Citation

Marks AN, Sol JA, Domitrovich JW, West MR, Ruby BC. Wilderness Environ. Med. 2020; ePub(ePub): ePub.

Affiliation

Montana Center for Work Physiology and Exercise Metabolism, University of Montana, Missoula, MT. Electronic address: brent.ruby@mso.umt.edu.

Copyright

(Copyright © 2020, Elsevier Publishing)

DOI

10.1016/j.wem.2020.01.009

PMID

32359881

Abstract

INTRODUCTION: Wildland firefighters (WLFF) work long hours in extreme environments, resulting in high daily total energy expenditure. Increasing work-shift eating episodes and/or providing rations that promote convenient eating has shown augmented self-selected work output, as has regular carbohydrate (CHO) consumption. It remains unclear how current WLFF feeding strategies compare to more frequent nutrient delivery. Our aim was to determine WLFFs' self-selected field total energy intake (TEI), composition, and feeding patterns during wildland fire suppression shifts.

METHODS: WLFF were deployed to fire incidents across the United States throughout the 2018 fire season. Preshift food inventories collected at basecamp provided item-specific nutrient content (kilocalories, CHO, fat, protein). Work shift consumption (TEI, feeding frequency, episodic composition) was monitored in real time by field researchers on fireline via observational data capture using mobile tablets. Shift work output was also quantified via actigraph accelerometry.

RESULTS: Eighty-six WLFF (27.5±6.4 y; 16 female, 70 male) worked 14.0±1.1 h shifts, with a TEI of 6.3±2.5 MJ (1494±592 kcal) (51±10, 37±9, 13±4% for CHO, fat, and protein, respectively). WLFF averaged 4.3±1.6 eating episodes (1.4±1.3 MJ [345±306 kcal] and 44±38 g CHO·episode^-1). WLFF who consumed >20 kcal·kg^-1 averaged less sedentary activity than those consuming <16 kcal·kg^-1. Data are presented as mean±SD.

CONCLUSIONS: Not including fire camp meals (breakfast, dinner), the present work-shift TEI approximates 33% of previously determined WLFF total energy expenditure and demonstrates that current WLFF consumption patterns may not deliver adequate nutrients for occupational demands.

Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.

Language: en

Keywords

carbohydrate; field study; occupational physiology; performance monitoring; wildland firefighting