Physiological Demands of the Firefighter Candidate Physical Ability Test

The Candidate Physical Ability Test (CPAT) is used by fire departments across North America to screen for minimal physical capabilities in potential candidates, but its physiological demands are unknown. We examined oxygen uptake and carbon dioxide output (V x O2, V x CO2) and heart rate (HR) responses with the portable system in 57 subjects (23 females) who were familiarized before completing the CPAT in times similar to those of actual candidates. Two men and nine women failed to complete the circuit because of fatigue. Thirty-two men (91%) and four women (15%) completed the circuit under the criterion time (10 min 20 s) with mean completion times for men (8 min 32 s +/- 51 s) and women (11 min 16 s +/- 1 min 28 s, P < 0.05). For all finishers, V x O2 during the test was 38.5 and 36.6 mL x kg(-1) x min(-1), corresponding to 73% and 71% of V x O 2max for men and women, and HR was 90% and 91% of maximum (P > 0.05). RER averaged 1.02 for men and 0.97 for women suggesting elevated anaerobic metabolism. Women had a drop in RER after the second event, and they were significantly slower at each event after the step mill than the men. Prediction of circuit completion time by backward stepwise regression yielded models with absolute V x O 2max alone or relative V x O 2max plus body mass and handgrip strength accounting for more than 67% of the variance but with large errors of estimation exceeding 75 s. The CPAT challenged both the aerobic and anaerobic energy supply systems, and the average V x O2 and HR were similar to reported values during firefighting simulations with incumbent firefighters.