217 research outputs found
Leg dominance and performance in change of directions tests in young soccer players
The present study aimed to examine the influence of leg dominance on the change of direction (COD)
performance. In this study participated 94 healthy young highly trained male soccer players belonging
from two categories (n = 27 vs. n = 67; 14.81 ± 0.40 vs. 16.64 ± 1.25 years of age; 170.61 ± 5.61 vs.
173.73 ± 7.19 cm of height; 64.74 ± 8.44 vs. 66.70 ± 7.95 kg of weight, for U16 and U18, respectively).
Fitness assessments were performed two times in a period of three months, and included: (1)
anthropometry measures, (2) 30–15 IFT, (3) 10-m sprint test, (4) 505-COD test, 90° COD test and
cross-over hop test. A paired sample t-test was performed to evaluate the asymmetries at the
intragroup level in each of the COD’s tests. A symmetry index was used to analyse the asymmetries
between categories, and an independent sample t-test was used to compare the variability between
the two categories in each of the three tests performed. The effect size was also evaluated. Analysis
demonstrated that evidence a trend for a better performance with the preferred leg in the cross-over
hop and 505-COD tests, and with the non-dominant leg in the 90° COD. However, in the intragroup
analysis, only the 505-COD test registered differences, and no differences were notice din the
intergroup comparison. Only in the 505-COD test the percentage of variability (CV) was statistically
significant (7.03 ± 4.18% vs. 4.03 ± 2.02% from U16 and U18, respectively). In sum, bilateral differences
were noticed in the intragroup comparison, although only in 505-COD test the leg dominance
showed to influence performance. In the intergroup analysis any difference was noticed between age
categories
Effects of combined plyometric, strength and running technique training program on change-of-direction and countermovement jump: A two-armed parallel study design on young soccer players
Context and objective: Players must be capable to have a good change-of-direction (COD) skill aiming to be the fastest as possible to react immediately to the opponent or even to help players to be more agile since COD is a physical determinant of agility. Thus, the aim of this study was to test the effects of a six-week combined training intervention in the COD and countermovement jump (CMJ) of young soccer players, while comparing with a control group only performing the regular field-based training sessions.Methods: A sample of 80 non-professional players (40 experimental group and 40 control group) between the ages of ten and twelve was taken [(Age: 10.70 & PLUSMN; 1.02)]. The tests that were carried out from the beginning to the end of the intervention were: CMJ test, 505COD Test and Illinois Test. Paired sample t-test was used for determining differences as a repeated measures analysis (pre- post). An ANCOVA test was performed using the pretest as a covariate and the times pre and post as factors.Results and conclusions: Repeated measures ANCOVA revealed significant influence of baseline level on the 5-0-5 COD (p = 0.001; r/2p=0.170), the Illinois (p = 0.018; r/2p=0.070) and the CMJ (p = 0.047; r/2p=0.050). Significant interactions group*time (p < 0.001; r/2p=0.137), 5-0-5 COD (p < 0.001; r/2p=0.274), and CMJ (p < 0.001; r/2p=0.392) were found, while no significant interactions were found in Illinois (p = 0.293; r/2p=0.014). The current research revealed that a combined training intervention consisting of strength training, plyometrics, and running techniques can be significantly beneficial for improving COD performance and CMJ.Universidad de Granada/CBU
Imagen de ciencia de estudiantes de Magisterio
En este artículo se indaga en la imagen de ciencia de estudiantes de Magisterio de distintas especialidades, posibles futuros docentes de disciplinas científicas en la etapa de Educación Primaria (6-12 años). La investigación, en la que han participado 1260 estudiantes, se realizó durante tres cursos académicos comprendidos entre 2008 y 2011. Basado en el análisis de un cuestionario extraído del INPECIP, este estudio arroja como principales conclusiones que los participantes no poseen un conocimiento claro de cómo se genera y evoluciona el conocimiento científico. Grosso modo, la imagen de ciencia no depende del sexo, de si sus estudios preuniversitarios han guardado relación con disciplinas científicas, ni de la especialidad de Magisterio cursada. Se detectan, no obstante, diferencias de matiz en relación con las tres variables.This article explores the science image of Preservice Prymary Teachers. These,belonging to different degrees program, are going to teach scientific subjects in PrimaryEducation. The research, which involved 1260 students, was conducted over three academicyears, between 2008 and 2011. This study is based on the analysis of a questionnaire modifiedfrom INPECIP. It shows that the participants do not have a clear understanding of howscientific knowledge is generated and evolve. Roughly, the image of science does not depend ongender or if their Secondary studies was related to scientific disciplines. Neither depends onthe specific Primary Teacher Program degree. Nevertheless, nuance differences are detected,and discussed in this paper
Effects of a 10-Week Combined Coordination and Agility Training Program on Young Male Soccer Players
The current literature has shown how working on coordination and agility produces effects
on specific aspects in team sports. The purpose of this study was to examine the effects of a ten-week
coordination training program applied to soccer on different tests that evaluate speed (30 m speed
test), agility (Illinois Agility Test (IAT)) and lower body strength (countermovement jump (CMJ)).
Forty U16 male soccer players from two nonprofessional teams (twenty in the control group (CG)
(aged = 14.70 ± 0.47, body weight = 60.15 ± 8.07 kg, height = 1.71 ± 0.06 m) and twenty in the
experimental group (EG) (aged = 14.50 ± 0.51, body weight = 58.08 ± 9.78 kg, height = 1.69 ± 0.06 m))
performed a combined coordination and agility program during 10 min every training day (3 days a
week) for 10 weeks. The results of this study showed that coordination training produced adaptations
in the power (CMJ of EG (p = 0.001)) and agility capacities (IAT of EG (p = 0.002)) of young soccer
players, but not on speed performance at longer distances (CG, p = 0.20 and EG, p = 0.09). Despite
the benefits of the training program, a combination of training methods that includes power, agility,
speed, and strength can enhance such improvements.Football Connection (FOOC) (Marca No. 4.073.379)
Weekly variations of short-duration maximal jumping performance in soccer players: exploring relationships with accumulated training load and match demands
Purpose: The aim of this study was 2-fold: (1) to analyze variations of short-duration maximal jumping performance in players exposed to a match and those who were not and (2) to analyze the relationships between changes in the short-duration maximal jumping performance and different accumulated training load and match demands measures. Methods: Twenty-four professional soccer players (age: 20.3 ± 1.7 years) were monitored daily for their training load and match demands over 6 weeks. In addition, they performed a weekly short-duration maximal jumping performance test (72 h after the last match). Results: Negative moderate correlations were found between percentage of change of countermovement jump (CMJ) height and Acummulated training load (ATL) of total distance (TD), high metabolic load (HML), accelerations (ACC), and decelerations (DEC) (r = -0.38, p = 0.004; r = -0.33, p = 0.013; r = -0.39, p = 0.003; and r = -0.30, p = 0.026). No correlations were found for match load (ML). TD, HML, ACC, and DCC (r = 0.27, r = 0.25, r = 0.31, and r = 0.22, respectively) were used to predict the percentage of change of CMJ height. Conclusion: Match participation has negative effects on CMJ performance. The ATL of HML, ACC, DCC, and TD have a significant influence on both CMJ measures changes. Also, the ATL values of those metrics are the best predictors of the percentage changes of CMJ performance
Organic carbon and environmental quality of riverine and off-shore sediments from the Gulf of Cádiz, Spain
6 páginas, 2 figuras, 3 tablas, 14 referencias.-- [email protected] we show that heavy metal geoaccumulation
is apparent in the Tinto and Odiel estuary and, at a
lower magnitude, in off-shore sediments. Values above
probable effects level (PEL) are recorded for As, Cu, Hg,
Pb and Zn in the Tinto and Odiel estuary, for As and Hg in
the associated off-shore sediments and for As in the Guadiana
River. Significant correlations were found between
total organic carbon (TOC) and Cr, Cu, Ni and Zn in the
Tinto and Odiel estuary, and Cr, Cu, Ni, Pb, Hg and As in
the Guadiana River. PCA analysis differentiated the three
studied locations.Peer reviewe
Organic carbon and environmental quality of riverine and off-shore sediments from the Gulf of Cádiz, Spain
6 páginas, 2 figuras, 3 tablas, 14 referencias.-- [email protected] we show that heavy metal geoaccumulation
is apparent in the Tinto and Odiel estuary and, at a
lower magnitude, in off-shore sediments. Values above
probable effects level (PEL) are recorded for As, Cu, Hg,
Pb and Zn in the Tinto and Odiel estuary, for As and Hg in
the associated off-shore sediments and for As in the Guadiana
River. Significant correlations were found between
total organic carbon (TOC) and Cr, Cu, Ni and Zn in the
Tinto and Odiel estuary, and Cr, Cu, Ni, Pb, Hg and As in
the Guadiana River. PCA analysis differentiated the three
studied locations.Peer reviewe
Testing variations of methodological characteristics in the 5-0-5 test: impact of the linear sprint on change-of-direction deficit in adult male soccer players
Purpose. The study compared the change-of-direction deficit (CODD) using the first 10-m sprint of a 40-m sprint test (CODDoriginal), the 10-m time that precedes the 5-0-5 test (CODD5-0-5start), and the best 10-m split of a 40-m sprint test (CODDbest).
Methods. A cross-sectional study design was applied. Twenty elite male soccer players (age: 21.6 ± 2.0 years; experience: 8.7 ± 2.3 years; body mass: 73.2 ± 6.1 kg; stature: 174.8 ± 4.5 cm) voluntarily participated in this study. They were assessed in the following tests: (i) 40-m linear sprint test and (ii) 5-0-5 test with a pre-planned 180° change-of-direction (COD) (left and right sides). CODD for both sides was calculated as the difference between average 5-0-5 and CODDoriginal, COODbest, and CODD5-0-5start.
Results. The time over 10 m during the 30–40-m split of a 40-m sprint test was significantly shorter than the first 10 m of the same sprint test (best times: p 0.999, d = 0.133; average times: p = 0.990, d = 0.047). Comparisons of CODD revealed significant differences between approaches (best times: F = 201.7, p 0.05).
Conclusions. CODD calculated with the first 10 m and the best 10 m of a sprint test was significantly different; similarities existed between the initial 10 m of a 40-m sprint test and the 5-0-5 test. Therefore, to save time and resources, practitioners could use the first 10-m acceleration phase of the 5-0-5 since no significant differences were found between the initial 10 m of a linear sprint test
a cohort design
Background and Objectives: The aim of this study was twofold: (i) to observe the individual results of fitness status [countermovement jump (CMJ)], hop test, linear sprinting time, stride frequency, stride distance, force–power–velocity, peak power maximal and maximal speed, and repeated sprint ability (RSA) and functional performance (overhead squat, single-leg squat test, dumbbell hip-hinge, Thomas test, hip extension, and internal and external hip rotators) and (ii) to analyze the relationship between anthropometrical measures and values of fitness status with % of difference in the Thomas test, hip extension, and internal and external hip rotators. Materials and Methods: The study followed a cohort design. Sixteen female soccer players competing in the second division of the Spanish league were monitored during the first days of the pre-season. These players were evaluated three times during the preseason of the cohort period. The dataset showed a negative moderate correlation between time and percentage of difference in hip angle and another positive moderate
correlation between maximal sprint and percentage of difference in hip angle (r = 0.54, p = 0.02 and r = 0.53, p = 0.04), respectively. The correlations of stride time and distance with hip extension are interesting, as professional soccer players should have higher levels of hip flexor flexibility during the stride phase, recoil of the instep kick action.9E1A-F9DD-3EB8 | Filipe Manuel ClementeN/
Effect of Physical Exercise Program Based on Active Breaks on Physical Fitness and Vigilance Performance
The scientific literature has shown the beneficial effects of chronic Physical Exercise (PE) on a wide range of tasks that involve high-order functioning. For this reason, the present study aimed to investigate the effects of active breaks on physical fitness and vigilance performance in high school students through eight weeks of physical training. A total of 42 healthy students (age = 16.50 ± 0.59 years; height = 171.08 ± 8.07 cm; weight = 67.10 ± 13.76 kg) from one Andalusian high school (Spain) were assigned for convenience and matched into two groups, a Control Group (CG) and an Active-Break Group (ABG). The ABG performed two active breaks (based on strength and self-loading exercises) during the school day, first at 10:00 a.m. and second at 12:30 p.m. The participants were assessed before and after the training program using the Alpha-Fitness test battery and the Psychomotor Vigilance Task (PVT). Significant differences were observed in the post-training PVT results, compared with the pretraining PVT, showing ABG responding faster than CG. Thus, the presents study demonstrated that eight weeks of physical training affects vigilance performance (compared to CG) and improves the efficiency of vigilance in high school students, contributing to enhancement of quality of education.The research was supported by the Consejería de Educación, Cultura y Deportes de Castilla-La Mancha, co-financed with European Union ERDF funds, under Grant number: SBPLY/19/1805001/000147). This work is part of a two-year project entitled “Active Breaks Influence on Attentional Primary School Students”
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