Virtual reality based active shooter training: Added physical stress increases anxiety but not stress biomarkers

Tactical first responders such as firefighters and law enforcement officers are often exposed to concurrent or consecutive stressors. Exposure to concurrent stress challenges (i.e., combined mental and physical stress) has been shown to exacerbate stress biomarker responses. However, this has not been shown with short duration stressors (e.g., < 3 min). Therefore, this study compared markers of stress and perceived anxiety in response to a physical stressor [exercise alone; (EA)] to that of a dual stress challenge (DSC) which included a virtual reality based active shooter drill in addition to the exercise task. Fifty-four subjects (n = 54) completed either EA (n = 27) or DSC (n = 27). Measurements included salivary α-amylase (sAA), secretory immunoglobulin A (SIgA), heart rate (HR), and state anxiety inventory (SAI) which were collected four times: 1) 30 min prior to exercise 2) immediately prior to exercise 3) 5 min post exercise 4) 30 min post exercise. Both DSC and EA resulted in significant increases in salivary stress biomarkers (p < 0.05). The DSC resulted in significantly greater SAI values 5 min post exercise compared to the EA treatment. A secondary analysis demonstrated significantly lower sAA concentrations overall in females (n = 25) compared to males (n = 29), as well as significantly lower SIgA at five and 30 min post stress compared to males. These findings demonstrated that added mental stress causes significant increases in perceived anxiety compared to physical stress alone, and females demonstrate reduced stress biomarker responses to acute stress.