Extreme sports have obtained a both significant profile and following during recent years. The definition of what constitutes an extreme sport is fluid, as new extreme sports are introduced on a regular basis; all extreme sports tend to produce a profound surge of excitement in the athlete (an "adrenalin rush"), while requiring the athlete to assume significant physical risks. As a general rule, an extreme sport will require the athlete to perform at a high rate of speed, where the athlete is subject to significant effects of gravity, or where the athlete is exposed to special dangers due to the performance of a stunt with limited, or no, safety equipment.
The expression extreme sports is a relatively recent media creation, popularized by international events such as the ESPN "X Games" and the Australia "Gravity Games," held annually in Perth. There have always been athletes prepared to take remarkable risks in the pursuit of a personal sports goal, from the first daredevils who attempted to conquer Niagara Falls during the nineteenth century using barrels and other contraptions, to risk takers such as American motorcycle jumper Robert "Evil" Knievel. Well-established modern sports such as bobsled, luge racing, and parachute jumping, each possessing inherent speed and risks, would clearly have been accepted as extreme sports had the concept been current at the time of their invention in the early twentieth century.
Extreme sports is a notion that extends beyond the strict confines of a rigid classification system. While many extreme sports are the subject of intense competition on an international level, the greater appeal of these activities for their participants lies in the combination of the achievement of successfully conquering a difficult athletic objective, while exposing one self to potential injury or death. Extreme sports tend to be individual as opposed to team pursuits; personal fulfillment is often a very powerful feature in extreme sport participation. With technological developments a significant factor in the development and identification of new extreme sports, the classification is open for the inclusion of any activity that meets the general definition of speed, risk, and difficulty.
The largest demographic in the extreme sports is that of ages 12 through age 35. While males constitute the majority of extreme sports participants, most extreme sports are not restricted by requirements of greater muscularity or speed. Extreme sports tend to place primary emphasis upon the technique used by the participants.
Another compelling distinction between the definition of conventional sport and the extreme sports category is the lesser importance in the extreme sports of the classic pillars of physical fitness (endurance, muscle strength, speed, power, and flexibility). The successful extreme athlete must build significant levels of all around fitness to participate in sports such as rock climbing, which engages every muscle in the body. That same fitness level, while useful, is not essential to participate in extreme sports such as a sky diving or motocross.
The extreme sports tend to place less emphasis upon formal coaching and training, due to their appeal to individual athletes. It is both a hallmark and an attraction of the extreme sports that a novice to the particular sport can participate very soon after their introduction to the activity. Conventional sports such as American football and cricket have extensive and rather rigid rules of play that must be adhered to by the participants; extreme sports have rules that are typically broad and subject to adaptation by an individual athlete.
It is a part of the ethos of the extreme sports that a sport must be perceived as one beyond the mainstream or possess an otherwise counter cultural edge to be a true extreme sport. Bobsled is a fast and extremely dangerous sport, where the sled and crew hurtle down an icy track at speed exceeding 90 mph (135 km/h). Bobsledders assume serious risks of harm, but as bobsled is established as one of the sports of the Winter Olympics, it is rarely regarded as an extreme activity. In contrast, snowboarding, also a multi-disciplinary Olympic sport, is perceived as an extreme sport because the snowboard can be readily extended into more extreme environments such as a ungroomed mountain slope in a way that the bobsled or other regulated sports cannot be taken.
Another distinguishing feature regarding the sports included in the extreme sports category is the nature of the equipment required by the athlete. Most of the equipment is relatively simple to operate, such as a skateboard, bungee cord, or wakeboard; in some sports, a simple piece of equipment is used in conjunction with a mechanized device, such as a tow boat or other transportation.
Extreme sports are played in the air, along the surface of the earth, and on and below the surface of the water. Within the extreme sports classification, activities can be further sub-divided into two groups: sports that are inherently extreme in their execution, and those sports that are made extreme by the adaptation of an additional feature.
The inherently extreme sports are those that from the time of their invention possessed all of the qualities of danger, thrill-seeking, and specialized technique.
The extreme sports that require the participant to enter into a controlled fall from a height in the air are readily identified as extreme sports. The aerial extreme sports include sky diving, bungee jumping (where the athlete jumps from a fixed structure, such as a bridge, attached to a cord that restrains the jumper from striking the surface), hang gliding (where the glider is suspended from a wind powered craft), and parasailing (the subject is towed by boat and the parachute is used to elevate them into the air).
Sky diving and bungee jumping require the athlete to transported to a height, where they are released; a parachute performs the same function as the bungee cord attached to the athlete's leg, as it controls the landing. BASE parachute jumping (Building, Antenna, Span, and Earth) is a form of sky diving where the participants jump from very tall fixed structures using parachutes, often in contravention of local regulations, a further extreme sport hallmark. Hang gliding and parasailing permit the athlete to both control the manner of their ascent into the air and descent to the surface. In all case, a common feature of these extreme sports is the fact that the control that the participant has over the successful conclusion to the jump or the ride is never complete—wind and other environmental conditions area constant threat to athletic success and safety.
The most prominent of the ground-based inherently extreme sports are rock climbing and skateboarding. Rock climbing requires greater overall strength and fitness than perhaps any other extreme sport. Skateboarding, in all of its variations, requires highly developed balance and proprioception skills. Skateboards are very simple machines, typically constructed from a composite synthetic material and technologically advanced wheels. Tony Hawke is the American boarder who took skateboarding and the multitude of dangerous, acrobatic half pipe tricks into the public consciousness in the late 1990s. The skateboard and its rider can be manipulated into a variety of spins, twists, and flips high above an unforgiving concrete surface.
The inherently extreme water sports include both surfing and free diving, activities that exited for centuries before the extreme sports label. Both sports have the common risk of drowning or otherwise sustaining a serious injury. Competitive water skiing, including the modern variants of wakeboarding (a device similar in shape and function to a snow board) and knee boarding, presents serious risks to the users as they perform aerial tricks and jumps from fixed platforms at high speeds.
With the addition of elements that may include duration of the event, obstacles, or through the combination of risk factors, many sports that are mainstream athletic activities become extreme. There are numerous examples of these adaptations. Canoeing and kayaking are activities that have existed since pre-historic times. When a canoeist or kayaker challenges a set of white water rapids that possess the power to obliterate the craft and send the paddler to their death, an extreme element is added. Rafting on dangerous white water rivers possesses a similar quality.
Similarly, the marathon and other distance running races present risks to participating athletes due to the combination of musculoskeletal stress and the demands paced upon the cardiovascular system. These risks are generally well known and the athlete seeks to limit their effect through proper training. Ultra marathoning is the extreme variation, where the runners often cover distances of 100 mi (160 km), over rugged terrain with the additional environmental risks presented by wild animals, elevation changes, and temperature variations.
The "ECO Challenge" is an extreme race that has been organized at different locations throughout the world in recent years. It is an extreme sport contested over a number of days that requires its participants to traverse wilderness areas by running, biking, and kayaking.
The mountain bicycle was one that was readily adapted for extreme sport participation, especially when taken into wilderness, off-road areas. BMX (bicycle motocross) is an example of a machine that is readily operated on a suburban street; the BMX machines are used in a wide range of extreme sport competitions, both racing over courses specially adapted to provide the rider with the challenge of bouncing over mogul like hills, as well as performing a variety of aerial stunts.