The Importance of Individual Choice and Intention in Exercise Adherence and Weight Management.

Abstract

J Obes Metab Syndr 2021;30:317-319 Physical activity has been described as a wonder drug because it has positive effects on physical and mental well-being and can prevent various chronic diseases. The World Health Organization1 recommends that all adults should engage in 150–300 minutes of moderate-intensity aerobic physical activity or 75–150 minutes of vigorous-intensity activity a week, or a level of moderateand vigorous-intensity physical activity that corresponds to the above guidelines, in addition to muscle-strengthening activities on 2 or more days per week. However, a study examining the prevalence of aerobic physical activity among South Korean adults reported that physical activity gradually decreases with age, with the prevalence being 45.3%, 41.4%, 39.3%, and 30.4% among adults in their 40s, 50s, 60s, and 70s, respectively.2 Moreover, only 23.9% of South Korean adults and 18.3% of the elderly3 participate in muscle-strengthening activities, which indicates inadequate levels of physical activity for most of the adult and elderly population. Few adults meet these guidelines, and lack of time has often been cited as a cause.4 This is especially problematic for adults who are overweight or obese, as these conditions increase the risk of comorbidities. Doing 300 minutes or more of moderate-intensity physical activity a week is recommended as a means of weight loss and control, which is a higher level than recommended for the general adult population. However, it can be difficult to achieve this recommended level of physical activity.5 In addition, more than half of those who begin to regularly exercise stop within the first 3 to 6 months. In a study on adherence to physical activity in an unsupervised setting, Sperandei et al.6 reported that the dropout rate reached 47% within 2 months and 86% within 6 months. However, to achieve long-term weight management, it is necessary to continue exercising. While external factors such as weight loss and changes in physical appearance motivate people to begin exercising, enhancing their intrinsic motivation is a key factor in promoting exercise adherence. It has been suggested that exercise intention is important for exercise adherence and that stronger exercise intention is associated with greater exercise adherence.7 In other words, having greater psychological needs such as competence, autonomy, and relatedness attached to physical activity leads to higher self-determined motivation (intrinsic control) to engage in physical activity.8 Self-determined motivation influences changes in health behavior,9 and motivated behaviors facilitate long-term participation in sports.10 The satisfaction of psychological needs promotes autonomous as well as intrinsic motivation; therefore, it affects exercise adherence. In contrast, when participants’ behaviors are not auton-