The aim of this study was to determine an appropriate method to characterize Royal Australian Navy intermittent intensity tasks.
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 (
) were measured continuously. Mean and peak values and time spent in incremental zones were calculated.
Scenario 2 elicited the highest oxygen cost (18.1 L, mean
1.5 L.min−1, time >2.5 L.min−1: 0.8%), yet scenario 4 elicited the highest mean
(1.8 L.min−1, oxygen cost 14.4 L), and participants spent a greater duration >2.5 L.min−1
(23.3% or 1 minute 55 seconds).
A small difference (0.3 L.min−1) was observed between scenarios 2 and 4 for mean
>2.5 L.min−1 demonstrated scenario 4 had a higher metabolic demand.