Player Monitoring in Professional Soccer: Spikes in Acute:Chronic Workload Are Dissociated From Injury Occurrence

Abstract

This study aimed to determine whether spikes in acute:chronic workload ratio (ACWR) are associated with injury incidence, and to examine the differences in external load due to greater or lesser exposure to matches and the long-term effects of the load during a chronic seasonal period. Fifteen professional soccer players belonging to the squad of a European Champions League club were enrolled in this study. External training and match load were assessed from all athletes using a global positioning system (GPS). We calculated the uncoupled ACWR for 10 consecutive competitive microcycles. Injuries were identified and determined by the days of absence. The differences in external load were determined using a linear mixed-model approach. In addition to the null hypothesis testing, the effect size was calculated. Thirteen athletes who did not suffer an injury exceeded several times the critical threshold of an ACWR > 1.5. This is equivalent to 1 player exceeding the critical threshold for ACWR in total distance (TD), 2 players for ACWR at distance covered above moderate speed (MSD), 2 players for ACWR at distance covered above high speed (HSD), 2 players for ACWR at distance covered above very high speed (VHSD), and 2 players for ACWR in DC at sprint per week. One athlete experienced a non-contact muscle strain injury and another a contact-injury manifested as a concussion; both athletes document an ACWR < 1.5 within the 4 weeks prior to the injury event. Players with lesser participation in official games covered lower TD (−19.6%, very-large ES), MSD (−24.8%, very-large ES), HSD (−25.1%, moderate ES), VHSD (−25.5%, moderate ES), and DC at sprint (−30.6%, moderate ES) over the course of the 10-weeks period in comparison with the players with greater participation in official games. The present study demonstrated that spikes in the ACWR were not related to a subsequent injury occurrence in professional soccer players. Differences in participation in official games caused significant imbalances in the chronic external loads between players in a squad, which should be minimized in training sessions in order to prevent substantial changes in workload for those who usually do not play.

Assessment of External Load during Matches in Two Consecutive Seasons Using the Mediacoach® Video Analysis System in a Spanish Professional Soccer Team: Implications for Injury Prevention

“…Differences in participation in official games, as in our second studied season, can cause significant imbalances in the chronic external loads between players in a team [45]. This situation should be considered and minimised in training sessions to prevent imbalances in workload for those who usually play or not.…”

A novel approach for sports injury risk prediction: based on time-series image encoding and deep learning

“…Although the method provides several practical metrics, the reliability and validity of the method will significantly be affected by individual differences and the training load quantification method. For instance, Gabbett et al (2016) found an association between exponentially weighted moving averages of training load and injury risk that was not found in some research ( Suárez-Arrones et al, 2020 ). It is important to note that most studies use a single evaluation method to quantify training loads, such as distance, session RPE, and other indicators, which may lead to statistical indicators of training load associated with injury risk that are not personalized.…”

“…Identifying potential risk factors for sports injuries through training load monitoring and timely adjustment of the training program is vital for developing injury prevention strategies ( Schwellnus et al, 2016 ; Soligard et al, 2016 ). Although there is much research evidence that excessive or sudden increases in training load are an important cause of injury ( Gabbett, 2016 ; Gabbett et al, 2016 ), these phenomena were not found in the research reports by Suárez-Arrones et al (2020) . These conflicting research findings hinder the development of injury prevention strategies based on load management.…”

Relationship Between Variations Accumulated Workload and Sprint Performance in Elite Adolescent Soccer Players

“…These high scores may be associated with disease incidence, poor performance, and the onset of overtraining [36,38]. With this, the use of the ACWR to understand changes in the load and how these changes relate to risk of injur, has received increasing scientific attention [41,42]. ACWR is calculated by dividing the AWL (the workload of the week preceding the injury, fatigue component) by the CWL (the aver-age workload of the four weeks preceding the injury, fitness component) [41,42].…”

“…With this, the use of the ACWR to understand changes in the load and how these changes relate to risk of injur, has received increasing scientific attention [41,42]. ACWR is calculated by dividing the AWL (the workload of the week preceding the injury, fatigue component) by the CWL (the aver-age workload of the four weeks preceding the injury, fitness component) [41,42]. Considering the training intensity parameters mentioned above, coaches can determine the physical and physiological effects of training sessions on players.…”