Sprint versus isolated eccentric training: Comparative effects on hamstring architecture and performance in soccer players.

Jurdan Mendiguchia,Pascal Edouard,Marco Fonseca,Rogerio Pereira,Filipe Conceição,Hernani Lopes,Jean-Benoît Morin,Pedro Jiménez-Reyes,Daniel Boullosa

doi:10.1371/journal.pone.0228283

Abstract

AimsThe purpose of this study was to compare the effects of hamstring eccentric (NHE) strength training versus sprint training programmed as complements to regular soccer practice, on sprint performance and its mechanical underpinnings, as well as biceps femoris long head (BFlh) architecture.MethodsIn this prospective interventional control study, sprint performance, sprint mechanics and BFlh architecture variables were compared before versus after six weeks of training during the first six preseason weeks, and between three different random match-pair groups of soccer players: “Soccer group” (n = 10), “Nordic group” (n = 12) and “Sprint group” (n = 10).ResultsFor sprint performance and mechanics, small to large pre-post improvements were reported in “Sprint group” (except maximal running velocity), whereas only trivial to small negative changes were reported in “Soccer group” and “Nordic group”. For BFlh architecture variables, “Sprint” group showed moderate increase in fascicle length compared to smaller augment for the “Nordic” group with trivial changes for “Soccer group”. Only “Nordic” group presented small increases at pennation angle.ConclusionsThe results suggest that sprint training was superior to NHE in order to increase BFlh fascicle length although only the sprint training was able to both provide a preventive stimulus (increase fascicle length) and at the same time improve both sprint performance and mechanics. Further studies with advanced imaging techniques are needed to confirm the validity of the findings.

Highlights

Performing soccer-specific actions at high speed is a paramount physical feature of high-level soccer players
The results suggest that sprint training was superior to nordic hamstring exercise (NHE) in order to increase biceps femoris long head (BFlh) fascicle length only the sprint training was able to both provide a preventive stimulus and at the same time improve both sprint performance and mechanics
The main findings were (a) the addition of two weekly sessions of sprint training to regular soccer practice induced moderate improvements in biceps femoris long head fascicle length compared to the small increases showed after isolated eccentric strength training or not changes when practicing soccer training alone; (b) biceps femoris muscle pennation angle showed a small increase only when nordic hamstring exercise was added to soccer training, and not in the case of sprint training; (c) sprinting training added to regular soccer training produced small to large improvements in both sprint acceleration performance and the underlying mechanical outputs, which contrasts with trivial or even small negative changes in the case of hamstring eccentric strength training or when practicing soccer training

Summary

Introduction

Performing soccer-specific actions at high speed is a paramount physical feature of high-level soccer players. It seems logical to expect sprinting to be a key parameter in soccer both from a performance and injury point of view. Both the swing and the stance phase of sprinting, where the hamstring muscles are put under tension while lengthening (eccentric musculotendinous contraction) to decelerate knee extension have been suggested as possible scenarios of injury occurrence [4,5] and have laid the foundations of current prevention methods (eccentric strength training) of HMI in soccer [6]

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Results

Conclusion