Effect of high-intensity interval training exercise on sleep quality in women with probable post-traumatic stress disorder: A pilot randomized controlled trial.

Poor sleep quality is a major problem for women with post-traumatic stress disorder (PTSD). Potential causes of poor sleep quality include elevated symptoms of anxiety, hyperarousal, and decreased high frequency-heart rate variability (HF-HRV). Exercise training both decreases anxiety symptoms and increases HF-HRV among samples without PTSD. The effect of exercise training on sleep quality, HF-HRV and PTSD-related symptoms has not been tested in a sample of women exposed to trauma. This study aimed to evaluate the impact of High-Intensity Interval Training (HIIT) on sleep quality in a sample of women with probable PTSD and test if reductions in anxiety or hyperarousal symptoms and/or increased HF-HRV mediate improved sleep quality. Thirty women with poor sleep quality and a Post-Traumatic Diagnostic Scale (PDS-5) score indicative of PTSD (≥ 28) were randomly assigned to either six-weeks of HIIT or a waitlist control (WL). Sleep quality, PTSD and anxiety symptoms were assessed at baseline (BL), weeks 2, 4, 6, and post-intervention (POST). HF-HRV was measured at BL and POST. A mixed model ANOVA 2 group × 5 time interaction for sleep quality was significant (p < 0.001; HIIT BL: 11.27 ± 2.55; POST: 5.60 ± 2.03 versus WL BL: 9.47 ± 2.83; POST: 8.23 ± 2.39; Hedges' d = -1.57). Anxiety and hyperarousal symptom reductions significantly mediated sleep quality changes. HF-HRV mediation models were non-significant. HIIT-based cycle exercise training in a sample of women with probable PTSD improves sleep quality, and reductions in trait anxiety and hyperarousal symptoms mediated these improvements. CLINICAL TRIAL REGISTRATION: (Clinical Trials. gov) Identifier: NCT05097352.