Its highly inspiring finding: Being physically fit appears to cut a person's risk of colds almost in half, and when fit people do catch colds, the symptoms tend to be milder.
How might this work? Exercise temporarily boosts the immune system. (And apparently, the boost is enough to combat any added germ exposure in the gym.) The researchers report:
The number of days with symptoms among those who said they were physically active on five or more days of the week and felt fit was almost half (43% to 46% less) that of those who exercised on only one or fewer days of the week.
The severity of symptoms fell by 41% among those who felt the fittest and by 31% among those who were the most active.
In the US, an average adult can expect to have a cold two to four times a year, while children can catch between half a dozen and 10 colds a year, on average, all of which costs the US economy around $40 billion dollars.
iVillage reports here that the researchers found fitness level to be the most significant factor in the number of colds that a person got, beyond age and marital status and gender. But there's also an alternative explanation:
Infectious disease expert Dr. Marc Siegel, an associate professor of medicine at New York University, agreed that "exercise plays a major role in immune response."
However, Siegel added that people who are physically fit may report fewer sick days because they are "more macho." Perceived wellness may counter feelings of feeling ill, he noted.
But the effect is not purely psychological, Siegel added. "It's a combination of psychological and physical factors," he said.
This program aired on November 2, 2010. The audio for this program is not available.