More Exercise You Get, The
Fewer Colds You're Likely To Get
A more active day apparently helps to keep a cold at bay. Researchers
who report this also say people don't have to put in an athletic
performance to get the benefit.
"A regularly active person has a lower risk of getting a
cold," said Charles Matthews of the University of South Carolina.
Matthews and his colleagues looked at 12 months of data on 547 healthy
men and women who had taken part in a broader study of health behaviours.
The men and women, whose average age was 48, reported regularly
on their physical activities and the number of colds they got.
At the higher end, the activities were enough to fit into the
U.S. Surgeon General's recommended minimums, Matthews said. Those
federal guidelines call for 30 minutes of brisk walks, lawn mowing
or other moderate activity on most days of the week. At the lower
end, the participants were doing nothing more intense than light
dusting, which is below the recommended level.
Over the year, the more active people averaged one cold, which
was 23 per cent lower than the average for the least active group,
said the report in the August issue of the journal Medicine and
Science in Sports and Exercise.
The benefit was especially striking in the fall, when about 40
per cent of colds occurred, Matthews said. The risk reduction among
the more active people was 32 per cent, he said.
Studies have found that exercise seems effective in reducing the
chance that a person will even get a cold. If the evidence continues
to mount, federal health officials might decide to promote the benefit
as another reason to exercise, said David Nieman of Appalachian
State University, who was not part of the Matthews team.
"This is getting so scientifically sound that it is going
to demand attention at the National Institutes of Health level,"
Nieman said. "Overall, I feel the evidence is so compelling
that I think people can use it as a reason to be active."
In one of Nieman's studies, women who walked regularly and still
got colds had symptoms that lasted less than five days, while similar
women who did not walk had colds that lasted seven days.
Being physically active seems to stimulate immune cells that target
cold infections, Nieman said. The heightened stimulation seems to
last only one to three hours and then subsides. But day after day
of making the immune system spike may lower the overall risk of
catching cold, he said.
However, Nieman has also found that very hard exercise seems to
draw down immune defences. In his research, people who ran a marathon
had a higher risk of a cold for several days after the event.
And exercise apparently can't cure the common cold, Nieman said.
Other researchers have deliberately given people colds, then had
them exercise, and found exercise neither improved nor worsened
the course of the cold, he said.
On the Net:
Medicine and Science in Sports and Exercise: www.ms-se.com
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