Abstract
BACKGROUND: Excessive exercise is recognized as a predictor of poor outcome in eating disorders. However, little is known about how excessive exercise might affect the treatment process. The aim of this study was to describe process of weekly changes in eating disorder psychopathology, general psychopathology and exercise, and the possible interactive effects of excessive exercise on these changes during inpatient treatment of longstanding eating disorders. METHODS: Eighty-four patients meeting the DSM-IV criteria for Anorexia Nervosa, Bulimia Nervosa, or Eating Disorders Not Otherwise Specified received inpatient cognitive-behavioural therapy including, physical activity and nutritional counselling treatment over 12 weeks. Excessive exercise was defined as having ≥6 episodes of driven exercise during week 1 of treatment. Excessive exercisers received one additional session of individual counseling with the clinical exercise physiologist. The study used repeated measurements during treatment and collected measures of eating disorders: psychopathology (EDE-Q), general psychopathology (SCL-5), and frequencies of exercise and body mass index (BMI). Statistical analysis was performed using repeated measures ANOVA. RESULTS: Both eating disorders and general psychopathology were reduced from admission to discharge in excessive exercisers and non-exercisers. There was an overall interaction effect between time (week) and excessive exercise for the process of exercise and eating disorders psychopathology reduction. This interaction effect was also found in week 10 vs 11 regarding general psychopathology. The excessive exercisers showed steep reduction at first, followed by a smaller increase towards the end of treatment in both eating disorder and general psychopathology; this pattern was not found among the non-exercisers. CONCLUSION: The process of change in exercise and psychopathology during inpatient treatment of longstanding eating disorders differs across excessive and non-excessive exercisers. Although excessive exercisers were given special attention for their exercise cognition and behavior during treatment, it is apparent that this part of treatment must be further developed.