Firefighters during training as divers: physiologic and psychomental stresses

Objectives. Fire departments train divers for search, rescue and recovery in and under water. Their tasks likely exert major physical and psychological stress. This study hypothesizes that training is well balanced, following a learning spiral. Methods. Seven firefighters participated, performing 272 dives in different waters. Measurements included pulmonary function (body plethysmography); heart rate (HR) and air consumption during dives; personality variables with the state-trait anxiety inventory (STAI) and psychological stress with the task load index (NASA-TLX). Results. Pulmonary function was maintained at the end of training dives. During the dives, mean HR was 108 +/- 23 bpm and mean air consumption 37 +/- 15 L/min. Both values remained unchanged during training. The three highest STAI stanines (severe trait anxiety) were not considered, but median stanines and very low values were over-represented. Demands within the seven NASA-TLX areas were perceived differently. Sum of the scales 'very low', 'low' and 'mean' was >= 60%. In turn, the scale 'very high' was in none of the demands >10%. Conclusion. Physiological values remained unaltered throughout training, i.e. workload and increase in competence properly matched. The moderate manifestation of psychomental stress speaks for a group of highly selected individuals. Both candidate selection and design of the learning spiral was successful.