GU energy gels come in a variety of caffeinated and non-caffeinated flavors and are a maltodextrin-based carbohydrate source that is easily digestible for fueling immediately before and especially during athletic activity. Each packet contains 100 calories and essential electrolytes. This is a highly concentrated energy source and must be consumed with water for proper absorption and digestion. A great fuel source for long endurance events or for more intense activity when most of your blood has been diverted to hard-working muscles making digestion more difficult. Technical Features:Carbohydrates - GU provides athletes with a dose of 100 calories in the form of 70-80% maltodextrin and 30-20% fructose (The ratio depends upon the flavor.). Why the mix? It’s a complex carbohydrate, and studies have shown that some complex carbs are actually digested faster than simple sugars like table sugar and honey.Amino Acid Blend - GU features a unique blend of amino acids to combat muscle fatigue, accelerate the conversion of carbohydrates into usable energy, and maintain mental focus.Electrolytes - Sodium and potassium to replenish what is lost during strenuous activity.Caffeine - Some GU flavors are caffeinated while others are not. We add caffeine for two reasons: It acts as a stimulant and it lowers the perceived effort.