In this episode, my guest is Dr. Matt Walker, Ph.D., Professor of Neuroscience and Psychology and the Founder & Director of the Center for Human Sleep Science at the University of California, Berkeley. He is also the author of the international best-selling book Why We Sleep and the host of "The Matt Walker Podcast." We discuss the biology of sleep, including its various stages and what specifically happens to those stages when we don't get enough sleep. We also discuss the effects of sunlight, caffeine, alcohol, naps, hormones, exercise, marijuana, sexual activity, and various supplements on sleep. The episode consists of both basic science information and many science-supported actionable tools. Read the full show notes for this episode at hubermanlab.com.Thank you to our sponsorsAG1: https://athleticgreens.com/hubermanLMNT: https://drinklmnt.com/hubermanlabWaking Up: https://wakingup.com/hubermanMomentous: https://livemomentous.com/hubermanTimestamps00:00:00 Introducing Dr. Matt Walker  00:02:16 Sponsors: AG1, LMNT & Waking Up00:06:00 What Is Sleep?  00:10:20 REM (Rapid Eye Movement) aka 'Paradoxical Sleep'  00:16:15 Slow Wave Sleep aka 'Deep Sleep'  00:24:00 Compensating For Lost Sleep  00:32:20 Waking in the Middle Of The Night  00:39:48 Uberman (Not Huberman!) Sleep Schedule  00:42:48 Viewing Morning Sunlight  00:49:20 Caffeine  01:07:54 Alcohol  01:14:30 Growth Hormone & Testosterone  01:16:14 Emotions, Mental Health & Longevity  01:20:40 Books vs. Podcasts  01:21:20 Lunchtime Alcohol  01:25:00 Marijuana/CBD  01:36:00 Melatonin  01:54:14 Magnesium  01:58:10 Valerian, Kiwi, Tart Cherry, Apigenin  02:15:00 Tryptophan & Serotonin  02:19:24 Naps & Non-Sleep-Deep-Rest (NSDR)  02:28:23 Is It Possible To Get Too Much Sleep?  02:34:35 Sex, Orgasm, Masturbation, Oxytocin, Relationships  02:47:30 Unconventional Yet Powerful Sleep Tips  02:59:10 Connecting to & Learning More from Dr. Walker  03:04:42 The New Dr. Matt Walker Podcast, Reviews & Support  Disclaimer & Disclosures Learn more about your ad choices. Visit megaphone.fm/adchoices