Respiratory gas exchange and physiological demands during a fire fighter evaluation circuit in men and women

Abstract

We examined the oxygen uptake (VO2) and carbon dioxide output (VCO2) during completion of a circuit developed for testing fire fighters and related performance time to laboratory measures of fitness. Twenty-two healthy university students (ten women) were trained in the tasks then performed the circuit as quickly as possible. Breath-by-breath gas exchange and heart rate were continuously measured with a portable system. Median circuit time was 6:13 (min:s, 25-75% = 5:46-6:42) for men and 7:25 (25-75% = 6:49-10:21) for 8 women finishers (P = 0.023), and VO2 averaged 68 and 64% VO2max for the men and women during the circuit. Both men and women had high respiratory exchange ratios (>1.0) suggesting marked anaerobic energy contribution. Physiological variables associated with circuit time were assessed by backward stepwise regression yielding a significant model that included only peak work rate during arm cranking exercise as a function of circuit completion time across men and women combined (P < 0.001). For men, but especially for women, the time required for the simulated victim drag (68.2 kg mannequin) was positively correlated with total time to complete the other circuit elements (r = 0.51, r = 0.96 respectively). The simple correlation between circuit time and VO2max (mL/kg/min) revealed poor relationships for men (r = -0.37, P > 0.05) and women (r = 0.20, P > 0.05). These data demonstrated that upper body fitness as reflected by peak work rate during arm cranking correlated with total circuit time for the men and women in our population sample.

Energy Cost of the Trondheim Firefighter Test for Experienced Firefighters

“…Close linear relationships were found. The results suggest that applied tests can be standardised and performed in most fire stations like the tests examined by Canadian groups [18,21,25,31]. Moreover, performance of properly designed tests depends heavily on the firefighters' fitness.…”

“…Fire fighting and rescue work may be very demanding for the cardiorespiratory system [6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28]. However, all these studies have some limitations in examining physical demands of real fire fighting.…”

“…Some studies provide only indirect measures of aerobic demand like heart rate (HR) or air consumption during exercises [7,10,13,15,23,28,29]. Oxygen uptake (V O2 ) has also been measured during fire fighting tasks [6,8,9,11,12,17,18,19,20,21,24,25,26]. This is important since the relationship between HR and V O2 may differ considerably between exercise on ergometers (treadmill) and during fire fighting tasks [9].…”

“…A number of studies, mostly by Canadians, examined tests that can be performed at most fire stations, independently of their specific design [18,21,25,31]. The tests included 8-10 tasks, each solved in less than 1 min.…”

The Impact of Firefighter Personal Protective Equipment and Treadmill Protocol on Maximal Oxygen Uptake

“…(18) The high level of VCO 2 reflects elevated bicarbonate buffering of hydrogen ions resulting in part from increased lactate metabolism during high levels of muscle tension. (39) Therefore, smaller RER max in PIP represents less anaerobic metabolism during maximal performance tests. In addition, PIP Boots and Shoes demonstrated average values of lactate concentration less than 8 mmol/L, which suggests that the work load was not high enough for recruiting active muscle fibers and caused cellular fatigue.…”