 Loth recommends older adults who need more hydration set an alarm to remind them to drink water throughout the day. She said getting enough water each day is crucial to our health, but how much water should we really be drinking? She says it depends on multiple factors. Your age, your size, the heat, how active you are. But in general, we tend to recommend about 13 cups of water a day for men, nine for women, more if they're pregnant or breastfeeding.