I know Jennifer Aniston loves her Smartwater, and I do too. That's because it's enhanced with electrolytes, a scientific term for salts. If you look on the bottle, you'll see ingredients such as sodium chloride, potassium, and magnesium, which are basically mineral salts. Your cells need these minerals in order to pass electrical impulses to other cells for normal bodily functions. Your kidneys work hard to keep the electrolyte concentrations in your blood consistent, but when you exercise intensely and sweat, you also lose electrolytes. If you don't replace these essential minerals, your performance declines, and you can eventually suffer serious health issues.
If you're exercising for long periods of time or sweating excessively from a workout, it's a good idea to take advantage of electrolyte-enhanced products. Sport drinks like Gatorade contain these necessary electrolytes, and they also contain sugar for quick energy and flavor. If you don't want to carry around a heavy, fake-flavored sport drink while exercising, then Luna Sport Moons, Jelly Belly Sport Beans, or Gu are great alternatives. If you want to avoid the sugar altogether, then go for Smartwater or Function Water.
Fit's Tip: Refueling on lost electrolytes isn't necessary for a regular 30-minute cardio workout, but hydration is. So be sure to drink water often. If you're training for a marathon or doing a three-hour cardio-kick-boxing workshop, then opt for sport drinks with electrolytes, since they'll give you both the minerals and fluids you need.