Maximizing Acceleration and Change of Direction in Sport: A Case Series to Illustrate How the Force-Velocity Profile Provides Additional Information to That Derived from Linear Sprint Time.

Andrés Baena-Raya,Manuel A Rodríguez-Pérez,Pedro Jiménez-Reyes,Alberto Soriano-Maldonado

doi:10.3390/ijerph18116140

Abstract

Sprint running and change of direction (COD) present similar mechanical demands, involving an acceleration phase in which athletes need to produce and apply substantial horizontal external force. Assessing the mechanical properties underpinning individual sprint acceleration might add relevant information about COD performance in addition to that obtained through sprint time alone. The present technical report uses a case series of three athletes with nearly identical 20 m sprint times but with different mechanical properties and COD performances. This makes it possible to illustrate, for the first time, a potential rationale for why the sprint force-velocity (FV) profile (i.e., theoretical maximal force (F0), velocity (V0), maximal power output (Pmax), ratio of effective horizontal component (RFpeak) and index of force application technique (DRF)) provides key information about COD performance (i.e., further to that derived from simple sprint time), which can be used to individualize training. This technical report provides practitioners with a justification to assess the FV profile in addition to sprint time when the aim is to enhance sprint acceleration and COD performance; practical interpretations and advice on how training interventions could be individualized based on the athletes’ differential sprint mechanical properties are also specified.

Highlights

The ability to efficiently perform a change of direction (COD), defined as rapidly accelerating, decelerating, and quickly changing speed and direction, greatly determines performance in the majority of sports [1,2]
Considering only sprint time outcomes may overlook the mechanical capabilities underpinning individual sprint acceleration [5], which might further explain both sprint acceleration and COD performance
The greater the horizontal GRF, the faster the transfer of force toward the new direction and, the faster the transition into the propulsive phase [14]. These findings clearly indicate that horizontal parameters underpin COD performance, athletes and practitioners do not usually have access to force platforms, which highlights the need to use alternative methods to evaluate horizontal force application during acceleration

Summary

Introduction

The ability to efficiently perform a change of direction (COD), defined as rapidly accelerating, decelerating, and quickly changing speed and direction, greatly determines performance in the majority of sports [1,2]. It has been suggested that linear sprint, commonly assessed with photocells, might be a good indicator of individual sprint acceleration and maximal velocity capabilities during COD [1]. Previous research suggests that athletes who are faster in linear sprint tend to be faster in COD [3,4]. Considering only sprint time outcomes may overlook the mechanical capabilities underpinning individual sprint acceleration (i.e., the horizontal external force produced at various velocities during sprint running) [5], which might further explain both sprint acceleration and COD performance. Exploring the influence of force production on COD performance has been a matter of research, especially through vertical force measures (i.e., maximal dynamic strength, eccentric strength and isometric strength) [2]. It has been demonstrated that stronger and more powerful athletes usually sprint and change direction faster than weaker individuals [6,7,8,9,10]

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Conclusion