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This study sought to assess how post-game creatine kinase (CK) levels correlate with the number of sprints and the impact of the ACTN3 polymorphism on this response. This research constituted a descriptive/observational, retrospective cross-sectional study. DNA was extracted from blood samples for ACTN3 polymorphism genotyping. CK was measured 48 h after official matches, and the number of sprints (>19 km/h) was tracked using Global Positioning System (GPS) technology. The main cohort included 23 professional soccer players from the top tier of the Brazilian Championship. We analyzed 115 GPS + CK data sets. The replication cohort comprised 18 professional soccer players from the First Division of the Championship, had the same methodology applied, and featured a total of 90 GPS (sprints > 25.2 km/h) + CK data sets. For the main cohort, a significant positive correlation was seen between the number of sprints and the CK levels (p = 0.009). Athletes with the ACTN3 RR genotype had higher CK levels as more sprints were performed during the match (p = 0.017). However, the relationship was not found for X allele carriers (p > 0.05). For the replication cohort, there was a near-significant correlation between CK levels and the number of sprints (p = 0.05), and RR individuals showed a significant association (p = 0.01), whereas X allele carriers did not (p = 0.06). A greater number of sprints during matches is linked to higher CK levels, primarily among players with the ACTN3 RR genotype, which is potentially due to an increased presence of type II muscle fibers. These findings were replicated for both cohorts of elite Brazilian soccer players, emphasizing the importance of genetic factors in injury prevention.

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Abstract Objectives: To analyze bone mineral content (BMC) and area bone mineral density (aBMD) accrual in adolescent male footballers who started their first football season. Methods: 17 athletes (14.8 ± 0.4 years) were monitored across 15 weeks of football training. Participants were evaluated for somatic maturation (HPHV), BMC, and aBMD at three time points: before (M1) and after (M2) a preparatory phase, and at the end of the competitive phase (M3). BMC and aBMD were measured using DXA scans. Participants were divided into groups according to maturation status (circa-PHV and post-PHV), and the amount of accumulated training load (median split). Results: A significant effect (12.1 g/week, standard error (SE) = 2.6 g/week) was observed for lower limbs BMC across the three time points. There were no significant effects of time for upper limbs BMC. There was a significant effect of time for total body aBMD (0.007, SE = 0.003 g/cm2/week) across the three time points. Adolescents at post-PHV had a significant 245.6 g (SE = 56.1 g) higher BMC compared to adolescents at circa-PHV. No significant effects were observed for the accumulated training load. Conclusion: Systematic football training, even during the growth spurt, has a positive impact on adolescent bone markers despite the accumulated training load and maturation.

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A observação da adoção do futebol feminino na União Recreativa de Cultura e Desporto de Coina entre 1981 e 1990 mostra como qualquer abordagem à triangulação entre lazer, paisagem e natureza deverá ser efetuada com alguma meticulosidade, tomando as características peculiares da instituição em causa como primordiais, e nem sempre equiparáveis a outros territórios. A adoção do futebol em Coina acabou por moldar todo um território regional e elevou um pequeno topónimo periférico da Grande Lisboa ao mapa mental dos seguidores nacionais deste desporto. Este case study mostra como o futebol entrou nas estratégias de implementação do direito ao lazer feminino em Portugal e assumiu diferentes formas e variáveis díspares no tempo e no espaço.

The observation of the adoption of femalefootball at the União R.C.D.de Coina(Portugal) between 1981 and 1990 shows how the triangulation between leisure, landscape and nature has to be carryout with some meticulousness, taking the innercharacteristics of eachinstitution. Onceanalyzed as primordial, probably it would not bealways comparable to the rest of the country. The adoption of football inthe village ofCoina ended up shaping an entire regional territory and placed a small peripheral placeof Lisbon' outskirtson the mental map of the nationalfollowers of this sport. This case study shows how football entered into the strategies for implementingwomen's right to leisure in Portugal,and it had different forms and variables throughtime and space.

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This study aimed to analyze the effect of laterality and instructional video on the soccer goalkeepers' dive kinematics in penalty. Eight goalkeepers from youth categories (U15, U17, U20) were randomly divided into control (CG) and video instruction groups (VG). The latter performed 20 penalty defense trials on the field with balls launched by a machine, ten before and after watching a video instruction to improve the diving kinematics. The CG only performed the dives. Three cameras recorded the collections. A markerless motion capture technique (OpenPose) was used for identification and tracking of joints and anatomical references on video. The pose data were used for 3D reconstruction. In the post-instruction situation, the VG presented differences in comparison to the CG in the: knee flexion/extension angle, time to reach peak resultant velocity, frontal step distance, and frontal departure angle, which generated greater acceleration during the dive. Non-dominant leg side dives had higher resultant velocity during 88.4 - 100% of the diving cycle, different knee flexion/extension angle, and higher values ​​in the frontal step distance. The instructional video generated an acute change in the diving movement pattern of young goalkeepers when comparing the control and the video instruction group in the post condition.

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In this study, we examined whether experience level and various dual motor and cognitive or single tasks influenced young soccer players' physical performance during small-sided games. Participants were 72 players from U-13 (n = 36) and U-17 (n = 36) groups who participated in 3-to-a-side small-sided games under four experimental conditions: control, a secondary motor task, an additional related secondary cognitive task, and an additional secondary non-specific task. We used GPS devices to measure physical performance in terms of distances covered and accelerations at different thresholds. We found no significant interaction effect between player experience and task condition (p = .540), meaning that dual tasks had comparable effects on players of different experience levels. There were significant main effects of both experience level (p < .001) and condition (p < .001) on most physically related variables. Older players outperformed younger ones, particularly in high-intensity actions. While secondary motor tasks decreased physical performance, secondary cognitive tasks, irrespective of specificity, did not impair players' performances. In conclusion, experience level did not influence the players' physical response to dual tasks, and a secondary motor task was more disruptive to physical performance than either of two types of secondary cognitive tasks. Cognitive tasks can be incorporated into soccer training without compromising physical performance.

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This study aimed to verify whether peripheral perception, tactical behaviour, and physical performance are influenced by acute physical fatigue in soccer players. The study included 24 trained soccer players (18.6 ± 1.5 years) from two Brazilian clubs. The TSAFT90 test was used to induce acute physical fatigue. The results showed that physical fatigue did not affect peripheral perception (p = 0.360). Regarding tactical behaviour, improved efficiency was observed for the principles of offensive coverage (p = 0.029), width and length with the ball (p = 0.044), and concentration (p = 0.008). On the other hand, a reduction was observed in the number of tactical actions of offensive coverage (p = 0.020) and recovery balance (p = 0.042). Also, improved accuracy in the principles of defensive balance (p = 0.009), recovery balance (p = 0.021) and defensive unity (p = 0.003) occurred under physical fatigue. A reduction in the physical performance outcomes total distance covered (p < 0.001), average speed (p < 0.001), sprints (p = 0.029), number of accelerations (p = 0.008) and decelerations (p = 0.008) were also detected. The internal (p < 0.01) and external (p < 0.01) workload was higher under physical fatigue. Overall, acute physical fatigue did not influence peripheral perception. However, physical performance was reduced under fatigue, the perceived effort increased, and tactical behaviours were affected by decreasing tactical actions performed near the ball, increasing errors in defensive movements in the lateral corridors and the last defensive line, and improving offensive tactical actions performance.

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The search for increased performance and physical performance are linked to the use of ergogenic resources. The vertical jump is one of the measures commonly used to evaluate the performance of lower limbs in athletes. Transcranial direct current stimulation (tDCS) is a non-invasive, safe, economically viable technique that can modulate cortical excitability, which can influence the increase in the performance of athletes in general. This study aimed to investigate whether the use of tDCS on the primary motor cortex (M1) improves the performance of soccer players. A cross-sectional study was conducted. Twenty-seven players were randomized into three groups: Active tDCS group (n = 9), Sham group (n = 9), and control group (n = 9). Stimulation was applied at 2 mA for 15 min using a cephalic mount. Visual Pain Scale (VAS) and Subjective Recovery Scale (SRS) were monitored before and after tDCS. In addition, the participants performed the Countermovement Jump (CMJ) before and after the stimulation intercalated with Heart Rate (HR) and Rating of Perceived Exertion (RPE CR-10). No differences were found in any of the performance variables analyzed (p > 0.05) nor in the responses of HR (p > 0.05), RPE (p > 0.05), VAS (p > 0.05), and SRS (p > 0.05) between groups. The tDCS in M1 did not change the performance of the vertical jump, and there was no improvement in the subjective scales. New studies should also be developed with different stimulus intensities in different cortical areas and sports modalities.

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Este texto objetiva analisar as condições para atuação futebolística das mulheres jogadoras da equipe Foz Cataratas após a associação realizada com o clube Athletico Paranaense em 2019. Para tanto optou-se por um estudo de caso realizado através de observações e entrevista semiestruturada aplicadas à quatorze jogadoras e ao dirigente. As narrativas foram analisadas com base na metodologia denominada Análise de Conteúdo (Bardim, 1979). Verificou-se que as ações fomentadas pelas entidades futebolísticas impactaram positivamente ao trazer oportunidades para um número maior de mulheres, mas não garantiu melhorias nas condições de atuação das jogadoras e não remeteu a profissionali-zação no futebol de mulheres, especialmente para equipes com baixo capital simbólico, localizadas fora dos centros futebolísticos (AU).

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Este texto objetiva analisar as condições para atuação fu-tebolística das mulheres jogadoras da equipe Foz Cataratas após a associação realizada com o clube Athletico Paranaense em 2019. Para tanto optou-se por um estudo de caso realizado através de observações e entrevista semiestruturada aplicadas à quatorze jo-gadoras e ao dirigente. As narrativas foram analisadas com base na metodologia denominada Análise de Conteúdo (Bardim, 1979). Verificou-se que as ações fomentadas pelas entidades futebolísti-cas impactaram positivamente ao trazer oportunidades para um número maior de mulheres, mas não garantiu melhorias nas con-dições de atuação das jogadoras e não remeteu a profissionali-zação no futebol de mulheres, especialmente para equipes com baixo capital simbólico, localizadas fora dos centros futebolísticos.

The aim of this text is to analyze the conditions in which women players from the Foz Cataratas team can play football after the association with the Athletico Paranaense club in 2019. To this end, we opted for a case study carried out through observations and semi-structured interviews applied to fourteen female players and the manager. The narratives were analyzed using the methodology known as Content Analysis (Bardin, 1979). It was found that the actions promoted by soccer organizations had a positive impact by bringing opportunities to a greater number of women, but did not guarantee improvements in the playing conditions of the players and did not lead to the professionalization of women's soccer, especially for teams with low symbolic capital, located outside the soccer centers.

Este texto tiene como objetivo analizar las condiciones para el rendimiento futbolístico de las jugadoras del equipo Foz Cataratas después de la asociación con el club Athletico Paranaense en 2019. Para ello, optamos por un estudio de caso realizado a través de observaciones y entrevistas semiestructuradas con catorce jugadoras y el dirigente. Las narrativas fueron analizadas utilizando la metodología de Análisis de Contenido (Bardin, 1979). Se constató que las acciones promovidas por las organizaciones de fútbol tuvieron un impacto positivo al traer oportunidades a un mayor número de mujeres, pero no garantizaron mejoras en las condiciones de juego de las jugadoras y no condujeron a la profesionalización del fútbol femenino, especialmente para los equipos con bajo capital simbólico, localizados fuera de los centros futbolísticos.

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This descriptive study aimed to investigate the current practices of Portuguese and Brazilian soccer coaches in the design and implementation of small-sided games (SSGs) in soccer. A total of 187 male coaches participated in the online survey, consisting of 82 Portuguese and 105 Brazilian individuals. These coaches held various positions within the technical staff, with 63 serving as head coaches, 38 as assistant coaches, 38 as physical trainers, and 48 in other roles related to the technical staff. Additionally, the participants represented both youth (n = 102) and adult competitive levels (n = 59), along with some who were not currently associated with a specific group. The survey consisted of 32 questions divided into three main sections: (i) the timing of SSG application, (ii) the methods used for applying SSGs, and (iii) the reasons for applying SSGs. The Chi-square test revealed a statistically significant association between nationality and the frequency of SSGs used in training sessions during the pre-season (p = 0.039) and in-season (p < 0.001). Moreover, significant association between nationality and the time allocated to employing SSGs for targeting aerobic training (p < 0.001) was found. There was a significant association between nationality and the weekly frequency of SSGs use for targeting sprint training (p = 0.019). The Chi-square test identified significant associations between nationality and the use of SSGs for targeting technical training (p = 0.002), as well as for tactical training (p = 0.002). In summary, this study underscores that SSGs are primarily employed to enhance aerobic fitness, change of direction, technical skills, and tactical behaviors. Coaches generally favor employing SSGs two to three times a week, with typical sessions lasting between 16 to 30 minutes. Notably, the major discrepancies between nationalities lie in the importance assigned to the use of SSGs. However, in practice, the formats and objectives for implementing SSGs remain relatively similar.