On-Duty Resting Heart Rate Variability at the Fire Station Is Related to Cardiorespiratory Fitness and Physical Activity Levels in Firefighters

Objective: The aim of the study is to measure the association between the physical activity (PA) levels and cardiorespiratory fitness on the firefighters' cardiac autonomic function at rest at the fire station. Methods: Anthropometry, heart rate variability, fitness, and PA levels were assessed at the fire station in 98 career Quebec male firefighters. Results: Partial correlations, adjusted for age, waist circumference, and perceived stress revealed that heart rate and several heart rate variability indices were significantly correlated to estimated maximal oxygen consumption and to high-intensity PA but not to moderate-intensity PA. Conclusions: These results suggest that both cardiorespiratory fitness and high-intensity physical training are related to the cardiac autonomic function of firefighters. Therefore, fire department should promote PA programs to improve physical fitness among firefighters.