title: Development of a walking aerobic capacity test for structural firefighters.
abstract: Firefighting requires high fitness to perform job tasks and minimize risk of job-related cardiac death. To reduce this risk, the International Association of Firefighters has recommended firefighters possess a VO2max ≥ 42 ml·kg-1·min-1. This recommendation is not universally applied because existing screening tests require costly equipment and do not accommodate firefighters unable to run. The purpose of this study was to develop a walking test to predict VO2max in firefighters using a standard treadmill. Thirty-eight male firefighters wore a vest weighing 20% of their body weight and performed a walking VO2max test on a standard treadmill. Walking speed was dependent on leg length and ranged from 3.6 to 4.3 mph. The test began with a 3-minute warm-up, after which the speed was increased to test speed. Every minute thereafter, the grade increased 1% until participants reached exhaustion. For cross-validation, 13 firefighters also performed a running VO2max test. The average test time was 16.95 ± 2.57 minutes (including warm-up) and ranged between 8 and 22 minutes. Average VO2max was 48.4 ± 6.5 ml·kg-1·min-1. Stepwise linear regression included time as the only significant independent variable explaining 76% of the variance in VO2max (p < 0.001). The standard error of the estimate was 3.2 ml·kg-1·min-1. The equation derived is: VO2max (ml·kg·min-1) = 11.373 + time (minute) × 2.184. On average, VO2max values measured while walking were 4.62 ± 5.86 ml·kg-1·min-1, lower than running values. This test has good potential for predicting VO2max among structural firefighters, and minimal equipment needs make it feasible for fire departments to administer.
authors.affiliation: Human Performance Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon.
authors.forename: Karlie J
authors.initials: KJ
authors.lastname: Moore
authors.forename: Jason T
authors.initials: JT
authors.lastname: Penry
authors.forename: Katherine B
authors.initials: KB
authors.lastname: Gunter
mesh_terms: D000328:Adult; D005080:Exercise Test; D061388:Firefighters; D005390:Fires; D006801:Humans; D008297:Male; D055641:Mathematical Concepts; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology; D012420:Running / Q000502:physiology; D013997:Time Factors; D016138:Walking / Q000502:physiology*; D014938:Work Capacity Evaluation