Influence of kick frequency on metabolic efficiency and performance at a severe intensity in international monofin-swimmers

Abstract

The aim of this study was to examine the effect of kick frequency on metabolic efficiency and performance in elite monofin-swimmers at the surface. Seven participants of international calibre were requested to perform three separate Time Limit exercises conducted at an intensity corresponding to 97.5% of the velocity at the maximal oxygen uptake. The first Time Limit exercise was systematically conducted at a freely chosen kick frequency (FCK_F) and the other Time Limit exercises were performed in random order at FCK_F-10% and FCK_F + 10%. The slow component of oxygen uptake ([Vdot]O_2sc) was identified independently of the Time Limit exercise (ranging from 180 to 243 ml · min⁻¹, P < 0.05). No significant change in energy cost of aquatic locomotion (ranging from 565 to (596 J · m⁻¹) and [Vdot]O_2sc responses was observed between the three Time Limit exercises. An increase or decrease of 10% of the FCK_F was associated with a significant reduction in Time Limit of −47.3% and −49.1%, respectively (P < 0.05). The analysis of the Time Limit exercise indicates that the selection of kick frequency other than FCK_F is detrimental to overall monofin-swimming performance. Furthermore, the study results showed that the indicators of metabolic efficiency such as energy cost or [Vdot]O_2sc do not determine the performance response in elite monofin-swimmers at a severe intensity.

Keywords:

• metabolic efficiency
• kick frequency
• aquatic locomotion
• performance
• elite monofin-swimmers