Inside every cell of your body is a molecular clock, ticking in a roughly 24-hour rhythm. These circadian rhythms affect nearly every aspect of your health—from when you feel sleepy to when you're most creative, from hormone production to immune function. Understanding and aligning with your internal clock can transform your wellbeing.
What Are Circadian Rhythms?
Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. They're driven by a master clock in the brain called the suprachiasmatic nucleus (SCN), which responds primarily to light signals from the eyes.
How Circadian Rhythms Affect You
- Sleep and wakefulness – Melatonin production increases in the evening and decreases in the morning.
- Body temperature – Drops at night to promote sleep, rises in the morning to promote wakefulness.
- Hormone release – Cortisol peaks in the morning, growth hormone peaks during deep sleep.
- Cognitive performance – Most people perform best on complex tasks mid-morning.
- Metabolism – The body processes food differently at different times of day.
Signs Your Rhythms Are Off
When circadian rhythms are disrupted, you might experience:
- Difficulty falling or staying asleep
- Daytime fatigue despite adequate sleep
- Mood changes and irritability
- Difficulty concentrating
- Digestive issues
Aligning With Your Clock
To optimize your circadian rhythms:
- Get morning light – Expose yourself to bright light within an hour of waking.
- Maintain consistent sleep times – Even on weekends.
- Limit evening light – Dim lights and avoid screens 1-2 hours before bed.
- Eat at regular times – Avoid late-night eating.
- Exercise in the morning or afternoon – Avoid intense exercise close to bedtime.
"Circadian rhythms are the most basic form of intelligence in our biology." – Satchin Panda
Living in harmony with your circadian rhythms isn't about rigid schedules—it's about working with your biology, not against it. Small changes in light exposure and timing can yield profound results.