Exercise Decreases Upper Respiratory Tract Infection

Summary
Data available showed that there was an inverse relationship between physical fitness and the occurrence of upper respiratory tract infection (URTI).  A recent study correlated fitness levels and exercise with instances of URTI. The results recorded a reduction both in the number of days with URTI and the severity and symptoms between the high versus low groups for perceived fitness and exercise. “These data are consistent with government guidelines urging the general public to include exercise within their daily routines to improve health,” per the researchers.

Introduction
The prevalent URTI rates and the resulting economic burden could be attributed to the multitude of viruses and lifestyle factors. The solution could be regular exercise, which is known to enhance immunity against infection as shown by previous studies. However, these studies have been criticized for inadequately validated methods. The goal of the current study was to prove, with the help of properly validated methods, that there was a link between fitness levels and URTI rates. “The purpose of this research exercise was to study the relationship between both physical activity and physical fitness level with URTI during a 12-week period,” state the authors.

Methodology
•    For this study, 1,002 men and women aged between 18 and 85 years were recruited for a 12-week period. Half the number of participants was studied during winter, while the study on the other half was conducted during fall.
•    The participants answered relevant questionnaires on lifestyle, BMI, diet, perceived fitness levels, exercise schedules, stress, etc.
•    For logging details of the URTI occurrences, researchers used a reliable and valid system called WURSS-21 (Wisconsin Upper Respiratory System Survey), which measured symptoms, functional impairments, global severity and change.
•    Various statistical tools were used for analysis.

Key findings
•    There was a difference in the frequency, severity and symptoms of URTI incidences between groups with high and low levels of fitness.
•    Total days with URTI were reduced by 46 percent in the highly fit and by 43 percent in people who had five or more days of aerobic activity per week.
•    The severity of a URTI incident was 32 percent less in the high-fitness group and 41 percent less in the “aerobic activity” group.
•    URTI symptoms also showed a similar trend in highly fit individuals and in those having almost daily aerobic activity.

Shortcomings/Next steps
Contact with URTI pathogens at work and from children should be included as an additional variable. The significance of risk reduction percentages within subgroups needs to be clearly delineated. The exact mechanism for lesser URTI occurrence with exercise is yet to be understood. However, speculation attributes it to fresh circulation or release of antibodies and immune defense cells.

Conclusion
Owing to the numerous viruses that cause URTI and other factors that affect its incidence, it has been almost impossible to develop a customized cure or preventive medicine for the common cold. This study suggests a simple solution, easily adaptable to all, in the form of fitness and exercise regimens. While the exact reason is still not known, it is hypothesized that exercise increases one’s immune defenses and controls release of stress hormones (which can lower immunity). Though this is a temporary phenomenon lasting for a few hours after exercise, it might be the key to reducing overall URTI occurrences.

For More Information:
Upper Respiratory Tract Infection is Reduced in Physically Fit and Active Adults
Publication Journal: British Journal of Sports Medicine, November 2010
By David C. Nieman, Dru A. Henson; Appalachian State University, Kannapolis and Appalachian State University, Boone, North Carolina

*FYI Living Lab Reports Are Summaries of the Original Research.