Wearable Inertial Measurement Unit to Accelerometer-Based Training Monotony and Strain during a Soccer Season: A within-Group Study for Starters and Non-Starters.

Hadi Nobari,Katsuhiko Suzuki,Hassane Zouhal,Rafael Oliveira,Jorge Pérez-Gómez,Mustafa Sögüt

doi:10.3390/ijerph18158007

Abstract

The purpose of this study was to analyze the intragroup differences in weekly training monotony (TM) and training strain (TS) between starter and non-starter male professional soccer players at accelerometry based variables throughout the periods of a season. TM and TS of different accelerations and decelerations zones for twenty-one players were followed for forty-eight weeks. Regardless of group, players obtained the highest mean TM (starters = 3.3 ± 0.6, non-starters = 2.2 ± 1.1, in arbitrary unit, AU) and TS (starters = 1288.9 ± 265.2, non-starters = 765.4 ± 547.5, AU) scores in the pre-season for accelerations at Zone 1 (<2 m/s2). The results also indicated that both groups exhibited similar TM and TS scores in accelerations at Zones 2 (2 to 4 m/s2) and 3 (>4 m/s2) across the entire season. While the starters showed the highest TM and TS scores at deceleration Zone 1 (<−2 m/s2) in the end-season, the non-starters exhibited the highest scores at the deceleration Zone 1 in pre-season. It seems that in pre-season, coaches applied higher levels of training with greater emphasis on deceleration for non-starters. This tendency was reduced over time for non-starters, while starters presented higher values of deceleration Zone 1. These results highlight the variations in TM and TS across the different periods of a full season according to match starting status among professional soccer players, and the results suggest that non-starter players should receive higher levels of load to compensate for non-participation in matches throughout a soccer season.

Highlights

The dual sets TMAcZ1 and TSAcZ1 are shown in Table 1 and Figure 1a,b
The results showed that both starters and non-starters obtained the highest mean training monotony (TM) and training strain (TS) scores in the pre-season and the highest accelerations at Zone 1
The findings of the study highlighted the variations in TM and TS with regard to the match starting status of players and certain periods of the season

Summary

Introduction

Monitoring training load in professional soccer is one of the primary focuses of coaching staff in order to analyze individual training requirements, to optimize physical fitness, and to minimize the risk of injury [1,2]. The process of training load monitoring can be categorized as either internal or external with respect to the load units [3]. Internal training load is related to the psychophysiological stress imposed on players during training and competition, and it is usually measured using ratings of perceived exertion, blood lactate, oxygen consumption, and heart rate.

Objectives

Methods

Results

Discussion

Conclusion