It's easy to underestimate the importance of hydration—especially in a city like Los Angeles, where busy schedules, long commutes, outdoor workouts, and warm weather are part of everyday life. Most people know they should drink more water, but few realize just how much hydration affects nearly every system in the body. From your brain and muscles to your skin and immune system, water plays a vital role in helping you function at your best. If you've been feeling unusually tir
