Moderate exercise does not worsen symptoms.

• Position: Cold viruses - Brief Article - Statistical Data Included

Common cold symptoms do not intensify or last longer when a person participates in light to moderate exercise, according to a Ball State University, Muncie, Ind., study. In fact, regular and moderate exercise may strengthen the body's immune system and help protect it against infection, contends Thomas Weidner, director of the school's Athletic Training Research and Education Laboratory. "Exercise pumps the immune system. It leads us to believe that regular and moderate exercise could keep us from getting colds."

He inoculated 50 individuals with a rhinovirus before dividing them into two groups. Twenty-five of them ran, climbed stairs, and rode bikes for 40 minutes at 70% of their maximum heart rate. The second 25-person group was instructed to remain sedentary except for walking...