Skiing
Skiing is the use of skis to glide on snow. Variations of purpose include basic transport, a recreational activity, or a competitive winter sport. Many types of competitive skiing events are recognized by the International Olympic Committee (IOC), and the International Ski Federation (FIS). History. Skiing has a history of almost five millennia. Although modern skiing has evolved from beginnings in Scandinavia, it may have been practiced more than 100 centuries ago in what is now China, according to an interpretation of ancient paintings. However, this continues to be debated. The word "ski" is one of a handful of  words that Norway has exported to the international community. It comes from the Old Norse word "skíð" which means to "split piece of wood or firewood". Asymmetrical skis were used in northern Finland and Sweden until at least the late 19th century. On one foot, the skier wore a long straight non-arching ski for sliding, and a shorter ski was worn on the other foot for kicking. The underside of the short ski was either plain or covered with animal skin to aid this use, while the long ski supporting the weight of the skier was treated with animal  fat in a similar manner to modern ski waxing. Early skiers used one long pole or spear. The first description of a skier with two ski poles dates to 1741. Troops in continental Europe were equipped with skis by 1747. Skiing was primarily used for transport until the mid-19th century. But, since then it has also become a recreation and sport. Military ski races were held in Norway during the 18th century, and ski warfare was studied in the late 18th century. As equipment evolved and ski lifts were developed during the late 19th and early 20th centuries, two main  genres of skiing emerged—Alpine (downhill) skiing and Nordic skiing. The main difference between the two is the type of ski binding (the way in which the ski boots are attached to the skis). Types. Alpine. Also called "downhill skiing", Alpine skiing typically takes place on a piste at a ski resort. It is characterized by fixed-heel bindings that attach at both the toe and the heel of the skier's boot. Ski lifts, including chairlifts, bring skiers up the slope. Backcountry skiing can be accessed by helicopter, snowcat, hiking and snowmobile. Facilities at resorts can include night skiing , après-ski, and glade skiing under the supervision of the ski patrol and the ski school. Alpine skiing branched off from the older Nordic type of skiing around the 1920s when the advent of ski lifts meant that it was no longer necessary to climb back uphill. Alpine equipment has specialized to the point where it can now only be used with the help of lifts. Alpine Touring setups use specialized bindings which are switchable between locked and free-heel modes. Climbing skins are temporarily attached to the bottom of alpine skis to give them traction on snow. This permits  Nordic style uphill and back-country travel on alpine skis. For downhill, travel the heels are locked and the skins are removed. Nordic. The Nordic disciplines include cross-country skiing and ski jumping, which both use bindings that attach at the toes of the skier's boots but not at the heels. Cross-country skiing may be practiced on groomed trails or in undeveloped backcountry areas. Ski jumping is practiced in certain areas that are reserved exclusively for ski jumping. Telemark. Telemark skiing is a ski turning technique and FIS-sanctioned discipline, which is named after the Telemark region of  Norway. It uses equipment similar to Nordic skiing, where the ski bindings are attached only at the toes of the ski boots, allowing the skier's heel to be raised throughout the turn. However, the skis themselves are often the same width as Alpine skis. Competition. The following disciplines are sanctioned by the FIS. Many have their own world cups and are included in the Winter Olympic Games. Equipment. Equipment used in skiing includes: Technique. Technique has evolved along with ski technology and ski geometry. Early techniques included the telemark turn, the stem, the stem Christie, snowplough, and parallel turn . New parabolic designs like the Elan SCX have enabled the more modern carve turn. On other surfaces. Originally and primarily a winter sport, skiing can also be practiced indoors without snow, outdoors on grass, on dry ski slopes, with ski simulators, or with roller skis. A treadmill-like surface can also be used, to enable skiing while staying in the same place. Sand skiing involves sliding on sand instead of snow, but the skier uses conventional skis, ski poles, bindings and boots for the surface.