Determinants of Exercise Behavior for Adolescents with Mild Congenital Heart Disease

Background: Due to medical advances, most children with congenital heart disease (CHD) are expected to survive to adolescence, even to adulthood. Evidence indicates that their cardiopulmonary function and exercise capacity can reach the level of normal children after surgical repair. However, it is necessary to further investigate the performance in exercise behavior and the determinants of exercise behavior for adolescents with CHD.

Purposes: The purposes of this study were to investigate the amount and intensity of exercise that adolescents with mild CHD engaged in, and to examine the determinants of personal exercise beliefs, interpersonal influences on exercise and availability of physical environment among adolescents with mild CHD.

Methods: The research utilized a repeated measures design. The research subjects were the 12 to 18 year-old students with CHD whose exercise with no limits and vigorous exercise limits only recommended by cardiologists. There were two times for data collection: one was the summer vacation in July-August, 2008 from the pediatric cardiology outpatient departments at three large medical centers in the northern Taiwan. The other one was the semester in December, 2008. The method of data collection was survey by self-reported questionnaires, including demographic data, exercise behavior, exercise self-efficacy, perceived benefits and barriers for exercise, exercise support, modeling and restrictions from significant others, and availability of physical environment for exercise. Structure equation modeling was performed to analyze data.

Results: The respondents during summer vacation engaged in significantly more mild and total exercise than they did in fall semester. The respondents during summer vacation engaged in significantly less vigorous exercise than they did in fall semester. The female respondents engaged in significantly less moderate, vigorous, and total exercise, but non-significant in mild exercise, when compared with male peers. There was no significant difference in the exercise intensity between the respondents engaged in and the cardiologists recommended during these two periods. Approximately 62% of respondents with no exrcise limits recommended by cardiologists did not engage in vigorous exercise in summer vacation, whereas 70% of respondents with vigorous exercise limit only recommended by cardiologists engaged in vigorous exercise in fall semester. The effect between interpersonal influences on exercise and moderate-to-vigorous exercise was mediated by personal exercise beliefs. Based on the revised model, peer influences showed significant effects on moderate-to-vigorous exercise by the mediator of exercise self-efficacy. There was no significant difference in the determinants of exercise behavior during two periods. More exercise benefits the respondents perceived, more mild and total exercise they engaged in summer vacation, and less mild and total exercise they engaged in fall semester. More family influences the respondents received, more mild exercise they engaged in summer vacation, and less mild exercise they engaged in fall semester.

Conclusions: Adolescents with mild CHD engaged in more exercise during summer vacation, but more vigorous exercise occurred in the fall semester. A noteworthy percentage of adolescents with mild CHD did not follow the exercise intensity recommended by cardiologists. The self-efficacy in personal exercise beliefs played the important role in determining the performance of moderate-to-vigorous exercise. The results of this study may provide appropriate exercise behavior suggestions among adolescents with mild CHD and may be the clinical references for health professionals, the evidence of contextual intervention strategies, and related health policies for promoting exercise behavior among adolescents with mild CHD.