When you work out, you sweat. Water is lost, but so are salts. Drinking plain water to replace the sweat will create an unbalanced electrolyte situation. This is a bad thing, because your body needs the sodium and potassium to balance the water in your cells. Gu Electrolyte Brew can help maintain this proper electrolyte balance.Gu Electrolyte Brew helps to maintain your nervous system function which in turn allows you to race smart and push on the pedals with anger. Think like this -- your local state championships come down to a sprint finish after hours in the saddle and you will want your body to perform at the highest levels. We know that sodium and potassium are important to stave off the inevitable and often untimely cramping that comes from race efforts. In addition to the salts, Electrolyte Brew has a blend of complex and simple carbohydrates that is optimized for absorption to help keep energy levels steady. It is not meant as a replacement for Gu energy gels, rather as a complement to them. It also contains citric acid which is essential for the breakdown of amino acids and glucose to form ATP, the muscle fuel. The light flavor is easy to drink and doesn't get tiresome on long rides. Gu Electrolyte Brew is available in Lemon Lime, Orange, Raspberry, and Blueberry Pomegranate. One box contains 16 single serving packets. Each 34g packet makes 21 fluid oz.