Effects of re-warm-up protocols on the physical performance of soccer players: A systematic review with meta-analysis.

This systematic review aimed to (1) identify and summarize studies that have examined the effects of re-warm-up (RWU) protocols on the physical performance of soccer players (vertical jump height and sprint time) and (2) establish a meta-comparison between performing a re-warm-up and not performing one regarding the outcomes of the aforementioned outcomes. A systematic review of EBSCO, PubMed, SciELO, SPORTDiscus, and Web of Science databases was performed on 12 January, 2021, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. From the 892 studies initially identified, four studies were reviewed, and three of these were included in the present meta-analysis. Compared to a control condition, there was a moderate effect of RWU on vertical jump height (ES = 0.66; p = 0.001; I2 = 0.0%). However, compared to a control condition, there was a trivial effect of RWU on linear sprint time (ES = 0.19; p = 0.440; I2 = 38.4%). The nature of RWU enhances the performance of players with an emphasis on actions requiring vertical jumps. Therefore, the results provide essential information that soccer coaching staff can use to improve the performance of their teams. The limited number of studies available for the meta-analysis may have magnified the impact of heterogeneity on linear sprint time findings. More high-quality studies, with homogeneous study designs, may help to clarify the potential benefits of RWU for linear sprint time.

Impact of Physical Activity-Based Interventions on Children and Adolescents' Physical Self-Concept: A Meta-Analysis.

Background: Observational studies associate physical activity (PA) with improved perceptions of children and adolescents' physical self-concept (PSC) and global self-concept (GSC). However, only a few PA-based interventions exist for improving PSC and their results have been inconclusive. Objective: To determine the effect of specific PA-based programmes on the PSC (including its sub-dimensions) and GSC of children and adolescents, and to assess possible moderators. Methods: The databases Web of Science, Scopus, SportDiscus, PubMed, CINAHL, and Cochrane Library were reviewed in February 2020. Only studies with pre-post measurements and control groups were included. The impact of PA-based interventions was explored through different meta-analyses and moderator analyses. Results: Altogether, 20 studies were included in the meta-analysis. Positive and significant effects of PA were determined on self-perceived physical appearance (g = 0.13; 95% CI = 0.03, 0.23), self-perceived sport competence (g = 0.30; 95% CI = 0.09, 0.51), self-perceived physical fitness (g = 0.19; 95% CI = 0.05, 0.32), PSC (g = 0.31; 95% CI = 0.10, 0.52), and GSC (g = 0.17; 95% CI = 0.01, 0.33). The existence of additional interventions in PA-based programmes (e.g., interventions focused on psychological factors or healthy habits) moderated the influence of PA on self-perceived sport competence and physical fitness. Moreover, environment and time were distinguished as moderators for self-perceived physical appearance and sport competence. Further, intervention type, gender, and frequency of intervention moderated the effects of PA on PSC. Conclusions: PA-based interventions, especially in school, seem to be beneficial for the development of positive physical self-perceptions.

Diferencias en el autoconcepto entre alumnado con altas capacidades y alumnado general: un metaanálisis desde 2005 hasta 2020 / Differences in self-concept between gifted and non-gifted students: Ameta-analysis from 2005 to 2020

Los estudiantes con altas capacidades, aquellos que presentan una mayor probabilidad de lograr metas extraordinarias en uno o más dominios, generalmente difieren del alumnado general en algunas de las dimensiones del autoconcepto, o la percepción que tiene una persona de sí misma. Sin embargo, la investigación actual sobre altas capacidades ha evolucionado introduciendo nuevos posibles moderadores en estas diferencias por lo que se hace necesaria una actualización sobre el tema. El objetivo del presente metaanálisis (referencia: CRD42018094723) fue sintetizar los estudios desde 2005 sobre las diferencias en el autoconcepto entre estudiantes con altas capacidades y alumnado general. Los resultados mostraron que los alumnos con altas capacidades presentan niveles superiores de autoconcepto global y académico, especialmente el matemático. Sin embargo, no se hallaron diferencias en autoconceptos conductual y emocional, y hubo puntuaciones levemente más bajas en autoconcepto social. En el autoconcepto físico, estos estudiantes puntúan notablemente más bajo que el alumnado general. Las diferencias en esta subdimensión están moderadas por los procedimientos de identificación, la procedencia y la edad, por lo que se sugieren que los estereotipos sociales acerca de las altas capacidades, así como los hábitos de actividad física podrían estar detrás de las dichas diferencias.(AU)

Gifted students (i.e., those who are more likely to achieve ex-traordinary goals in one or more domains) generally differ from the non-gifted students in some of the dimensions of self-concept (i.e., a person's perception of him/herself). However, the current research on giftedness has evolvedto introduce new possible moderators of these differences so it has become necessary to carry out an update on the topic. The aim of the present meta-analysis (reference: CRD42018094723) was to synthesise the studies since 2005 on differences in self-concept between gifted and non-gifted students. The results showed that gifted students have higher levels of general and academic self-concept, especially in math self-concept. However, no differences were found in behavioural and emotion-al self-concepts, andonly slightly lower scores in social self-concept. In physical self-concept they scored significantly lower than non-gifted stu-dents. The differences in this sub-dimension are moderated by identifica-tion procedures, geographical area, and age, so it is suggested that social stereotypes about giftedness as well as physical activity habits may be some of the reasons for these differences.(AU)

Active School Breaks and Students' Attention: A Systematic Review with Meta-Analysis.

School physical activity breaks are currently being proposed as a way to improve students' learning. However, there is no clear evidence of the effects of active school breaks on academic-related cognitive outcomes. The present systematic review with meta-analysis scrutinized and synthesized the literature related to the effects of active breaks on students' attention. On January 12th, 2021, PubMed, PsycINFO, Scopus, SPORTDiscus, and Web of Science were searched for published interventions with counterbalanced cross-over or parallel-groups designs with a control group, including school-based active breaks, objective attentional outcomes, and healthy students of any age. Studies' results were qualitatively synthesized, and meta-analyses were performed if at least three study groups provided pre-post data for the same measure. Results showed some positive acute and chronic effects of active breaks on attentional outcomes (i.e., accuracy, concentration, inhibition, and sustained attention), especially on selective attention. However, most of the results were not significant. The small number of included studies and their heterogeneous design are the primary limitations of the present study. Although the results do not clearly point out the positive effects of active breaks, they do not compromise students' attention. The key roles of intensity and the leader of the active break are discussed. INPLASY registration number: 202110054.

Body Dissatisfaction in Adolescents: Differences by Sex, BMI and Type and Organisation of Physical Activity.

The aim of this study was to assess the differences in body dissatisfaction (BD) of male and female adolescents by body max index (BMI) and the quantity, type and organisation of physical activity (PA). To do so, 652 adolescents aged 12-17 years participated in a cross-sectional study. The cognitive-affective component of BD was assessed with the Body Shape Questionnaire (BSQ) and the perceptual component with Gardner's scale for the assessment of, body image (BI). PA was measured with the International Physical Activity Questionnaire (IPAQ-SF) and the item 1 from the Physical Activity Questionnaire for Adolescents (PAQ-A). The results show that sex and BMI are key variables when determining BD. Moderate-to-vigorous PA (MVPA) was moderately associated with a greater body satisfaction in males but no association was found between BD and the participation and organisation of PA. Moreover, the results suggest that participants in aesthetic/lean PA are at a higher risk of suffering from BD than participants in other PA types. These findings provide useful information for the design of programmes promoting healthy lifestyles, weight control and BI concern during the school period.

Effect of Physical Activity on Self-Concept: Theoretical Model on the Mediation of Body Image and Physical Self-Concept in Adolescents.

Objective: The aim of this research was to study the mediation of body dissatisfaction, physical self-concept, and body mass index (BMI) on the relationship between physical activity and self-concept in adolescents. Materials and Methods: A sample of 652 Spanish students between 12 and 17 years participated in a cross-sectional study. Physical self-concept and general self-concept were assessed with the Physical Self-Concept Questionnaire (CAF), body dissatisfaction with the Body Shape Questionnaire (BSQ), and physical activity was estimated with the International Physical Activity Questionnaire (IPAQ-SF). BMI was utilized as a measurement of body composition. Structural equation modeling was used to assess the results. Results: The resulting models showed good fit indexes. Final model for all participants explained the 17% of the variance of body dissatisfaction, 57% of physical self-concept, and 60% of general self-concept. Physical activity had a positive and indirect effect on self-concept (ß = 0.29, p < 0.01) and direct effects on body dissatisfaction (ß = -0.26, p < 0.01) and physical self-concept (ß = 0.20, p < 0.01). BMI had a direct effect on body dissatisfaction (ß = 0.31, p < 0.01) and on physical self-concept (ß = -0.10, p < 0.01) and an indirect effect on general self-concept (ß = -0.24, p < 0.01). However, it was only associated with physical activity in males, playing a mediating role between physical activity and body dissatisfaction. Conclusion: Physical activity can help individuals to achieve a positive self-concept and promote psychological well-being in adolescents through the improvement of physical perceptions and body satisfaction. The importance of BMI, body dissatisfaction, and physical self-concept on the configuration of the self-concept is also emphasized. Educational policymakers and Physical Education teachers should implement strategies to promote physical activity in the schools and provide a Quality Physical Education programs to increase physical activity during adolescence.