Do Fire-fighters Develop Specific Ventilatory Responses in Order to Cope with Exercise Whilst Wearing Self-contained Breathing Apparatus?

In the present study we compared the ventilatory performance whilst wearing self-contained breathing apparatus (SCBA) during exercise, of a group of male fire-fighters (FF, n = 8), with a matched group of male civilians (CV, n = 7). The mean (SEM) physiological characteristics of the subjects (FF vs CV) were: age 31 (2) years vs 32 (4) years; height 179 (2) cm vs 183 (3) cm, P < 0.05; mass 80 (2) kg vs 84 (3) kg; maximum oxygen uptake 4.52 (0.14) 1 x min(-1) vs 4.39 (0.27) 1 x min(-1). Volunteers performed a 23-minute fire-fighting simulation (Firetest), without and with SCBA (Fire-fighter II, Siebe-Gorman/North Safety, Cheshire, UK). During SCBA wear, the FF group used significantly less air and rated their breathlessness significantly lower than the CV group. The mean tidal volume (V(T)) of the FF group remained constant between non-SCBA and SCBA wear conditions, but the CV group increased their mean V(T) by 18%, (P < 0.01). There were no significant between-group differences during the Firetest in total breath duration, inspiratory or expiratory duration, breathing frequency (fb), or heart rate. These data suggest that the respiratory responses of firefighters while wearing SCBA, which are characterised by increases in (fb) but not V(T), may help to reduce their breathlessness during exercise while wearing SCBA.