Search

© 2020 Elsevier Ltd Background: During the past decade, an extensive body of work has documented the Constraints-Led Approach (CLA) as a prominent methodology for developing collective synergetic tendencies in sports teams. Objectives: This study aimed to quantify and compare findings, in existing research, related to key synergetic properties of dimensional compression and reciprocal compensation in team sports performance. Method: A literature search was conducted for articles published until December 2019, on electronic databases PubMed, Scopus, EBSCO, SPORTDiscus, Web of Science, and Google Scholar. Inclusion criteria were defined before the selection process. From selected articles information was extracted on authors, year of publication, study design, study context, sample, sport, variables assessed, type of constraints manipulated, statistical methods, and main findings. The manuscripts' methodological quality was assessed through the Downs and Black checklist. A meta-analysis was performed using a random-effects model and subgroup analyses were conducted for two potential moderators: dimensional compression and reciprocal compensation. Results: A total of 62 and 26 studies met the inclusion criteria for systematic and meta-analysis, respectively. Results revealed that investigations tended to mostly evaluate how task constraints manipulations shaped emergent tactical behaviors of male football players within training contexts. A high level of heterogeneity (I2 = 99.56%, p < .001) was found across studies and publication biases were observed in the literature. Conclusions: The high level of heterogeneity is possibly justified by the diversity of metrics applied to assess players' performance behaviors. The level of research heterogeneity observed also supports the assumption that variable behaviors enhance adaptive tendencies in teams. Observed publication and inflation biases highlighted the need to adopt methodological procedures that avoid systematic flaws in future investigations.

The use of preclinical models to investigate antitumor effects of exercise on breast tumor (BT) development and progression are critical. However, published results have not been quantitatively summarized or examined for potential exercise-moderating variables. We conducted this review to summarize and quantify the effect-size of exercise on BT outcomes in preclinical studies. A literature search was performed in MEDLINE, PubMed, Web of Science and System for Information on Grey Literature in Europe (SIGLE) databases. Risk of bias was assessed using SYRCLE’s RoB tool. A total of 116 correlations were performed to analyze 28 preclinical studies published through December 2016, which included 2,085 animals and 51 exercise programs. Positive effects of small, medium and large magnitude were observed in tumor incidence, growth and multiplicity, respectively. In the tumor microenvironment, positive effects of large magnitude were also observed in proliferation and apoptosis but not in angiogenesis. Moderator variables correlated with higher intervention effects were identified along with a considerable heterogeneity in exercise protocols that precluded us from clearly perceiving the benefits of exercise exposure. In conclusion, exercise performed under specific conditions benefits BT outcomes. Preclinical studies with exercise designs mimicking exercise exposure that can be used in clinical contexts are needed.

Background:This meta-analysis study aims to assess the efficacy of school-based and after-school intervention programs on the BMIs of child and adolescents, addressing the correlation between some moderating variables.Methods:We analyzed 52 studies (N = 28,236) published between 2000–2011.Results:The overall effect size was 0.068 (P < .001), school (r = .069) and after-school intervention (r = .065). Programs conducted with children aged between 15–19 years were the most effective (r = .133). Interventions programs with boys and girls show better effect sizes (r = .110) than programs that included just girls (r = .073). There were no significant differences between the programs implemented in school and after-school (P = .770). The effect size was higher in interventions lasting 1 year (r = .095), with physical activity and nutritional education (r = .148), and that included 3–5 sessions of physical activity per week (r = .080). The effect size also increased as the level of parental involvement increased.Conclusions:Although of low magnitude (r = .068), the intervention programs had a positive effect in prevention and decreasing obesity in children. This effect seems to be higher in older children’s, involving interventions with physical activity and nutritional education combined, with parent’s participation and with 1-year duration. School or after-school interventions had a similar effect.

Objectives: A quantitative review of the effects of requisite responses and methods of stimulus presentation for assessing decision-making expertise in sport was undertaken. Design: An electronic literature search was conducted in the online databases: SPORTDiscus with Full Text and ISI Web Knowledge All Databases. Articles for analysis were selected according to prior defined criteria. Methods: We considered 111 effect sizes in studies involving 882 expert and non-expert participants. Effect sizes were calculated for six common protocols for measures responses: verbalized knowledge, eye movement measures, decision time, response accuracy, movement accuracy, and movement time. Two moderator variables were also considered to assess effects of research protocols on the dependent variables: “the requisite response” and “stimulus presentation”. A random effect model was used to calculate effect sizes. Results: Analysis of moderator variables suggested that expertise effects were more apparent for “requisite responses” when participants were required to actually perform sporting actions and for “stimulus presentation” under in situ task constraints than for other conditions. Conclusions: Future empirical work on expertise and decision-making needs to consider task representativeness in considering requisite responses of participants in simulating performance environment conditions. Use of representative task constraints with performers required to perform sport actions in in situ conditions appeared the most functional empirical protocols to enhance validity of data.

No clear consensus has been reached regarding the association of IL-10 polymorphisms and periodontitis. Therefore, we performed a meta-analysis of case–control studies and a systemic review in an effort to systematically summarize the existing knowledge. Studies were identified by searching PubMed database until December 2011. IL-10 −1082 (−1087) A>G, −819 (−824) C>T and −592 (−597) C>A polymorphisms were included in the present meta-analysis. We calculated the specific odds ratios along with their 95 % confidence intervals to compare the distribution of alleles and genotypes between cases and controls. An additive “per-allele” model (major allele vs. minor allele) was performed, and dominant and recessive models were also considered. The random-effects model was applied for the analysis. Cumulative analysis was also performed. Heterogeneity and publication bias were assessed. Nine case–control studies involving 841 periodontitis cases (644 chronic periodontitis and 197 aggressive periodontitis cases) and 748 controls were included. We found statistically significant association of IL-10 −819 (−824) C>T and IL-10 −592 (−597) C>A polymorphisms in Caucasians. The IL-10 −819 (−824) T and −592 (−597) A alleles may confer a relative increase in the risk for chronic periodontitis in Caucasians. Future studies may be important to reinforce these findings., This work was partially supported by the PhD grant SFRH/BD/44490/2008 of the Science and Technology Foundation (FCT) from Portugal.

OBJECTIVE: To review the use of accelerometry as an objective measure of physical activity in adults and elderly people. METHODS: A systematic review of studies on the use of accelerometty as an objective measure to assess physical activity in adults were examined in PubMed Central, Web of Knowledge, EBSCO and Medline databases from March 29 to April 15, 2010. The following keywords were used: "accelerometry," "accelerometer," "physical activity," "PA," "patterns," "levels," "adults," "older adults," and "elderly," either alone or in combination using "AND" or "OR." The reference lists of the articles retrieved were examined to capture any other potentially relevant article. Of 899 studies initially identified, only 18 were fully reviewed, and their outcome measures abstracted and analyzed. RESULTS: Eleven studies were conducted in North America (United States), five in Europe, one in Africa (Cameroon) and one in Australia. Very few enrolled older people, and only one study reported the season or time of year when data was collected. The articles selected had different methods, analyses, and results, which prevented comparison between studies. CONCLUSIONS: There is a need to standardize study methods for data reporting to allow comparisons of results across studies and monitor changes in populations. These data can help design more adequate strategies for monitoring and promotion of physical activity. OBJETIVO: Analisar o uso da acelerometria como medida objetiva da atividade física em adultos e idosos. MÉTODOS: Revisão sistemática nas bases PubMed, Web of Knowledge, EBSCO e Medline, de 29 de março a 15 de abril de 2010. As palavras-chave utilizadas na busca foram: "accelerometry", "accelerometer", "physical activity", "PA", "patterns", "levels", "adults", "older adults" e "elderly", isoladamente ou combinadas usando "and" ou "or". As listas de referências dos artigos recuperados foram examinadas para captar artigos potenciais. Dos 899 estudos localizados, 18 foram revistos integralmente, com seus dados extraídos e analisados. RESULTADOS: Onze estudos foram realizados nos Estados Unidos, cinco na Europa, um em Camarões e outro na Austrália. Poucos envolveram idosos, e apenas um referiu a estação ou período do ano em que decorreu a coleta de dados. Os métodos, análises e resultados divergiram entre os estudos, impossibilitando uma análise mais aprofundada. CONCLUSÕES: Deve-se promover a padronização de procedimentos que permitam comparar resultados entre estudos e monitorizar alterações numa população. Esses dados contribuem para a adequação das estratégias de monitoramento e promoção da atividade física. OBJETIVO: Analizar el uso de la acelerometría como medida objetiva de actividad física en adultos y ancianos. MÉTODOS: Revisión sistemática en las bases PubMed, Web of Knowledge, EBSCO y Medline, del 29 de marzo al 15 de abril de 2010. Se utilizaron en la búsqueda las palabras-clave: "accelerometry", "accelerometer", "physical activity", "PA", "patterns", "levels", "adults", "older adults" y "elderly", de forma aislada o combinadas usando "and" o "or". Las listas de referencias de los artículos recuperados fueron examinadas para encontrar artículos potenciales. De los 899 estudios localizados, 18 fueron revisados integralmente, y sus datos extraídos y analizados. RESULTADOS: Once estudios se realizaron en los Estados Unidos, cinco en Europa, uno en Camerún y otro en Australia. Pocos involucraron ancianos, y sólo uno se refirió a la estación o período del año en que transcurrió la colecta de datos. Los métodos, análisis y resultados discreparon entre los estudios, imposibilitando un análisis más a fondo. CONCLUSIONES: Se debe promover la estandarización de procedimientos que permitan comparar resultados entre estudios y monitorear alteraciones en una población. Estos datos contribuyen adecuación de las estrategias de monitoreo y promoción de la actividad física.

Prostate cancer (PCa) is one of the most commonly diagnosed internal malignancies affecting men. Due to the important roles of IL-6 in different physiological and pathophysiological processes, IL-6 polymorphisms may modulate PCa risk. IL-6 −174 G>C (rs 1800795, also designated −236 G>C) and −636 G>C (rs 1800796, also designated −572 G>C) promoter polymorphisms have been implicated in PCa susceptibility, albeit still controversial. A literature search using PubMed and Highwire databases was conducted, resulting in eight case–control studies concerning the IL-6 −174 G>C polymorphism (11,613 PCa cases and 13,992 controls) and four case–control publications regarding the IL-6 −636 G>C polymorphism (1,941 PCa cases and 3,357 controls). In order to derive a more precise estimation, a meta-analysis based upon these selected case–control studies was performed. There was no significant association between IL-6 −174 G>C polymorphism and PCa increased risk. Nevertheless, the presence of allele C and the CC genotype were statistically significantly associated with decreased PCa risk in the overall analysis for IL-6 −636 G>C polymorphism. Additional studies in larger samples and analyses of functional repercussions of these SNPs in prostate tumor cells are necessary to validate these findings.

Age-related DNA damage is regarded as one of the possible explanations of aging. Although a generalized idea about the accumulation of DNA damage with age exists, results found in the literature are inconsistent. To better understand the question of age-related DNA damage in humans and to identify possible moderator variables, a meta-analysis was conducted. Electronic databases and bibliographies for studies published since 2004 were searched. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for age-related DNA damage were calculated in a random-effects model. A total of 76 correlations from 36 studies with 4676 participants were included. Based on our analysis, a correlation between age and DNA damage was found (r = 0.230, p = 0.000; 95% confidence interval = 0.111 - 0.342). The test for heterogeneity of variance indicates that the study´s results are significantly high (Q (75) = 1754.831, p = 0.000). Moderator variables such as smoking habits, technique used, and the tissue/sample analyzed, are shown to influence age-related DNA damage (p=0.026; p=0.000; p=0.000, respectively). Nevertheless, sex did not show any influence on this relation (p=0.114). In conclusion, this meta-analysis showed an association between age and DNA damage in humans. It was also found that smoking habits, the technique used, and tissue/sample analyzed, are important moderator variables in age-related DNA damage.