Here’s the plot twist that might rattle your reusable water bottle: the “8x8 rule” (eight 8-ounce glasses) isn’t backed by hard, modern science. It likely originated from a 1945 recommendation that included water from all sources—including your morning coffee and that juicy watermelon you ate for lunch.
Your body is not a one-size-fits-all machine. A marathon runner in Phoenix has very different needs than a desk worker in Seattle who mainlines iced lattes. The real answer is more flexible, and honestly, far less stressful.
