Resting heart rate, heart rate reserve, and metabolic syndrome in professional firefighters: A cross‐sectional study

Background Little is known about the associations of resting heart rate (RHR) and heart rate reserve (HRR) with metabolic syndrome (MetS) in firefighters. Methods For each of 288 professional firefighters, HRR was calculated as the difference between measured RHR and estimated maximum HR. For comparison, VO 2 max based on a treadmill test was included. MetS was defined according to the NCEP/ATP III criteria. Results The prevalence of MetS was 14.2%. The average of RHR was 61.5 beat/min. Only 5.8% of the firefighters had RHR of ≥80 beat/min. Between the firefighters in the lowest and highest quintiles, the prevalence ratios (95% confidence intervals) for MetS were 1.88 (0.71‐4.94), 5.90 (1.74‐20.02), and 8.03 (1.86‐34.75) for RHR, HRR, and VO 2 max, respectively. Both HRR and VO 2 max, but not RHR, were significantly associated with MetS and its most component risk factors in middle‐aged firefighters. Conclusions HRR, a simple cardiovascular fitness measure, was inversely associated with MetS among middle‐aged professional firefighters.