Arena polo has rules similar to the field version, and is less strenuous for the player. It is played in a enclosed arena, much like those used for other equestrian sports; the minimum size is . There are many arena clubs in the United States, and most major polo clubs, including the Santa Barbara Polo & Racquet Club, have active arena programmes. The major differences between the outdoor and indoor games are: speed (outdoor being faster), physicality/roughness (indoor/arena is more physical), ball size (indoor is larger), goal size (because the arena is smaller the goal is smaller), and some penalties. In the United States and Canada, collegiate polo is arena polo; in the UK, collegiate polo is both.