Exercise as a psychological therapy in obese adolescents.

?Childhood obesity has reached epidemic proportions globally (Wang & Lobstein, 2006). Obesity has been linked with psychopathology in adolescents seeking treatment (Zametkin, Zoon, Klein & Munson, 2004). To avoid serious health consequences in adulthood, the high incidence of psychopathology in this population needs to be addressed. Exercise has the potential to improve both physical and psychological health simultaneously; however, there is a lack of research investigating the effects of exercise upon psychopathology in obese young people. Therefore, this thesis provides an examination of the effects of a supervised exercise therapy intervention upon psychopathology related outcomes in obese adolescents using a randomised controlled trial (RCT) method. The primary trial hypothesis was that exercise therapy would lead to improvements in participants' physical self-esteem and reductions in psychopathology. Two qualitative studies explored obese adolescents' experiences of participation in an exercise therapy intervention and a further study investigated their ratings of perceived exertion (RPE) during exercise.The population sample consisted of 81 obese (body mass index (BMI) > 2.5 SDS, adult equivalent BMI of > 30) adolescents aged between 11-16 years who had been referred to a children's hospital for evaluation of obesity or responded to a community advert. Participants were randomised to exercise therapy, an equal contact exercise-placebo intervention or usual care control. Intervention participants attended three one-to-one sessions per week, over eight-weeks and then completed a home programme for six-weeks. Participants were interviewed at the end of the eight-week intervention and again after the home programme. Outcomes included self-perceptions (self-esteem), depression, affect, physical activity and BMI. Repeated measures mixed analysis of covariance (controlling for baseline scores) revealed significant differences in physical self-worth, associated measures of self-esteem and physical activity over time in favour of the exercise therapy condition. There were no significant differences in BMI. Findings from the qualitative studies revealed that obese adolescents were happier than when they began the programme, expressed surprise at how much they were capable of achieving in terms of exercise and felt empowered to continue to exercise over the long-term. Some felt that the intervention was not long enough and many of the common barriers to exercise typically reported by other young people, such as time, were cited at interview. Obese adolescents reported RPE during exercise to be significantly greater for the lower limbs compared with aerobic exertion.This study is the first RCT to demonstrate that a brief supervised exercise therapy intervention has the potential to significantly improve psychopathology related outcomes and increase physical activity in obese adolescents, relative to usual care. Findings indicate that obese children can successfully perform short intermittent bouts of structured exercise, given the opportunity, and that physical activity can contribute to the enhancement of their psychological and social well-being. Results also suggest that obese adolescents find prolonged bouts of exercise fatiguing in the lower limbs particularly which underlines the critical need for future interventions aimed at treating obesity to be aware of the importance of assessing ratings of perceived exertion during exercise. It is hoped that this thesis will generate additional research interest and concern about the psychopathology of young people who are obese. In particular, raise awareness of the importance of assessing the efficacy of obesity treatments in relation to psychopathology outcomes in future trials. It is also hoped that the exercise therapy guidelines provided here would inform health practitioners in the delivery of exercise therapy and highlight the potential contribution exercise therapy could make to the treatment of childhood obesity in pragmatic environments such as the NHS.