Physiological Demands of a Self-Paced Firefighter Air-Management Course and Determination of Work Efficiency

Andrew R Jagim; Joel A Luedke; Ward C Dobbs; Thomas Almonroeder; Adam Markert; Annette Zapp; Andrew T Askow; Richard M Kesler; Jennifer B Fields; Margaret T Jones; Jacob L Erickson

doi:10.3390/jfmk8010021

Physiological Demands of a Self-Paced Firefighter Air-Management Course and Determination of Work Efficiency

J Funct Morphol Kinesiol. 2023 Feb 6;8(1):21. doi: 10.3390/jfmk8010021.

Authors

Affiliations

¹ Sports Medicine, Mayo Clinic Health System, La Crosse, WI 54650, USA.
² Exercise & Sport Science Department, University of Wisconsin-La Crosse, La Crosse, WI 54601, USA.
³ College of Health Professions, Trine University, Angola, IN 46703, USA.
⁴ La Crosse Fire Department, La Crosse, WI 54603, USA.
⁵ Fire Rescue Wellness, Chicago, IL 60653, USA.
⁶ Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
⁷ Illinois Fire Service Institute, Champaign, IL 61820, USA.
⁸ Exercise Science and Athletic Training, Springfield College, Springfield, MA 01109, USA.
⁹ Patriot Performance Laboratory, Frank Pettrone Center for Sports Performance, George Mason University, Fairfax, VA 22030, USA.

Abstract

Firefighters often complete air management courses (AMC) to assess the ability to tolerate personal protective equipment, appropriately manage the breathing system and assess occupational performance. Little information is known relative to the physiological demands of AMCs, nor how to assess work efficiency in order to characterize occupational performance and evaluate progress.

Purpose: To assess the physiological demands of an AMC and examine differences across BMI categories. A secondary aim was to develop an equation to assess work efficiency in firefighters.

Methods: Fifty-seven firefighters (Women, n = 4; age: 37.2 ± 8.4 yr.; height: 182.0 ± 6.9 cm; body mass: 90.8 ± 13.1 kg; BMI: 27.8 ± 3.6 kg·m^-2) completed an AMC per routine evaluation while wearing a department issued self-contained breathing apparatus and full protective gear. Course completion time, starting pounds per square inch (PSI) on the air cylinder, changes in PSI, and distance traveled were recorded. All firefighters were equipped with a wearable sensor integrated with a triaxial accelerometer and telemetry to assess movement kinematics, heart rate, energy expenditure, and training impulse. The AMC consisted of an initial section involving a hose line advance, rescue (body drag), stair climb, ladder raise, and forcible entry. This section was followed by a repeating loop, which consisted of a stair climb, search, hoist, and recovery walk. Firefighters repeated the course loop until the self-contained breathing apparatus air supply pressure reached 200 PSI, at which time they were instructed to lay down until the PSI reached zero.

Results: Average completion time was 22.8 ± 1.4 min, with a mean distance of 1.4 ± 0.3 km and an average velocity of 2.4 ± 1.2 m·s^-1. Throughout the AMC, the mean heart rate was 158.7 ± 11.5 bpm equating to 86.8 ± 6.3% of the age-predicted max heart rate and a training impulse of 55 ± 3 AU. Mean energy expenditure was 464 ± 86 kcals and work efficiency was 49.8 ± 14.9 km·PSI^-1·s. Regression analysis determined that fat-free mass index (R² = 0.315; β = -5.069), body fat percentage (R² = 0.139; β = -0.853), fat-free mass (R² = 0.176; β = -0.744), weight (R² = 0.329; β = -0.681), and age (R² = 0.096; β = -0.571) were significant predictors of work efficiency.

Conclusions: The AMC is a highly aerobic task with near-maximal heart rates reached throughout the course. Smaller and leaner individuals achieved a higher degree of work efficiency during the AMC.

Keywords: firefighter; occupational demands; occupational performance.

Grants and funding

94465008/Mayo Clinic Health System and the University of Wisconsin - La Crosse