Water. It's so easy to choose other fluids (or none at all), but water is so imperative! It helps regulate out body temp, helps prevent constipation, help keep us feeling full, carries nutrients and oxygen to our cells, and lubricate our joints. Just a 2% loss in body fluids can affect athletic performance (weigh yourself before and after a workout to test for this). Many factors affect how much water we need (exercise, environment, illness, pregnancy to name a few) but urine is the best indicator of hydration 😳. So drink WATER!!!