You may already have heard of the Circadian Rhythm and you may be aware that it is this rhythm that makes you feel sleepy at night and helps you open your eyes in the morning.

What you may be surprised to learn, is that the Circadian Rhythm is responsible for A LOT more than that! In fact, almost everything!

Let’s talk a little about what the Circadian Rhythm actually is…. defines Circadian Rhythm as a daily rhythmic activity cycle, based on 24-hour intervals, that is exhibited by many organisms.

To expand on this, Circadian Rhythm is controlled and can be optimised by 2 main inputs, namely, light and food, or the absence thereof.

You see, our bodies’ biological cycles run roughly in 24 hour cycles.

At night, we feel sleepy, we go to sleep and sleep for around 8 hours,HOPEFULLY!

During those 8 hours of sleep, the brain and body go through a variety of processes at roughly the same time every night.

The Queensland Government In Australia Has Put This Idea Together Beautifully –

1) Your brain Sorts And Processes The Day’s Information

Don’t be fooled into thinking that when you’re asleep your brain has shut off too.

Your brain is actually quite busy while you sleep, sorting and storing information from the day. 

This process is particularly important for creating long term memories, as your brain consolidates all the information it’s picked up during the day and files it away for later use.

2) Hormones Flood Your Body

There are a number of different hormones released during sleep, all with different purposes.

Melatonin, released by the pineal gland, controls your sleep patterns. Levels increase at night time, making you feel sleepy. While you’re sleeping, your pituitary gland releases growth hormone, which helps your body to grow and repair itself. 

3) Your Sympathetic Nervous System Chills Out

During sleep, your sympathetic nervous system – which controls your fight or flight response – gets a chance to relax. 

Studies have shown that when we’re deprived of sleep, sympathetic nervous system activity increases, which is also mirrored by an increase in blood pressure. 

Scientists studying coronary disease are investigating whether there’s a relationship between decreased sleep duration and increased risk of heart disease.

4) Cortisol Levels Lower

Levels of cortisol, often called the stress hormone, decreases during the first few hours of sleep before rising to peak soon after you wake up. This helps makes you feel perky when you wake up and switches on your appetite.

5) Your Muscles Paralyse

While asleep, you cycle through periods of non-rapid eye movement sleep (NREM) and rapid eye movement sleep (REM). It’s during REM sleep that we have the most vivid dreams.

During this stage, your muscles are temporarily paralysed, meaning you can’t move. Some scientists think this might be so that you don’t physically act out your dreams.

6) Anti-Diuretic Hormone (ADH) Helps You Not Have To Pee

Ever wondered why you have to go to the toilet to pee every couple of hours during the day, but can sleep a whole eight without heading to the loo? Thank ADH, an anti-diuretic hormone released by the brain under a circadian rhythm which switches off the need to urinate so often overnight.

7) Your Immune System Releases Inflammation Fighting Cytokines

While you’re sleeping, your immune system releases a type of small proteins called cytokines.

If you’re sick or injured, these cytokines help your body fight inflammation, infection and trauma. 

Without enough sleep, your immune system might not be able to function at its best.

This is only scratching the surface of what our bodies do while we sleep!

Some other crucial benefits of a healthy sleep cycle include –

Skeletal Bone Health
 Heart Health
Immune System Health
 Healthy Weight
Liver Health
Sexual Health and Fertility




As we can see from the image above, our circadian rhythm may hold clues as to the best times of day for certain activities.

We are generally biologically primed to wake up around 6am as we see that our blood pressure rises and cortisol and adrenaline are increased .

It is often recommended to workout between 3pm & 5pm, for example.

“Yeah thanks, this is all wonderful, but how do I optimise my Circadian Rhythm ? “

Well, Thanks for asking! It’s actually quite easy! 

Here Are Some Of My Go To ‘Biohacks’ For Optimising My Circadian Rhythm –

Finish Your Last Meal Early

It is often quoted on wellness websites or sleep blogs and even in Dr Satchin Panda’s recent book The Circadian Code that we should aim to finish our last meal at least 3 hours before bed.

The reason for this is that our digestive systems need to be empty for our core body temperature to drop sufficiently to lull us into deep restorative sleep and that allows your internal organs ample time to do their own healing and repairs!

Personally, I like to finish my last meal by 4pm usually as I aim for a 9pm lights out scenario.

Yes, this is a 5 hour window before sleep, but hey, I don’t do things by halves!

This also sets me up for a great Time Restricted Eating pattern (Fasting) but more on that another day.

Cut Out As Much Artificial Light As Possible!

Nowadays, most indoor lighting is unbalanced and mostly made up of bright blue or white light and this bright light tells our brains that it must be day time or why else would there be bright light!

If our brains think it’s day time, then melatonin production will be delayed when it should be increasing and we will suffer with poorer quality sleep! Even if we’re getting 8 hours, it’ll be of lower quality!

Use blue blocking glasses after sunset, light your house with more warm orange/red hued light bulbs or use your red light therapy device as ambient lighting! ( Our Target Light , Half Stack or Full Stack devices can be used for this purpose perfectly! )

( A pleasant coincidence is the red light therapy can positively benefit both circadian rhythm and melatonin, the sleep hormone. Read more here!)

Get Bright Light In Your Eyes And Your Skin As Early As Possible!

Easier said than done if you live in the Northern Hemisphere!

Do whatever you can to get up with the sun and to get that early morning sun directly into your eyes and onto your skin!

When your eyes and skin get that bright early morning light, it sets off a slew of hormonal responses that get you ready and alert for the day ahead!

AND if you get the early morning light, it resets the circadian clock which will begin to count down the hours until sunset and the melatonin production can start to set you up for a good sleep!


I hope all this makes sense and you guys have a good idea of what you can do and why!

The best part is, you can do it from the comfort of your own home!

Stay safe everyone!

#PreventionProtocols #BringHealthHome #StayHome

Author: Bryan Gohl
StrongFirst Bodyweight Certified Coach (SFB)