The Effects of Habitual Physical Activity on Number of Colds and Incidence of Cold Symptoms

The purpose of this investigation was to compare frequency of colds and symptoms of upper respiratory infection in college students who have different levels of habitual physical activity. Subjects were Eastern Illinois University students (N=535, aged 18-25). A survey was conducted which included questions inquiring about demographic information, physical activity habits, the number of colds contracted the month before the survey, and symptom number and severity. Data collection occurred between February 12th and March 1st, 1998. This particular time period was chosen for several reasons, including that student stress level should have been lower than at the beginning or end of the semester, and students had been back from break for a month, giving them time to acclimate to the environment in which they chose to live (dormitory, apartment, etc.). An ANOVA was conducted to check for significant differences in mean symptom score between activity groups (p=.0577). Moderate exercisers had the lowest mean symptom score followed by heavy exercisers, moderate actives, light actives, and sedentary, respectively. A Chi Square analysis was calculated for activity level and number of colds experienced within a month prior to survey distribution (p=.14). The mean number and intensity of symptoms gradually decreased with increased physical activity, with the exception of the heavy exercise group. Although the Chi square analysis was not statistically significant, the data showed that the mean rating of colds was least for the moderate actives and the moderate exercisers. Both the ANOVA and Chi Square analyses, when graphed, showed a J-curve appearance to the data, keeping in line with the current theory proposed by Nieman. This theory suggests that sedentary and heavy exercisers will have the most risk of infection, while moderate exercisers are at the least amount of risk. Also, Chi Square analyses were conducted for other factors which might effect immunity. Significant differences in symptom score were found between men and women, smokers and nonsmokers, and athletes and nonathletes