The Relationship Between Firefighters’ Physical Activity Levels and Cardiorespiratory Fitness

Abstract

Improved physical activity (PA) and cardiorespiratory fitness (CRF) levels are necessary for firefighters to adequately perform strenuous occupational demands. These demands have been associated with increased cardiovascular events leading to disability and death. Sudden cardiac death accounted for 44% of all annual on-duty deaths in U.S. firefighters from 1995-2004. Thus, the National Fire Protection Association (NFPA) has made it a priority to emphasize PA levels in order to maintain and increase CRF. PURPOSE: The purpose of the study was to investigate the relationship between sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) to CRF in career firefighters. METHODS: Firefighters wore an accelerometer for eight consecutive on- and off-duty days. The accelerometer was worn on the right hip and tracked SB, LPA, and MVPA. Freedson’s (1998) cut point determined PA intensity, while Choi’s (2011) algorithm was used to remove non-wear time. Additionally, each participant completed a stage-graded exercise test with submaximal square-wave verification bout to determine maximal oxygen uptake (VO2max). VO2max was also estimated using self-reported physical activity rating and a non-exercise regression equation. Pearson’s correlations were performed between the PA components and VO2max as well as between estimated and actual VO2max (ml/kg/min). RESULTS: Preliminary results (n=9) for total wear time for the accelerometer was 920 (min) with 58.7% SB, 37.7 % LPA, and 3.6% MVPA. There were no significant correlations between VO2max and SB (r = -0.18, P = 0.637) or LPA (r = 0.33, P = 0.388). Further, there was no significant correlation between estimated (45.2 ± 7.5) and actual VO2max (39.2 ± 7.1) (r = 0.52, P = 0.149). There was a statistically significant correlation between VO2max and MVPA (r = 0.74, P = 0.022). CONCLUSION: The initial results suggest that firefighters are meeting ACSM’s PA guidelines but are not are not meeting the NFPA’s minimal CRF recommendation of 42 ml/kg/min. Therefore, further research is necessary in order to make recommendations regarding PA and CRF for active firefighters. Twenty-one additional firefighters are expected to complete the study for a total sample of 30.