Assessment of A Lifesaver`s Instantaneous Velocity in Mannequin Carry using Diferent Types of Fins

Abstract

The purpose of the study was to compare the instantaneous velocity produced by a lifesaver in a 25 m mannequin carry test, while performing barefoot and with four fin types. Comparisons between the first and second half parts of each test were also accomplished. Complementarily, the fatigue effect over the test distance was analyzed through the assessment of the slope of the velocity over time and of the fatigue index. One licensed male lifesaver performed 5x25m maximal swim test carrying a mannequin (barefoot and with flexible, short, stiff and fiber fin types). A cable speedometer was connected to the mannequin in order to measure instantaneous velocity. Results showed that swimming with barefoot does not allow high mannequin carries performances. Flexible fins were the ones that produce the lower velocity values in the 25m mannequin carry effort. It was observed that fiber fins were the ones who allowed for higher mean velocity irrespectively of the effort part considered. Short and stiff fins use allowed for an increase of velocity during the first half effort part with a consequent reduction of fatigue effects. For the second half effort part, and for the total effort, short fins were the ones which induced lower velocity decay, followed by fiber fins. Short fins and fiber fins revealed the lower fatigue indexes. It was concluded that the selection of the best fin type is dependent of the fin length and could change with the effort distance.