Cold & Sun exposure in the morning align your circadian cycle and boost motivation
Dopamine boost, circadian cycle alignment
The most recent habit that I am deliberately cultivating this year is a cold shower followed by a 15-minute walk and sunlight exposure.
Cold showers and sunlight exposure are powerful enhancers to keep our circadian rhythm aligned. I keep it as a single practice because:
The circadian cycle and core body temperature cycle are perfectly synchronized in our body, so there are synergetic effects.
It is easier to cultivate one habit than two.
Cold shower after waking up
The magic around cold exposure is rather powerful. It has multiple positive effects on the brain and body, which are explained in detail here. The effect I am most interested in is a circadian cycle alignment and dopamine boost:
A cold shower increases core body temperature and creates a cortisol spike. Both are good to have early in the morning to align the circadian rhythm.
A proper cold exposure tremendously increases a baseline of dopamine for a few hours, which means you will feel motivated and energized for mental work.
The rule-of-thumb is that 11 minutes of cold exposure per week is enough to get some benefits. You are supposed to split it between several times. The temperature range is individual, but you should feel uncomfortable and safe. The range is likely to be between 45 to 60 F (7 to 15 C). In order to get a metabolic increase, it is better not to use a warm shower after and even let the body dry off without using a towel.
I found it easy to do a 2-minute cold shower every day rather than on the selected days. If I miss a day or even two, I don’t panic and just return to the routine when I am ready. I do not use a warm shower after, but I towel off.
After the cold shower, I feel an increase in energy, alertness, and focus. And after 7 months, I feel that I am better at directing my attention and spend much less time procrastinating.
Sunlight gazing after the cold shower
The science says that daylight is the most powerful signal that resets our biological clock. Food, exercise, and temperature are other cues that the brain can use to reset the circadian rhythm, but light has a disproportionally larger impact.
I was struck to learn that even a bacteria has some prototype of a circadian rhythm and responds to the light and dark cycles of our planet.
You can listen to this podcast to learn more about details and biological mechanisms.
In a nutshell, early in the morning, when the solar angle is low, there is a particular contrast of yellow and blue light in the spectrum, which is “read" by the specific cell on our retina. These retinal cells send electrical signals to the central processor in the brain called the suprachiasmatic nucleus “telling” that the sun is rising. After that, the central processor sends signals to the whole body and every cell to wake up.
This process triggers the whole cascade of events on different levels: from neurotransmitters and hormone release (e.g., dopamine and cortisol) to gene expression and metabolic change. These processes synchronize the body’s circadian rhythm with the external environment.
I pair sunlight exposure with a cold shower early in the morning and find it very helpful to be focused in the first half of the day and fall asleep with more ease in the evening.
How to find our natural circadian rhythm called chronotype is in the next post.
P.S. The image is me at sunrise in Arches National Park.
