Evolution of physical performance in professional soccer across four consecutive seasons

Background: Main purpose of this research was to investigate the changes of physical match performance in Polish Ekstraklasa across four consecutive seasons. Material and methods: A total of 949 official matches from season 2017/2018 to 2020/2021 were analyzed. Such match running performance variables as total distance, high-speed running, sprinting, and number of high-intensity runs were involved. Each season data were divided into two rounds (spring round and autumn round). Due to the pandemic of COVID-19 additional post-lockdown round (Spring I 2019/2020) occurred. Results: Comparison in the results between Spring 2017/2018 and Spring 2020/2021 indicated significant increases in total distance (2.1%, p<0.001), high-speed running (11.9%, p<0.001), sprinting distance (7.7%, p<0.01) and number of high-intensity runs (9.7%, p<0.001). Moreover, within season analysis exhibited that during spring rounds Ekstraklasa teams covered significantly longer (p<0.01) distances in high-speed running than during autumn rounds. Reduction in physical match performance was reported after the 12-week pandemic lockdown. Conclusions: The results of this study confirmed the growing importance of such match activities as high-speed running, sprinting and number of high intensity runs which increased in Polish Ekstraklasa by 8-12% within last 4 years. This growing tendency was disrupted by unexpected off-season period caused by COVID-19 lockdown.

Monitoring post-match fatigue during a competitive season in elite youth soccer players

Introduction: Countermovement jump (CMJ) and perceived wellness measures are useful for monitoring fatigue. Fatigue indicators should simultaneously show sensitivity to previous load and demonstrate influence on subsequent physical output; however, this has not been examined. This study examined the efficacy of CMJ and wellness measures to both detect post-match fatigue and predict subsequent physical match output in elite youth soccer. Methods: Sixteen soccer players (18 ± 1 years) participated in 36 English Football League Youth Alliance League fixtures. Physical match outputs (total distance, high-speed running, very high-speed running, and accelerations and decelerations) were recorded using a 10 Hz global positioning system and 200 Hz accelerometer device during competitive match play. CMJ height and perceived wellness were assessed weekly and daily, respectively, as indirect indicators of fatigue. Four sub-units of wellness (perceived soreness, energy, general stress, and sleep) were measured using customised psychometric questionnaires. Results: Simple linear regression showed that match accelerations and decelerations (AD) were predictive of energy (R2 = 0.08, P = 0.001), stress (R2 = 0.09, P &lt; 0.001), and total wellness (R2 = 0.06, P = 0.002) 2 days post-match. CMJ (R2 = 0.05, P = 0.002), stress (R2 = 0.08, P &lt; 0.001), sleep (R2 = 0.03, P = 0.034), and total wellness (R2 = 0.05, P = 0.006) 5 days pre-match (MD-5) were predictive of AD during the subsequent match. Conclusion: CMJ and wellness may be useful in detecting post-match fatigue. Wellness scores, but not CMJ, on MD-5 influence subsequent match output and therefore may be used to plan and periodise training for the upcoming microcycle.

Match-related physical performance in professional soccer: Position or player specific?

The purpose of this study was to examine to what extent the physical match performance of professional soccer players is both position and player specific. First, official match data from the 2019/20 German Bundesliga season was used to search for players that met the inclusion criteria of playing a minimum of four entire matches in at least two different playing positions. Overall, 25 players met the criteria prior to the COVID-19 induced break, playing a minimum of eight matches. Second, the physical match performance of these players was analyzed separately for each position they played. The following four parameters were captured: total distance, high-intensity distance, sprinting distance, and accelerations. Third, the 25 players’ physical match performance data was then compared to normative data for each position they played to understand whether players adapted their physical performance (position dependent), or maintained their performance regardless of which position they were assigned to (position independent). When switching the position, the change in physical match performance of the respective players could be explained by 44–58% through the normative positional data. Moreover, there existed large individual differences in the way players adapted or maintained their performance when acting in different positions. Coaches and practitioners should be aware that some professional soccer players will likely incur differences in the composition of physical match performance when switching positions and therefore should pay special consideration for such differences in the training and recovery process of these players.

Physical Activity of the Right- and Left-Footed Professional Soccer Players from Symmetrical Defensive Positions

The main purpose of this study was to compare the physical match performance of right- and left-footed external defenders during official matches of Polish Ekstraklasa. The sample comprised 991 individual observations from 296 matches during the 2019/2020 season. Variables such as total distance, distance covered in high-speed running and sprinting, and number of high-intensity runs were analysed. Additionally, the data were presented in relation to match duration and effective playing time. Right external defenders (right ED) covered significantly longer total distance (p < 0.001, 1.5%), high-speed running distance (p < 0.001, 5.6%) and sprinting distance (p < 0.001, 11.4%) compared to left external defenders (left ED). The number of high-intensity runs was greater for right RD as well (p < 0.001, 6.4%). Physical match activity for left ED who are left-footed was significantly higher (p < 0.001) in comparison with right-footed left ED. The number of offensive actions played on the right side of the pitch was significantly (p < 0.001) higher than those performed on the left side. Players whose dominant foot is in accordance with the side of the pitch cover longer distances during the match. Moreover, the number of offensive actions played through the wings could affect the physical performance of external defenders.

The Influence of COVID-19 Pandemic Lockdown on the Physical Performance of Professional Soccer Players: An Example of German and Polish Leagues

The purpose of this study was to investigate whether the in-season pandemic lockdown influenced physical match performance in professional soccer players who participated in the competition of German Bundesliga and Polish Ekstraklasa. The data from 306 games for German Bundesliga and 296 games for Polish Ekstraklasa were divided into before- and after-lockdown periods. The physical performance of German Bundesliga teams after the 63-day COVID-19 lockdown did not differ significantly from that in the first part of the season. In contrast, Polish Ekstraklasa teams, after the 81-day lockdown, displayed significantly shorter total distances (p < 0.001), shorter high-intensity running distances (p = 0.03), and fewer high-intensity actions (p = 0.02). Moreover, when the effective playing time was considered, teams covered significantly less relative total distance (p < 0.001) and relative high-intensity running distance (p = 0.02). The results of the current study suggest that physical performance during the matches of the German Bundesliga was not influenced by the COVID-19 lockdown, contrary to those of the Polish Ekstraklasa. This difference could have been caused by different break lengths and different restrictions implemented in these countries during the pandemic lockdown.