Exercise Helps Keep Colds at Bay
NEW YORK (Reuters Health) - People who exercise regularly appear
to be less likely than couch potatoes to catch colds, US researchers
"Our research provides evidence that being active may actually
reduce the number of colds people get in a year," lead author
Dr. Charles E. Matthews of the University of South Carolina in
Columbia told Reuters Health.
Given that colds are a leading cause of visits to the doctor
and missed work days, Matthews added that employers might do well
to encourage their workers to get off their duffs on a regular
"While getting a cold is generally a minor nuisance for the
individual, the wider public health implications are that being
active may also reduce healthcare costs and increase productivity
in the workplace by reducing the number of individuals getting
a cold," he said.
Matthews and his colleagues obtained their findings from surveys
of 547 healthy adults, administered at regular intervals over
the course of a year. During the study period, the participants
noted how many colds they had experienced, and how often they
engaged in moderate physical activity.
For the purposes of the investigation, exercise considered moderate
or vigorous included anything that people engaged in during their
daily lives that was more strenuous than a walk, including household,
occupational and leisure activities.
The average adult develops between two and five colds each year.
However, the investigators report in the August issue of Medicine
& Science in Sports & Exercise, people who reported being the
most active had 25% fewer colds over the course of a year, relative
to those who were the least active.
In an interview with Reuters Health, Matthew explained that
previous studies have suggested that extremely low or high levels
of activity can have negative effects on the immune system, thereby
increasing the risk of developing colds. For example, he noted,
people who run a marathon appear to have a significantly higher
risk of a cold during the week after the race than non-runners.
In contrast, he added, "moderate levels of activity have been
hypothesized to be associated with enhanced immune function, and
our data--indicating a reduced risk for infection--are consistent
with this hypothesis."
SOURCE: Medicine & Science in Sports & Exercise 2002;34:1242-1248.
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