title: Energy cost and energy sources during a simulated firefighting activity.
abstract: This study aimed to 1) analyze the energy requirement (VO2eq) and the contribution of the aerobic (VO2ex), anaerobic alactic (VO2al), and anaerobic lactic (VO2la-) energy sources of a simulated intervention; 2) ascertain differences in mean VO2 and heart rate (HR) during firefighting tasks; and 3) verify the relationship between time of job completion and the fitness level of firefighters. Twenty Italian firefighters (age = 32 ± 6 yr, VO2peak = 43.1 ± 4.9 mL·kg·min) performed 4 consecutive tasks (i.e., child rescue; 250-m run; find an exit; 250-m run) that required a VO2eq of 406.26 ± 73.91 mL·kg (VO2ex = 86 ± 5%; VO2al = 9 ± 3%; VO2la- = 5 ± 3%). After 30 minutes, the recovery HR (108 ± 15 beats·min) and VO2 (8.86±2.67mL·kg·min) were higher (p < 0.0001) than basal values (HR = 66 ± 8 beats·min; VO2 = 4.57 ± 1.07 mL·kg·min), indicating that passive recovery is insufficient in reducing the cardiovascular and thermoregulatory strain of the previous workload. Differences (p < 0.001) between tasks emerged for mean VO2 and HR, with a lack of significant correlation between the time of job completion and the firefighters' aerobic fitness. These findings indicate that unpredictable working conditions highly challenge expert firefighters who need adequate fitness levels to meet the requirements of their work. Practically, to enhance the fitness level of firefighters, specific interval training programs should include a wide variety of tasks requiring different intensities and decision-making strategies.
authors.affiliation: Department of Human Movement and Sport Science, University of Rome Foro Italico, Rome Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Perroni
authors.forename: Antonio
authors.initials: A
authors.lastname: Tessitore
authors.forename: Cristina
authors.initials: C
authors.lastname: Cortis
authors.forename: Corrado
authors.initials: C
authors.lastname: Lupo
authors.forename: Emanuele
authors.initials: E
authors.lastname: D'artibale
authors.forename: Lamberto
authors.initials: L
authors.lastname: Cignitti
authors.forename: Laura
authors.initials: L
authors.lastname: Capranica
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000886:Anthropometry; D004734:Energy Metabolism; D005390:Fires; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D011481:Protective Clothing; D013312:Stress, Physiological / Q000502:physiology*; D013647:Task Performance and Analysis
chemical_list: D007773:Lactates