekend schedule.

Often our weekend sleep habit deviates significantly from week days. We tend to sleep very late and wake up late too on weekends. And when on Monday morning, we get up early and get ready, our body is not quite ready. This maladaptation of biological rhythm will not occur if we keep our weekend routine close to normal.

10.Night routine :

Night time relaxing activity like reading light books, taking warm bath, listening to soft music, doing skin care routine etc prepares our body for a good nights sleep.

11.Night shift dos and don’ts :

Night shift hits our biological clock in worst possible way. But at times, there is no way we can deny ourselves from it. 

So how to reset biological clock of body if in case, you are on night shifts ?

Work at maximum bright light at night during shift hours. Once you are on way to home use sunglasses, that will dim sun lights a bit and brain will start off synthesizing melatonin. Upon reaching home sleep in a noise free complete dark room with light block curtains and blinds on.

12.Handle stress positively :

Day to day stress hampers sleep-awake cycle bitterly. Practice meditation, breathing exercise etc. Also spend time with nature .  s It is an effective way how to stay calm and lessen stress.

13.Physical activity :

Physical activity, even as less as 15 min of yoga / stretching/ morning walk daily betters sleep cycle. Hence it avoids the diseases that would happens when we do not sleep enough

Best time to exercise is morning hours. Or you may workout  in afternoon also.

But do not exercise before going to sleep, as some people do because of tight schedule. This hour is to loosen up.

14. Avoid night Social life :


Clubbing is not cool, if you are really concerned about your physical and mental health. Our social life should be exclusive to day time.

“SOCIAL ACTIVITY -ISOLATION” act as external indicators ( zeitgebers ). When we are socially active our body perceives it as day. And when we are isolated, our body senses it is night and time to rest. So if you ask me how to reset biological clock of body, I would say stay away from clubbing and partying at night.

15.Dietary Vitamin A :

Deficiency of this vitamin A impedes sleep awake cycle. Hence take adequate vitamin A containing foods like carrot, spinach, red pepper, papaya, egg, fish, meat, dairy products etc in diet.

16.Avoid alcohol and drugs :

Alcohol and other drugs alter genes of biological clock at cellular level. Hence these substances malfunction biological clock. Avoid these as much as feasible.

17.Medical help :

If all the above mentioned methods fail to reset biological clock, then take medical consultation. Following treatments might help.

Exposure to very bright light for 1-2 hour

Used to treat certain health conditions 

  • To gradually shift and restore sleep cycle 


To conclude the key is to maintain a routine life and be regular at it. That is how you can reset biological clock and persistently maintain it too.

Share this article to maximum of you find it useful. Comment below your doubts or suggestions if any.


All the informations provided here are for educational and awareness purpose only. Kindly do not use these as alternative to medical consultation.

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