Alpine skiing

Alpine skiing, or downhill skiing, is the sport or recreation of sliding down snow-covered hills on skis with fixed-heel bindings. It is characterized by the requirement for mechanical assistance getting to the top of the hill, since the equipment does not allow efficient walking or hiking, unlike cross-country skis which use free-heel bindings. It is typically practiced at ski which provide services such as ski lifts, artificial snow making and grooming, first aid, and restaurants. Back-country skiers use alpine skiing equipment to ski off the marked pistes, in some cases with the assistance of snowmobiles, helicopters or snow cats.

A skier following the fall line will reach the maximum possible speed for that slope. A skier with skis pointed perpendicular to the fall line, across the hill instead of down it, will accelerate more slowly. The speed of descent down any given hill can be controlled by changing the angle of motion in relation to the fall line, skiing across the hill rather than down it. However, ski runs are generally of finite width and a skier using this technique to slow down will eventually move sideways to the edge of the run. At this point the skier must turn to continue the descent in another direction. In theory, a run down the hill would consist of straight sections across the hill, which must be sharp turns to the complementary angle, as if the skier is being reflected from the edges of the run.

Downhill skiing technique focuses on the use of turns to smoothly turn the skis from one direction to another. Additionally, the skier can use the same techniques to turn the ski away from the direction of movement, generating skidding forces between the skis and snow which further control the speed of the descent. Good technique results in a flowing motion from one descent angle to another one, adjusting the angle as needed to match changes in the steepness of the run. This looks more like a single series of S's than turns followed by straight sections.