RESUMEN
PURPOSE: Many studies have shown that regular exercise produces positive effects on health. The purpose of this study was to examine the differences of health-related quality of life by stage of exercise and the interaction effect of age, sex and stage of exercise. METHOD: A total of 1266 participants were interviewed with structured questionnaire. Stage of exercise was assessed with a single item and respondents were classified with respect to exercise intention and behavior. Health-related quality of life was measured with SF-36 Health Survey Questionnaire. RESULT: Health-related QOL were found to be different by stage of exercise. The subjects who were reached maintenance stage showed significantly higher scores on physical functioning, bodily pain, general health perception, mental health, role limitation due to emotional problems, social functioning, and vitality than those in preparation, contemplation, and precontemplation stage. In addition a significant interaction effect between stage of exercise and age was found on physical functioning, bodily pain, general health perception, mental health, and vitality. CONCLUSION: Perceived health-related QOL varies with stage of exercise. This finding suggests that health is related to both intention and behavior of exercise. Therefore it is important to consider cognitive-motivational and behavioral stage of change for developing exercise programs.