Impact of Age and Years in the Fire Service on Firefighter Health and Physical Performance Outcomes

<b>Background</b>: Age is considered an independent cardiovascular disease (CVD) risk factor, but limited data exist concerning the impact of age and years in the fire service on firefighter health and physical performance. <b>Objectives</b>: We assessed the impact of age and years in the fire service on structural firefighter health and physical performance. <b>Methods:</b> 142 firefighters completed an annual clinical assessment. General linear model (GLM) multivariate and univariate analyses were performed across age groups, with years of fire service experience as a covariate. Partial Eta squared (η_p²) values for the GLM statics and Cohen's d for pairwise comparisons were used to assess effect size. <b>Results</b>: GLM analyses revealed statistically significant differences (<i>p</i> < 0.05) for several demographic, body composition, blood biomarker, and physical performance parameters. Pairwise comparisons revealed that younger firefighters displayed more favorable health and fitness profiles than their older counterparts. Interestingly, when accounting for years of fire service experience, differences for only the following variables remained: body mass index, waist circumference, lean mass, visceral adipose tissue, triglycerides, cardiopulmonary exercise test time-to-exhaustion, and VO₂max. <b>Conclusions</b>: These findings suggest differences in CVD risk biomarkers, physical fitness levels, and body composition metrics across age groups. However, years of fire service experience appears to have a greater impact on these variables, suggesting that firefighters' time in the fire service may accelerate the effects of aging on these outcomes. While age-specific health interventions are recommended to manage and mitigate CVD risk effectively, there also should be consideration for the years of fire service.