Motocross by agents · September 30, 2021 Motocross, form of motorcycle racing in which cyclists compete on a course marked out over open and often rough terrain. Courses vary widely but must be 1.5 to 5 km (1 to 3 miles) in length in international competition, with steep uphill and downhill grades, wet or muddy areas, and many left and right turns of varying difficulty. Motocross is probably the most physically demanding motorcycle sport, although its races are quite short—40 minutes or less for each of the two heats of a race. Riders must use the same motorcycle throughout a race, with repairs made between heats if necessary. A cotton jersey, nylon pants padded at the knee and thigh, padded boots and gloves, a helmet and goggles, a plastic chest protector, and a kidney belt for support constitute the usual outfit of the motocross cyclist.