Physical workload and task efficiency across four mannequin towing techniques in water rescue

Abstract

Direct in-water rescue is a safety-critical task in which towing technique and rescue-support equipment may influence both rescuer workload and task output. This study compared physical workload, towing performance and physiological economy across four mannequin towing techniques: Extended Arm Tow, Double Armpit Tow, “Sailor” Technique Tow and Rescue Tube Tow. Eighteen male water lifeguards (age 18.8 ± 1.3 years; V ˙ O 2 max 56.1 ± 5.0 mL·kg −1 ·min −1 ) completed randomized 50-m towing trials after an incremental swimming test to determine maximal oxygen uptake. Towing velocity, gas-exchange variables, heart rate, peripheral oxygen saturation, perceived exertion, oxygen cost per meter and body-mass-normalized oxygen cost per meter were assessed. Rescue Tube Tow produced the highest mean towing velocity and the lowest body-mass-normalized oxygen cost per meter, indicating the most favourable workload–performance profile. Double Armpit Tow elicited the lowest time-based cardiorespiratory strain but did not optimize transport efficiency. Oxygen cost per meter may support ergonomic evaluation of workload–performance efficiency in rescue tasks.