Characteristics of slow and fast performers on a firefighter air consumption test.

An air consumption test (ACT) is a physical ability test used in the fire service. The purpose of this study was to compare demographics and physiological differences between slow versus fast performers on an ACT. 160 career firefighters had air consumption, total task time, body mass index (BMI), peak heart rate (HR), body fat percentage (BF%), and oxygen consumption (VO) measured. K-means clustering was used to dichotomize between slow and fast groups during an ACT. Independent samples t-tests and Cohen's d measures of effect size were used to examine differences between groups. There were no significant differences in groups for age (t = -1.05, p = 0.30, d = 0.17), BMI (t = -1.85, p = 0.07, d = 0.32), or HR (t = 0.99, p = 0.32, d = 0.16). There were significant differences between groups for BF% (t = -3.35, p < 0.01, d = 0.57), relative (t = 3.52, p < 0.01, d = 0.58) and absolute VO (t = 4.29, p < 0.01, d = 0.68), air consumption (t = -4.87, p < 0.01, d = 0.81), and total task time (t = -15.04, p < 0.01, d = 2.58).