Impact Of Years Of Experience On The Stress Responses To Firefighting

Research demonstrates that firefighters (FF) experience elevated stress levels during live fire-training evolution (LFTE) scenarios, which is posited to exacerbate cardiovascular disease (CVD) risk. However, it has yet to be evaluated if these occupational stress response levels differ as a FF gains experience in the field. PURPOSE: This study assessed the differences in stress response to a LFTE between FF with greater years of experience. METHODS: Forty-four (n = 44) FF completed an annual clinical health assessment. Years of experience were used to delineate between less experienced (LOW; <6 years) and experienced FF (EXP). Salivary samples were collected baseline (BL), immediately post (POST), and 30-min post the LFTE and analyzed for α-amylase (AA), secretory immunoglobulin-A (SIgA), and cortisol (CORT). Data was analyzed via a general linear model (GLM) analysis and percent mean changes from BL analysis. Data are shown as mean [UL, LL] and 95% confidence intervals (CIs). RESULTS: GLM analysis revealed an overall time effect (p < 0.001, ηₚ2 = 0.225) with no group x time effect (p = 0.571, ηₚ2 = 0.028) for the salivary stress biomarkers. Percent mean change from BL analysis revealed the LOW exhibited clinically significant increases in CORT POST (209.5% [14.4, 404.6], p = 0.036) and 30-min post (125.9% [17.5, 234.2], p = 0.024), while the EXP exhibited increases POST (178.3% [8.2, 348.4], p = 0.040). Both groups experienced clinically significant increases in SIgA (LOW: 72.5% [29.7, 115.4], p = 0.001; EXP: 56.8% [19.4, 94.1], p = 0.004) and AA (LOW: 225.1% [123.3, 326.9], p < 0.001; EXP: 147.6% [58.9, 236.3], p = 0.002) POST and the LOW AA remained elevated 30-min post (150.9% [71.5, 230.3], p < 0.001). CONCLUSIONS: These data demonstrate that LOW FF have greater stress levels. It is plausible that years of job experience can influence one’s ability to deal with occupational stress, yet future work should elucidate the impact of stress on CVD risk and occupational performance.