A 7-Month Multidisciplinary Healthy Lifestyle Intervention Effectively Improved Cardiometabolic Risk Profile of Firefighters.

OBJECTIVE: We investigated the effect of a 7-month healthy lifestyle intervention on cardiometabolic risk factors (CMRF) among male career military firefighters (FFs). METHODS: Forty-nine FFs participated in a 7-month workplace multiddisciplinary healthy lifestyle intervention designed to reduce CMRF through exercise, diet, and improved sleep. Medical assessments, accelerometry, and surveys at the beginning and end determined program effectiveness. RESULTS: At the end of the intervention period, there was a significant improvement in measures of body composition and blood glucose. The prevalence of hypertension also decreased significantly ( P < 0.01). The 57% of participants who fully adhered to the program had significantly greater improvements across multiple CMRF. Participants increased their physical activity and improved their diet following the intervention. CONCLUSIONS: This healthy lifestyle intervention was effective in changing behavior and lowering cardiometabolic risk among FFs.

Longitudinal changes in cardiorespiratory fitness among firefighters based on a fixed 12.0 MET standard and an age-adjusted fitness standard.

BACKGROUND: Firefighting is a physically demanding profession. Firefighters (FFs) need adequate physical fitness (PF) to perform duty tasks efficiently. While FFs' work demands are constant throughout their career, there is an expected age-related decline in PF. OBJECTIVE: To describe longitudinal changes in cardiorespiratory fitness (CRF) based on a fixed (12.0 METs) and an age-adjusted standard and compare the prevalence of fit/unfit firefighters (FFs) over eight years. METHODS: 297 Brazilian male firefighters were randomly selected. CRF was assessed by the 12-minute Cooper test. To compare the prevalence's of fit/unfit FFs depending on the standard (12 METs vs. age-adjusted), the McNemar test was used. RESULTS: The reduction in the prevalence of fit firefighters was 4.4-fold higher when the analysis did not consider age. CONCLUSION: After eight years, the prevalence of fit FFs decreased by 30.5% based on the fixed standard, while this reduction was only 7% when using an age-adjusted standard.

Cardiorespiratory fitness assessment among firefighters: Is the non-exercise estimate accurate?

BACKGROUND: Minimum cardiorespiratory fitness (CRF) has been recommended for firefighters due to job requirements. Thus, it is important to identify accurate and readily available methods to assess CRF in this population. Non-exercise CRF estimates (NEx-CRF) have been proposed but this approach requires validation in this population. OBJECTIVE: To evaluate the accuracy of a NEx-CRF, as compared to a field maximum exercise test, among career military firefighters of both genders using a comprehensive agreement analysis. METHODS: We evaluated the accuracy of a NEx-CRF estimate compared to the Cooper 12 min running test among 702 males and 106 female firefighters. RESULTS: Cooper and NEx-CRF tests yielded similar CRF in both genders (differences <1.8±4.7 ml/kg-1.min-1; effect size <0.34). However, NEx-CRF underestimated Cooper-derived CRF among the fittest firefighters. NEx-CRF showed moderate to high sensitivity/specificity to detect fit or unfit firefighters (71.9% among men and 100% among women). Among men, the NEx-CRF method correctly identified most firefighters with less than 11 METs or greater than 13 METs, but showed lower precision to discriminate those with CRF between 11-13 METs. CONCLUSIONS: The NEx-CRF method to estimate firefighters' CRF may be considered as an alternative method when an exercise-based method is not available or may be used to identify those who require more traditional testing (CRF 11-13 METs).

Firefighters' basal cardiac autonomic function and its associations with cardiorespiratory fitness.

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.