Mountain bike racing in the context of "Mountain biking at the Summer Olympics"

Cycle sport is competitive physical activity using bicycles. There are several categories of bicycle racing including road bicycle racing, cyclo-cross, mountain bike racing, track cycling, BMX, and cycle speedway. Non-racing cycling sports include artistic cycling, cycle polo, freestyle BMX, mountain bike trials, hardcourt bike polo and cycleball. The Union Cycliste Internationale (UCI) is the world governing body for cycling and international competitive cycling events. The International Human Powered Vehicle Association is the governing body for human-powered vehicles that imposes far fewer restrictions on their design than does the UCI. The UltraMarathon Cycling Association is the governing body for many ultra-distance cycling races.

Bicycle racing is recognised as an Olympic sport. Bicycle races are popular all over the world, especially in Europe. The countries most devoted to bicycle racing include Belgium, Denmark, France, Germany, Italy, the Netherlands, Spain and Switzerland. Other countries with international standing include Australia, Luxembourg, Slovenia, United Kingdom, United States and Colombia.

Cyclo-cross (cyclocross, CX, cyclo-X or 'cross) is a form of bicycle racing. Races typically take place in the autumn and winter (the international or "World Cup" season is October–February), and consist of many laps of a short (2.5–3.5 km or 1.5–2 mile) course featuring pavement, wooded trails, grass, steep hills and obstacles requiring the rider to quickly dismount, carry the bike while navigating the obstruction and remount. Races for senior categories are generally between 40 minutes and an hour long, with the distance varying depending on the ground conditions. The sport is strongest in the traditional road cycling countries such as Belgium (Flanders in particular), France and the Netherlands.

Cyclo-cross has parallels with mountain bike racing, cross-country cycling and criterium racing. Many of the best cyclo-cross riders cross train in other cycling disciplines; however, cyclo-cross has reached such size and popularity that some racers are specialists, and many prioritize cyclo-cross races over other disciplines. Cyclo-cross bicycles are similar to road racing bicycles: lightweight, with somewhat narrow tires and drop handlebars. They are typically differentiated by their greater tire clearances, lower gearing, stronger frames, cantilever brakes or disc brakes and more upright riding position. They also share characteristics with mountain bikes in that they use knobby tread tires for traction and disc brakes. They have to be lightweight because competitors need to carry their bicycle to overcome barriers or slopes too steep to climb in the saddle. The sight of competitors struggling up a muddy slope with bicycles on their shoulders is the classic image of the sport, although unridable sections are generally a very small fraction of the race distance.

The Union Cycliste Internationale (French pronunciation: [ynjɔ̃ siklist ɛ̃tɛʁnɑsjɔnal]; UCI; English: International Cycling Union) is the world governing body for sports cycling and oversees international competitive cycling events. The UCI is based in Aigle, Switzerland.

The UCI issues racing licenses to riders and enforces disciplinary rules, such as in matters of doping. The UCI also manages the classification of races and the points ranking system in various cycling disciplines including road and track cycling, mountain biking, cyclo-cross, Gravel, and BMX, for both men and women, amateur and professional. It also oversees the World Championships.

Mountain bike orienteering (MTB-O or MTBO) is an orienteering endurance racing sport on a mountain bike where navigation is done along trails and tracks. Compared with foot orienteering, competitors usually are not permitted to leave the trail and track network. Navigation tactics are similar to ski-orienteering, where the major focus is route choice while navigating. The main difference compared to ski-orienteering is that navigation is done at a higher pace, because the bike can reach higher speeds. As the biker reaches higher speeds, map reading becomes more challenging.