Excessive steps: Physical activity patterns in pre-selected hospitalized patients with anorexia nervosa under physical activity restrictions

A common factor in the pathogenesis of anorexia nervosa (AN) is compulsive exercise, often driven by a desire for weight loss. In an inpatient clinical setting, patients with AN are typically restricted from engaging in exercise as part of their daily clinical routine to prevent weight loss. As individually practiced physical activity (PA) is a relevant parameter, the aim of this study was to measure PA behavior in an inpatient AN population and compare it with healthy controls. A total of 128 participants, 64 female patients with AN (20 ± 6.1 years) and 64 sex and age-matched healthy controls (20 ± 4.7 years) were measured using accelerometers during 4 consecutive days (2 weekdays and 2 days at the weekend). AN patients were selected from a larger inpatient population based on clinical observation of insufficient weight gain during treatment, reflecting a subgroup with suspected elevated activity behavior. AN patients showed significantly longer daily walking durations (185 ± 44.6 min, vs. 121 ± 43.1 min), a higher step count (20498 ± 2224 vs. 13106 ± 4043) and longer running times (22 ± 31.2 min vs. 7 ± 8.9 min), whereas healthy controls spent more time during cycling (15 ± 11.8 min vs. 1.8 ± 2.3 min), all p < 0.01. PA did not differ significantly between weekdays and weekends in both groups. Despite PA restrictions, AN patients seem to engage more in PA than healthy controls during in-patient treatment. These results could be used in clinical settings to create awareness on compulsive exercise and for educational purposes during treatment.