The adiZero XT is for trail runners who want a go-fast shoe or just don't like bulk. The low-profile midsole reduces weight and gets you close to the ground for great balance. The shoe is very flexible with an aggressive, mud-release outsole, which allows you to be as nimble as a billy goat. The snug midfoot locks the foot in place and aids in making this a great shoe for technical trails and performance-oriented runners.