The Effects of a Healthy Lifestyle Intervention on Fire Recruits’ Health

Abstract

Firefighting is dangerous, and firefighters sustain various occupational risks as well as prevalent chronic diseases, including cardiovascular disease (CVD), cancers, and mental illness. While fire recruits are future firefighters trained in academies to be equipped with the knowledge and skills necessary for their firefighting careers, research on fire recruits is scarce. Because existing evidence shows that the prevalent chronic diseases among firefighters are primarily driven by lifestyle factors, and primary prevention is well established to improve population health, this dissertation aims to examine the effects of a lifestyle intervention on fire recruits, in relation to the prevalent chronic disease risk factors. First, we developed a 7-item healthy lifestyle (HLS) score, MEDI-lifestyle score, to measure recruits’ adherence to a HLS. The ideal HLS is a combination of no smoking, optimal body mass index (BMI), adequate physical activity, decreased TV screen time, high quality dietary intake, sufficient sleep time, and a habit of taking naps. The MEDI-lifestyle score ranges from 0 to 7, with higher scores indicating better adherence. We enrolled 92 fire recruits from two New England academies and measured their metrics at entry to the academies. We found that those with the highest baseline adherence to a HLS had lower hypertension prevalence and better aerobic fitness as compared with those with the lowest adherence. Second, we investigated the effects of existing training environments and probationary firefighter status on recruits’ health. In this prospective cohort study, the same cohort (i.e. the 92 recruits as described above) was followed through academy graduation, and then for an average of eight months after graduation as probationary firefighters. We found academy training significantly improved recruits’ body fat, push-up, pull-up and 1.5-mile running capacities. However, these benefits were largely lost after recruits graduated and had spent eight months as probationary firefighters. Moreover, one of our novel findings demonstrates that participants’ blood pressures kept increasing over time throughout the follow-up period, despite the health/fitness improvements during academy training. Third, we enrolled two more fire academy classes (one from a New England academy that also served as a source for the previous two studies, the other from a Florida academy), which took place during the COVID-19 pandemic, and had them receive a HLS intervention throughout academy training. By comparing the intervention group with the historical control group (i.e. the existing recruit cohort enrolled for the first two studies), we found that a combination of a HLS intervention and impact of the pandemic had mixed effects as compared to existing academy training. Regarding recruits’ HLS behaviors, depressive symptoms, and blood pressures, there were benefits presumably from the intervention. On the other hand, the pandemic impacted group improved less on fitness and anthropometric testing than the control group in response to training, which was likely due to pandemic-related interruptions and restrictions on physical training. In sum, while probationary firefighter status has adverse effects on new firefighters’ health/fitness, and existing academy training increases fire recruits’ blood pressures despite other health/fitness gains throughout training, a HLS intervention on new firefighters may be useful as one primary prevention measure among firefighters to reduce the risk of chronic diseases, and improve firefighters’ career longevity.