The impact of frequency and intensity of physical exercise on long-term PTSD symptoms following war zone stressor exposure among military veterans

Military veterans exposed to war zone stressors are at heightened risk for developing long-term posttraumatic stress disorder (PTSD). Conventional therapeutic interventions often face challenges such as high drop-out rates and limited efficacy, underscoring the need to identify alternative protective factors. Prior research has suggested that physical exercise may buffer trauma-related mental health outcomes. This study examined the longitudinal, bidirectional relationship between war zone stressor exposure and long-term PTSD symptoms among Norwegian Afghanistan veterans, focusing on the moderating effects of physical exercise frequency and intensity. Utilizing two waves of longitudinal data from Norwegian Afghanistan veterans (n = 3,233; 8.5% female), a cross-lagged panel design was employed to assess associations between war zone exposure and long-term PTSD symptoms. Participants were stratified by self-reported exercise frequency and intensity to evaluate potential moderating effects. Significant cross-lagged effects of war zone exposure on long-term PTSD symptoms were observed only in the low-frequency (β = .13, p < .01) and low to moderate exercise intensity group (β = .12, p < .01). No such effects were found in the high-frequency (β = .02, p = .622) or high-intensity groups (β = .01, p = .774), suggesting a protective role of frequent and intense exercise. These findings highlight physical exercise as a promising, scalable, and non-stigmatizing complement to conventional mental health interventions. Encouraging regular or vigorous exercise may strengthen psychological resilience and serve as a preventive strategy in long-term veteran care strategies.