Comparison of external load measures per minute based on match seasonal periods and playing positions of a soccer Turkish super league team.

BACKGROUND: Turkish Super League teams need more information about the external load. Considering the specific country and the coaches' philosophies, the purpose of this study was to compare the external match load of a Turkish Super League team considering the different playing positions and in-season periods. METHODOLOGY: A longitudinal study design was employed by observing 29 official matches of the same team. A total of fifteen players, consisting of five defenders, five midfielders, and five forwards, were analyzed using the Sentio Sports Optical Tracking System. The following outcomes were extracted in each match: total distance (TD), walking [from 0 to 7.2 km/h], jogging [from 7.2 to 14.4 km/h], running [from 14.4 to 20 km/h], high speed running (HSR) [> 20 km/h], metabolic power (MP), maximum deceleration (Decmax) [Dec < -3 m/s2], total deceleration distance (Dectotal), maximum acceleration (Accmax) [Acc > 3 m/s2], and total acceleration distance (Acctotal). Statistical analysis consisted of ANOVA and Bonferroni correction post hoc tests. RESULTS: The main results showed that all variables were similar between periods of the season (p > 0.05) except for walking (p = 0.021 witha large effect size), which revealed lower values in the mid-season period. When analyzing periods of the season considering playing positions, there were several significant results for TD, walking, jogging, running, HSR, Dectotal and Acctotal (p < 0.05, with small to large effects). A tendency for higher values was noted in the mid and end-season. Considering the playing positions comparisons, midfielders showed higher values than defenders for TD, MP, Dectotal and Acctotal (p < 0.05 with large effect for all). Midfielders also showed higher values than forwards for TD, jogging, Dectotal and Acctotal (p < 0.05 with a large effect for all). CONCLUSIONS: The present study emphasizes the significance of analyzing data based on minute, playing position, and season period. Findings reveal that defenders consistently displayed the lowest values in all external load measures during matches compared to other positions throughout the season. Furthermore, midfielders demonstrated a higher activity profile during the initial and middle stages of the season compared to other positions, with a slight tendency to decrease load towards the end of the season.

Mechanical performance improvement of super absorbent polymer-modified concrete.

In this study, a method has been developed to reduce the negative effects of superabsorbent polymers on concrete mechanical properties. The method involves concrete mixing and curing, with the concrete mixture being designed using a decision tree algorithm. Instead of the standard water curing approach, air curing conditions were used during the curing process. In addition, heat treatment was applied to reduce any possible negative effects of the polymers on the concrete's mechanical properties and to enhance their performance. The details of all these stages are presented in this method. Various experimental studies were conducted to demonstrate the validity of this method, which proved to be effective in reducing the negative effects of superabsorbent polymers on concrete mechanical properties. •The method can be used to eliminate the negative effects of superabsorbent polymers.•The proposed method yielded promising results, demonstrating that the expected level of compressive strength, modulus of elasticity and toughness in concrete can be achieved in 5-10 days instead of 28 days•The widespread use of superabsorbent polymers in the concrete industry and reinforced concrete systems can be attributed to their many benefits.

Within-week differences in external training load demands in elite volleyball players.

PURPOSE: The aim of this study was to analyze the within-week differences in external training intensity in different microcycles considering different playing positions in women elite volleyball players. METHODS: The training and match data were collected during the 2020-2021 season, which included 10 friendly matches, 41 league matches and 11 champions league matches. The players' position, training/match duration, training/match load, local positioning system (LPS) total distance, LPS jumps, accelerations, decelerations, high metabolic load distance (HMLD), acute and chronic (AC) mean and AC ratio calculated with the rolling average (RA) method and the exponentially weighted moving average (EWMA) method, monotony and strain values were analyzed. RESULTS: All the variables except strain, Acc/Dec ratio and acute mean (RA) showed significant differences among distance to match days. Regarding the players' positions, the only difference was found in the AC ratio (EWMA); in all microcycles, the middle blocker player showed workload values when compared with the left hitter, setter and libero. CONCLUSION: Overall, the analysis revealed that the intensity of all performance indicators, except for strain, acc/dec and acute mean load (RA), showed significant differences among distance to match day with moderate to large effect sizes. When comparing players' positions, the middle blocker accumulated the lowest loads. There were no significant differences among other positions.

Classified metabolic power-based measures in professional football players: comparison between playing positions and match period.

OBJECTIVE: The aim of this study was (i) provide reference data of metabolic power-based measures during professional football matches; and to (ii) analyze the between-position and between-halves differences of power-based measures during professional football matches. METHODS: Forty-six professional male players from two Turkish Super League teams were observed during two seasons, and 58 matches were analyzed. Total distance, equivalent distance, Low Power (LP), Intermediate Power (IP), High Power (HP), Elevated Power (EP), Max Power (MP) and power metabolic measures Pmet at different match moments were considered. RESULTS: Significant between-position differences were observed for IP (p: 0.000; d: 0.284), HP (p ≤ 0.001; d = 0.45), EP (p ≤ 0.001; d = 0.44), and for MP (p ≤ 0.001; d = 0.56), with the central defenders (CD) showing the lower values, and the central midfielders (CM) showing the higher values for the overall measures. CONCLUSION: Power-based measures are dependent on playing positions. While the CD have lower Pmet values when compared to all positions, the CM have the greatest values. Training and recovery strategies must be ensured for CM players, especially those who have greater match participation.

Prediction of Match Outcomes with Multivariate Statistical Methods for the Group Stage in the UEFA Champions League.

The aim of this study was to analyse the win, draw, and loss outcomes of soccer matches with situational variables and performance indicators. Data from group stage matches spanning the ten years between the 2010/2011 and 2019/2020 seasons in the European Champions League, were used. One-way analysis of variance (ANOVA) and Tukey HSD (honestly significant difference) tests indicated performance indicators which affected the outcome of matches. K-mean clustering, with statistically significant variables, categorized the quality of the opposition into three clusters: weak, balanced, and strong. Multidimensional scaling (MDS) and decision tree analysis were applied to each of these clusters, highlighting that performance indicators of the teams differed according to the quality of their opponent. Furthermore, according to the decision tree analysis, certain performance indicators, including scoring first and shots on target, increased the chances of winning regardless of the quality of the opposition. Finally, particular performance indicators increased the chance of winning, while others decreased this, in accordance with the quality of the opposition. These findings can help coaches develop different strategies, before or during the match, based on the quality of opponents, situational variables, and performance indicators.