Nervous System Effects
Neurons begin to decrease at around 30 years of age. Luckily nature has created an over abundance of
brain cells so mental impairment does not occur. Short-term memory decreases and becomes more
difficult to access. A significant decrease in metal functioning is generally the result of a pathological
condition such as arteriosclerosis. Reflex response decreases by approximately ten-percent as a result of
a reduction in the number of neurotransmitter and receptor sites by age 50. Motor skills and reaction times
can become dangerously slow or wholly inaccurate.
Brain size and weight decrease with age. The decrease is mostly in the area of the cerebral cortex, the
area associated with higher level functions. Decreased blood flow is usually the result of arterial
narrowing, which increases the risk of stroke. An Ischemic Stroke is one in which a blood vessel in the
brain becomes blocked as a result of a clot either in the brain or traveling to the brain. A Hemorrhagic
Stroke is the result of a burst blood vessel. Both types of strokes result in a loss of blood flow to the
affected area of the brain. It is extremely important to follow the recommended breathing recommendation
when lifting weights to avoid drastic increases in blood pressure, which can easily bring on a
cardiovascular event in the elderly.
There are continued debates and studies to fuel the debates as to whether neurons are replaced in the
brain. However, it may still be said that what you use develops, what you do not use atrophies or wastes
away.
The sensory system becomes less sensitive with regard to vision, hearing, smell, and taste. At the same
time, the senses may become more sensitive to harsh condition such as bright lights and loud noises.
Near vision becomes impaired due to stiffening of the cornea (lens). This can result in potential exercise
injury as well due to the inability to judge distances and focus. As a reference, inner limits of vision range
from about 3 inches (7.6cm) in children to 32 inches (81.3cm) at age 60. Overall vision may be impaired in
the elderly due to macular degeneration (retinal scarring) or cataracts. Color perception may also be
affected and care is necessary where color identification of gym equipment is necessary.
Older populations lose the ability to hear high frequency (high pitched) sounds. Certain consonant
identification is affected as well; i.e., f, g, s, t, z, ch, sh, and th. Therefore instructions must be clearly
defined and in a tone readily identifiable to the hearing impaired to avoid confusion or injury.
Although exercise has not been proven to increase cognition, it has been shown to reduce depression and
improve self-confidence.
Immune System Effects
The Immune System becomes less effective in fighting off infections by roughly fifty-percent. The
reduction of T-cell response to infection is due to the reduced functionality of the thymus gland. Reduced
antibody production results in a decreased ability to destroy viral and bacterial components. Cancer is
another possible result of a deficient immune system, which does not react to and destroy the runaway
growth of tumor cells. It is interesting to understand the interaction of lymphocytes and macrophages in
the Immune System, although it is recommended study, it is beyond the scope of this course. In many
cases, the elderly immune system is compromised by drug therapy, i.e., steroidal arthritis drugs, cancer
treatments. Increases in the levels of autoantibodies result in an increased incidence of autoimmune
diseases in the elderly.