Jenni Raines1, Rodney Snow2, David Nichols3, Brad Aisbett4. 1. 1.Centre for Physical Activity and Nutrition Research, Australia Research, Deakin University, Burwood 3125, Australia 2.Bushfire Co-Operative Research Centre, East Melbourne 3002, Australia. 2. 1.Centre for Physical Activity and Nutrition Research, Australia Research, Deakin University, Burwood 3125, Australia. 3. 2.Bushfire Co-Operative Research Centre, East Melbourne 3002, Australia 3.Research and Innovation, Country Fire Authority, Burwood 3151, Australia. 4. 1.Centre for Physical Activity and Nutrition Research, Australia Research, Deakin University, Burwood 3125, Australia 2.Bushfire Co-Operative Research Centre, East Melbourne 3002, Australia brad.aisbett@deakin.edu.au.
Abstract
PURPOSE: (i) To evaluate firefighters' pre- and post-shift hydration status across two shifts of wildfire suppression work in hot weather conditions. (ii) To document firefighters' fluid intake during and between two shifts of wildfire suppression work. (iii) To compare firefighters' heart rate, activity, rating of perceived exertion (RPE), and core temperature across the two consecutive shifts of wildfire suppression work. METHOD: Across two consecutive days, 12 salaried firefighters' hydration status was measured immediately pre- and post-shift. Hydration status was also measured 2h post-shift. RPE was also measured immediately post-shift on each day. Work activity, heart rate, and core temperature were logged continuously during each shift. Ten firefighters also manually recorded their food and fluid intake before, during, and after both fireground shifts. RESULTS: Firefighters were not euhydrated at all measurement points on Day one (292±1 mOsm l(-1)) and euhydrated across these same time points on Day two (289±0.5 mOsm l(-1)). Fluid consumption following firefighters' shift on Day one (1792±1134ml) trended (P = 0.08) higher than Day two (1108±1142ml). Daily total fluid intake was not different (P = 0.27), averaging 6443±1941ml across both days. Core temperature and the time spent ≥ 70%HRmax were both elevated on Day one (when firefighters were not euhydrated). Firefighters' work activity profile was not different between both days of work. CONCLUSION: There was no difference in firefighters' pre- to post-shift hydration within each shift, suggesting ad libitum drinking was at least sufficient to maintain pre-shift hydration status, even in hot conditions. Firefighters' relative hypohydration on Day one (despite a slightly lower ambient temperature) may have been associated with elevations in core temperature, more time in the higher heart rate zones, and 'post-shift' RPE.
PURPOSE: (i) To evaluate firefighters' pre- and post-shift hydration status across two shifts of wildfire suppression work in hot weather conditions. (ii) To document firefighters' fluid intake during and between two shifts of wildfire suppression work. (iii) To compare firefighters' heart rate, activity, rating of perceived exertion (RPE), and core temperature across the two consecutive shifts of wildfire suppression work. METHOD: Across two consecutive days, 12 salaried firefighters' hydration status was measured immediately pre- and post-shift. Hydration status was also measured 2h post-shift. RPE was also measured immediately post-shift on each day. Work activity, heart rate, and core temperature were logged continuously during each shift. Ten firefighters also manually recorded their food and fluid intake before, during, and after both fireground shifts. RESULTS: Firefighters were not euhydrated at all measurement points on Day one (292±1 mOsm l(-1)) and euhydrated across these same time points on Day two (289±0.5 mOsm l(-1)). Fluid consumption following firefighters' shift on Day one (1792±1134ml) trended (P = 0.08) higher than Day two (1108±1142ml). Daily total fluid intake was not different (P = 0.27), averaging 6443±1941ml across both days. Core temperature and the time spent ≥ 70%HRmax were both elevated on Day one (when firefighters were not euhydrated). Firefighters' work activity profile was not different between both days of work. CONCLUSION: There was no difference in firefighters' pre- to post-shift hydration within each shift, suggesting ad libitum drinking was at least sufficient to maintain pre-shift hydration status, even in hot conditions. Firefighters' relative hypohydration on Day one (despite a slightly lower ambient temperature) may have been associated with elevations in core temperature, more time in the higher heart rate zones, and 'post-shift' RPE.
Authors: Grace E Vincent; Sally Ferguson; Brianna Larsen; Nicola D Ridgers; Rod Snow; Brad Aisbett Journal: Int Arch Occup Environ Health Date: 2018-04-06 Impact factor: 3.015
Authors: Stephanie E Chappel; Brad Aisbett; Grace E Vincent; Nicola D Ridgers Journal: Int J Environ Res Public Health Date: 2016-09-30 Impact factor: 3.390
Authors: Grace E Vincent; Brad Aisbett; Brianna Larsen; Nicola D Ridgers; Rod Snow; Sally A Ferguson Journal: Int J Environ Res Public Health Date: 2017-02-12 Impact factor: 3.390
Authors: Caleb Leduc; Sabir I Giga; Ian J Fletcher; Michelle Young; Sandra C Dorman Journal: Int J Environ Res Public Health Date: 2021-07-02 Impact factor: 3.390