Researchers are reporting in the latest issue of British Journal of Sports Medicine that there may be a positive connection between regular exercise and the ability to ward off respiratory infections.
David C Nieman, of the Human Performance Laboratory at Appalachian State University in Kannapolis, N.C., and colleagues, sought to test the relationship between physical activity or fitness level and the rates of upper respiratory tract infection (URTI). They monitored URTI symptoms and severity in a group of 1,002 community adults (ages 18 to 85) and contrast across levels of physical activity and fitness levels while adjusting for potential confounders. Subjects reported frequency of aerobic activity, and rated their physical fitness level using a 10-point scale. The researchers report that a general linear model, with adjustment for seven confounders, was used to examine the effect of exercise frequency and fitness level on the number of days with URTI and severity of symptoms.
Nieman, et al. (2010) report the number of days with URTI during the 12-week period was significantly reduced, 43 percent in subjects reporting less than five days per week aerobic exercise compared to those who were largely sedentary (less than one day per week) and 46 percent when comparing subjects in the high versus low fitness tertile. URTI severity and symptomatology were also reduced 32 percent to 41 percent between high and low aerobic activity and physical fitness tertiles.
The researchers concluded that perceived physical fitness and frequency of aerobic exercise are important correlates of reduced days with URTI and severity of symptoms during the winter and fall common cold seasons.
Reference: Nieman DC, Henson DA, Austin MD and Sha W. Upper respiratory tract infection is reduced in physically fit and active adults. Br J Sports Med. November 2010. doi:10.1136/bjsm.2010.077875.