GU is an energy gel

Energy gel

Energy gels are carbohydrate gels that provide energy for exercise and promote recovery, commonly used in endurance events such as running, cycling, and triathlons. Energy gels are also referred to as endurance gels, sports gels, nutritional gels, and carbohydrate gels. They come in small,...

 designed to be quickly and easily digestible

Digestion

Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....

 so it can be eaten during endurance events, especially long distance running

Running

Running is a means of terrestrial locomotion allowing humans and other animals to move rapidly on foot. It is simply defined in athletics terms as a gait in which at regular points during the running cycle both feet are off the ground...

. It is a soft solid, like its namesake goo

Goo

Goo is a term for a slimy, semi-liquid, shapeless mass."Goo" or "GOO" may also refer to:- Computing :* Goo , a programming language in the Lisp family* goo , a Japanese web search engine...

, and is squeezed directly into the mouth from 1.1 oz

Ounce

The ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 28 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...

 (32 g) 100 calorie

Calorie

The calorie is a pre-SI metric unit of energy. It was first defined by Nicolas Clément in 1824 as a unit of heat, entering French and English dictionaries between 1841 and 1867. In most fields its use is archaic, having been replaced by the SI unit of energy, the joule...

 (420 kJ) packets. The product is available in several different flavors such as vanilla bean

Vanilla

Vanilla is a flavoring derived from orchids of the genus Vanilla, primarily from the Mexican species, Flat-leaved Vanilla . The word vanilla derives from the Spanish word "", little pod...

, chocolate

Chocolate

Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...

, berry

Berry

The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....

, orange

Orange (fruit)

An orange—specifically, the sweet orange—is the citrus Citrus × sinensis and its fruit. It is the most commonly grown tree fruit in the world....

, banana

Banana

Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....

, and plain.