Nuun Sport is formulated with 5 essential electrolytes: Sodium, which is key for rehydration; Potassium, which regulates healthy hydration balance; Magnesium, which maintains muscle, nerve, and cell function; Calcium, which helps maintain proper hydration; and Chloride, which maintains proper pH levels.Each Nuun Sport tube comes with 10 individual tablet servings that can be taken up to 3 times per day.