Nuun Endurance Tub (16 Servings) Nutrition Mixed Berry : The new Nuun Endurance Tub (16 Servings) features a complete electrolyte and carbohydrate-enhanced drink mix for serious athletes. This powder blend is designed for long and more intense training sessions and athletic events because it provides efficient fluid absorption while minimizing stomach distress. This Elite Hydration Drink Mix works to support the athlete's endurance efforts on the long road or trail ahead. Dissolve one serving of powder into 16 oz. of water. One pack includes 60 calories and 16 grams of carbohydrates. Contains 20mg magnesium, 15mg calcium, 200mg potassium, and 380mg sodium.