Optimising Your Circadian Rhythm

Our bodies are amazing machines...They boast an intricate system of clocks that signal our body’s functions. One of these systems is called our circadian rhythm.  Light plays a significant role in our circadian rhythm, so can influence our sleep and wake cycles, sympathetic and parasympathetic nervous system balance, mitochondrial function, immune function, inflammation, hormonal regulation and neurotransmitters(1). Dysfunction in our circadian rhythm can manifest in many ways including sleep disorders, mood issues, blood sugar irregularities, poor recovery from exercise, depression, anxiety, HPA axis activaiton and chronic health disorders. By using light and other behavioural techniques, we can optimise our circadian rhythm to improve health issues and enhance our health.

  • Enjoy time in the sun...Endorphins are released from the skin, in response to ultraviolet light exposure and feed back into the brain and create a pleasure response

The SCN (supra-chiasmatic nucleus) in the brain is responsible for controlling our circadian rhythm and hormones such as cortisol and melatonin.

Melatonin is a hormone that regulates sleep-wake cycles and is important for helping you to sleep and provides anti-oxidant function. It fluctuates over a 24 hour period generally in opposition to cortisol. Cortisol is one of our stress hormones that gets us up in the morning via the cortisol awakening response.

When you open your eyes in the morning, the light that enters your eyes signals the SCN. As a result, your cortisol levels should steadily rise by 50-150% over the 30 minutes after waking, then gradually declines throughout the day. You should wake up feeling alert, energized, and ready for your day. This surge is called the cortisol awakening response (CAR). Many people have disruptions in this response and struggle to get out of bed each morning, taking hours (and a couple of coffees) to feel awake and ready for their day. A healthy CAR is crucial for blood sugar stability, general adrenal function and our hormonal and nervous system.

When the SCN detects darkness (a reduction in the blue light entering our eyes) then it stimulates the pineal gland to secrete melatonin. This process ideally ramps up from 9pm, peaks at 2am and decreases until dawn. While we’re asleep, a whole array of internal housekeeping activities can be switched on. As dawn approaches, our body can shift back into activity mode as cortisol rises (CAR) and melatonin drops.


Individuals are increasingly eating and working at hours that are at odds with their biological clock, leading to circadian misalignment and disruptions. Sleep disturbance has been linked with elevated evening cortisol,13 while exposure to light at night suppresses melatonin production,14 exacerbating sleep issues and contributing to patients’ difficulty falling and staying asleep, in addition to reducing overall sleep quality.(3)

Using strategies listed below can send our body with the correct messages to optimise our health through resetting our circadian rhythm.


  • Maintain regular sleep cycles - Sleep and wake at a consistent time each day, even on weekends. Keeping this as close to sunset and sunrise will be supportive however it must of course, also be practical. Between 10pm-2am is when our main physical healing happens...if we are asleep. So get to bed early enough to be asleep by 10pm to allow your body more efficient regeneration and healing.
  • Spend the first 20 mins of your day outside in the sun without sunglasses - the light entering your eyes signals your brain that it is day time.
  • Spend 10mins outside just before sunset - as the blue light dwindles, the body receives a signal that it is wind down time.


  • Perform 7 minutes of high intensity exercise within 10 minutes of waking up, ideally do this in the sun.
  • Exercise in the morning if you can, or at least before 4pm. Exercising in the sun just after waking at sunrise would supercharge the messages you are sending your body.


  • Control your lighting environment at night - turn down bright lights as the evening progresses. Use lamps where possible.
  • Eliminate screens (TV, iPad, phones etc) after sunset. If this is not practical, turn off all screens as far from bedtime as possible. The blue wavelength light from the screens is a strong signal to our bodies that it is day time.
  • Wear blue light blocking glasses (many available online) if using screens or bright lights after dark.
  • Place light filters on your screens - using flux on computers or brightness filters on smartphones after dark.


  • practice active relaxation and or meditation – find what works for you, check out progressive muscle relaxation
  • try different breathing exercises
  • Reserve activities that don't require screens for before bed, such as stretching, meal preparation, showering, journaling etc.
  • Try journaling, applying essential oils, magnesium salt bath, stretching.
  • Warm your body temperature - Take a hot shower, hot bath or use a heating pad to warm your middle to trigger proper chemistry for sleep.

Sleeping Environment

  • Create a bedroom that encourages sleep, that is relaxing and you are comfortable in
  • Create a bedroom that is dark, quiet and cooler temperature
  • Wake up using a sunrise simulating alarm clock
  • maintain fresh air flow in your bedroom by opening a door or window
  • keep phones, TVs and computers out of the bedroom

Shift workers

  • Take a brisk walk during the night so the body can receive light/dark signals from the environment, especially the moonlight
  • Eat meals as close to times of natural light and fast during the night
  • Light exposure early in the morning or at sunset when possible
  • Wear blue light blocking glasses
  • Check melatonin levels regularly

Food, supplements and medications

  • Eat during (or as close to) the hours the sun is out.
  • Eat at regular times each day, even on weekends.
  • Take your magnesium before bed - this can help relax muscles and calm the nervous system.
  • Supplements and herbs can support sleep - California poppy, passion flower, ashwagandha, magnesium with lutein, zeaxanthin, valerian, lavender, calcium, theanine, GABA, 5-HTP, melatonin, magnolia.
  • Avoid caffeine and alcohol - these can affect sleep quality and influence cortisol levels.
  • Avoid medications that interfere with sleep – these include sedatives, antihistamines, stimulants, cold medication, steroids, and caffeine containing medication
  • eat your last meal well before you go to sleep – 4 hours for a large meal, 3 hours for a moderate meal, 2 hours for a small meal, 1 hour for a snack
  • reduce the size of your portion in your evening meal, especially the amount of meat
  • include some natural carbohydrate with your evening meal – sweet potato, potato, vegetables, brown or wild rice etc.
  • avoid sugar, caffeine, alcohol and other stimulants towards the evening
  • Try this homemade tea recipe below:


Banana Tea for sleep (4)

Banana peel is packed with magnesium so try this sleepy tea before bed...

  • Wash an organic banana, cut off the ends and cut in half (leave the peel on).
  • Put it in four cups of boiling water and boil it for 3-4 minutes.
  • Remove from the stove and steep it.
  • Add honey or cinnamon to taste.
  • Drink the water loaded with magnesium.
Waking during the night 
If you wake up at night and cant get back to sleep within 20 minutes, leave your bed and do something relaxing in another room such as reading a book, meditating, listening to relaxing music or progressive muscle relaxation (link PMR to https://head2toehealth.com.au/quick-easy-relaxation-technique/). Check in with yourself every 20 minutes or so to see if you are feeling sleepy. If you're not sleepy then continue with your relaxing activity until you feel you are ready for sleep again.

It is crucial to establish and maintain consistent sleep routines and cycles, your health depends on it. Making just one change per week can allow you to gain momentum in moving toward great quality sleep, improved healing and body maintenance and ultimately, better health.



  1. Dr Kharrazian Institute - https://kharrazianinstitute.com/
  2. https://siimland.com/benefits-of-melatonin-the-sleep-hormone/
  3. https://www.metagenicsinstitute.com.au/metagenics-update/emed-articles/2020/supporting-sleep-quality-with-nutrients-and-herbs?utm_medium=email&utm_source=sharpspring&sslid=MzM2sDQ1MTMztLA0BAA&sseid=MzKwNDOxNDQ1MgYA&jobid=4ff890f4-0f57-4204-9a85-3a2accc4cf7f#focus
  4. Dr. Michael Breus


Written by Dr. Jess Harvey B.Sc. (Anat, Phys), B.Ap.Sci (Comp. Med.), Ma Osteo., Registered Osteopath and Director of Head 2 Toe Health.

We provide Osteopathy, Acupuncture, Massage, Life Coaching and Counselling in Springwood (Brisbane) and Oxenford (Gold Coast). We aim to get you as well as possible, as fast as possible, permanently. We believe in a thorough approach to restoring and maintaining health and address many aspects of our lifestyles that can contribute to pain, stiffness, dis-ease and disease. For any further information, please contact us on info@head2toehealth.com.au or 07) 3208 8308.

This information is intended as a general guide only and is not specific for any particular condition or situation. This information is for educational purposes only. Please seek specific advice for your individual circumstances.