Cardiorespiratory Fitness Is Inversely Associated With Aortic Arterial Stiffness in Firefighters

Objectives The aim of this study was to determine whether cardiorespiratory fitness (CRF), expressed as VO2max (mL/kg/min), is associated with resting AS (carotid-femoral pulse wave velocity [cf-PWV]) and the AS response to simulated fire suppression activities in firefighters. Methods In firefighters (n = 20, 34 ± 8 years), AS was determined using cf-PWV (m/s) before and after a fire simulation exercise. VO2max was determined using a standard treadmill protocol. Linear regression models, adjusted for body fat percentage, are reported as unstandardized (b) and standardized (β) betas (effect sizes). Results H1: there was a moderate (ie, β = 0.5-0.8), inverse association between cf-PWV and VO2max (b = -0.80; 95% confidence interval [CI], -0.14 to -0.02; β = 0.71). H2: there was a moderate, positive association between Δcf-PWV and VO2max (b = 0.05; 95% CI, 0.00-0.10; β = 0.62). Conclusions These findings indicate that CRF may protect against arterial stiffening in firefighters.