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PHYSICS 101:
Course Description:
This is a simple and informative explanation of the physical dynamics of Short Track, pulled from John Coyle's blog, which can be found at http://johnkcoyle.wordpress.com/2008/01/27/torino-3-12-a-short-track-speedskating-primer/
How Does It Feel?:
Remember those times of walking on slick, wet ice - to your car across frozen puddles, or down the sidewalk after a freezing rain? Conversely, remember that moment when your shoes first touched dry asphalt after sliding across the puddle, or the instant when you regained traction after passing back underneath the porch roof?
To a speedskater, that is exactly it feels like to be on ice with our long blades - it is feeling of traction and grip, stability and power.
A 17" speedskating blade on perfectly smooth ice is grippier than rubber on asphalt and more stable than a ski on snow. The blade, its sharp edge, and its tracking ability while in motion, are able to smoothly receive every ounce of energy provided by powerful leg muscles to propel the skater forward. Granted, the motion is sideways - like tacking in the wind with a sailboat - but the 17 inch blade is like yards of canvas gathering wind. The lateral forces of the skater's powerful quadriceps are released to the ice in a tangential motion and converted to forward speed smoothly yet powerfully. Each stroke on the ice is a combination brute force (sheer power) and ballet (no wasted motion, fluid extension to the very tips of the range).
Now imagine that ultimate grip - on good ice no amount of effort will result in a slip - with a slow concentrated push from the legs - massive force passing in liquid slow motion through the blade to the ice. The strength of the contracted leg is absolute, and the hold of the blade provides an supreme feeling of power.
The controlled release of the piston-like skating strokes brings to mind the action of a hydraulic cylinder - a fluid, consistent, and powerful extension. If you have ever had the ill-fortune to push a stalled car, and were lucky enough to have a curb or wall as a backstop for your feet, then that incredible push you were able to deliver to the car to get it moving is the closest thing in life to the feeling of a speedskating stroke. Speedskaters regularly push over 1000lbs cleanly on the hip-sleigh in the gym.
Now, add to this powerful motion the g-force dynamics of a jet fighter and you have the right combination. As a skater moves towards the corner, there is a momentary feeling of weightlessness as the body lifts with the final skate stroke, and then falls as the body and center of gravity compress downward and sideways to enter the corner. As the direction of the skater changes, centripetal forces cause a 2G acceleration to crush the body lower (double your weight). In order to stay aligned over the center of the 1mm blades, the skater rolls inward, and the upper body leans way out over the blocks. The powerful motion of the crossovers (corner strokes) then take over and compel the preservation of the momentum carried into the corner. Timed right, you'll see the powerful combination of the full extension of the left leg underneath the right leg (the 'classic' speedskating pose) with both blades carving firmly just prior to the apex of the corner (the center-most block).
Having two feet down at that precarious moment preserves the integrity of the corner and allows the skater to enter a 'pivot' - a one footed completion of the change of direction back toward the far end of the rink, and then begin to relax the arc of the corner a bit through the latter half - reducing the G forces and allowing multiple crossover strokes of acceleration into the straightaway. The apex block is also the focal point of most crashes and many disqualifications.
At this point of the turn the muscles of the body are stressed to the max - imagine squatting down to a 90 degree bend on one leg… holding it, and then putting on a 150lb backpack (the additional pressure provided by the 2G acceleration of the turn). Then balance all of that on a 1mm blade while leaning over far enough to put your elbow on the ground…
As the skater exits the corner, the body decompresses and lifts with the center of gravity returning to vertical. A pair of straightway strokes later, and it starts again.
Is It Hard?
This extremely controlled and concise motion is difficult. However - the motions are repetitive - unlike ballet, gymnastics, or figure skating the number of required motions is drastically reduced. That said though, the real difficulty of the sport lies in the constant compression of the body required to form the aerodynamic shape. Wind resistance, ultimately, is the primary obstacle to speed. If speedskating races were held a vacuum, a skater could stand nearly upright and kick out a series of highly powerful shallow strides in rapid sequence to attain maximum speed. However, with the friction of wind the comes with speeds approaching 40 mph, the skater is required to try and form a teardrop shape, with arms and legs bent in a greater than 90 degree angle.
The loss of muscular leverage at these compressed angles is severe - I won't try to describe the physics, but just imagine these two examples: 1) Imagine if you had someone sitting on your shoulders. Now, in a fully upright standing position, imagine bending your knees slightly and then straightening them again. If you can imagine that situation, you probably can imagine that performing that minor knee bend and subsequent straightening would be very easy. The human body's power output from near-full extension of the muscles involved is tremendous. Most of us could imagine even jumping a little with that weight on our back. However, this position is ineffective due to the constraints of wind resistance.
Instead… 2) Imagine squatting down - all the way down, sitting on your heels. Then extend one leg straight out - kind of a Russian dancer stance. Now imagine lifting the heel of the extended leg up off the ground. Finally try to stand up using only the completely bent leg's power: nearly impossible for anyone other than an acrobat, Russian dancer, or speedskater. Do that with double your weight and you have the pivotal moment of the sport. The compressed body position required by the aerodynamics of the sport demands high power from the legs in a full range of motion, with an extreme amount of coordination of balance and timing, and an alignment of weight and effort. These subtle refinements require a series of heretofore unused muscles in the abdomen, hip, knee, and ankle to constantly adjust to ensure that the powerful compressed stroke passes evenly sideways without interruption or slippage.
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