Put down the bubbly soft drink: Swapping that daily 100-plus-calorie soda for a cool glass of water will save you thousands and thousands of calories over time.

Think about adding a glass of water to your beauty routine. Mild to moderate dehydration can lead to dry skin, while severe dehydration may cause skin that's shriveled and lacks elasticity, according to the Mayo Clinic.

You wouldn't drive a car without gas, right? Then don't even think about hitting the gym without guzzling some water. Water transports essential nutrients to your muscle cells so you can power through your workouts and recover from your sweat sessions faster, according to the American College of Sports Medicine. To boot, it prevents you from overheating when you're really giving that spin or hot yoga class your all.

How does your brain get the nutrients it needs to function? You guessed it: water. Even better, a 2012 British study found that undergrads who brought water with them to exams performed better than students who took the test without water by their sides.

Depriving yourself of enough water could leave you feeling down. According to a small French study in 2014, researchers found that people who didn't typically drink a lot of water reported better moods when they boosted their water intake. On the flip side, subjects who were used to drinking a lot of water were in a worse mood when they drank less water. Moral of the story: Keep chugging that H₂O to keep a smile on your face.