New York Times, 9/17
How Much Water Do You Actually Need? Here’s how to know when you truly need to hydrate.

If you’ve spent any time on social media or visited an athletic event lately, you’ve surely been bombarded with encouragements to drink more water. Celebrity influencers lug around gallon-sized water bottles as the hot new accessory. Twitter bots constantly remind us to make more time to hydrate. Some reusable water bottles even come emblazoned with motivational phrases — “Remember your goal,” “Keep drinking,” “Almost finished” — to encourage more drinking throughout the day. The purported benefits of excess water consumption are seemingly endless, from improved memory and mental health to increased energy to better complexion. “Stay hydrated” has become a new version of the old salutation, “Stay well." ”We’ve all been taught that eight 8-ounce glasses of water per day is the magic number for everyone, but that notion is a myth, said Tamara Hew-Butler, an exercise and sports scientist at Wayne State University. Unique factors like body size, outdoor temperature and how hard you’re breathing and sweating will determine how much you need, she said. A 200-pound person who just hiked 10 miles in the heat will obviously need to drink more water than a 120-pound.

https://www.nytimes.com/2021/09/17/well/live/how-much-water-should-I-drink.html