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Podcast 179: Dr. Samer Hattar on Circadian Health & Light Exposure


Podcast 179: Dr. Samer Hattar on Circadian Health & Light Exposure

On this week’s episode we take an in-depth look at the science behind your circadian rhythm and how light exposure affects your body.

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WHOOP VP of Performance Kristen Holmes sits down with Dr. Samer Hattar, a world-renowned expert in the field of non-image forming photoreception–how light affects circadian rhythms, sleep, mood, learning, stress and hormone levels, appetite, and mental health. Dr. Hattar is credited with discovering neurons in the eye that set our circadian clocks and regulate mood and appetite, which was a groundbreaking discovery in the field of circadian health. Dr. Hattar explains what the consequences are if you view light at the wrong time, the importance of light exposure in the morning, and how light exposure can affect our next-day mood and behavior. He also discusses synchronizing eating windows and meal timing with our internal clocks and explains how disruption of the circadian rhythm has significant influences on exercise function. We have new ways to interact with the WHOOP Podcast! You can email us – – or you can call our new listener line (508-443-4952) and leave a question or comment, and your question might be answered on a future episode.  

Dr. Samer Hattar Circadian Health Podcast Episode Chapters

3:44 - The light-dark cycle and the circadian clock 6:34 - Consequences of viewing light at the wrong time 9:26 - Sleep behaviors 12:44 - Light exposure in the morning 15:35 - Viewing light during the day and blocking blue light 16:55 - Light exposure at night 19:37 - Circadian health and digestion 25:07 - Eating windows and meal timing 28:46 - Exercise routines 34:25 - WHOOP Journal additions on circadian health 36:37 - Time zones and shifting your circadian rhythm 40:15 - Your body’s temperature minimum