Carbohydrates for Energy - Endura Rehydration Performance Fuel is a 6% carbohydrate formula, providing 20 g of carbohydrates per dose as recommended for intense exercise or exercise lasting longer than 1 hour. The combination of microcrystalline fructose and maltodextrin improves carbohydrate absorption and fluid uptake. Electrolytes - To maintain active hydration, Endura Rehydration Performance Fuel contains sodium, potassium, calcium and magnesium to replace electrolytes lost in sweat. The sodium and potassium are at levels recommended for athletes during endurance exercise. Magnesium - Endura Rehydration Performance Fuel contains a patented form of magnesium, Meta Mag®, that ensures high absorption and bioavailability with a low risk of gastrointestinal side effects.