Acute changes in affective valence and perceived distress predict reductions in PTSD symptom severity

There is a growing amount of experimental evidence demonstrating therapeutic chronic effects of exercise (e.g., resistance exercise, running, and walking) on PTSD symptoms. However, it is currently unclear how individuals with PTSD experience exercise within individual exercise sessions (e.g., pleasurable or distressing), and if these acute experiences influence PTSD symptoms over time. Purpose: The objective of this study was to examine the acute effects of high intensity resistance exercise on affect, perceived arousal, and distress among individuals who screened positive for PTSD, using a randomized controlled design. Additionally, this study sought to explore longitudinal relations among affect, arousal, distress, and PTSD symptom severity. Methods: This study analyzed pooled data from two methodologically similar randomized controlled trials (i.e., a pilot and replication study). Participants (n = 52) were randomly assigned to exercise or non-exercise time-matched control. Data were analyzed with a series of longitudinal mixed-effects regression models. Results: The analyses suggest that positive affect increased, and distress decreased significantly during exercise sessions, relative to control. Independent of group, increases in positive affect and decreases in distress also significantly predicted decreases in PTSD symptom severity over the course of the study. Conclusions: Taken together, these findings suggest that high intensity resistance exercise is safe for individuals who screen positive for PTSD, pleasurable, and may have a therapeutic impact on trauma survivors. No evidence for symptom exacerbation was found. Future experimental studies are needed to verify these findings and determine if the observed relationships are similar for other exercise modes, durations, and intensities.