For years, doctors and health experts have been encouraging people
to exercise on a regular basis in order to lose weight and improve
their health; however, researchers believe they have found that
physical activity may not help everyone achieve these goals. According
to studies, there is a minority of people who may not benefit at
all from exercise, regardless of how strenuous it may be.
In order to demonstrate this belief, researchers conducted a study
involving nearly 750 volunteers who had not participated in regular
physical activity for six months. Each volunteer was put through
a strict 20-week endurance-training program where they were instructed
to ride stationary bikes. By the last six weeks of the study, the
volunteers had increased their exercise to 50 minutes three times
a week, at 75 percent of the maximum output they were capable of
before the study began.
After the trial was through, researchers found that the volunteers
varied in their "trainability" -- how much improvement is
likely to be seen after an exercise program.
For example, training improved maximum oxygen consumption (a measure
of a person's ability to perform well) by 17 percent on average.
However, those who were most "trainable" gained over 40
percent while the least trainable showed no improvement at all.
Similar patterns were seen in other markers
of fitness such as:
- Cardiac output
- Blood pressure
- Heart rate
Insulin sensitivity -- an indicator for risk of diabetes and heart
disease -- also varied: 58 percent of volunteers showed an improvement
while 42 percent showed no improvement or even got worse.
Researchers concluded that in order for one to benefit from exercise,
a tailored training program must be implemented to meet the individual's
specific health needs.
New
Scientist December 2, 2004
BBC
News December 2, 2004
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