Physical workload during firefighting in Chilean volunteers Javier A. Freire Herrera a,* , Felipe E. Meyer Cohen a and Elías S. Apud Simón a a Unit of Ergonomics, Faculty of Biological Sciences, University of Concepcion, Edmundo Larenas s/n, Concep- cion, Chile Abstract. The study was performed in a sample of 39 firemen. The state of health for each fire fighter was evaluated by means of a clinical examination and also through some specific exams. Aerobic capacity was estimated as an indicator of physical fitness. In each load, cardiac frequency and oxygen consumption were measured under a steady state condition. Additionally, body composition was calculated using a Tanita professional scale. Physical effort at work was determined by measuring car- diac frequency using a telemetric unit. Evaluations were carried out during night shifts, registering information under the fol- lowing conditions: night shifts without emergency, fire simulation, training exercises and real fire fighting. In general terms, it is possible to state that fire fighters are healthy according to the result of the clinical examination. However, it is very impor- tant to highlight that 70% of the firemen consume alcohol and 80% were smokers. The average aerobic capacity of the sample was 2.6 l/min or 34.5 ml/kg/min. In terms of overweight and obesity, the body mass index was 25.7, whereas the percentage fat mass reached an average of 22.9 %. The cardiovascular load in the night shifts without emergencies did not surpass 40%, which in Chile is considered the highest limit for sustained work. However, during training, simulations and real fires, the firemen had higher cardiac frequencies, reaching peak levels close to 100% cardiovascular load. Keywords: aerobic capacity, fire fighters, cardiovascular load 1. Introduction 1.1. Physical conditions of firemen volunteers A Chilean fireman fighter works voluntarily, with- out renumeration. This fact indicates that the majority also hold other jobs, which could eventually be an additional factor of physical or mental fatigue. It is necessary to mention that in order to join any fire department in Chile, one must meet certain require- ments. Among them are being over 18 and under 40 years old, and being in adequate health. In the case of firefighting, there exist some activities that are at the very limit of physical and psychological capacities, a product of environmental conditions and organiza- tional difficulties, due to the unpredictable magnitude of these tasks. The knowledge of this reality forces us to take ef- fective measures, with the objective of avoiding fati- gue in volunteers and increasing safety in the activi- ties that they perform. In that sense, a study carried * out by the National Association of the Protection against Fires between 1977 and 1995 shows that close to 50% of all deaths that occurred during fire emergencies were not directly the result of firefight- ing, but instead were due to heart attacks. It is em- phasized that their deaths were caused directly by the high demands of the job. 1.2. Physical demands of fire fighting Fighting fires is a difficult job and physically hard. According to Womack (2000) [6], the energy de- mands of fire extinguishing activities, during the ini- tial minutes, reach about 40 ml/kg/min of oxygen consumption, with a heart rate of about 180 heart beats/minute and a pulmonary ventilation close to 130 liters of air per minute. * Javier Freire, Casilla 160-C, correo-3 Concepción, Chile. Email: javierfreire@udec.cl. Tel.:56–041–2204426; Fax: 56–041– 2522045. 432 Work 41 (2012) 432-436 DOI: 10.3233/WOR-2012-0193-432 IOS Press 1051-9815/12/$27.50 © 2012 – IOS Press and the authors. All rights reserved