AND EFFECT: an understanding of the requirements for productive
exercise is essential for the production of good results
from exercise. Which, in at least one sense, is a misleading
statement, because exercise does not PRODUCE physiological
improvement, increases in muscular size and strength; instead
exercise STIMULATES physiological changes. But any actual
improvements that follow are a result of the body's response
to that stimulus provided by exercise.
The things you can be, the limits of your potential size,
strength, intelligence and several other things, were determined
before you where born, were dictated by your genetics; but
what you will be is largely determined by stimulation provided
by experience. Given the proper stimulation, your body will
respond by improving; assuming that only all the requirements
for such improvement are provided, essentially meaning that
you cannot grow without food, water, air, and regardless
of any stimulation.
you never perform work or exercise with your hands, never
expose your hands to force of any kind, you will never the
less find that the skin on the palms of your hands is thicker
than the skin on the back of your hands. Why? Because the
palms are more likely to be exposed to potentially dangerous
forces, and thus need to be stronger than the back of your
hands. The same thing being true in regard to your feet:
skin on the bottom is thicker than skin on the top for the
And if you never walked a step in your life the skin on
the bottom would still be thicker then that on top. And
much the same situation exists in regard to your muscles:
with no exercise of any kind, some of your muscles would
be larger and stronger than some others.
By far the vast majority of children born in this country
today, will grow up without having been exposed to anything
in the way of either hard work or meaningful exercise, yet
their muscles, with no stimulation from any source, will
never the less grow to a certain size and strength. And
just why does growth stop at that point? Because the body
does not sense any need for greater muscular size and strength;
the existing level, low as it is, nevertheless is enough
to provide any requirements imposed by the activities of
Additional increases in muscular size and strength will
be provided only if the body senses that such greater strength
is needed; you have probably heard the expression”
If you don't use it, you will lose it." Which is a
true statement, but it is also true that if you don't need
it you will never get it in the first place. So you must
convince your body that greater muscular size and strength
is required, that the existing levels are not enough for
With no stimulation for growth the body will nevertheless
provide enough strength to meet your actual needs, PLUS
AT LEAST SOME ADDITIONAL STRENGTH AS A RESERVE FOR EMERGENCY
USE. If that "extra" level of strength is never
used, then no growth will occur; but if you do call upon
that "extra" emergency level of strength, than
you are sending a clear signal to the body that even more
strength is required. Thus the need for so-called "overload"
in productive exercise; and while you can obviously not
lift an impossibly heavy weight, you must, at least, lift
as much as possible, and then must attempt to lift the impossible
Which DOES NOT mean trying to lift the impossibly-heavy
weight once. But it does mean that you should try to stop
when it becomes momentarily impossible to perform one or
more repetitions in good form. Do as many repetitions in
good form, and then, after you fail, try to do one more
But isn't that dangerous? No, it is not dangerous: so long
as the style of performance, or "form," of an
exercise remains constant, then the force imposed upon the
body also remains constant. If you perform ten repetitions
and then fail, the last repetition will certainly fell heavier
then the first one did; but that is an illusion, the last
repetition felt heavier only because of fatigue from the
earlier repetitions had momentarily reduce your starting
level of strength.
If your starting level of strength is 100, and if you exercise
with 80 pounds of resistance, then the first repetition
will be relatively easy, the weight will feel light; because,
at that point in the exercise, you still have "extra"
strength that you are not yet using, you are working at
a "submaximal" level of resistance.
Then, repetition-by-repetition, it will appear that the
weight is getting heavier; but, as stated above, that is
an illusion; the weight seems to be getting heavier only
because you are getting weaker from fatigue. During the
final repetition, your strength, and the resistance will
be the same. So, during that final repetition, you are working
with maximum resistance. One more repetition in good form
is then momentarily impossible because your remaining strength
is then less the level of resistance. At that point, your
remaining strength might be 79, down only 21 percent from
your fresh level, but 79 will not lift 80, so you are forced
Danger from exercise occurs only when the imposed force
of resistance exceeds the existing level of structural strength
of some part of the body; if the "breaking strength"
of a muscle, a tendon, or a bone is 100, then a force of
100 or more will break something, will cause an injury.
Just "how heavy" the weight feels is of no importance;
but it must fell heavy at the end of a properly-performed
exercise; if not, then there is no overload, and thus little
or no stimulation for growth. Remember: you must convince
the body that additional strength is required.
Having done that properly, than you should avoid any hard
exercise long enough for the body to respond properly. If
growth stimulation is provided too often, without enough
time for full recovery between workouts, then growth becomes
impossible; in extreme cases, too much exercise will cause
losses in size and strength. And if you are training regularly,
but are not getting any stronger, then you are probably
training too much, or too often.
If you take a wood rasp and use it to scrape the skin on
the palm of your hand, scrape it hard but not so hard that
you remove the skin on your hand, and if you do this about
twice each week, then you will rather quickly produce a
heavy callus on your hand in the place that you scraped
it. Such scraping tells the hand that the existing level
of skin thickness was not enough to deal with the forces
being encountered, so the development of a callus is an
attempt by the body to strengthen your hand. But if, instead,
you scrape it too often, then no callus will ever be produced;
instead, the skin itself becomes thinner. The muscles respond
to overload in a very similar manner.
In exercise you have a choice: you can exercise "hard"
or you can exercise "a lot," but you cannot do
both. Relatively "light" exercise is usually a
waste of time and energy, regardless of how much of it you
perform, because there is little or no overload. "Heavy"
exercise, working to failure, does provide overload, but
very little of it is actually required to stimulate muscular
growth, and too much will prevent growth, or even cause
losses in size and strength.
article edited and reprinted by permission of I.A.R.T.