Cycling is an activity most commonly performed on a bicycle – when it is it is also referred to as bicycling or simply biking. It is the use of the bicycle, unicycle (unicycling), tricycles (tricycling), quadracycles (quadracycling), and other similar wheeled human-powered vehicles (HPVs) for the purpose of transport, as a form of recreation, or in racing. It is done on roads and paths, across open country or even over snow and ice (icebiking).

Bicycling is a highly efficient mode of transportation and optimal for short to moderate distances. Compared to motor vehicles, bicycles have numerous benefits including the provision of exercise, generating renewable energy and thus no air pollution, reducing traffic congestion, minimizing noise pollution (nearly silent operation), easier and less costly parking, much lower likelihood of causing a fatality, high maneuverability, ability to travel on roads or special paths, and lower user cost as well as societal costs (negligible damage to roads, and less pavement required).

Organized rides

Many cycling clubs hold organized rides in which bicyclists of all levels  participate. The typical organized ride starts with a large group of riders, called the mass, bunch or even peloton. This will thin out over the course of the ride. Many riders choose to ride together in groups of the same skill level to take advantage of drafting.

Most organized rides, for example Cyclosportives, Challenge Rides or reliability trials, and hill climbs include registration requirements and will provide information either through the mail or online concerning start times and other requirements. Rides usually consist of 25, 50 and 100 mile routes, each with a certain number of rest stops that usually include refreshments, first aid and maintenance tools.

Mountain

Mountain biking grew in the late 20th century, including recreation and racing. Most mountain biking takes place on dirt roads, trails and in purpose-built parks. Downhill mountain biking has just evolved in the recent years and is performed at places such as Whistler Mountain Bike Park. Slopestyle, a form of downhill, is when riders do tricks such as tailwhips, 360s, backflips and frontflips.

Shortly after the introduction of bicycles, competitions developed independently in many parts of the world. The most famous of all bicycle races is the Tour de France. This began in 1903, and continues to capture the attention of the sporting world.

As the bicycle evolved its various forms, different racing formats developed. Road races may involve both team and individual competition, and are contested in various ways. They range from the one-day road race, criterium, and time trial to multi-stage events like the Tour de France and its sister events which make up cycling’s Grand Tours. Track bicycles are used for track cycling in Velodromes , while cyclo-cross races are held on rugged outdoor terrain, which is performed on road, grass, and mud. Riders in cyclocross must get off their bikes at certain intervals and hop over barriers. In the past decade, mountain bike racing has also reached international popularity and is even an Olympic sport.