Staying Young At Heart: The anti-aging effects of exercise
Number: 00S07. Issue: Spring 2000
Author[s]:
Jennifer Lin and Janice Lin
Keywords:
Abstract:
Are there ways to prevent aging? Can we rely on ourselves to maintain a long and healthy life? Dr.
Ronald Klatz, President of the American Academy of Anti-Aging, believes that
the struggle against aging is a multi-faceted process. "There is no one
best method to prevent aging," Klatz says. "Anti-aging is early
detection, prevention and reversal of aging-related disorders."
Exercise,
whether one is young or old, is a vital factor in maintaining health. Regular
physical activity can reduce the chances of contracting diseases typically
found in the elderly, such as diabetes, obesity, and high blood pressure. As
reported by the American Heart Association, exercise can also prevent
osteoporosis and colon cancer. In doing so, exercise prolongs one?s life span
and leads to healthier living. "If you prevent cardiovascular disease, you
will save seven to thirteen years. If you prevent cancer through exercise,
[which] stimulates the immune system, you can pick up another three years. If
you prevent diabetes, you can pick up another year and a half. Potentially, if
you do all the right things, you can probably expect ten to thirteen years of
longer, healthier living," Klatz says.
As with
most things, however, too much exercise can cause harm to the body, often
taking the form of tissue breakdown through the formation of free radicals,
reactive chemical molecules. "Exercise is a trade-off," Lester
Packer, UC Berkeley Professor of Molecular and Cell Biology, says. "There
are certainly many beneficial effects of exercising, particularly when one
trains. Through physical training, the body adjusts the proteins that it
synthesizes and strengthens the antioxidant defense mechanism. These
antioxidants are substances or enzyme systems that counteract the toxic effects
of free radicals. The body needs free radical reactions to live, but if free
radicals are generated at random, they can be toxic and damage all sorts of
biological molecules, which would lead to damage of cells and tissues, and can
lead to acceleration of aging and to the occurrence of age-related diseases. If
you?re not trained in exercise, you can generate free radicals [through
exercise] that may be damaging."
Instead,
most physicians and professors agree that an exercise prescription should be
made after careful analysis of an individual?s abilities. The intensity of the
exercise should target 60 percent of maximum heart rate, approximated by 220
minus the individual?s age. "At any age, the type of physical exercise you
undertake should be adjusted to your own lifestyle and what you might be able
to train for. I think regular exercise is a good thing," Packer says.
In
developing an exercise program, individuals can tailor one to their needs by
including more endurance (aerobic) training or resistance (weight) training.
"Weight training is slow and repetitive, stimulating the production of
bone, muscle and the neuroendocrine system, which is the complex interaction of
the hormones between the brain and the body. Aerobic exercise works primarily
on circulation, the heart, and the pulmonary function," Klatz says.
For maximum
results, various types of exercises should be included. "The change that
takes place in the human body with exercise is going to be specific to the type
of stress you put on it," Joseph Signorile, University of Miami Associate
Professor of Exercise Physiology, says. "Each type of exercise carries its
own benefits. I believe the best thing is to design an exercise program that
can address the needs of the individual in what we call a periodized program.
In a periodized program, when we work, we gear that work toward a specific
need. After we finish that period of work, we give a recovery period and then
we try to address the next need. Everything needs to be addressed as individual
entities, and I don?t think you can do that all at once. I think you need to do
it in a good cyclic program that addresses each while not allowing you to lose
any of them over a long period of time."
As one ages, joints lose their flexibility, causing
movements to be slower and more painful. Inactivity among the elderly
population results in reduced bone density and bone loss, known as
osteoporosis, which in turn leads to a higher likelihood of fractures.
According to James L. Christiansen and John M. Grzybowski in Biology of Aging,
elderly who engage in exercise have bone mass that is 40 percent denser than
inactive peers. "For osteoporosis, weight training [is most useful],"
Klatz says. "Bones are stimulated by mechanical energy. Weight training delivers
mechanical stress to the bone and stimulates the neuroendocrine system to
release calcitonin to repair and [build] new bone."
Loss of
muscle mass is another symptom associated with aging, but is more often caused
by inactivity rather than by aging. Through exercise, the elderly can gain lean
body mass and improve functional mobility. Atrophy, the wasting away of the
muscle, causes loss of muscle tone, weakening the skeletal muscle contraction.
Another muscular problem frequently encountered by the elderly is cramping due
to decreased circulation. "It?s known that people who go up in space and
sit around for a long time, highly immobilized in zero gravity
(weightlessness), often develop bone defects. They lose bone. In order to keep
the bone strong, you need to have physical exercise," Packer says.
Exercise
can also improve maximum oxygen consumption, a measure of how much oxygen one?s
body can process, which normally decreases with age; less activity results in
less use of muscles that require oxygen. Exercise improves the body?s ability
to use oxygen to produce energy.
With age
comes a decreased body size, and thus a decreased heart size. The left
ventricle, the chamber which accepts blood from the lungs, decreases while the
left atrium, which pumps blood into circulation, increases. In many instances,
the veins expand, and, as a result, the valves fail to function. The blood, in
turn, is trapped in tiny capillaries that may bulge or rupture. By exercising,
the elderly can reduce blood pressure while maintaining the elasticity of blood
vessels, lowering the chance of a rupture. "Aerobic exercise reduces high
blood pressure," Klatz says. "You want to relax the arteries of the
body. Sympathetic nervous tone lowers blood pressure and helps improve circulation.
Aerobic exercise tones the heart and the major blood vessels. It also
stimulates the growth of new blood vessels, and dilates capillaries. You have
hundreds of miles of capillary blood vessels circulating through your body.
Many times, they shrink and shut down as we get older; aerobic exercise helps
open them up and improve circulation. When you open them up, you reduce
pressure. Aerobic exercise reduces the chance of heart attack by 50
percent."
Studies
have also shown that exercise can reduce the chances of getting diabetes
mellitus by stabilizing glucose metabolism. "Exercise helps to regulate
the insulin-receptor sites on the cells of the body," Klatz says.
"Exercise also helps regulate the pancreas? sensitivity to glucose and its
release of insulin. Exercise counteracts the endocrine system and is very
effective in the prevention of diabetes among the elderly."
As tissues
lose elasticity, pain can occur because an increased pressure or friction is
applied to the nerves. Many diseases related to old age result from
neurochemical changes that occur in the body. A decreased level of
acetylcholine (a neurotransmitter which helps conduct nerve impulses) results
in Alzheimer?s disease, norepinephrine deficiency causes disease, and lack of
dopamine brings about Parkinson?s disease.
By engaging in consistent activity, both youth and elderly
can slow the aging process. The greatest benefit of engaging in an exercise
program is the increased chance of habitual exercising. For almost everyone,
the main challenge lies in continuing the physical activity after it has been
started. "Elderly do not exercise for the same reason [younger] people
don?t exercise," Klatz says. "It?s an anathema. Exercise is
strenuous, time consuming, and uncomfortable. Most people are pleasure-seeking.
If they?re not highly motivated, they won?t exercise. It?s not something we?re
innately programmed to do; we?re innately programmed to relax and conserve
energy, causing obesity. Given the choice, most people will sit around and watch
television."
College
students, in the prime of their years, oftentimes forget to exercise to
maintain their physical well-being. This short-sightedness can speed up the
aging process. "I don?t think that our body should be neglected for years
and years," Signorile says. "When we sit down and condemn ourselves
to inactivity for hours rather than going out and engaging in physical
activity, we?ve already planted the seeds of aging when we?re young. While we
may not be able to prevent aging, we may be able to prevent, through lifelong
exercise, what we consider the properties of aging ? that is, our ability to
remain independent. When everything is said and done, that?s really what we all
want. We want to keep our self-respect; we want to keep our independence; we
want to know we can take care of ourselves all through our life."
REFERENCES:
Ronald Klatz, President of the American Academy of
Anti-Aging
Joseph Signorile, University of Miami Associate Professor
of Exercise Physiology
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