Of 450 patients eligible for this longitudinal trial, 258 were enrolled; 192 were not enrolled because of scheduling issues, patients’ lack of time, or refusal.26
The mean (SD) patient age was 42 (12) years; 75% were women; 62% were college graduates; 54% were white, 22% were African American, 9% were Asian, and 15% were multiracial; and 31% of the total were Hispanic. Patients had asthma for a mean of 21 years, and 52% were taking daily asthma maintenance medications. According to the Asthma Control Questionnaire data, 37% had well-controlled asthma (score ≤0.75) and 39% did not have well-controlled asthma (score ≥1.5). Severity of Asthma Scale scores ranged from 0 to 19, indicating that most patients had mild to moderate disease. The mean BMI was 29; 31% of patients were normal weight, 29% were overweight, and 40% were obese.
Overall, 233 of the 258 patients responded to the open-ended questions and cited a total of 394 benefits of physical activity and exercise, with a mean of 2 benefits per patient. Benefits were grouped into 7 categories encompassing physical and mental health (). The most common benefit was to improve overall health, cited by 37%, followed by to maintain or lose weight, cited by 26%.
Responses to Open-Ended Questions About the Benefits of Physical Activity and Exercise by Category and Exercise Status
From the exercise domain of the Paffenbarger Index, we found that 114 patients (44%) reported doing any exercise. Compared with those who did not exercise, those who did were more likely to consider exercise to be beneficial for respiratory function (18% vs 31%, P = .02) and for mental health/stress reduction (16% vs 30, P = .008) (). Similar proportions, 28% and 24%, respectively, considered exercise beneficial for weight maintenance and reduction (P = .39).
Exercise habits were evaluated according to demographic and asthma characteristics. In bivariate analysis, patients who did any exercise were more likely to be younger, to be male, to have more education, to have a lower BMI, and to have better asthma control (). In multivariate analysis, male sex (P = .01), being a college graduate (P = .04), and not being obese (P < .001) remained significant (). Asthma severity and control were not significant in the model.
Exercise Habits of 258 Patients According to Demographic and Asthma Characteristicsa
Multivariate Analyses for Exercise Habitsa
Patients did a total of 31 different exercises: 17 were vigorous and 14 were moderate in intensity. Overall, 35% of patients reported doing vigorous-intensity exercises, the most common being using a treadmill, running or jogging, aerobics, using an elliptical machine, and Pilates (). Overall, 33% of patients reported doing moderate-intensity exercises, the most common being weight lifting, stretching, yoga, and toning (). In bivariate analysis, younger age, male sex, more education, lower BMI, and well-controlled asthma were associated with doing vigorous-intensity exercises (), and in multivariate analysis, younger age (P = .01), male sex (P = .007), being a college graduate (P = .04), and not being obese (P = .002) remained associated (). For moderate-intensity exercise, male sex, more education, and not being obese were associated in bivariate analysis, and only not being obese (P = .01) remained associated in multivariate analysis. Similar associations were found for exercising 3 or more days per week, with younger age (P = .03) and not being obese (P = .008) remaining significant in multivariate analysis. Male sex (P = .01) and not being obese (P = .01) also remained significant in multivariate analyses for exercising more minutes per week. Thus, obesity was the strongest and most consistent variable associated with exercise habits, whereas asthma control and severity did not remain associated in multivariate models.
Most Common Types of Exercises According to Asthma Control and Body Mass Index
The number of different exercises also was compared according to asthma and BMI characteristics. Except for more patients with better-controlled asthma participating in running or jogging, there were no differences in the number and types of exercises performed according to asthma control (). Nonobese patients, however, were more likely than obese patients to participate in both moderate- and vigorous-intensity exercises and in more than 1 exercise.
Finally, only 22% of the total sample met overall national guidelines for total weekly exercise. Twenty percent met guidelines for vigorous-intensity exercise (ie, ≥20 minutes 3 days per week), and an additional 2% met guidelines for moderate-intensity exercise (ie, ≥30 minutes 5 days per week). In multivariate analysis, only not being obese (P = .02) was associated with meeting overall weekly exercise guidelines. Of the 114 patients who did any exercise, 49% met guidelines, 16% did not meet guidelines but participated in a combination of vigorous- and moderate-intensity exercises 2 or more days per week, and 35% did not approach guidelines. Of the 114 patients, those who met guidelines were more likely to do vigorous-intensity exercise (P < .001), to do 2 or more types of exercise (P < .001), to do vigorous- and moderate-intensity exercises (P = .003), and to exercise 3 or more days per week (P < .001). In multivariate analysis, all these variables remained associated (P ≤ .05).