Purpose: Our aim was to assess the effect of a moderate-intensity, year-long exercise program on the risk of colds and other upper respiratory tract infections in postmenopausal women.
Subjects: A total of 115 overweight and obese, sedentary, postmenopausal women in the Seattle area participated.
Methods: Participants were randomly assigned to the moderate-intensity exercise group or the control group. The intervention consisted of 45 minutes of moderate-intensity exercise 5 days per week for 12 months. Control participants attended once-weekly, 45-minute stretching sessions. Questionnaires asking about upper respiratory tract infections in the previous 3 months were administered quarterly during the course of the year-long trial. Poisson regression was used to estimate the effect of exercise on colds and other upper respiratory tract infections.
Results: Over 12 months, the risk of colds decreased in exercisers relative to stretchers (P = .02): In the final 3 months of the study, the risk of colds in stretchers was more than threefold that of exercisers (P = .03). Risk of upper respiratory tract infections overall did not differ (P = .16), yet may have been biased by differential proportions of influenza vaccinations in the intervention and control groups.
Conclusions: This study suggests that 1 year of moderate-intensity exercise training can reduce the incidence of colds among postmenopausal women. These findings are of public health relevance and add a new facet to the growing literature on the health benefits of moderate exercise.