When it comes to hydration, potassium and magnesium are both essential electrolytes. Through your body’s Sodium-Potassium Pump, your cells are constantly pumping out sodium and pumping in potassium, maintaining fluid balance. In your kidneys, the organs responsible for maintaining electrolyte concentrations, magnesium is essential to storing potassium. When magnesium levels are optimal, your kidneys are able to retain higher levels of electrolytes, keeping you hydrated. Unless you’re running a marathon and losing a substantial amount of sodium through sweat, you don’t need all of the sodium found in other hydration products.