Total energy intake and self-selected macronutrient distribution during wildland fire suppression

Author

Alexander N. Marks, University of Montana, MissoulaFollow
Joseph A. Sol
Joseph W. Domitrovich
Molly R. West
Brent C. Ruby, University of Montana, Missoula

Year of Award

2019

Document Type

Thesis

Degree Type

Master of Science (MS)

Degree Name

Health and Human Performance (Exercise Science Option)

Department or School/College

Health and Human Performance

Committee Chair

Brent Ruby

Committee Co-chair

Charles Palmer

Commitee Members

Brent Ruby, Charles Palmer, Joshua Slotnick

Keywords

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

Publisher

University of Montana

Subject Categories

Exercise Physiology | Other Medicine and Health Sciences | Other Physiology | Systems and Integrative Physiology

Abstract

Introduction: Wildland firefighters (WLFF) work long hours in extreme environments resulting in high daily total energy expenditure (TEE). Increasing work shift eating episodes and/or providing rations that promote convenient feeding 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 study’s aim was to determine WLFFs’ self-selected field total energy intake (TEI), composition, and patterns feeding during wildland fire suppression shifts.

Methods: 86 WLFF (16 female, 70 male; 27.5 ± 6.4 yr) deployed to fire incidents across the United States throughout the 2018 fire season. Pre- and post-shift food inventories collected at basecamp provided item-specific nutrient content (calories [kcal], 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 determined via actigraph accelerometry.

Results: Work shift length averaged 14.0 ± 1.1 hr, 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.

Conclusion: The present work shift TEI approximates 33% of previously-determined WLFF TEE and demonstrates that current WLFF consumption patterns may not deliver adequate nutrients for the occupational demands.

Recommended Citation

Marks, Alexander N.; Sol, Joseph A.; Domitrovich, Joseph W.; West, Molly R.; and Ruby, Brent C., "Total energy intake and self-selected macronutrient distribution during wildland fire suppression" (2019). Graduate Student Theses, Dissertations, & Professional Papers. 11430.
https://scholarworks.umt.edu/etd/11430