Objective: The aim of this study was to determine an appropriate method to characterize Royal Australian Navy intermittent intensity tasks.
Method: Sixteen personnel performed four scenarios: (1) storing: repeatedly handle a 10 to 15 kg crate; (2) firefighting: walk 45 m wearing protective equipment and fighting a fire; (3) and (4) toxic hazard response: casualty evacuation tasks wearing protective equipment. Heart rate and oxygen consumption ((Equation is included in full-text article.)) were measured continuously. Mean and peak values and time spent in incremental zones were calculated.
Results: Scenario 2 elicited the highest oxygen cost (18.1 L, mean (Equation is included in full-text article.)1.5 L.min, time >2.5 L.min: 0.8%), yet scenario 4 elicited the highest mean (Equation is included in full-text article.)(1.8 L.min, oxygen cost 14.4 L), and participants spent a greater duration >2.5 L.min(Equation is included in full-text article.)(23.3% or 1 minute 55 seconds).
Conclusions: A small difference (0.3 L.min) was observed between scenarios 2 and 4 for mean (Equation is included in full-text article.), yet (Equation is included in full-text article.)>2.5 L.min demonstrated scenario 4 had a higher metabolic demand.