Every cell in your body has a ‘clock’ and is on a twenty-four-hour schedule, also known as a circadian rhythm. These 24-hour cycles are running in the background to ensure that essential functions and processes are being carried out. One of the most important and well-known circadian rhythms is the sleep-wake cycle, which is naturally aligned with the cycle of day and night or more accurately, light and darkness.

Understanding circadian rhythms and how they impact our sleep-wake cycle can be essential for maintaining a healthy metabolism. Let’s discuss what circadian rhythms are, how they are affected by different factors, and how to improve your sleep for a healthier, flexible and robust metabolism!

The circadian rhythm is one of two main triggers that causes the release of cortisol in the body. Cortisol is a hormone with many important functions in the human body, such as regulating the stress response, metabolism, inflammation, and immune function.

Cortisol spikes in the morning and reduces throughout the day. Melatonin is released in darkened environments (after the sun has set), which initiates a feeling of sleepiness and supports our transition to sleep. People who are under stress may have surges of cortisol that are superimposed on our innate circadian patterns (otherwise known as our internal 24-hour body clock).

Too much stress throughout the day may elevate cortisol levels, which can remain elevated into the night causing insomnia or poor-quality sleep. In many cases, we see disruptions in the continuity of sleep (waking during the night) and/or issues with falling asleep. This can throw SHMEC out of check, especially HEC – hunger, energy and cravings.

Most folks find it challenging to stick to their health habits and goals when they’re tired, craving foods to give them a boost (mentally and physically), and struggling to find enough energy to get the bare minimum done (forget about exercise)!

If you want to leverage the power of circadian rhythms to support your body change goals, you need to know how to regulate the sleep-wake cycle. So let’s get to it!

How to regulate your circadian rhythm for better sleep

Morning light and evening dark can be used to modulate the diurnal rhythm of cortisol and melatonin to support our sleep/wake cycle. Safely expose yourself (eyes included) to early morning light if/when you can. A morning walk within the first 60 minutes of waking is a great way to do this. If time does not permit a walk, simply pop outside or open a window. Spend a few minutes basking in the light or looking outside. Please be mindful of safe sun exposure to both your skin and eyes. Take appropriate measures to protect yourself according to your needs and time of year. As much as possible, avoid or limit blue light exposure in the evening or close to bedtime. 

Morning protein. Morning protein can help regulate the circadian rhythm. Eating protein in the AM or as your first meal of the day, sends helpful signals to the ‘clock genes’ that influence energy metabolism and whole-body insulin sensitivity. Meaning, your breakfast protein shake or protein-based meal is supporting your body change goals in more ways than you think! Even if you’re doing a method of time-restricted eating, try to have at least a small serving of protein by 10 a.m. or whenever you choose to break your fast.

Reduce alcohol. Alcohol lowers melatonin and can disrupt the circadian rhythm. It is best to avoid or reduce alcohol, especially as you get closer to bedtime. 

Warm bath. A warm bath or shower an hour or two before bed will improve your ability to both fall asleep and stay asleep. It works by temporarily raising body temperature and then allowing it to drop again, which will make you feel sleepy. Cold showers work in the reverse way. They are best suited to the AM because they boost alertness.

Honour the natural rhythm of cortisol by tapering stimulating activities as the day goes on. Create an evening transition or wind-down routine that supports the natural decline in cortisol, while simultaneously supporting the natural increase in melatonin levels. If you tend to expose yourself to stressful activities – news, TV shows, or work at night, you might want to consider rescheduling those activities.

Keeping to a schedule is an excellent way to support your circadian rhythm and to promote general health, including the health of your metabolism, mood, sleep, and the stress response system. 

The ‘3-2-1 formula’ 

This is a framework adapted from Dr. Jess Andrade. It outlines 3 simple but highly effective strategies to support your transition to sleep starting 3 hours before your bedtime. Stack one, two or all three of them together as part of your evening ritual. Here’s how it works:

– 3 hours before bed: No more food or alcohol. 

– 2 hours before bed: No more work (especially if it’s stressful). 

– 1 hour before bed: No more screen time (includes phones, TVs and computers). 

This is purely a tip and may not be suitable for everyone, but it’s certainly worth a try if you don’t get enough sleep due to those reasons.


Support a healthy circadian rhythm with morning light. Keep your exposure to light at night to a minimum. Two walks twice a day, timed accordingly, can support the timing and release of hormones that support our sleep/wake cycle. 

Eat at approximately the same time every day, which also supports the circadian rhythm.

Get enough sleep, or work on sleep quality if you’re tired despite sleeping enough. Start with the 3-2-1 formula.

If you wake during the night, your sleep issues might be related to blood sugar dysregulation. Stabilizing blood sugar levels will help you get more restful sleep. Break your fast with morning protein or by 10 a.m. for consistency.

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