Rodrigo Santos

Comparing Tactical Behaviour of Soccer Players in 3 vs. 3 and 6 vs. 6 Small-Sided Games

Abstract The present study aimed to compare players’ tactical behaviour in 3 vs. 3 and 6 vs. 6 soccer small-sided games (SSGs). The sample comprised 3,482 tactical actions performed by 18 U-11 youth soccer players from a Portuguese club, in 3 vs. 3 and 6 vs. 6 SSGs. All participants played eight minutes in both situations and field size was adapted according to the number of players involved (30 m x 19.5 m for 3 vs. 3 and 60 m x 39 m for 6 vs. 6). The System of Tactical Assessment in Soccer (FUT-SAT) was used for data collection and analyses. Descriptive analysis was conducted to verify frequencies and percentages of the variables assessed. The chi-squared (χ2) test was performed to compare the frequencies of the variables between 3 vs. 3 and 6 vs. 6 SSGs and Standardized Residuals (e) were used to examine the influence of the frequency of one or more variables within 3 vs. 3 and 6 vs. 6 SSGs. Data treatment was performed through SPSS for Windows®, version 18.0. Results indicated that players displayed safer behaviours in 6 vs. 6 SSG and more aggressive behaviours in 3 vs. 3 SSG. Findings can aid coaches and teachers to develop different players’ tactical skills according to the chosen SSG (3 vs. 3 or 6 vs. 6) form.

Comparison of tactical behaviour and performance of youth soccer players in 3v3 and 5v5 small-sided games

Soccer is a predominantly tactical sport and tactical skills are particularly important for enhancing performance, since the actions are unpredictable, thus forcing players to constantly adapt to the situations. Our aim is to compare the tactical behaviour and performance of soccer players in 3v3 and 5v5 small-sided games (SSGs). The sample comprised 10 U-11 youth soccer players who performed 1,563 tactical actions in both 3v3 and 5v5 SSGs. We used the System of tactical assessment in Soccer (FUT-SAT) to assess players’ tactical behaviour and performance. Descriptive analyses were performed Shapiro-Wilk normality test was conducted T-test for repeated measures and Wilcoxon test were used to compare data between both situations (P<0.05). Significant differences were found in all categories of variables except in the category Tactical Performance Index (TPI). Players performed considerably more frequently the principles of Penetration and Delay in 3v3 and Offensive Unity and Balance in 5v5 SSGs. We concluded that while players’ tactical performance has not changed, 3v3 and 5v5 demand different tactical behaviour from the players. These data can contribute to practice since coaches should take into account the changes in tactical behaviour when considering the number of players in soccer SSGs during training sessions.

Removal of Sodium Dodecylbenzenesulphonate and Cetyltrimethylammonium Bromide Using a Carbon Composite Derived from Modified Zn–Al-Layered Double Hydroxide

We describe the synthesis of a composite carbon derived from zinc–aluminium-layered double hydroxides. The material was characterized by powder X-ray diffraction, Fourier transform infrared/attenuated total reflectance spectroscopy, thermogravimetric analysis–differential scanning calorimetry–mass spectrometry, measurement of BET specific surface area, zeta-potential analysis and scanning electron microscopy. The resulting material was used for adsorption studies with an anionic surfactant, sodium dodecylbenzenesulphonate, and a cationic surfactant, cetyltrimethylammonium bromide, as adsorbates. The adsorption of the surfactants was well described by the typical Langmuir pattern. An investigation of the influence of initial pH of a medium on surfactant adsorption showed that high pH values decrease the adsorption capacity of the adsorbent. The adsorption processes were exothermic. The results also showed that the adsorption of the two surfactants was chemical and that the kinetic models were best described by a pseudo-second-order model.