The three Olympic sliding sports - bobsled, luge, and skeleton - are all contested on an icy downhill track. But skeleton is different from the other two because sliders (as participants are called) pilot their sleds headfirst on their stomachs.
The sleds have no brakes or steering mechanism, and sliders sometimes reach speeds that approach 80 m.p.h. So it's no wonder that skeleton is considered one of the more daring events at the winter Games.
It is called one of the world's first sliding sports. It started in the late 1800s when sliders in Switzerland used to race down the road from St. Moritz to Celerina.
Still, despite its longevity, skeleton had appeared in the Olympics only twice - in 1928 and 1948 - before it was added to the Games in 2002.
Until then, only men had been allowed to compete in skeleton. Women's skeleton was added to the roster at Salt Lake City in 2002 and has remained an Olympic event.
A skeleton sled is basically the frame, or "bones," of a bobsled, but without a shell, or covering. The sled can weigh more than 70 pounds, and sliders carry it at the beginning of a race in order to get a running jump-start down the hill.
Sliders protect themselves by wearing helmets and chin guards. The tracks have a safety barrier, known as a "lip," to keep the athletes from flying off the edge.
In 2002, the US swept the Olympic gold medals in skeleton. Jim Shea Jr. won the men's gold, while Tristan Gale won the women's.
This year, many observers think Team Canada may be able to sweep the medals as the Americans did last time. Jeff Pain is the reigning men's world champion, and fellow Canadian Mellisa Hollingsworth-Richards is coming off her first World Cup title (2005).
Other top men's contenders include Gregor Staehli of Switzerland and Kristan Bromley of Britain.
On the women's side, Maya Pedersen of Switzerland and Diana Sartor of Germany are also expected to contend for medals.
The women's first skeleton competition is Thursday and the men face off Friday.
Ever since he was a kid, Kevin Ellis has wanted to go to the Olympics. It seemed he was on his way in track and fieldwhen he qualified for the 1996 Olympic trials in the 110-meter high hurdles. But he didn't make the team. So he became an accountant.
Ten years later, Mr. Ellis is finally getting to compete for Olympic gold. Not in the high hurdles or at the summer Games, but at Turin, Italy, in the sliding sport of skeleton.
The 32-year-old says he's living his Olympic dream by doing what nearly every kid does with the first dusting of snow - sled down a hill.
"It's the same concept," he says. But skeleton is much faster and more intense. Instead of gliding downward on a coating of snow, sliders launch themselves headfirst down a winding, ice-covered track at speeds faster than your family's car will reach on an Interstate highway. But their sleds have no steering devices or brakes.
"Going down feels like one of those dreams [where you think] you're flying," says Katie Uhlaender, the only female slider on the US team in Turin. "Your heart's beating fast, you're accelerating around the corner, you swing, and then it's like you're Superman."
The sliders in Turin will start the race at the top of a track that is 5,522 feet high and 4,708 feet long. They will drop 384 feet from start to finish, while negotiating 19 turns.
Staying relaxed and knowing the track are important parts of a successful run. But the world's elite sliders suggest that one of the most essential aspects of skeleton is leaving their fear at the top.
"The difference between going fast and not is racing on the edge, putting yourself out there and maxing out the run," Ellis says. "At all times, you have to stay focused."
Sliders make two runs, and their times are added together to determine the winners of the event.
"Style points don't exist," says Ryan Davenport, a two-time world champion from Canada. "All that matters is how fast you are from top to bottom."
Mr. Davenport retired from elite-level sliding in 1999, after winning two world championships and seven Canadian national titles. He now builds sleds for some of the world's top sliders. Olympians who will use his sleds in Turin include Ellis and fellow American Eric Bernotas, reigning women's world champion Maya Pederson of Switzerland, and the entire Canadian team.
A skeleton sled is designed for speed. It consists of a metal frame that has a flat surface on the top where a slider is able to lie on his or her stomach. The sled has handles on the sides of the top, and it has steel runners on the bottom.
"A sled isn't very responsive," Davenport says. "You can count on hitting walls, getting thrown around."
Sliders are able to make only a few subtle adjustments during a run. These can be accomplished by making shifts in body position on the sled - by shifting body weight to one side of the sled or by tilting one's head.
To know when and how to make these changes, sliders must be able to think clearly while speeding downhill at high speeds. Uhlaender calls this feeling "relaxed chaos." It's part of what attracted her to skeleton.
After some prodding from a friend, she went to her first skeleton school in November 2002. Four months later, she was the national champion. Now the 21-year-old is looking for her first Olympic medal.
"Basically, I love the sport," Uhlaender says. "It's the combination of physical explosion, running, focusing, hitting a zone.... The mental state on a sled feels awesome."
According to these sliders, any competitor could walk away from the track in Turin with gold.
"It's anybody's race," Ellis says. "If you make a mistake or two on this track, you're out of the race. It's left to who makes the least mistakes."