Slow Breathing Reduces Biomarkers of Stress in Response to a Virtual-Reality Active Shooter Training Drill




Dillard, Courtney

Journal Title

Journal ISSN

Volume Title



Tactical occupations (i.e., military, law enforcement personnel) regularly encounter lifethreatening situations while on duty. Acute participation in virtual reality active shooter scenarios has been shown to increase markers of stress. Although tactical occupations are trained to utilize slow breathing during high stress scenarios, there is no evidence supporting the effectiveness of slow breathing in relation to a virtual reality-active shooter training drill ( VR-ASD). The purpose of the study is to determine the impact of acute slow deep breathing on markers of stress in response to a virtual reality active shooter drill. METHODS: A parallel between subjects design was used, during which, eighty-one (n=81) subjects performed 5 min of either slow breathing method 1 (SB1), slow breathing method 2 (SB2), or normal breathing (NB) immediately pre and post VR-ASD. Salivary samples, heart rate, and state-anxiety inventory were collected 30 min pre, 5 min pre, 5 min post, and 30 min post VR-ASD. Saliva was analyzed for stress markers: α-amylase (sAA) and secretory immunoglobulin-A (Sig-A). sAA and SIgA were analyzed via 3x4 (treatment x timepoint) factorial ANOVAs. HR and SAI were analyzed via 2x4 factorial ANOVA. RESULTS: Both methods of slow breathing resulted in significantly lower sAA concentrations at 5 (p < 0.001), and 30 min post VR-ASD (SB1: p= 0.008; SB2: p < 0.001) compared to NB. In the NB condition, sAA concentrations were significantly elevated 5 min post VR-ASD (p < 0.001) compared to all other timepoints but did not change across time in SB1 or SB2 (p > .05). A significant increase in SIgA concentrations was noted 5 min post VRASD compared to all the other time points (p < 0.001). CONCLUSION: The VR-ASD resulted in a significant increase in stress markers sAA and SIgA. Both SB1 and SB2 prevented a significant increase in sAA concentrations and resulted in lower concentrations post VR-ASD. Future studies should investigate the effects of longitudinal participation in slow breathing.



stress, stress biomarkers, virtual-reality, active shooter, salivary stress markers, law enforcement, tactical occupations


Dillard, C. (2023). Slow breathing reduces biomarkers of stress in response to a virtual-reality active shooter training drill (Unpublished thesis). Texas State University, San Marcos, Texas.


Rights Holder

Rights License

Rights URI