The benefits of exercise are well-studied and well-documented. They include
bone
health
, weight control, prevention of heart disease, and a potent
enhancement of well-being. In the pre-industrial era, merely staying alive
and gathering the resources for survival entailed a lot of physical exertion.
Farming, hunting, the use of hand-tools rather than power tools, etc.,
are obvious examples. The use of labor-saving devices (automobiles, power-tools,
etc.) has increased productivity but has reduced the necessity of the
human body to directly impact the environment.

Exercise can be classified in several different ways: “Aerobic” exercise
refers to that which uses large groups of muscle so as to help develop
the capacity of the heart and lungs to deliver oxygen to the body. This
is important in the maintenance of the health of the heart. This form
of exercise should be preceded by a period of stretching and “warming
up,” as well as a short period (until breathing returns to normal) of
“cooling down” afterwards.

Isometric
exercise
refers to muscle contraction without actual movement of the
involved limbs. This enhances muscle strength, and is a convenient method
of exercise when sitting at a desk. There are, however, problems with
this technique, Stretching is a form of exercise which does not develop
muscular strength but rather promotes a full range of motion in the joints
and ligaments. Muscles are also lengthened, and warmed up during the process
of stretching. These are valuable results in their own right, and also
serve to prevent injury during more vigorous exercise.

Exercises such as Yoga and T’ai
chi
complement the other forms in that they stress the co-ordination
of the mind with the body, flexibility, and relaxation. These are powerful
forms of exercise that are coming into a new appreciation in western cultures,
are especially appropriate for the elderly, since they are inherently
less stressful on the body, and, if begun young enough in life (it is
never too late to gain benefit) may result in improved functioning of
the body (immune system and stress-management) systems not achievable
by more conventional forms of exercise.

A very significant benefit of exercise over one’s lifetime is that fractures in the elderly are much less likely to occur. This results from maintenance of balance, muscle strength, and joint mobility, which together make falls and other injuries much less likely. Indeed, the prevention of falls is more powerful than any known medication in in reducing pathological fracture.