Mountain bike racing (shortened MTB or ATB racing) is a competitive cycle sport held on off-road terrain. The Union Cycliste Internationale (UCI) recognised the discipline relatively late in 1990, when it sanctioned the world championships in Purgatory, Colorado. The first mountain biking world cup series took place in 1991. Its nine-race circuit covered two continents—Europe and North America—and was sponsored by Grundig. Mountain biking can generally be broken down into multiple categories: cross country, trail riding, all mountain (also referred to as “Enduro”), downhill, freeride and dirt jumping.