Gymnastik- och idrottshögskolan, GIH

Introduction

Power output is a critical component of athletic performance (McGuigan et al., 2012); therefore, strength and conditioning specialists are nowadays employed to help athletes increase the power-generating capacity in specific motor tasks. Due to the widespread need to assess power output in common strength training exercises, the development and validation of various assessment approaches has led to studies aimed at identifying the external optimal load (OL) to maximize power output (Cormie et al., 2007). The aim of this study was to compare conventionally used linear position transducer and force plate based methods with a new methodology for calculation of peak power (PP) and average power (AP) output in conjunction with the load-power relationship.

Methods

Nineteen male elite athletes performed loaded squat jump (LSJ) and power clean (PC) with different external loads to determine the load/power relationship. Nine methods were used simultaneously in data collection: vertical ground reaction force (VGRF), ground reaction force (GRF) i.e. vertical, anterio-posterior and medio-lateral reaction force components, 1 linear encoder (1Encoder), 1 linear position transducer (1LPT), 1LPT and VGRF (1LPT+VGRF), 2 linear position transducers (2LPTs), 2LPTs and VGRF (2LPTs+VGRF), 5 linear position transducers (5LPTs), 5LPTs and GRF (5LPTs+GRF; novel method). Power output was calculated for each lift according to the sensor or sensors simultaneously used and the results were compared.

Results

Power output calculated separately with LPTs and GRF method differed significantly from combined methods such as 1LPT+VGRF, 2LPTs+VGRF, and 5LPTs+GRF (novel method). The optimal load in LSJ and PC with respect to PP output was identified at loads between 30 and 50% of their body mass (bm), respectively; and with respect to AP output equal to loads between 85 and 75% of bm, respectively.

Discussion

This study indicates that test methodology influences the results of the power output and the load–power relationship in LSJ and PC exercises. The results of this study suggest the possibility that the combined methods provide a better representation of muscle power generation during dynamic movements involving the non-linear trajectories of the barbell than kinematic or kinetic methods alone.

References

Cormie, P., McBride, J. M., & McCaulley, G. O. (2007). J Appl Biomech, 23(2), 103-118. McGuigan. (2012). Strength and Power Assessment Protocols. Physiological Tests for Elite Athletes (2nd ed., pp. 207-230). Stanningley Leeds, United Kingdom: Human Kinetics.