Couch potatoes are nearly twice as likely to catch a cold, and a third more likely to suffer bad symptoms of a cold, compared with counterparts who keep fit, American researchers reported.
They tracked 1,002 adults in Wisconsin aged 18-85 for 12 weeks in the autumn and winter of 2008, monitoring them for respiratory illness and weight, and quizzing them about diet, lifestyle, and aerobic exercise.
People who described themselves as fit or who exercised up to five days a week or more, had between 4.4 and 4.9 "cold" days on average.
For those who fell in the middle category of fitness, and exercised between one and four days a week, this was 4.9-5.5 days.
But among counterparts who said they were of low fitness and who exercised only one day a week or less, the tally was between 8.2 and 8.6 days.
Good fitness also caused the severity of cold symptoms to fall by between 31 and 41 percent compared with the most sedentary lifestyle.
Bouts of exercise unleash a temporary rise in immune defenses, helping to boost preparedness against viral intruders, the study suggested.
It cited figures that the average adult in the United States can expect to have a cold two to four times a year, and children between six and 10 colds a year. The cost to the U.S. economy is put at around $40 billion annually.
The paper, published in the British Journal of Sports Medicine, is headed by David Nieman, director of the Human Performance Laboratory at the Appalachian State University in North Carolina.
Copyright AFP
To discover six free ways to remain cold-free — Go Here Now.