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In practice it is important to circle swim
so nobody gets injured, but in meets it is just as important to
swim in the middle of the lane. I have caught many of you
circle swimming at meets and we have talked about it after your
race. We came across this short article by Jan Prins in Swimming World. Jan is a
professor of kinesiology at the University of Hawaii.
It isn't often when we can sound both
frivolous and deadly serious at the same time. This is one of
those occasions because, distilled to its purest form, the winner
in our sport is the swimmer who stays as close to a straight-line
path as possible and covers this path in the shortest possible
time.
How this is accomplished is complicated,
but in the realm of biomechanics, this is where we usually start -
by examining the most fundamental concepts associated with motion:
distance and linear displacement.
By definition, a distinction is made
between "distance" and "displacement." While "distance" is a
change in position, "displacement" is the difference between where
we start and finish.
We can agree that in competitive swimming,
"displacement" doesn't have much practical significance because
most races start and end at the same wall. what is of
importance is "distance," which for each race is a fixed
measurement.
Consider the dimensions of a typical lane
in short course meters. The swimmer moves in a rectangle, 25
meters long and usually 2-1/2 meters wide. The diagonal
distance between the two opposite ends is 25.12 meters.
If the swimmer swims at a pace of 2
meters/second - which is a pace equal to a 50-second 100 meter swim
- and moves diagonally instead of at right angles to the walls, it
will take an additional 6-hundreths of a second to cover each
length. Multiply this by the number of lengths, and it is
easy to see that watching that black line on the bottom of the pool
and not racing in circles is critical. Also, remember: if the
athlete swims at a pace that is slower than the example, more time
will be added to the final result.
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