Validity and reliability of a 6-a-side small-sided game as an indicator of match-related physical performance in elite youth Brazilian soccer players

ABSTRACT

The aims of this study were: (i) to compare the external and internal load during a 6-a-side small-sided game (6v6-SSG) according to age-group; (ii) to relate these parameters between the 6v6-SSG and official matches; and (iii) to test the reliability of the 6v6-SSG. A total of 51 Brazilian youth soccer players participated in this study (U11 [n = 16]; U13 [n = 10]; U15 [n = 9]; U17 [n = 8]; U20 [n = 8]). Three experiments were conducted. Experiment A: fifty-one U11 to U20 players were submitted to 6v6-SSGs (n = 10 games; two for each age-group). Experiment B: thirty-two players were randomized to also play official matches (n = 6 matches). Experiment C: thirty-five youth players played the 6v6-SSG twice for test and retest reliability analysis. External load was obtained using Global Positioning Systems and the internal load parameter was calculated through mean heart rate. Statistical approaches showed progressive increases in all parameters according to categories (U11< U13< U15< U17< U20; p < 0.05; ES = 0.42?23.68). Even controlling for chronological age, all parameters showed likely to almost certain correlations between 6v6-SSG and official matches (r = 0.25?0.92). Collectively, the proposed protocol indicates good reliability (CV% = 2.0?12.6; TE% = 2.3?2.7%; ICC = 0.78?0.90). This research suggests that the 6v6-SSG is an alternative tool to indicate match-related physical performance in youth soccer players.     

Social Physique Anxiety and Intention to Be Physically Active: A Self-Determination Theory Approach

Purpose: Based on self-determination theory, the purpose of this study was to analyze the relationship between social physique anxiety and intention to be physically active, while taking into account the mediating effects of the basic psychological needs and behavioral regulations in exercise. Method: Having obtained parents' prior consent, 390 students in secondary school (218 boys, 172 girls; M_age = 15.10 years, SD = 1.94 years) completed a self-administered questionnaire during physical education class that assessed the target variables. Preliminary analyses included means, standard deviations, and bivariate correlations among the target variables. Next, a path analysis was performed using the maximum likelihood estimation method with the bootstrapping procedure in the statistical package AMOS 19. Results: Analysis revealed that social physique anxiety negatively predicted intention to be physically active through mediation of the basic psychological needs and the 3 autonomous forms of motivation (i.e., intrinsic motivation, integrated regulation, and identified regulation). Conclusion: The results suggest that social physique anxiety is an internal source of controlling influence that hinders basic psychological need satisfaction and autonomous motivation in exercise, and interventions aimed at reducing social physique anxiety could promote future exercise.     

Effects of replica running shoes upon external forces and muscle activity during running

Abstract

Twelve participants ran (9 km · h^?1) to test two types of running shoes: replica and original shoes. Ground reaction force, plantar pressure and electromyographic activity were recorded. The shoes were tested randomly and on different days. Comparisons between the two experimental conditions were made by analysis of variance (ANOVA) test (P ≤ 0.05). The time to first peak, loading rate of the first peak and impulse of the first 75 ms of stance were significantly different between the shoes (P ≤ 0.05), revealing an increase of impact forces for the replica shoes. The peak plantar pressure values were significantly higher (P ≤ 0.05) when wearing replica shoes. During running, the contact area was significantly smaller (P ≤ 0.05) for the replica shoe. The electromyographic activity of the analysed muscles did not show changes between the two shoes in running. These findings suggest that the use of replica running shoes can increase the external load applied to the human body, but may not change the muscle activity pattern during locomotion. This new mechanical situation may increase the risk of injuries in these movements.     

PART III: KINANTHROPOMETRY

Whole-body bone mineral density and bone mineral mass in young adult rugby union players.     

Italian technical literature in the field of architectural restoration: The case study of the Historic Memories about the Vatican Church by Giovanni Poleni

This paper provides a theoretical, methodological, and practical contribution to the debate about strategies for the divulgation of the Italian technical literature of the eighteenth century in English-speaking countries with attention to the Italian universities and cultural institutions of the time. The paper contains a survey of the historical bibliography of contemporary translations of non-technical treatises of architecture in the English language and it proceeds to draw up a set of guidelines (decalogue) of different recently proposed methodologies and strategies. It describes the selection of the treatise to translate, relevant to the context and authoritative knowledge in the European scientific background of the eighteenth century; it continues by proposing a synopsis of the original text in the Italian modern language, a strategy used in order to make historical technical treatises accessible to the contemporary scientific Italian language. Approaches and strategies are experimented with in the case study of Historic Memories about the Great Dome of the Vatican Church (Le Memorie Istoriche della Gran Cupola Vaticana) by Giovanni Poleni, one of the most authoritative scholars of eighteenth-century Europe.     

Behavioral heat intake as a function of reward duration in rats

Animals working for heat in a cold environment increase responding when reward duration is reduced, but in many instances the increase in responding is not sufficient to prevent a decrease in the amount of heat obtained. Eight experiments were conducted to investigate the reason why rats’ barpress responses for heat are less efficient at short reward durations. The results show that a ceiling effect is not involved and also that improper response-topography or differences in whole-body heat absorptivity or in response effort cannot explain the phenomenon. Evidence was found for the hypothesis that response rate does not increase sufficiently at short reward durations because many short rewards produce a greater afferent signal than do few long rewards. This inequality seems to be caused by characteristics of the stimuli that result in a greater relative change in skin temperature (ΔT) or in the rate of change of skin temperature (δT/δt) for short-duration rewards.     

Inclusion and Diversity from Hegelylacan Point of View: Do We Desire Our Desire for Change?

This paper discusses the problem of social exclusion, reported to be intrinsically connected to mathematical teaching from the perspective of Hegel's philosophy and Lacan's psychoanalysis. It provides a characterization of mathematics from a language viewpoint discusses the perennial demand for more mathematical achieving from the perspective of hysterics and obsessive symptoms and shows how desire is linked with the choice of values in assessment.     

“American Chimera: The Ever-Present Domination of Whiteness,Patriarchy, and Capitalism…A Parable”

In Greek mythology, the Chimera is a fire-breathing monster with three heads: one of a lion, one of a horned goat, and one of a powerful dragon. Of similar construction is the presence of three structures in US society, whiteness, patriarchy, and capitalism, which are overwhelmingly represented, valued, and espoused when examining areas of progress, i.e., family income, poverty rates, high school and college graduation rates, and home ownership. This modern American three-headed beast controls, manipulates, and permeates all aspects of US society irrespective of class, culture, or gender. Using critical race theory and critical whiteness studies, this critically interpretive parable draws from the ways in which whiteness, patriarchy, and capitalism function in social, cultural, economic, and educational spheres. The parable tells the story of Sue Libertad and analyzes how this metaphorical Chimera, despite its ubiquity, silently permeates all aspects of her life. Not until a tragic outbreak occurs, does the hegemony of this chimera erodes and Sue.     

Bias-Adjusted Three-Step Latent Markov Modeling With Covariates

Latent Markov models with covariates can be estimated via 1-step maximum likelihood. However, this 1-step approach has various disadvantages, such as that the inclusion of covariates in the model might alter the formation of the latent states and that parameter estimation could become infeasible with large numbers of time points, responses, and covariates. This is why researchers typically prefer performing the analysis in a stepwise manner; that is, they first construct the measurement model, then obtain the latent state classifications, and subsequently study the relationship between covariates and latent state memberships. However, such a stepwise approach yields downward-biased estimates of the covariate effects on initial state and transition probabilities. This article, shows how to overcome this problem using a generalization of the bias-corrected 3-step estimation method proposed for latent class analysis (Asparouhov & Muthén, 2014; Bolck, Croon, & Hagenaars, 2004; Vermunt, 2010). We give a formal derivation of the generalization to latent Markov models and discuss how it can be used with many time points by incorporating it into a Baum–Welch type of expectation-maximization algorithm. We evaluate the method through a simulation study and illustrate it using an application on household financial portfolio change. Our study shows that the proposed correction method yields unbiased parameter estimates and accurate standard errors, except for situations with very poorly separated classes and a small sample.