309 research outputs found

    Effects of short-term strength and jumping exercises distribution on soccer player’s physical fitness

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    The aim of this study was to examine the effects of a short-term (six weeks) preseason strength and jumping exercises distribution program on amateur adult soccer player’s indicators of physical fitness. Twenty male athletes (age 20.1±1.6 years) were randomly divided into two groups that completed a volume-equated training program differing only in exercises distribution: a group that completed three weeks of strength followed by three weeks of plyometric training (TT; n=10) and a group that completed six weeks of combined strength and plyometric drills (S+P; n=10). Athletes completed a triple hop test with the dominant (HOPd) and non-dominant leg (HOPnd), a 15 meters sprint, a change of direction speed (CODS) test (i.e. T test), and a 6×30 meters repeated sprint with change of direction for the best (RSCODb) and mean velocity (RSCODm), and the percentage of decrement (%Dec) in sprint time. Moreover, athletes performed a squat test for maximal power. Both strength and jumping training programs were performed two times per week, equated for exercises, frequency, volume, and intensity per session. The TT group completed the strength training volume during the first three weeks, and the plyometric training volume in the last three weeks, while the S+P combined strength and plyometric training during the six weeks. A 2 (group) × 2 (time: pre, post) ANOVA with repeated measures was used for statistical analysis. Analyses revealed significant improvements for the TT and S+P (HOPd: ES=0.91, 10.28 and 16.69%, respectively; HOPnd: ES=0.86, 11.49 and 14.71%, respectively; RSCODb: ES=0.84, 9.23 and 8.34%, respectively; RSCODm: ES=0.89, 8.56 and 7.51%, respectively). In the post-test there were no significant differences between the groups in any variable analyzed. In conclusion, both training approaches were equally effective at improving jumping and repeated sprinting ability. However, only after the S+P training approach a significant improvement in CODS was observed, with more substantial changes in maximal sprinting speed

    Physical performance during soccer-7 competition and small-sided games in U12 players

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    The aim of this study was to compare the activity profile (external loads) during soccer-7 competition versus 6 vs 6 small-sided games ( SSGs) in U12 players. Peak velocity (Vmax), total distance completed (DT), total distance relative to match duration, the percentage of DT in acceleration (%DAC) and in deceleration (%DEA), and the percentage of DT at different speeds were recorded. Six types of SSGs were randomly implemented: without pitch orientation-delimitation and with a limit of three ball-contacts per player (3TOU), with no limit of ball-contacts (MAN), with a greater number of players as internal-offensive wildcard players (2WI) or external-offensive wildcard players (4WE); and with pitch orientation-delimitation and crossing the rival goal-line while dribbling the ball without goalkeepers (INV) or using official goalkeepers (GKP). The physical demands of SSGs were compared with the average of two soccer-7 match plays. During soccer-7 match plays a lower %DAC and %DEA (p < 0.05) were observed compared to 2WI, 4WE, INV and GKP, and to INV and GKP, respectively. The Vmax and %HI were greater (p < 0.05) in soccer-7 match plays compared to all SSGs. In conclusion, the demands imposed on U12 players during different formats of SSGs differ from the soccer-7 match play demands, presenting a low stimulation of the actions performed at high-speed and an adequate simulation of acceleration-deceleration actions

    Soccer small-sided games activities vary according to the interval regime and their order of presentation within the session

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    In order to investigate the physical demands of widely used in soccer small-sided games (SSGs), we compared game variations performed under different interval (fixed or variable) and timing regimens (beginning or end of a training session). Twelve male players wore GPS devices during the SSGs to record total distance, relative distance, distance at different speeds, and maximum velocity variables. Four variations of SSGs (4x4) were randomly applied: beginning of a training session with fixed and variable recovery, or end of a training session with fixed and variable recovery. During the beginning or end of a training session settings with fixed recovery duration, 2-min of playing and 2-min of recovery were provided. During the beginning and end of a training session settings with variable recovery, athletes kept playing until a goal was scored, or up to 2-min if no goals were scored. Results were analysed using MANOVA. Total distance and relative distance were higher in the beginning compared to end of training sessions for both fixed and variable recovery duration (small to moderate effect sizes). Distance at various speed ranges (i.e., 13-18 km/h and >18 km/h) was higher (p = 0.01) at the beginning than at the end of training sessions with variable recovery. In addition, distance >18 km/h was higher at the beginning of a training session with variable recovery than fixed recovery and at the end of a training session with variable recovery than fixed recovery. In conclusion, several physical demand characteristics are affected by the moment of SSG application, while others respond to the recovery regime during SSGs, thus providing indications to the coaches to prescribe the intended training intensity by manipulating the context

    Effects of different post-activation potentiation warm-ups on repeated sprint ability in soccer players from different competitive levels

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    This study aimed to compare the effects of a traditional warm-up with two post-activation potentiation (PAP) warm-up strategies on the repeated sprint ability (RSA) of soccer players from national (NL) and regional (RL) competitive levels. Sixteen young players (NL, n = 8, age = 20.7 +/- 1.4 y, body mass = 68.5 +/- 7.0 kg, body height = 177.4 +/- 5.2 cm; RL, n = 8, age = 20.8 +/- 1.0 y, body mass = 68.7 +/- 4.0 kg, body height = 176.6 +/- 5.6 cm) were recruited to complete a traditional warm-up (CONTROL), a PAP warm-up incorporating squats with a load (similar to 60% 1RM) that allowed a high speed (1 m/s) of movement and a high number of repetitions (PAP-1), and a PAP warm-up with a load (similar to 90% 1RM) that allowed a moderate speed (0.5 m/s) of movement and a reduced number of repetitions (PAP-0.5). A RSA test (six 20-m sprints with 20 s of recovery) was performed 5 min after the PAP warm-up to assess the effects of the different protocols on the fastest sprint (RSAb) and the mean time of all sprints (RSAm). A meaningful improvement of RSA performance was observed with PAP-0.5, attaining a large effect on NL (RSAb, ES = -1.5; RSAm, ES = -1.3) and only a small effect on RL athletes (RSAb and RSAm, ES = -0.2). Moreover, when each RSA sprint performance was compared between NL and RL players, after PAP-0.5 greater performance for all sprints was observed in the NL players. Therefore, adding a heavy strength-based conditioning exercise during the warm-up prior to a RSA test may induce significant performance improvements in NL, but only small effects in RL players

    Post-activation potentiation: effects of different conditioning intensities on measures of physical fitness in male young professional soccer players

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    The aim of this study was to compare the effects of different warm-up conditioning intensities on the physical fitness (i.e., post-activation potentiation -PAP), of professional male field soccer players. Athletes (n = 10; age: 21.6 ± 3.2 years) completed a control warm-up and warm-ups aimed to induce PAP, in random and counterbalanced order. After control and experimental warm-up sessions participants completed a triple hop test with the dominant (H3Jd) and a non-dominant (H3Jnd) leg, a squat jump (SJ), a countermovement jump (CMJ), a change of direction ability (COD) test, a repeated sprint with a COD (RSCOD) test and a linear 30-m sprint test (S-30). The control warm-up (WU) protocol was designed according to athlete's regular warm-up practice. The experimental warm-ups included the same exercises as the WU, with addition of one set of half-back squats for 10 repetitions at 60%, 5 repetitions at 80%, and 1 repetition at 100% of 1RM (60%-1RM, 80%-1RM and 100%-1RM, respectively.) Threshold values for Cohen's effect sizes (ES) were calculated and used for group's comparison. Likely to most likely improvements were shown in H3Jd (ES = 0.52), H3Jnd (ES = 0.51), COD (ES = 0.38), fasted sprint (RSCODb) (ES = 0.58) and the total time of all sprints (RSCODt) (ES = 0.99) only after the 80%-1RM protocol in comparison to the WU. Conversely, 100%-1RM and 60%-1RM protocols, compared to WU, induced possibly to most likely poorer performance in all jumps, COD and RSCODb (ES = -0.07 to -1.03 and ES = -0.48 to -0.91, respectively). Possibly to most likely improvements were shown in all jumps, COD, RSCODb and RSCODt after the 80%-1RM warm-up protocol in comparison to the 100%-1RM and 60%-1RM warm-up protocols (ES = 0.35 to 2.15 and ES = 0.61 to 1.46, respectively). A moderate warm-up intensity (i.e., 80%-1RM back squat) may induce greater PAP, including improvements in jumping, repeated and non-repeated change of direction speed in male soccer players

    Fibronectin fixation on poly(ethyl acrylate)-based copolymer

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    The aim of this paper is to quantify the adhered fibronectin (FN; by adsorption and/or grafting) and the exposure of its cell adhesive motifs (RGD and FNIII7-10) on poly(ethyl acrylate) (PEA) copolymers whose chemical composition has been designed to increase wettability and to introduce acid functional groups. FN was adsorbed to PEA, poly(ethyl acrylate-co-hydroxyethyl acrylate), poly(ethyl acrylate-co-acrylic acid), and poly(ethyl acrylate-co-methacrylic acid) copolymers, and covalently cross-linked to poly(ethyl acrylate-co-acrylic acid) and poly(ethyl acrylate-co-methacrylic acid) copolymers. Amount of adhered FN and exhibition of RGD and FNIII7-10 fragments involved in cell adhesion were quantified with enzyme-linked immunosorbent assay tests. Even copolymers with a lower content of the hydrophilic component showed a decrease in water contact angle. In addition, FN was successfully fixed on all surfaces, especially on the hydrophobic surfaces. However, it was demonstrated that exposure of its cell adhesion sequences, which is the key factor in cell adhesion and proliferation, was higher for hydrophilic surfaces. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.Contract grant sponsors: Centre for Industrial Technological Development (CDTI) of Ministry of Economy and Competitiveness, Project Customized Eye Care-Oftalmologia personalizada _CEYEC CENIT-Sol 00028336 SFPECEPP and Health Institute Carlos III through the CIBER- BBN (Bioingenieria, Biomateriales y Nanomedicina); CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development FundBriz, N.; Antolinos Turpín, CM.; Alio, J.; Garagorri, N.; Gómez Ribelles, JL.; Gómez-Tejedor, JA. (2013). Fibronectin fixation on poly(ethyl acrylate)-based copolymer. Journal of Biomedical Materials Research Part B: Applied Biomaterials. 101B(6):991-997. https://doi.org/10.1002/jbm.b.32907S991997101B6Roach, P., Eglin, D., Rohde, K., & Perry, C. C. (2007). Modern biomaterials: a review—bulk properties and implications of surface modifications. Journal of Materials Science: Materials in Medicine, 18(7), 1263-1277. doi:10.1007/s10856-006-0064-3Schmidt, D. R., Waldeck, H., & Kao, W. J. (2009). Protein Adsorption to Biomaterials. Biological Interactions on Materials Surfaces, 1-18. doi:10.1007/978-0-387-98161-1_1Ertel, S. I., Ratner, B. D., & Horbett, T. A. (1990). Radiofrequency plasma deposition of oxygen-containing films on polystyrene and poly(ethylene terephthalate) substrates improves endothelial cell growth. Journal of Biomedical Materials Research, 24(12), 1637-1659. doi:10.1002/jbm.820241207Way, T.-D., Hsieh, S.-R., Chang, C.-J., Hung, T.-W., & Chiu, C.-H. (2010). Preparation and characterization of branched polymers as postoperative anti-adhesion barriers. Applied Surface Science, 256(10), 3330-3336. doi:10.1016/j.apsusc.2009.12.029Hsieh, S.-R., Chang, C.-J., Way, T.-D., Kwan, P.-C., & Hung, T.-W. (2009). Preparation and Non-Invasive In-Vivo Imaging of Anti-Adhesion Barriers with Fluorescent Polymeric Marks. Journal of Fluorescence, 19(4), 733-740. doi:10.1007/s10895-009-0469-8Lee, M. H., Ducheyne, P., Lynch, L., Boettiger, D., & Composto, R. J. (2006). Effect of biomaterial surface properties on fibronectin–α5β1 integrin interaction and cellular attachment. Biomaterials, 27(9), 1907-1916. doi:10.1016/j.biomaterials.2005.11.003Keselowsky, B. G., Collard, D. M., & Garcı́a, A. J. (2004). Surface chemistry modulates focal adhesion composition and signaling through changes in integrin binding. Biomaterials, 25(28), 5947-5954. doi:10.1016/j.biomaterials.2004.01.062Tzoneva, R., Faucheux, N., & Groth, T. (2007). 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    Effects of high-intensity training with one versus three changes of direction on youth female basketball players' performance

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    To compare the effects of high-intensity interval training (HIT) with one versus three changes of direction (COD) on young (age, 17.2 +/- 1.1 years) female basketball players' performance, six weeks of regular basketball training (control period) was followed by six weeks of high-intensity training added to regular training, two times per week, with a random allocation of athletes to either HIT with one (HIT-COD1; n=6) or three COD (HIT-COD3; n=6). Before and after the control and HIT-COD training periods athletes performed repeated-sprint ability test (RSA), modified agility T-test (MAT), V-cut, triple standing dominant (TS-D) and non-dominant (TS-ND) jump, TS-D and TS-ND with COD tests, and 30-15 Intermittent Fitness Test (30-15(IFT)). With the exception of a substantial improvement in V-cut in both groups, no substantial changes occurred during the control period. Both HIT-COD training programs improved V-cut, although only HIT-COD3 substantially improved RSA mean time (RSA(m)), MAT and the final speed reached in 30-15(IFT) (V-IFT). The between-group comparison revealed greater improvements in RSA(m) and V-IFT in HIT-COD3 than in HIT-COD1. In conclusion, supplementation of basketball training with HIT-COD drills adds improvements to young female basketball player's performance, especially when 3 COD are incorporated into HIT

    Effects of high-intensity training with one versus three changes of direction on youth female basketball players’ performance

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    To compare the effects of high-intensity interval training (HIT) with one versus three changes of direction (COD) on young (age, 17.2±1.1 years) female basketball players’ performance, six weeks of regular basketball training (control period) was followed by six weeks of high-intensity training added to regular training , two times per week, with a random allocation of athletes to either HIT with one (HIT-COD1; n=6) or three COD (HIT-COD3; n=6). Before and after the control and HIT-COD training periods athletes performed repeatedsprint ability test (RSA), modified agility T-test (MAT), V-cut, triple standing dominant (TS-D) and nondominant (TS-ND) jump, TS-D and TS-ND with COD tests, and 30-15 Intermittent Fitness Test (30-15IFT). With the exception of a substantial improvement in V-cut in both groups, no substantial changes occurred during the control period. Both HIT-COD training programs improved V-cut, although only HIT-COD3 substantially improved RSA mean time (RSAm), MAT and the final speed reached in 30-15IFT (VIFT). The between-group comparison revealed greater improvements in RSAm and VIFT in HIT-COD3 than in HITCOD1. In conclusion, supplementation of basketball training with HIT-COD drills adds improvements to young female basketball player’s performance, especially when 3 COD are incorporated into HIT

    Aportación de las personas mayores en los colegios intergeneracionales. La experiencia del proyecto ISCI

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    ISCI es un proyecto de investigación cuyo objetivo es diseñar, pilotar y validar un modelo de colegio intergeneracional en tres centros de Educación Primaria situados en las comunidades de Andalucía y Región de Murcia. Inspirándose en la experiencia acumulada por The Intergenerational School, en Estados Unidos, ISCI se propone impulsar un modelo de colegio intergeneracional elaborado, innovador y basado en evidencias, que pueda recrearse en el contexto educativo español, atravesado, en parte, por el fracaso escolar y la incertidumbre. El artículo describe las tareas y las aportaciones de fondo de los mentores intergeneracionales del proyecto

    Child Head Circumference and Placental MFSD2a Expression Are Associated to the Level of MFSD2a in Maternal Blood During Pregnancy

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    Gestational diabetes mellitus (GDM) is a world-wide health challenge, which prevalence is expected to increase in parallel to the epidemic of obesity. Children born from GDM mothers have lower levels of docosahexaenoic acid (DHA) in cord blood, which might influence their neurodevelopment. Recently, the membrane transporter Major Family Super Domain 2a (MFSD2a) was associated with the selective transportation of DHA as lysophospholipids. The expression of the DHA membrane transporter MFSD2a is lower in GDM placentas, which could affect materno-fetal DHA transport. Humans with homozygous inactivating mutations in the MFSD2a gene present severe microcephaly and intellectual impairments. Herein, we intended to identify early blood biomarkers that may be of use during pregnancy to monitor the offspring development and the adequate nutritional interventions, such as nutritional supplementation, that may be selected to improve it. We evaluated MFSD2a expression in maternal blood at the third trimester of pregnancy, and its potential relationship with the expression of placental MFSD2a at delivery and child outcomes. Three groups of pregnant women were recruited: 25 controls, 23 GDM with dietary treatment, and 20 GDM with insulin treatment. Maternal and neonatal anthropometric and biochemical parameters were evaluated. MFSD2a was analyzed in placenta, blood and serum. MFSD2a protein expression in maternal blood was significantly lower in GDM groups and correlated with placental MFSD2a and Z-score neonatal head circumference during the first 6 months of life. The cord/maternal serum ratio of DHA, a solid indicator of materno-fetal DHA transport, was reduced in GDM groups and correlated with MFSD2a in maternal blood at the third trimester and in placenta at delivery. This indicates that altered MFSD2a levels in maternal blood during pregnancy might influence placental nutrient transport and fetal neurodevelopment. Furthermore, MFSD2a levels in maternal blood on the third trimester were inversely correlated to DHA in maternal serum lyso-PL. Thus, the level of MFSD2a in maternal blood could be used as a potential biomarker for the early detection of disturbances of MFSD2a expression during pregnancy and the subsequent consequences for the neurodevelopment of the child, as well as it may help to choose the optimal treatment approach for the affected subjects
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