Your organs are programmed to function in cycles of 24 hours. This is called the circadian rhythm or sleep-wake cycle. Your body knows where we are in the 24 -hour cycle by detecting and releasing certain hormones at different times throughout this cycle.
The main hormones involved are cortisol, also known as the ‘stress hormone’, released by the adrenal gland which typically peaks first thing in the morning signaling to your body the beginning of the day, and melatonin, also known as the ‘sleep hormone’ a hormone released primarily by the pineal gland at night which signals the end of the day.
When these hormones are out of sync with each other and/or the time of day they should normally correlate with, your circadian rhythm is out of sync and may be in need of “resetting”.
What Does an Optimally Functioning Circadian Rhythm Look Like?
Waking up around the same time every morning feeling refreshed.
Feeling energized throughout the day (not needing a nap).
Gradually feeling sleepy during the evening at the same time daily.
Falling asleep within 30 minutes of getting into bed.
Staying asleep and not waking up throughout the night.
Resetting Your Circadian Rhythm:
There are practical steps we can take to ‘reset’ our circadian rhythm throughout the day.
1. In the morning
Try to wake up at the same time every day. With consistency, you will gradually set your circadian rhythm to start at this time every day. Ideally, try to avoid traditional alarms but, if necessary, use wake up lights or gentle alarm sounds to wake up in the morning. Traditional (intrusive) alarms have been shown to cause an unnecessary increase in heart rate and blood pressure.
Try to get 15-30 minutes of direct sunlight or daylight first thing in the morning. Take a walk outside or enjoy your morning tea/coffee outside. The aim here is to stimulate the photoreceptors in your eyes which supports cortisol release.
Try to get regular daylight exposure (not through windows) throughout the day to help reinforce this day-night cycle (without sunglasses).
2. In the evening:
Try to avoid eating (especially carb-heavy meals) 3 hours before going to bed to support digestion before laying down. However, some foods have been shown to increase melatonin and serotonin levels, helping us fall asleep better:
Nuts & seeds (pistachios)
Fish (salmon, tuna)
Set all phones, tablets and monitors to night mode and set it to the highest setting possible. If the screen does not have night mode, then try to use blue light blocking glasses or avoid them altogether and read a book. Always use dark mode on all applications and browsers and decrease screen brightness to the lowest setting possible. The aim here is to minimize the effect of blue light on melatonin release at night.
Turn off or dim all lights in your home after dinner.
Do not consume coffee, black tea, green tea or any source of caffeine after noon. Caffeine has a long half-life (approximately 5 hours). This means that 10 hours after caffeine ingestion, you can still have 25% of caffeine circulating in your bloodstream. Caffeine directly blocks the effects of Adenosine which is one of the main neurotransmitters involved in our sleep-wake cycle.
Do not do any vigorous exercise late in the evening. This helps to avoid the release of cortisol which naturally increases when your body is under stress. You want there to be a distinct pattern of high cortisol in the morning and low cortisol in the evening. Try to exercise in the morning or afternoon.
3. At night when going to bed
Blackout your room! Utilize blackout blinds or curtains and make sure light doesn’t enter the room, especially during the early morning when the sun starts to rise – unless your body wants to wake up with the sun. Use a comfortable eye mask that covers the entire visual field if the room is not completely dark. Cover any sources of light from electronics in the bedroom as well. The tiniest TV light can even cause issues.
Make sure that noise is minimal especially early in the morning. Consider comfortable earplugs, a sound machine or a fan if you cannot control noise (or if you have a noisy partner).
If you feel as though your sleep-wake cycle is off and need support, we offer circadian rhythm testing and personalized protocols. For more advice, check out 'How Should We Sleep?'.