There is something we seem to have forgotten in our modern world:
Our bodies are not separate from the natural world around us. We are biological beings living on a planet that moves through predictable cycles of light and darkness, warmth and coolness, activity and rest. And our biology responds to those rhythms.
For thousands of years, human beings rose with the sun, spent their days outdoors, watched the sun move across the sky, and rested when darkness arrived. Today, we can turn on a light at midnight, stare at a glowing screen until we fall asleep, wake up in the dark, and spend most of the day indoors.
Our environment has changed dramatically... but our biology hasn't.
At the heart of this relationship with nature is our circadian rhythm which is our internal 24-hour timing system.
This biological clock influences far more than when we feel sleepy or awake. Circadian rhythms are intertwined with metabolism, body temperature, immune function and the timing of hormones such as melatonin and cortisol.
And one of the most powerful signals our body uses to set this clock is light. Not the light from our phones. Not the lightbulbs in our homes... Natural Daylight.
Morning light is particularly important because it helps tell the brain that a new biological day has begun. Bright light early in the day can help synchronize the circadian clock and support alertness during the day and sleep at night.
This is one reason I love getting outside in the morning. Sunrise is when we set our circadian rhythm. And, the changing spectrum of sunlight -- visible light, UVA, UVB and infrared radiation is the way our biology evolved.
Just as our bodies need daylight, they also need darkness.
The setting sun is also a biological signal. As evening arrives, our environment naturally becomes darker, and our physiology begins transitioning toward rest. Artificial light, particularly bright, short-wavelength light in the evening, can suppress melatonin and shift the timing of the circadian system.
Dim the lights as evening approaches. Put the phone down. Turn off unnecessary screens. Light the room softly. Let your home become quieter.
We live in a world that encourages us to override almost every natural rhythm... eat whenever we want, stay awake whenever we want, work whenever we want and sleep whenever we can.
Nature has been showing us the rhythm of life all along; perhaps our bodies are simply waiting for us to listen.
