Morning Sunlight
Free, fast, and underrated for sleep + mood.
Why it matters
Circadian anchor
10 minutes of bright light within 30 min of waking advances melatonin onset that night by ~30 min.
Mood
Morning bright light has been used in clinical trials as a non-drug option for seasonal mood symptoms.
Sleep quality
Same exposure → faster sleep onset and more deep sleep that night vs indoor-only mornings.
The longer story
Your suprachiasmatic nucleus (the body's master clock) is set by morning light hitting your retina, not by what time you wake up. Get outside, no sunglasses, for 5-15 minutes within an hour of waking. Window glass cuts the relevant wavelengths by half or more, so step outside.
On overcast days, you still get 10x the lux of indoor lighting. The point isn't direct sun, it's the broad-spectrum daylight signal.
Sources
- · Wright et al. (2013). Entrainment of the human circadian clock to natural light.
- · Lewy et al. (1998). Morning bright light treatment of SAD.
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🌙Sleep