The aim of this research was to evaluate the influence of the mechanical properties of artificial turf systems on soccer players’ performance. A battery of perceptive physiological and physical tests were developed on four different structural systems of artificial turf (System 1: Compacted gravel sub-base without elastic layer; System 2: Compacted gravel sub-base with elastic layer; System 3: Asphalt sub-base without elastic layer; System 4: Asphalt sub-base with elastic layer). The sample was composed of 18 soccer players (22.44±1.72 years) who typically train and compete on artificial turf. The artificial turf system with less rotational traction (S3) showed higher total time in the Repeated Sprint Ability test in comparison to the systems with intermediate values (49.46±1.75 s vs 47.55±1.82 s (S1) and 47.85±1.59 s (S2); p<0.001). The performance in jumping tests (countermovement jump and squat jump) and ball kicking to goal decreased after the RSA test in all surfaces assessed (p<0.05), since the artificial turf system did not affect performance deterioration (p>0.05). The physiological load was similar in all four artificial turf systems. However, players felt more comfortable on the harder and more rigid system (S4; visual analogue scale = 70.83±14.28) than on the softer artificial turf system (S2; visual analogue scale = 54.24±19.63). The lineal regression analysis revealed a significant influence of the mechanical properties of the surface of 16.5%, 15.8% and 7.1% on the mean time of the sprint, the best sprint time and the maximum mean speed in the RSA test respectively. Results suggest a mechanical heterogeneity between the systems of artificial turf which generate differences in the physical performance and in the soccer players’ perceptions.

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Football fields of artificial turf are in constant evolution. The resulting improvements have given rise to a large diversity of structural components. There are various types of infill and fibre for artificial turf and different designs and materials for the support structure (sub-base and elastic layer). The design of the sub-base and the presence or absence of the elastic layer can influence turf performance and the surface’s useful lifetime. The aim of this study was to assess in situ the effect of the various support structures on the mechanical properties of artificial turf after deterioration caused by wear for a year. The assessed properties were force reduction (%), standard vertical deformation (mm), rotational traction (N·m), vertical ball rebound (%), and ball roll (m), according to the requirements in norm EN 15330-1:2007. The results demonstrate the effect of the structural base on the mechanical and functional performance of football fields of artificial turf, as well as the significant deterioration of the properties over a year which varied between 3.14% and 8.92% with regard to the installed system. These results show that the support structure that provides the greatest durability and adequate behaviour of the mechanical properties over time is that which has a sub-base of compacted gravel under an elastic layer.

The aim of this research is to understand the experience of the football sector on the use of artificial turf (satisfaction, safety, sporting feature, or the advantages and disadvantages). The study was conducted on a random selection of 627 male participants (404 amateur/semi-professional footballers, 101 coaches and 122 referees) that regularly train/compete on artificial turf in Spanish football leagues. The results of the skin abrasion, muscle strain and the possibility of sustaining an injury, on a Likert-type 10-point interval scale, gave a perception of 'somewhat dissatisfied' for the participants. The main advantages of artificial turf were their sports features, the evenness of the surface and the good state of conservation. Participants were satisfied with the artificial turf surface. Approximately three out of four participants gave an overall ranking of highly satisfied. The players were significantly less satisfied than the coaches and referees. The overall satisfaction with artificial turf fields was strongly influenced by previous experience, particularly those who had previously played on dirt pitches. These results highlight the versatility of artificial turf to adapt to any circumstance or requirement for local sport and top-level professional competitions alike.

The aim of the present study was to assess the accuracy of a multi-camera tracking system (Mediacoach®) to track elite football players’ movements in real time. A total of 207 observations of 38 official matches from Liga 1, 2, 3™ (2nd Spanish Division, season 2017/18) were included in the study (88 defenders, 84 midfielders, and 35 attackers of the same team). Total distance (TD, m) distance in zone 4 (DZ4) at a speed of 14–21 km/h, distance in zone 5 (DZ5) at a speed of 21–24 km/h (DZ5), distance in zone 6 (DZ6) at a speed of ≥24 km/h, maximum speed (km/h), and number of sprints (actions above 24 km/h) were registered with the Apex® GPS system (STATSports™, Newry, N. Ireland) and Mediacoach® semi-automatic tracking system (LaLiga™, Madrid, Spain). The level of agreement between variables estimated by the two systems was analyzed. Bias was also calculated by deducting the GPS estimated value from the video estimated value, and then dividing the difference score by the GPS estimated value. All variables showed high ICC values (>0.75) and very large correlations (r > 0.70). However the video-based performance analysis system overestimated the results obtained in the different speed zones (DZ5: +16.59 ± 62.29 m; LOA95%: −105.49 to 138.68; DZ6: +93.26 ± 67.76 m; LOA95%: −39.55 to 226.07), the number of sprints (+2.27 ± 2.94; LOA95%: −3.49 to 8.02), and the maximum speed (+0.32 ± 1.25 km/h; LOA95%: −2.13 to 2.77). The maximum bias was found in DZ6 (47%). This demonstrates that Mediacoach® is as accurate as a GPS system to obtain objective data in real time, adapted to physical and movement demands of elite football, especially for total distance and distances traveled at medium speeds.

García-Benítez, S, Courel-Ibáñez, J, Pérez-Bilbao, T, and Felipe, JL. Game responses during young padel match play: age and sex comparisons. J Strength Cond Res 32(4): 1144-1149, 2018-The purpose of this study was to assess match activity profile and temporal structure in U-16 and U-18 male and female padel players from the 2014 Spanish Youth National Championship. A total of 1,670 rallies from 12 matches were recorded through systematic observation. Variables pertaining to game and point duration, rest interval time, number of strokes per rally (SR), and match total duration were registered. Current findings show that significant influences of age and sex on game demands in youth padel players strengthen the importance of knowing specific game characteristics during formative stages for training accordingly. In particular, padel match activity in youth players was characterized by longer rallies, longer resting interval time, and more number of SR compared with other racket sports, resulting in lower effort index. More specifically, results revealed an increment on match requirements in U-18 players compared with U-16. Besides, we found a greater use of lobs in females, particularly in U-16 players. This information may constitute a useful guide for the design of appropriate game strategies and specific-training sessions according to competitive demands in youth padel players.

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The aim of this study was to analyze the influence of the match half and the playing position on physical requirements in the Spanish Professional Futsal League players during official games. The external load from distance, speed, acceleration and deceleration variables were obtained from fourteen elite futsal players during 10 official matches of the 2019–2020 season using a Local Positioning System with ultra-wideband technology installed on the futsal pitch. The results revealed similar results from physical requirements between first and second half (p > 0.05). Wingers demonstrated greater high-speed running distance (+4.04 m·min−1; CI95%: 0.35 to 7.72; ES: 0.87) than pivots (p > 0.05). There were a high number of accelerations (7.42–9.41 n·min−1) and decelerations (7.37–9.12 n·min−1) per minute in all player positions. The principal finding of the current manuscript did not evidence differences in the physical performance of players between the first and second half. The physical requirements varied among pivots and wingers regarding high-intensity actions. These outcomes add new contributions to the understanding of futsal physical demands.