LAUSR

Objective: To compare physiological responses between two firefighting simulations with different recovery periods, one having work bouts intercalated by a shortened recovery period. Methods: Thirteen male firefighters participated in two different simulations, which comprised two identical 25-minute effort bouts (E1 and E2) intercalated by a recovery period of either 20 (T20) or 5 (T5) minutes. Results: From E1 to E2, the increase of mean heart rate (HR) (26 ± 5 vs 14 ± 5 bpm, P < 0.001) and mean VO2 (1.8 ± 0.4 vs 1.3 ± 0.4 mL kg−1 min−1, P < 0.001) was higher in T5 than in T20. Conclusion: Results indicate that a shortened recovery time between firefighting work bouts intensifies cardiac strain disproportionately with metabolic rate, since mean HR increased by 19.3% and 10.8% while mean VO2 increased by only 7.2% and 5.0% in T5 and T20, respectively.