Higher cardiorespiratory fitness (≥12 METs) in male firefighters was positively correlated with overall cardiac autonomic function and higher parasympathetic activity (p < 0.03).
Cross-Sectional (n=64)
Does higher cardiorespiratory fitness improve resting cardiac autonomic function in male firefighters?
Higher cardiorespiratory fitness in firefighters is associated with improved resting cardiac autonomic function, characterized by higher parasympathetic modulation.
p-value: p=<0.03
BACKGROUND: Firefighters' activities require constant adjustments of the cardiovascular system with cardiac autonomic function (CAF) playing an important role. Despite the crucial role of CAF in regulating stress response, little is known about firefighters' CAF. OBJECTIVE: We aimed to characterize the resting on-duty and off-duty CAF of male firefighters, in association with cardiorespiratory fitness (CRF). METHODS: We evaluated 38 firefighters in an on-duty rest condition and 26 firefighters in an off-duty laboratory-controlled condition. CAF was addressed by means of heart rate variability (HRV). We compared HRV measurements between CRF categories (<12METs vs ≥12METs). Wilcoxon, Mann-Whitney texts and Spearman correlation were used and General Linear Model was applied for age and BMI adjustments. RESULTS: Firefighters' resting CAF is characterized by a predominant sympathetic modulation and a large inter-individual dispersion in all HRV indices, in both groups. We found a positive correlation between a higher CRF, the overall CAF and the higher parasympathetic activity (p < 0,03). Firefighters with CRF ≥12 METs showed a higher parasympathetic modulation. CONCLUSIONS: Firefighters' resting CAF is characterized by a predominant sympathetic modulation and a large inter-individual dispersion in all HRV indices, in both groups. Our results support mandatory physical training focused in improving firefighters' CAF as a cardiopretective effect.
Porto et al. (Tue,) conducted a cross-sectional in Occupational health (Firefighters) (n=64). Cardiorespiratory fitness (CRF) ≥12 METs vs. CRF <12 METs was evaluated on Cardiac autonomic function (CAF) measured by heart rate variability (HRV) (p=<0.03). Higher cardiorespiratory fitness (≥12 METs) in male firefighters was positively correlated with overall cardiac autonomic function and higher parasympathetic activity (p < 0.03).