Impact of acute exercise on performance and physiological stress during simulated firefighter occupational tasks

We aimed to determine how a bout of resistance or aerobic exercise impacts physiological responses and performance during firefighting occupational tasks. Thirty-two non-firefighters completed two baseline assessments and three trials: resistance exercise (RE), aerobic exercise (AE), or a rested control (CON). Trials were followed by an occupational task assessment (OTA; four rounds of 10 deadlifts (38.6–61.4 kg) and 0.24-km 40lb-sandbag carry) in an environmental chamber (35 °C/50% humidity) while wearing standard municipal firefighter gear. Time to complete by condition was not statistically different (CON: 18.9 ± 4.4, AE: 20.0 ± 3.6, RE: 20.2 ± 5.0 min; p = 0.16). During the OTA average heart rate (CON: 149 ± 16, AE: 166 ± 12, RE: 160 ± 13 bpm; p < 0.01), estimated core temperature (CON: 37.6 ± 0.4, AE: 38.7 ± 0.3, RE: 38.4 ± 0.5 °C; p < 0.01), and skin temperature (CON: 36.3 ± 0.5, AE: 37.5 ± 0.6, RE: 36.9 ± 0.9 °C; p < 0.01) were elevated following AE and RE compared to CON, and higher following AE compared to RE. Our findings suggest job performance may not be impacted, although physiological stress during the tasks may be elevated, following on-shift exercise, and more prominently following aerobic exercise.