With the PowerBar 5 Electrolytes Grapefruit tablets you can make your own isotonic drinks without calories. You can dissolve each tablet in about 500ml-750ml of water and you will contribute to your body the 5 main electrolytes (sodium, chloride, potassium, magnesium and calcium) in the proportion in which they are lost through sweat. With no added sugars and no calories, these pink grapefruit-flavoured tablets are ideal for training your basic stamina and keeping you hydrated.