Specialized group intervention for compulsive exercise in inpatients with eating disorders: feasibility and preliminary outcomes

Nina Dittmer, Ulrich Voderholzer, Mareike von der Mühlen, Michael Marwitz, Markus Fumi, Claudia Mönch, Katharina Alexandridis, Ulrich Cuntz, Corinna Jacobi, Sandra Schlegl

Patients with eating disorders (ED) often suffer from compulsive exercise behavior, which is associated with lower short-term response to treatment and poorer long-term outcome. Evidence-based interventions specifically targeting compulsive exercise behavior have been scarce so far. We developed a manualized group therapeutic approach integrating cognitive-behavioral therapy, exercise therapy and exposure with response management to promote healthy exercise behavior. Our objective was to examine the feasibility and acceptance of this new approach as add-on to regular inpatient treatment in a pilot study. Additionally, we wanted to estimate preliminary effect sizes. Thirty-two female, adolescent and adult eating disordered inpatients were recruited. According to the 4th ed. of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), twenty-six patients met criteria for Anorexia nervosa (AN), two for Bulimia nervosa and four for eating disorder not otherwise specified. Semi-structured interviews were conducted for qualitative evaluation of feasibility and acceptance of the new intervention. Patients completed the Commitment to Exercise Scale (CES) and the Compulsive Exercise Test (CET) for assessment of compulsive exercise, the Eating Disorder Inventory-2 for assessment of eating disorder pathology, the Beck Depression Inventory-II and Brief Symptom Inventory for assessment of depressive and general psychopathology and the Emotion Regulation Skills Questionnaire for assessment of emotion regulation before the beginning and at the end of the group intervention. Additionally, weight gain was monitored. Feasibility of our approach was confirmed. All patients reported a high satisfaction with both structure and content of the group. Between pre- and post-intervention, patients showed significant reductions in compulsive exercise (effect size CES: 1.44; effect size CET total: 0.93), drive for thinness (effect size: 0.48), depressive symptoms (effect size: 0.36), general psychopathology (effect size: 0.29) and acceptance of emotions (effect size: - 0.62). Patients with AN also showed significant mean weight gain during the intervention (effect size: - 0.44). Results of our pilot study indicate that our integrative approach to compulsive exercise in ED patients might represent a promising new therapeutic option. Feasibility and acceptance of the intervention were confirmed. Preliminary effect sizes on most outcomes were promising. As improvements in Body-mass-index, eating disorder and general psychopathology are also to be expected by routine inpatient treatment, a large randomized trial is currently underway to evaluate the efficacy of this new intervention.