section: Artificial tracks
question: When steering the luge, which muscles are used by artificial lugers?
article: Luge
candidates: Artificial luge tracks have specially-designed and -constructed banked curves plus walled-in straights. Most tracks are artificially refrigerated, but artificial tracks without artificial cooling also exist (for example, in St. Moritz). Tracks tend to be very smooth. The athletes ride in a flat, aerodynamic position on the sled, keeping their heads low to minimize air resistance. They steer the sled mainly with their calves by applying pressure on the runners--right calf to turn left, left calf to turn right. It takes a precise mix of shifting body weight, applying pressure with calves and rolling the shoulders. There are also handles for minor adjustments. A successful luger maintains complete concentration and relaxation on the sled while traveling at high speeds. Most lugers "visualize" the course in their minds before sliding. Fastest times result from following the perfect "line" down the track. Any slight error, such as a brush of the wall, costs time. Track conditions are also important. Softer ice tends to slow speeds, while harder ice tends to lead to faster times. Lugers race at speeds averaging 120–145 km/h (75–90 mph) around high banked curves while experiencing a centripetal acceleration of up to 5g. Men's Singles have their start locations near where the bobsled and skeleton competitors start at most tracks, while both the Doubles and Women's Singles competition have their starthouse located further down the track. Artificial track luge is the fastest and most agile sledding sport.