Some people seem to breeze through cold-and-flu season without so much as a sniffle. What’s their secret?
Regular exercise is a prime candidate. “If you look at all the lifestyle factors that decrease the number of days you suffer from common cold, being a physically active and fit person is the most important,” says David Nieman, a professor of public health and director of the Human Performance Lab at Appalachian State University.
Nieman has spent years examining the effect exercise has on human health and immune function. In one of his studies, he and his colleagues found that 30 minutes of brisk walking increased the circulation of natural killer cells, white blood cells and other immune system warriors.