The Whistler sliding track has been called the fastest in the world. Just this week Jeff Blair wrote that "Canada will make its stand against the German medal machine in bobsleigh, luge and skeleton on a track that's hit the outer limits of sliding sports."

So how do sliding sports work? Each of luge, skeleton and bobsleigh start with a ‘push' phase where the athlete sprints, pushing the sled to generate as much speed and acceleration as possible over the first 30m to propel their body down the 1500m ice track. On the 2010 Olympic Track in Whistler, male skeleton athletes will reach 148km/h. Bobsleighs may break 160 km/hr. At these speeds it is inevitable to have the forces of gravity will hit 5G's and possibly 6G's. As a result of these forces the athletes' heads weigh up to 40kg, which is why it is quite common for skeleton athletes to have their head, chin or face pushed into the ice at different points in the track.

"It's intense," says bobsled pilot Bree Schaaf, who got her first runs on the Whistler course at a World Cup event, where she finished sixth. "As soon as you hit turn 10, it gets serious. From there on, it's work, work, work, in terms of how fast the turns come at you. You're going constantly. They're just coming at you like fire."

Here are some pretty cool videos of skeleton. The first has the camera laced above the athlete so you can see the impact of the track on the sliders head. The second is a helmet cam view which is pretty amazing to watch also.

So how does the human body work during sliding sports? Key is the incredible explosiveness of the muscles of these athletes. They generate huge amounts of power in a very short period of time. They have lots of ‘fast-twitch' muscle fibres. These fibres are thicker, contain more protein, and are much stronger than more common ‘slow-twitch' fibres. You can build these fibres up though years of strength training in the gym and sprint training on the track. Regular people have about 40% fast twitch muscle, but sprinters like these sliding athletes might be able to train themselves up to about 80% fast twitch! Here's a great video from TIME Magazine on how they train:

The next thing to consider is the effect of G-Force on the body. That's the force of gravity that pushes into the body from above when they go around corners. In Whistler, the G-Forces will be about 5-6 times the gravity we feel just hanging out on earth. So a 200 lb sliding athlete would feel like they weigh 1200 lbs during the turns! Astronauts only experience 3G's on take off, and fighter pilots tend to pass out at around 12G's. So during the really high speed turns sliders might experience some tunnel vision and difficulty concentrating -- not ideal conditions when you are flying down a tunnel of ice at 150 km/hr.

"It feels like a polar bear is sitting on your chest!," said Schaff. "You feel like a tape recorder stuck on fast-forward. You zip by trees and crowds and somehow try to stay relaxed. You bump a wall, your teeth chatter and your vision gets blurry. At the end you are exhausted, out of breath, sweating even though it might be 20 below outside."

When we think about sliding sports we think about speed, crashes, and G-Force. But there is another factor we can't see as easily: the effect of vibration on the body. These athletes drop from the equivalent of 50 stories on a track of ice that's a mile long. There are 16 curves that drive them down into the ice. The ice is not perfectly smooth - the vibrations of the sleds flying across the ice get transferred straight into their bodies! Military research has shown that vibration causes some hearing loss, decreased muscle control, impaired vision and muscle fatigue.

So in sliding sports you're sliding down an icy toboggan run at 150+ km/hr, your vision is blurry, you have trouble concentrating, your muscles down work normally, and muscles get very tired, very fast. Oh - and at the hardest part of the course, your body weighs 1200 lbs.

Faster, higher, stronger ... and crazier. I love the Winter Olympics.

Dr. Greg Wells will be a regular contributor on CTVOlympics.ca. Follow him throughout the Olympics at www.twitter.com/drgregwells.