Grandmaster Ken MacKenzie - Taekwondo Times

Changing your Fitness Level
athletes, their average punch speed was over nine
m/s, but that is outside the meaningful range for
us mere mortals!)
We can, however, draw some useful information
from the comparative speed and mass of
kicks versus punches, since the human leg is
about 14 percent of total body mass, we start
to appreciate, in reflecting back on the equations
earlier, that a kick with twice the mass of
a punch, moving at 50 percent greater speed,
would result in significantly higher kinetic energy
at the point of contact. In fact, if you do the math
(with a punch at 2.9, as in the study mentioned,
and a leg at twice that amount), you will see that
it is six times as much! That means that it is
well worth significantly more time and effort to
improve your kicking speed and techniques as a
percentage of your overall training schedule.
There is a saying in boxing that, “80 percent
of fighting is conditioning, and 80 percent of
conditioning is running.” Now while that general
guideline may or may not be based on physics,
it does point the way to a couple of additional
results that follow from our new understanding
the equation for kinetic energy—namely that
conditioning counts for a lot. In order to set the
stage for these two principles, we must think
about the kinetic energy equation from the other
end, so to speak. So far, we have been looking at
the value of what comes out of the striking technique,
but the same equation tells us how much
energy has to go into the technique. That is, how
much energy does it take to get x mass moving at
y speed. (Yes, it would be nice if a punch created
more energy than we put into it, but it doesn’t
work that way!)
The first conditioning factor to consider is the
impact of dropping any extra weight you may be
carrying around. Because fat tissue stored on our
arms and legs adds mass without exerting more
66 November 2009 / taekwondotimes.com