Why is morning sunlight so important?

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Morning sunlight is crucial for setting the body's circadian rhythms and ensuring wakefulness throughout the day. It triggers a healthy pulse of cortisol early in the day, which promotes alertness and a robust immune response. Sunlight viewing also suppresses any residual melatonin, the sleep hormone, ensuring better wakefulness and setting you up for good sleep quality later on. Additionally, morning sunlight has been shown to have positive effects on mood, focus, and mental health. Lights in your home are not bright enough to replace the benefits of morning sunlight, but they can disrupt sleep if used too late at night. To fully benefit from the light, direct exposure outside is necessary since windows filter out key wavelengths 1 2 3.

Morning Sunlight Benefits

Andrew explains the benefits of morning sunlight viewing and how it affects our physiology. Sunlight is the most powerful stimulus for wakefulness throughout the day and has a positive impact on our ability to fall and stay asleep at night. Artificial lights can replace sunlight before the sun is out, but not after it has risen.
Huberman Lab
Sleep Toolkit: Tools for Optimizing Sleep & Sleep-Wake Timing | Huberman Lab Podcast #84
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