The primary purpose of compression shorts for MMA training is to provide a barrier between skin-to-skin or skin-to-mat contact. Originally developed for surfers, compression shorts are now very popular in MMA and BJJ gyms worldwide. Athletes may also wear compression shorts under their board shorts or fight shorts.
By using nylon, lycra, or spandex, they are tight-fitting and flexible, therefore eliminating injuries with extremities getting caught up – as you’d see with cotton and the like, as well as wicking sweat away. Most MMA compression shorts also come with a cup pocket for added protection during training.