Skeletal muscle,
in addition to having the basicproperties common to all tissue, possesses the
ability tocontract and move the body. This contraction, however,requires that
a large amount of energy be released. Infact, the metabolic rate of skeletal
muscle can increasemore than any other tissue of the body. Thus, while the skeletal
muscles consume a small percent of the oxygenuptake at rest, during heavy rebounding,
when the totalbody metabolic rate is increased fifteen to twenty timesthat of
rest, most of this increase occurs in the workingmuscles where the metabolic
rate may be as much as 100 times higher than at rest.
The energy needed
for rebounding aerobics is de-rived from oxidation of carbohydrates and fat
and fromsplitting of glycogen and energy-rich phosphates in themuscle cells.
.During prolonged rebounding of ten min-utes or more, the energy needed comes
from fats andcarbohydrates as the major fuels consumed. Protein degradation
occurs only under fasting conditions when thereserves of fat and carbohydrates
have been significantlydepleted. During short exhaustive work periods on the
rebounding device for a person out of shape, the energy needed comes mostly
from glycogen and phosphates.
When
your muscles contract during rebounding, the cleavage of adenosine
triphosphate (ATP) provides the energy for the contraction of your
skeletal muscles. In order to maintain the process of contraction
it is, there- fore, necessary to provide a continuous supply of ATP.
This is done through taking in the best possible nutri- tion, and
by continuing your training program as much as you can. Studies on
animals have shown that the stores of ATP and an associated enzyme
called phos- phocreatine are increased during a training period.
We
have presented a series of physiological facts relating to rebounding
aerobics which are highly technical and might be considered impractical
in a book for popular distribution such as this one. Yet, there
is much more to present. We've merely scratched the surface of the
physiological effects of physical conditioning by rebounding. We
hope to stimulate research by the re- bound exercise industry through
our presentation in this chapter of human physiological concepts
of *reboundology.
Some
of our technical information may be put into perspective when you
consider the response of the human organism to exercising on the
rebounder. The story of Mrs. Laverne Groff, cited at the beginning
of this chapter, is an example. Or, evaluate the case history described
to us by Mrs. Sara Glick of Lancaster, Pennsylvania. Mrs. Glick
is an Amish lady who practices reflexology and attempts to bring
about healing through the skill of her hands on the bottom of people's
feet. Lately, she has added the rebound unit as one of the healing
aides she teaches people to use. This came about as a result of
a dramatic occurrence that took place in her own family.
Mrs.
Click's grandchild. Mary anne Fischer, age eight, who lives in Clinton
County, Pennsylvania, be- came sick one morning. "She was tight
in the chest," said Mrs. Glick. "She had a cough. We first
gave her a collected letter reversal frequency data on 500 normal
and 350 MBD children.
The
first part of the test measures frequency of reversals on execution.
The child is asked to write a series I of numbers and letters as
they are dictated to him. The number of reversals the child makes
is compared to |normal and MBD children.
In
the second part of the test, which measures reversal recognition,
the child is presented with a page of letters and numbers. The child
is instructed to write an"X" over the incorrect letters
and numbers. Dr. Gardner said that the results are then compared
with what has been established as "normal" for children
of various ages and sex.
Realizing
that the child is suffering from a learning disability or MBD, procedures
for correction may then be instituted.
8 L.B.
Rowell. J.A. Murray, G.L. Brengelmann, and K.R. Kraning II. "Humancardiovascular
adjustments to rapid changes in skin temperature during exercise."Circulatory
Research. March 1970, pp. 131-137.
9 A.
Szent-Cyorgyi. Chemistry of Muscular Contraction. (New York: Academic
Press, 1953).
