Towards the use of multidimensional performance indicators in football small-sided games: the effects of pitch orientation

This study aimed to compare youth football players’ performance during two small-sided games with different pitch orientation: i) 40x30m and ii) 30x40m formats. Twenty under-15 players (age = 14.1 ± 0.5 years) participated in nine GK+4vs4+GK situations in each format, with the duration of six minutes each. Positional data were collected using individual GPS units, and computed for tactical and physical performance indicators. The SSG were video recorded, using notational analysis for collecting technical indicators. A novel method that incorporates time dependent notational information with spatiotemporal data was used to compute multidimensional parameters. Standardised effect sizes and non-clinical magnitude-based inferences were used to compare formats. Results showed that players covered more distance at higher intensities, presented more passes and dribbles and were more synchronised in the longitudinal axis while playing in the 40x30m pitch. In the 30x40m pitch, results showed a lower distance between team centroids, higher number of shots, more lateral passes and a wider team positioning. Multidimensional indicators, as players position and distance to the closest defender while shooting, revealed a more constant distance between attacker and defender in the 40x30m pitch. These results highlight the importance of integrating information from different indicators for a contextually valid information.     

The Effect of In-Season Traditional and Explosive Resistance Training Programs on Strength,Jump Height,and Speed in Recreational Soccer Players

Purpose: Resistance training is often performed in a traditional training style using deliberate relatively longer repetition durations or in an explosive training style using maximal intended velocities and relatively shorter repetition durations. Both improve strength, “power” (impulsivity), and speed. This study compared explosive and traditional training over a 6-week intervention in 30 healthy young adult male recreational soccer players. Method: Full body supervised resistance training was performed 2 times a week using 3 sets of each exercise at 80% of one repetition maximum to momentary failure. Outcomes were Smith machine squat 1 repetition maximum, 10 meter sprint time, and countermovement jump. Results: Both groups significantly improved all outcomes based on 95% confidence intervals not crossing zero. There were no between-group differences for squat 1 RM (TRAD = 6.3[5.1 to 7.6] kg, EXP = 5.2[3.9 to 6.4] kg) or 10 meter sprint (TRAD = ?0.05[?0.07 to ?0.04] s, EXP = ?0.05[?0.06 to ?0.03] s). Explosive group had a significantly greater increase in countermovement jump compared to the traditional group (TRAD = 0.7[0.3 to 1.1] cm, EXP = 1.3[0.9 to 1.7] cm). Conclusion: Both the traditional training and explosive training performed to momentary failure produced significant improvements in strength, speed, and jump performance. Strength gains are similar independent of intended movement speed. However, speed and jump performance changes are marginal with resistance training.     

高水平青年男子足球运动员赛前热身活动

采用可穿戴电子设备,对2019赛季“全国青少年男子足球超级联赛”19岁以下年龄组的一支参赛球队的24名青年运动员参加的8场正式比赛的赛前热身活动和比赛负荷进行量化分析。结果显示：（1）该运动队的赛前热身时间平均为（27.8±4.6） min,首发球员和替补球员在赛前热身活动中的各项负荷量化指标皆体现出极其显著的中等至非常大程度差异（P＜0.001,ES值介于0.72和3.17）;（2）首发且打满全场的运动员赛前热身活动的跑动总距离占比赛跑动总距离的18.6%±3.2%,加速度负荷总量占24.5%±4.1%,首发打满全场、首发被换下、替补45 min以上和替补未满45 min四组不同出场时间的运动员的赛前热身活动的各项负荷指标占比赛负荷指标的比重皆体现出显著性差异（P＜0.013,ηp2介于0.10和0.44）。研究认为,赛前热身活动的负荷量应该被计入比赛日的负荷总量,用于足球运动员的训练负荷管理与训练任务设计参照,且不同出场时间带来的负荷差异应该被纳入考量范围。     

The effects of two different swimming training periodization on physiological parameters at various exercise intensities

This study analysed the effects of two different periodization strategies on physiological parameters at various exercise intensities in competitive swimmers. Seventeen athletes of both sexes were divided to two groups, the traditional periodization (TPG, n?=?7) and the reverse periodization group (RPG, n?=?10). Each group followed a 10-week training period based on the two different periodization strategies. Before and after training, swimming velocity (SV), energy expenditure (EE), energy cost (EC) and percentage of aerobic (%Aer) and anaerobic (%An) energy contribution to the swimming intensities corresponding to the aerobic threshold (AerT), the anaerobic threshold (AnT) and the velocity at maximal oxygen uptake (vVO₂max) were measured. Both groups increased the %An at the AerT and AnT intensity (P?≤?.05). In contrast, at the AnT intensity, EE and EC were only increased in TPG. Complementary, %Aer, %An, EE and EC at vVO₂max did not alter in both groups (P?>?.05); no changes were observed in SV in TPG and RPG at all three intensities. These results indicate that both periodization schemes confer almost analogous adaptations in specific physiological parameters in competitive swimmers. However, given the large difference in the total training volume between the two groups, it is suggested that the implementation of the reverse periodization model is an effective and time-efficient strategy to improve performance mainly for swimming events where the AnT is an important performance indicator.     

Overcompliance and reluctance to make decisions: Exploring warning systems in support of public managers

Post-scandal effects in public management point to the occurrence of overcompliance in the work of public managers, leading to reluctance and paralysis in decision-making. This article discusses the proposition of an artifact in the form of a warning system to aid the analysis process and issuing of opinions (APIO) by public managers, providing more information and, consequently, less risk and fear. The Design Science Research method was used to exapt a scientific artifact to the context of public management. The textual structure of 178 opinions issued by public agencies was analyzed, as was the perception of 17 public managers of the characteristics of the APIO. Exaptating the artifact from a technological perspective is simple and feasible, as it involves processes with strong functional similarities. The greatest challenges to operationalize the artifact broadly and without restrictions, as occurs in scientific academia, are associated with informational behaviors.     

Intergenerational conflict and public education expenditure when there is co-residence between the elderly and young

The main objective of this paper is to show that a family arrangement in which the elderly co-reside with the young determines that the elderly support the public education expenditure. Considering that this type of family arrangement is more common in Latin American countries than in the United States, our study is concentrated in Brazil. This study is based on a panel of 2054 Brazilian municipalities using data from the 1991 and 2000 censuses.     

Kinematic analysis of three water polo front crawl styles

During water polo matches, players use different front crawl styles. The purpose of this study was to conduct a kinematic analysis of three water polo front crawl styles: front crawl with head under water, front crawl with head above water, and front crawl when leading the ball. Ten proficient water polo players performed 3 × 15 m sprints in each front crawl style, which were recorded three-dimensionally by two surface and four underwater cameras. The results showed no differences in performance and several kinematic characteristics among the water polo front crawl styles. However, front crawl when leading the ball showed shorter stroke length and greater stroke frequency. Front crawl with head underwater presented greater maximal finger depth and elbow angle at mid-stroke position. Front crawl with head above water and when leading the ball showed greater trunk obliquity and maximal depth of right and left foot, and shorter kick stroke frequency. The findings suggest that proficient players learn to master front crawl with head above water to achieve top velocity. Despite the common use of the front crawl with head underwater as the basis for water polo fast displacement, coaches should emphasize the use of the specific water polo styles to attain high performance.     

The association of child abuse and neglect with adult disability in schizophrenia and the prominent role of physical neglect

ObjectiveTo assess long-lasting effects of childhood trauma on the functional outcome of adult patients diagnosed with schizophrenia.MethodNinety-nine stable patients with schizophrenia followed in an outpatient program at a public university hospital in Porto Alegre, southern Brazil, were investigated for childhood traumatic experiences by the Childhood Trauma Questionnaire (CTQ) and for functional impairment by the World Health Organization Disability Assessment Schedule (WHO/DAS). The schizophrenia diagnosis was assessed by ICD-10 and DSM-IV criteria according to the Operational Criteria Checklist for Psychotic Illness (OPCRIT).ResultsChildhood trauma in general was associated with increased disability in adulthood, reflected by impaired Overall Behavior (p = .023) and Global Evaluation (p = .032). Analysis of specific traumatic domains revealed that increased childhood physical neglect was associated with functional impairment in Overall Behavior (p < .000), Social Role Performance (p = .037) and Global Evaluation (p = .014). Higher emotional abuse was associated with impaired Overall Behavior (p = .026), and higher emotional neglect with poor Global Evaluation (p = .047). Additionally, earlier onset of illness was associated with lower level of functioning evidenced by impairment in Overall Behavior (p = .042). Linear regression using WHO/DAS sections (Overall Behavior, Social Role Performance and Global Evaluation) as dependent variables and CTQ subscales indicated that only physical neglect had an effect on adult functionality.ConclusionsChildhood trauma was associated with functional and social impairment in adult patients with schizophrenia. Specific types of abuse and neglect, such as physical neglect and emotional abuse and neglect, influenced disability, and the most robust association was physical neglect. Studies involving more patients, with normal controls and additional measurements of biological liability, should be conducted to confirm this association and to increase the understanding of gene-environment relationship in schizophrenia and pathways to disability.Practice implicationsFurther investigation is warranted to clarify the association between childhood trauma and disability in schizophrenia, as well as to develop standardized instruments for the assessment of trauma and earlier detection of risk along with education of patients and families about adequate care, in an effort to reduce the incidence of disability in schizophrenia.