In this episode, I discuss our body’s most vital and essential nutrient—water. I explain the structure of water and how it is used by the cells and tissues of our body, how much water we each need to drink and when in order to optimize our mental focus and physical performance; and I include how exercise, humidity, heat, and caffeine affect our hydration needs. I explain how temperature and pH influence water’s physical properties and if there is any scientific basis for drinking so-called “pH water” or “alkalized water” to improve health. I explain how to test your tap water for contaminants (e.g., endocrine disruptors) and the documented problems with fluoride in drinking water. I provide options for filtering drinking water and describe different water types (e.g., reverse osmosis, hydrogen-enriched, electrolyzed reduced, deuterium depleted, etc.). Since the human body is mostly water (55-80% depending on one’s age) and water has essential roles in health, disease and cellular function, everyone ought to benefit from understanding how best to clean our tap water, hydrate effectively and in some cases, adjust the type of water we drink to allow our brain and body to function optimally in regard to health and performance. For recommended water filters, tests and the full show notes, please visit hubermanlab.com. Thank you to our sponsors AG1 (Athletic Greens): https://athleticgreens.com/huberman LMNT: https://drinklmnt.com/huberman Thesis: https://takethesis.com/huberman HVMN: https://hvmn.com/huberman InsideTracker: https://www.insidetracker.com/huberman Supplements from Momentous https://www.livemomentous.com/huberman Timestamps (00:00:00) Water (00:03:33) Tool Deliberate Cold Exposure, Immersion & Showers Mood & Fat Loss (00:15:26) Sponsors: LMNT, Thesis, HVMN, Momentous (00:19:27) Water: Physical Properties & Chemistry (00:26:32) Bonds & Water Phases, “Structured Water” (00:34:07) Body, Cells & Water (00:36:22) Sponsor: AG1 (Athletic Greens) (00:37:37) Water as a Solvent, Temperature & pH (00:41:49) Water Transport in Cells, Aquaporin Channels (00:49:46) Alkaline/pH Water; Temperature, pH & Water Transport (00:55:14) Water Cellular Function, Reactive Oxygen Species (ROS) & Antioxidants (01:01:20) Sponsor: InsideTracker (01:02:38) Tool: Baseline Hydration (01:11:35) Tool: Hydration & Exercise, Galpin Equation (01:15:40) Tool: Hydration, Sauna, Humidity & Sweat; Thirst, Caffeine (01:19:15) Hydration; Cognitive & Physical Performance  (01:23:53) Tool: Water Filtration; Nighttime Urination (01:29:35) Tap Water Tests, Disinfection Byproducts (DBPs), Fluoride & Thyroid Health (01:37:18) Tool: Water Filters (01:44:18) Tool: Resting Tap Water & Sediment (01:48:13) Tool: “Hard Water”; Magnesium, Calcium & Cardiovascular Health (01:53:40) Water Temperature (01:56:42) Water Types: Distilled, Reverse Osmosis, Hydrogen-Enriched (02:03:26) Hydrogen-Enriched Water, Magnesium, Optimize Hydration (02:11:13) Tool: Molecular Hydrogen Tablets, Water pH (02:14:05) Structured Water (02:16:39) Tool: Water Pipes, Faucet Filter (02:19:42) Zero-Cost Support, Spotify & Apple Reviews, YouTube Feedback, Sponsors, Momentous, Social Media, Neural Network Newsletter Title Card Photo Credit: Mike Blabac Disclaimer