High-intensity interval training in individuals with posttraumatic stress disorder: A randomized controlled pilot trial

Background: Exercise interventions have become more important in the treatment of mental disorders. Highintensity interval training (HIIT) has achieved promising results in the treatment of different mental disorders, like depression or panic disorder. To our knowledge, no study investigated the efficacy of HIIT as a sole treatment in a sample of individuals with fully diagnosed PTSD. Methods: 40 participants with PTSD were randomized to either HIIT or a control group (low intensity training, LIT). They underwent a 12 -day training period. The primary outcome were PTSD symptoms as assessed by the Clinician -Administered PTSD Scale (CAPS). Secondary outcome were self -reported posttraumatic, depressive and dissociative symptoms and overall psychological distress assessed at baseline, post treatment (one week after training) and follow up (six weeks post treatment). We used linear mixed models to assess the differential effects of the two trainings on clinical symptoms. Results: In both HIIT and LIT group, clinician- and self -rated PTSD symptom severity as well as depressive and dissociative symptoms and overall psychological distress decreased significantly from baseline to follow up with medium effect sizes related to PTSD symptomatology (Cohen's d = 0.76, p < .001) and small effect sizes related to depressive (Cohen's d = 0.45, p < .001), dissociative symptoms (Cohen's d = 0.42, p < .001) and overall psychological distress (Cohen's d = 0.43, p < .001). There were no differences in symptom change between groups. Conclusion: In our pilot study, HITT did not seem to be superior to LIT in a sample of individuals with PTSD.