scholarly journals Influence of Aerobic Power on Youth Players’ Tactical Behavior and Network Properties during Football Small-Sided Games

Sports ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 73 ◽  
Author(s):  
Gibson Moreira Praça ◽  
Raphael Brito e Sousa ◽  
Pablo Juan Greco

(1) Background: This study aimed to compare the incidence of tactical principles, the percentage of successful tactical principles, and the network properties between higher and lower aerobic power in young football players during small-sided games. (2) Methods: Eighteen Under-17 Brazilian players were recruited. Firstly, they performed the Yo-Yo Intermittent Recovery Test Level 2, which was used to split them into two groups with higher and lower aerobic power. In the sequence, they played three vs three small-sided games within each group. The System of Tactical Assessment in Soccer was used to analyze the tactical behavior demonstrated by measuring the incidence of tactical principles and the percentage of successful principles, while the macro variables, density and clustering coefficient from social network analysis for team sports was used to analyze players’ interactions. (3) Results: No differences were reported for the incidence of tactical principles (p > 0.05, small or small-to-moderate effect sizes), the percentage of successful offensive principles (p = 0.122, small-to-moderate effect size), or the network variables (p > 0.05; small effect sizes). The lower aerobic power group demonstrated a higher percentage of successful defensive tactical principles (p = 0.043; small-to-moderate effect size). (4) Conclusions: We concluded that aerobic power has a limited impact on player behavior, indicating that players’ actions within a small-sided game are mostly constrained by other parameters.

2016 ◽  
Vol 38 (5) ◽  
pp. 441-457 ◽  
Author(s):  
Jean-Charles Lebeau ◽  
Sicong Liu ◽  
Camilo Sáenz-Moncaleano ◽  
Susana Sanduvete-Chaves ◽  
Salvador Chacón-Moscoso ◽  
...  

Research linking the “quiet eye” (QE) period to subsequent performance has not been systematically synthesized. In this paper we review the literature on the link between the two through nonintervention (Synthesis 1) and intervention (Synthesis 2) studies. In the first synthesis, 27 studies with 38 effect sizes resulted in a large mean effect (d = 1.04) reflecting differences between experts’ and novices’ QE periods, and a moderate effect size (d = 0.58) comparing QE periods for successful and unsuccessful performances within individuals. Studies reporting QE duration as a percentage of the total time revealed a larger mean effect size than studies reporting an absolute duration (in milliseconds). The second synthesis of 9 articles revealed very large effect sizes for both the quiet-eye period (d = 1.53) and performance (d = 0.84). QE also showed some ability to predict performance effects across studies.


2013 ◽  
Vol 23 (6) ◽  
pp. 554-561 ◽  
Author(s):  
Kagan J. Ducker ◽  
Brian Dawson ◽  
Karen E. Wallman

Beta-alanine supplementation has been shown to improve exercise performance in short-term, high-intensity efforts.Purpose:The aim of this study was to assess if beta-alanine supplementation could improve 800 m track running performance in male recreational club runners (n = 18).Methods:Participants completed duplicate trials (2 presupplementation, 2 postsupplementation) of an 800 m race, separated by 28 days of either beta-alanine (n = 9; 80 mg·kg−1BM·day−1) or placebo (n = 9) supplementation.Results:Using ANCOVA (presupplementation times as covariate), postsupplementation race times were significantly faster following beta-alanine (p = .02), with post- versus presupplementation race times being faster after beta-alanine (–3.64 ± 2.70 s, –2.46 ± 1.80%) but not placebo (–0.59 ± 2.54 s, –0.37 ± 1.62%). These improvements were supported by a moderate effect size (d = 0.70) and a very likely (99%) benefit in the beta-alanine group after supplementation. Split times (ANCOVA) at 400 m were significantly faster (p = .02) postsupplementation in the beta-alanine group, compared with placebo. This was supported by large effect sizes (d = 1.05–1.19) and a very likely (99%) benefit at the 400 and 800 m splits when comparing pre- to postsupplementation with beta-alanine. In addition, the first and second halves of the race were faster post- compared with presupplementation following beta-alanine (1st half –1.22 ± 1.81 s, likely 78% chance of benefit; 2nd half –2.38 ± 2.31 s, d = 0.83, very likely 98% chance of benefit). No significant differences between groups or pre- and postsupplementation were observed for postrace blood lactate and pH.Conclusion:Overall, 28 days of beta-alanine supplementation (80 mg·kg-1BM·day-1) improved 800 m track performance in recreational club runners.


2021 ◽  
Vol 11 (10) ◽  
pp. 4390
Author(s):  
Carlos Sosa ◽  
Alberto Lorenzo ◽  
Juan Trapero ◽  
Carlos Ribas ◽  
Enrique Alonso ◽  
...  

The aim of this study was (I) to establish absolute specific velocity thresholds during basketball games using local positional system (LPS) and (II) to compare the speed profiles between various levels of competitions. The variables recorded were total distance (TD); meters per minute (m·min); real time (min); maximum speed (Km h−1), distance (m), percentage distance, and percentage duration invested in four speed zones (standing–walking; jogging; running; and high-speed running). Mean and standard deviation (±SD) were calculated, and a separate one-way analysis of variance was undertaken to identify differences between competitions. TD (3188.84 ± 808.37 m) is covered by standing–walking (43.51%), jogging (36.58%), running (14.68%), and sprinting (5.23%) activities. Overall, 75.22% of the time is invested standing–walking, jogging (18.43%), running (4.77%), and sprinting (1.89%). M·min (large effect size), % duration zone 2 (moderate effect size); distance zone 4 (large effect size), and % distance zone 4 (very large effect size) are significantly higher during junior than senior. However, % distance zone 1 (large effect size) and % duration zone 1 (large effect size) were largely higher during senior competition. The findings of this study reveal that most of the distance and play time is spent during walking and standing activities. In addition, the proportion of time spent at elevated intensities is higher during junior than in senior competition.


SAGE Open ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 215824402092059 ◽  
Author(s):  
Keith John Lay ◽  
Mehmet Ali Yavuz

This study investigates the effect of grammar-focused hands-on in-class data-driven learning (DDL) with a heavily contextualized corpus on the frequency of written errors attributable to common interlingual interference issues in low–intermediate Turkish learners ( n = 30) of English. Items representing the most common Turkish-to-English interlingual errors were selected through a two-step process involving the analysis of past studies and a subsequent ranking survey of teachers ( n = 10) of Turkish learners of English. Participants’ grammar development in terms of types of written errors was measured over a ten-week period through written tasks in a pre/posttest design, producing 19,328 words for analysis. The results, although variable by item, suggest that targeted DDL with the TED Corpus Search Engine (TCSE) helps reduce written errors in Turkish learners of English to a significant degree with a moderate effect size. Consequently, the investigation of DDL with the TCSE for the targeting of interlingual interference in other first-language contexts is recommended.


1989 ◽  
Vol 68 (3) ◽  
pp. 739-746 ◽  
Author(s):  
Richard de Lisi ◽  
Gowri Parameswaran ◽  
Ann V. McGillicuddy-Delisi

Girls and boys from Grades 4 ( ns = 15) and 9 ( ns = 15 and 16) in Bombay, India were individually administered water-level and crossbar assessments of horizontality representation. Ninth graders were more successful than fourth graders, especially on trials in which the apparatus was obliquely rotated. Ninth graders, however, did not perform at ceiling levels, and a sex difference with a moderate effect size favoring male over female adolescents was obtained for the water-level task. These findings of both developmental and individual differences in horizontality performance replicate previous findings in Western cultures.


Methodology ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 224-240
Author(s):  
David M. LaHuis ◽  
Daniel R. Jenkins ◽  
Michael J. Hartman ◽  
Shotaro Hakoyama ◽  
Patrick C. Clark

This paper examined the amount bias in standard errors for fixed effects when the random part of a multilevel model is misspecified. Study 1 examined the effects of misspecification for a model with one Level 1 predictor. Results indicated that misspecifying random slope variance as fixed had a moderate effect size on the standard errors of the fixed effects and had a greater effect than misspecifying fixed slopes as random. In Study 2, a second Level 1 predictor was added and allowed for the examination of the effects of misspecifying the slope variance of one predictor on the standard errors for the fixed effects of the other predictor. Results indicated that only the standard errors of coefficient relevant to that predictor were impacted and that the effect size for the bias could be considered moderate to large. These results suggest that researchers can use a piecemeal approach to testing multilevel models with random effects.


2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S197-S198
Author(s):  
J Pulley ◽  
D Galloway ◽  
Y Oh ◽  
J Devine ◽  
H Petrek ◽  
...  

Abstract Background The UC-PRO/SS tool developed by the IBD PRO Consortium is undergoing FDA Drug Development Tool qualification (COA DDT# 000040). Derivation of minimal clinically important difference (MCID) thresholds for improvement in bowel and functional signs and symptoms domain scores are presented here. Methods MCID estimates for bowel and functional domains were derived using anchor- and distribution-based approaches applied to data from three studies of Etrolizumab. Initial MCIDs were developed using Mayo Clinic Score (MCS) and Inflammatory Bowel Disease Questionnaire (IBDQ) response thresholds as anchors; Cronbach’s alpha SEM and Cohen’s moderate effect size statistics were calculated. MCIDs were then cross-validated internally and externally, i.e. within and across target populations, using clinical (modified and partial MCS) and patient-centered (IBDQ “general wellness” item 10 and EQ5D VAS) measures, to support generalizability. CDF plots with pooled data provide further empirical support. Results Study populations had mean ages of 39.2–40.5 years; were 54.5–58% male; 77.5–93.9% white; and had mean disease duration of 8.75–8.98 years. Six points was selected as the bowel domain threshold as change of this magnitude aligns with the anchor settings (5.89, 6.93, and 7.15 for IBDQ and 5.63, 6.12, and 7.63 for MCS) and exceeds measurement error as shown by distributional methods (Cronbach’s alpha SEM 2.071, 2.160, and 2.167, Cohen’s moderate effect size range 2.086, 2.135, and 2.191). A two-point threshold was similarly selected for the functional domain based on anchor settings (1.77, 1.98, and 2.53 for IBDQ and 1.56, 1.68, and 2.01 for MCS) and distributional methods (Cronbach’s alpha SEM 1.336,1.140, and 1.417, Cohen’s moderate effect size range 1.204, 1.270, and 1.309). External, cross-validation showed numerically robust differences (no overlapping CI’s) between the group achieving the MCID versus not across clinical and PRO variables for both domains. Magnitudes of change on IBDQ item 10 and EQ5D VAS variables scores exceeded the ½ SD for interpreting moderate levels of PRO score change. For the bowel domain, separation of CDF curves between responder groups showed cumulative percentages of approximately 60% and 70% based on IBDQ and MCS anchors, respectively, at the thresholds indicating change of a six-point magnitude. For the functional domain, separation between CDF curves at the 2-point threshold occurred at points indicating cumulative proportions of response greater than 50% using both anchors. Conclusion MCIDs of 6 and 2 points for the bowel and functional domains of the UC-PRO/SS are robustly defined and cross-validated, allowing interpretation of clinical improvement in symptoms among moderate to severe adult UC patients.


Author(s):  
André Filipe Paulino da Silva Bento ◽  
Luis Carrasco Páez ◽  
Armando Manuel de Mendonça Raimundo

Purpose: This review aimed to evaluate the utility of high-intensity interval training (HIIT) programs integrated into physical education classes. Method: Searches of electronic databases from January 2008 to March 2020. Inclusion criteria: Applied to adolescents aged 10–19 years; applied in school settings; reported results on physical fitness, physical activity (PA), and motivation; at least for 4 weeks; and randomized controlled trials. Studies with adolescents with physical or intellectual limitations were excluded, as well as other interventions parallel to HIIT. Results: Fourteen studies were included. All works present significant improvements in physical fitness and PA. Improvements in body composition recorded, at most, a moderate effect size. HIIT is presented as a powerful stimulus on cardiorespiratory fitness. Improvements in PA registered, a least, a moderate effect size. Conclusions: HIIT in the school context has great potential in improving physical fitness and PA in adolescents. HIIT efficiency (about 10 min) reflects the wide applicability that these protocols can have in physical education classes and great adaptation to the facilities.


2014 ◽  
Vol 8 (2) ◽  
pp. 7-15 ◽  
Author(s):  
Matevž Rašković

Abstract This paper measures the cultural effect size across five types of leadership practices by using the Leadership Practice Inventory (LPI) instrument and drawing on the GLOBE research project framework. It tests cultural universality vs. contingency in five LPI leadership practices in an East-West EU comparison, both with an ex-socialist past. It employs four different effect size statistics. The paper contributes to the narrowing of the empirical gap in researching leadership practices in a small, East-West European country context. Only two of the five leadership practices show statistically significant effect sizes. Furthermore, the leadership practice Encouraging the heart is the only one to display a relatively moderate effect size. Thus, the evidence seems to support the universalist perspective over the contingency perspective.


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