Chapter 16 Exercising
Jim Fixx - began running to heal a tennis injury. Intense running became his life
and he wrote a series of books during the 1970s advocating intense running and
jogging regimens. In 1984, he died of a cardiac arrhythmia after one of his runs.
He did have a family history of cardiovascular disease.
cardiac arrhythmia - Irregularity in the heartbeat rhythm.
types of exercise - Exercise can be divided into five basic types: (1) isometric,
(2) isotonic, (3) isokinetic, (4) anaerobic, and (5) aerobic.
isometric exercise - Exercise performed by contracting muscles against an
immovable object. It builds muscle strength. No joint movement is involved in
this type of exercise.
isotonic exercise - Exercise that requires the contraction of muscles AND
movement of joints. This builds both: (1) muscle strength and (2) muscle
endurance. Weight lifting is an example, however, many who train with weights
are more interested body appearance than in improving health.
isokinetic exercise - Exercise requiring force in BOTH directions of movement
(e.g., lifting and lowering) so specialized equipment is required. This type is
frequently used in "physical rehabilitation" settings for restoring strength in those
who have suffered muscle injuries.
anaerobic exercise - Exercise that requires short, intensive bursts of energy but
does not require sustained or increased oxygen use (e.g., power lifting). Such
exercise can be a risk for those with cardiovascular disease.
aerobic exercise - Exercise that requires an increased amount of oxygen
consumption over an extended period of time (e.g., running or swimming). The
two key factors are: (1) intensity and (2) duration. This is the BEST type of
exercise for improving cardiovascular and respiratory health for most people.
The results are that: (1) the amount of oxygen that can be used during exercise
is increased and (2) the amount of blood pumped with each heartbeat is
increased. This results in: (1) lower resting heart rate and (2) lower blood
pressure.
Kenneth Cooper - Was one of the earliest advocates of aerobic exercise. He
also advocated moderation (in contrast to Jim Fixx). Cooper recommended (1)
getting a medical check up before beginning a program, (2) getting an
electrocardiogram or stress test before beginning a program, and (3) exercising
in moderation.
physical fitness defined - Most exercise physiologists see fitness as involving
(1) muscle strength, (2) muscle endurance, (3) flexibility, and (4)
cardiorespiratory (aerobic) fitness.
organic fitness - capacity for action and movement that is determined by
inherent characteristics of the body. These include: (1) genetic endowment, (2)
age, and (3) health.
dynamic fitness - capacity for action and movement that is acquired through
various types of exercise.
strength vs. endurance training - Training for strength requires intense effort
with limited repetitions whereas training for endurance requires lower intensity
movements with greater numbers of repetitions.
flexibility - is obtained through slow sustained stretching exercises such as in
yoga or tai chi.
cardiovascular benefits vs. weight loss - relatively small amounts of activity
can have cardiovascular benefits. However, weight loss requires much more
effort. Experts suggest that formerly obese people need to exercise "60 minutes"
or more daily to maintain weight loss.
the myth of "spot reducing" - When significant weight loss occurs, fat will be
lost where it is most plentiful. However, the idea that one can target a specific
body area, as suggested by advertisers of exercise "gadgets" is a myth.
physical activity and cardiovascular health - During the early 1900s,
physicians discouraged exercise for those with coronary heart disease, CHD,
(fearing it might bring on a heart attack). During the 1950s, opinions reversed.
active vs. sedentary jobs - In England, Jeremy Morris found that active
conductors on London's "double decker buses" had lower rates of coronary heart
disease (CHD) than their more sedentary counterparts who drove the buses.
However, a methodological problem was that these subjects may have "selfselected" their jobs (i.e., more fit persons took the conductor jobs).
the benefits of past activity don't last - Harold Kahn compared mail carriers
who switched to more sedentary clerk jobs with men who had always been postal
clerks. After five years, the former mail carriers (who had lower rates of coronary
heart disease CHD), now had rates of (CHD) comparable to the men who had
always been sedentary. Previous activity loses its benefit after a few years.
Pafenbarger's longshoreman study - demonstrated that workers whose jobs
involved high intensity exercise had lower rates of CHD than less active workers.
And, "self selection" was not a problem in this study.
Paffenbarger's landmark Harvard Alumni investigation - After discovering old
medical records of Harvard students (dating back to 1916), he sent
questionnaires, regarding weekly energy expenditure, to those students who
were still living. He found that risk of heart attack "decreased" as energy
expenditures increased up to 2,000 kilocalories per week. Expenditures beyond
that produced no additional benefit (see Figure 16.1).
activity and cholesterol - Kramsch et al. fed two groups of monkeys (active and
sedentary) the same high cholesterol diet. The more active monkeys had higher
HDL (good cholesterol) levels and lower LDL (bad cholesterol) levels. Active
monkeys also had less narrowing of the arteries and fewer sudden deaths.
activity and osteoporosis - In both women, exercise reduces the risk of this
disease, characterized by a reduction in bone density, brittleness of bones, and a
loss of calcium from the bones.
psychological benefits of physical activity - are not as clear as are the
benefits for physical health. Martinsen and Morgan concluded that (1) aerobic
OR non-aerobic exercise was as effective as psychotherapy in treating mild to
moderate depression and (2) that there was NO evidence that activity helped
with severe depression.
activity and anxiety - Research suggests that a program of exercise can help
reduce levels of "state" but NOT "trait" anxiety. Two mechanisms are suggested:
(1) that exercise simply provides a "change of pace" and (2) that exercise creates
positive changes in neurotransmitter (e.g., serotonin) activity.
trait anxiety - A personality characteristic that manifests itself as a more or less
constant feeling of dread or uneasiness.
state anxiety - A temporary condition of dread or uneasiness stemming from
specific situations such as work, school, financial pressure, or relationships.
exercise and self esteem - Exercise may increase self esteem but probably
does so "indirectly," but decreasing levels of depression, anxiety, and stress.
exercise addiction - Some people get so involved with the reinforcing properties
of exercise (e.g., the endorphin-related "runner's high") that they ignore other
responsibilities and may endanger their own health. Because there is no
documented physical basis of addiction, researchers prefer the terms (1)
"obligatory exercise" or (2) "exercise dependence."
adherence to an activity program - Only about 25% of adults follow an
appropriate exercise regimen. Dropout rates for those who begin exercise
programs are "strikingly" similar to dropout rates for those in programs to stop
smoking, or drinking, or to lose weight.
who drops out - Many people cite (1) lack of time and (2) the amount of effort
required as barriers to exercising. Those most likely to drop out of exercise
programs will be: (1) smokers, (2) blue collar workers, (3) of lower income, and
(4) of lower educational level.
a "paradigm shift" - means a change in the way people think about things.
This has taken place with regard to exercise in recent years. The emphasis has
shifted from programs of very vigorous exercise (which most people can't follow
anyway) to an emphasis on moderate exercise. Experts now recommend 30
minutes of moderate exercise every day or most days of the week.
can exercise be fun? - Morgan has advocated that instead of engaging in
meaningless exercise that seems like drudgery (e.g., walking on a treadmill),
people should find enjoyable activities that keep them naturally active (e.g.,
gardening, or bicycling).