José Luis Felipe

Artificial turf surfaces: Perception of safety, sporting feature, satisfaction and preference of football users

Abstract 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.

Respiratory Function and Changes in Lung Epithelium Biomarkers after a Short-Training Intervention in Chlorinated vs. Ozone Indoor Pools

Background Swimming in indoor pools treated with combined chemical treatments (e.g. ozone) may reduce direct exposure to disinfection byproducts and thus have less negative effects on respiratory function compared to chlorinated pools. The aim of this study is to analyze the effects of a short-term training intervention on respiratory function and lung epithelial damage in adults exercising in indoor swimming pool waters treated with different disinfection methods (chlorine vs. ozone with bromine). Methods Lung permeability biomakers [surfactant protein D (SP-D) and Clara cell secretory protein (CC16) in plasma] and forced expiratory volumes and flow (FEV1, FVC and FEF25–75) were measured in 39 healthy adults. Thirteen participants swam during 20 sessions in a chlorinated pool (CP), 13 performed and equivolumic intervention in an ozone pool (OP) and 13 were included in a control group (CG) without exposition. Results Median plasma CC16 levels increased in CP swimmers (4.27±3.29 and 6.62±5.51 µg/L, p = 0.01, pre and post intervention respectively) while no significant changes in OP and CG participants were found. No significant changes in median plasma SP-D levels were found in any of the groups after the training period. FVC increased in OP (4.26±0.86 and 4.43±0.92 L, p<0.01) and CP swimmers (4.25±0.86 and 4.35±0.85 L, p<0.01). FEV1 only increased in OP swimmers (3.50±0.65 and 3.59±0.67, p = 0.02) and FEF25–75 decreased in CP swimmers (3.70±0.87 and 3.37±0.67, p = 0.02). Conclusion Despite lung function being similar in both groups, a higher lung permeability in CP compared to OP swimmers was found after a short-term swimming program. Combined chemical treatments for swimming pools such as ozone seem to have less impact on lung epithelial of swimmers compared to chlorinated treated pools.

Effect of the structural components of support on the loss of mechanical properties of football fields of artificial turf

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.

Influence of hard vs. soft ground surfaces on bone accretion in prepubertal footballers

Information regarding osteogenic effects of physical activity performed on different playing surfaces is scarce. A total of 42 children (9.2±0.2 years, Tanner stages I-II) participated in this study. 14 were playing on artificial turf soft ground (SG), 14 on a natural non-grass hard ground (HG) and 14 were assigned to the sedentary control group (C). Whole body and hip scans (dual energy X-ray absorptiometry), anthropometric variables (weight and height) and physical fitness (VO2max) were determined in all participants. Bone mineral content (BMC) values were higher in the SG group compared to the C group at the legs (209.75±5.11 g vs. 187.42±5.14 g, respectively), pelvis (122.72±4.27 g vs. 98.58±4.29 g respectively) and whole-body level (1 126.1±22.81 g vs. 1 035.34±22.92 g, respectively). The hard ground (HG) group also showed higher values in the majority of BMC variables compared to the C group. Additionally, bone mineral density (BMD) was significantly higher at all sites of the hip in both active groups compared to control (P<0.05). No differences between HG and SG were found. In summary, similar bone mass accretion is obtained by prepubescent footballers independently of the surface on which they practice football.

Determination of mechanical properties of artificial turf football pitches according to structural components

Structural components of artificial turf football pitches have been improved in the last decade. The aim of this study was to explore the influence of structural components on the in situ mechanical behaviour of third-generation artificial turf football pitches. In total, 21 pitches were analysed according to the specified FIFA procedures. The results revealed that each of the pitches complies with the requirements of FIFA regulations. Pile length sample, stabilising bulk density, tuft/m2 and sub-base material all demonstrated a significant influence on the mechanical properties of the surface (p < 0.05). Finally, the selected structural parameters explained 77.9%, 59.8% and 54.3% of variance in rotational traction, vertical deformation and force reduction, respectively. These results show the importance of the selection of the structural components in the design of artificial turf football pitches.

Influence of contextual variables and the pressure to keep category on physical match performance in soccer players

Previous studies have analysed the influence of contextual variables on performance and physical demands in soccer. However, the points needed to remain in the category have been an element that has not been analysed previously. The aim of the present study was to investigate the influence of match location, match period, strength of the opponent and the points required to keep category on physical performance in professional soccer players. Fourteen Spanish second B Division League matches played by a professional football team were analysed during the 2016/17 season using GPS devices. The 10 main players of each match used the GPS throughout the match. The variables of Total Distance (m), High Intensity Distance (m), High intensity Accelerations (n), Sprint Time (s) and Sprint Distance (m) were analysed. The most notable differences are found in Total Distance covered. Away games accumulated significantly more distance than those played at home, but only in the second half (+230.65 m, IC95%: 21.94 to 438.19, ES: 0.46, p = 0.031). There are no differences depending on the strength of the opponent. However, players covered greater distances during the first half in those matches that were played furthest from salvation (+235.86 m, 95% CI: 49.03 to 422.70, ES: 0.51, p = 0.014). Total Distance is the main parameter affected by situational variables. In addition, the pressure of being further away from saving the category increases the distance covered by players in a game.

Prediction of abandonment in Spanish fitness centres

Abstract Research question: The increase of physical exercise in fitness centres has turned these facilities in important active lifestyle promoters. However, only between 30% and 60% of subscribers still linked to the sports centre after a year. The aim of this study is to design a model to predict the drop out in fitness centres. Research methods: Monthly data corresponding to the actual behaviour of 14,522 members of three sport centres in Spain were recorded over the course of one year. In order to calculate the likelihood of drop out, logistic regressions were used to create predictive models for each centre. Results and findings: It was possible to predict abandonment of users of sport centres from their historical behaviour, although the predictive models obtained for each centre were not completely coincident. The effectiveness of the models was around 70%. Implications: The analysis of users’ behaviour in a fitness centre can allow to avoid the drop out and therefore the abandonment of physical activity. Segmenting the customers based on the likelihood of drop out may be useful for improving the effectiveness of the strategies of loyalty and for optimizing the organization of human and material resources.

Assessing Financial Condition of Municipal Sports Agencies: A Data Benchmarking Approach

This study analyzes the development of the financial condition of local decentralized public sports services over a period of 10 years, obtaining benchmarks to serve as a point of reference. In order to do this, the elements of flexibility, independence, and sustainability are analyzed through three indicators in 2,139 observations obtained from municipal sports service organi-zations in Spain from 2002 to 2011. The majority of the organizations show results that are theoretically adequate in terms of flexibility and sustainability, but not independence. For this reason, the statistics presented can be used as a point of reference in order to classify the organizations in the sector according to their financial performance.

Acreditación de los campos de fútbol de césped artificial: garantía de éxito

In recent decades, artificial turf is undergoing constant evolution, not only in quality but also in the quality of its structural components. This growth has created the need to know the artificial pavement conditions in relation to a predetermined quality standards, emerging different regulations based on the purpose and status of the surface. There are currently three different approval systems for such surfaces. On the one hand, the UNE-EN 15330-1:2007, which is specific for artificial turf surfaces for outside use, more oriented to community sports, recreation and education, and secondly, those that are more related with the high athletic performance, such as FIFA certification (1 and 2 stars), which is international, and the RFEF Mark of Quality (level 1 and 2) which is national. The implementation of these accreditations ensures the quality of the pavement, improving performance and placing it at the level of the natural grass.