Effect of exercise on upper respiratory tract infection in sedentary subjects.

OBJECTIVE To determine if exercise training affects the severity and duration of a naturally acquired upper respiratory tract infection (URTI) in sedentary subjects. METHODS Subjects were sedentary volunteers (two or fewer days a week of exercise for less than 30 minutes a day for the previous three months), 18-29 years of age, with a naturally acquired URTI (three to four days of onset). All subjects were screened-for example, asthma, hay fever-by a doctor and were afebrile. Volunteers were alternately assigned to an exercise (EX) group (four men, seven women) or a non-exercise (NEX) group (three men, eight women). Subjects in the EX group completed 30 minutes of supervised exercise at 70% of target heart rate range for five days of a seven day period. For the initial screening, and every 12 hours, all subjects completed a 13 item symptom severity checklist and a physical activity log. Cold symptom scores were obtained until the subjects were asymptomatic. Significance was set at p</=0.05. RESULTS There were no significant differences between EX and NEX group mean symptom scores for the morning and evening reporting periods. There were also no differences between the groups for the mean number of days from the baseline symptom score to when the subjects were asymptomatic. There were no differences between physical activity levels, other than what was assigned in the EX group. CONCLUSION Moderate exercise in sedentary subjects with naturally acquired URTI probably does not alter the overall severity and duration of the illness. Previously sedentary people who have acquired a URTI and have just initiated an exercise programme may continue to exercise.