These poly mesh shorts serve a dual purpose: not only are they great for workouts at the beach, but they are also well suited for intense aerobic exercises at the gym. The TYR trainer has a flat lock stitching and is made out of 100% polyester and includes durable flat lock stitching, ensuring that it will withstand even the most intense workout routine. They are designed with a drag affect to help everyone who wears them to get more out of their exercise.