Women's Nike Metcon DSX Flyknit 2 Set new personal records in one of the most versatile training shoes on the market. The Nike Metcon DSX Flyknit 2 training shoe was built to handle distance running, strength training, and CrossFit®, which is where the DSX name comes from. This shoe's flyknit upper is flexible and breathable, but also supportive. This trainer was born ready to handle your toughest workouts. Brand new in box.