Umaña Alvarado, Mónica
El artículo también se encuentra escrito en español. The growing participation of young people in soccer is a motivation so that the trainers, physical educators and parents know which are the special requirements to practice this sport in a safe manner, specially the nutritional requirements. The present revision includes generalities on the physiological demands of soccer, the differences between young people and adults when making prolonged exercise, the necessities ...
Barbero Álvarez, José Carlos; Gómez López, Maite; Barbero Álvarez, Verónica; Granda Vera, Juan; Castagna, Carlo
The physical and physiological demands of high-level male soccer have been studied extensively, while few studies have investigated the demands placed on females during match-play, however, there is no information available about the heart rate and activity profile of young female soccer players during match play. Therefore, the aim of this study was to examine cardiovascular (heart-rates HR) and physical demands of young female soccer players during a match. Players were observed during a fr...
Handziska, E; Handziski, Z; Gjorgoski, I; Dalip, M
The relationship between somatotype and cortisol and adrenocorticotropic (ACTH) hormone concentrations at rest or after exercise in adolescent soccer players at different time points throughout a soccer season is not understood. Therefore, the aim of this study was to examine the relationship between somatotype and cortisol and ACTH concentrations at rest and after exercise in adolescent soccer players at different time points during a soccer season. During the first 4 months of the soccer season, 47 soccer players (between 15-17 years of age) were tested at three different time points including at baseline, after 6 weeks, and at the end of 4 months. Testing included anaerobic threshold (AnT, km/h) and maximal speed of running (Max, km/h) were measured with Conconi protocol on treadmill. Before and after a maximal exercise Test, plasma levels of cortisol (ug/dL) and ACTH (pg/ml) were assessed by chemiluminometry enzyme amplificated method. Heath-Carter anthropometric somatotype model was used to determine 13 elements of somatotype. Descriptive statistics and multiple regression were used for statistical analysis (Psoccer training process could indicate a stagnation of training process, accordingly with insignificant changes of AnT. The significant correlations of some somatotypes with stress hormonal responses could only suggest that the somatotype characteristics of young soccer players could be of interest in process of selection and planning of soccer training process with an essential need for more studies.
Antosiak-Cyrak Katarzyna Z.
Full Text Available Purpose. The aim of the present study was assessment of laterality of the legs of young female soccer players and their non-training counterparts. Methods. The study sample comprised 9 female soccer players and 19 non-training girls. They underwent three measurement sessions, one every six months. The applied tests included kinesthetic differentiation, rate of local movements, static balance, single-leg hop, rate of global movements, strength and speed, and functional asymmetry of the legs tests. Results. The soccer players were better than the controls in their performance of the rate of local movements, rate of global movements, kinesthetic differentiation, single-leg 15m timed hop and static balance tests. Smaller differences between the results of the left and the right legs in soccer players, than in non-training girls, were noted in the rate of local movements, rate of global movements and kinesthetic differentiation tests. In the static balance test, the differences were greater in the group of soccer players. Conclusions. Lateralization of the lower limbs is a highly complex characteristic with a different variability in athletes than in nontraining individuals. The results of the present study also point to the specialization of soccer players’ left legs in body balance and single-leg hop tests.
Brito, João; Fontes, Ivo; Ribeiro, Fernando
To investigate the effects of an official soccer match on postural stability in youth elite soccer players.......To investigate the effects of an official soccer match on postural stability in youth elite soccer players....
Leslie Andrews Portes
Full Text Available The objective of this study was to determine anthropometric and physical fitnesscharacteristics of Brazilian male children and adolescents at the beginning of soccer training. Inthis study, 282 male soccer players ranging in age from 10 to 13 years were evaluated. The athletesparticipated in a formal soccer training program 3 times per week, with each training lasting 3hours. Anthropometric and physical fitness parameters were obtained. The boys were divided intoage classes and prevalence data were analyzed using Pearson’s chi-square test. Parametric datawere compared by one-way ANOVA or the Kruskal-Wallis test, when necessary. The resultsare expressed as the mean ± standard deviation and a p value <0.05 was considered to be significant.Growth, development, body adiposity and physical fitness characteristics were adequateand proportional to age among the boys studied (p<0.05. It was concluded that anthropometricand physical fitness characteristics of young male elite soccer players improve with and areproportional to age. Children and adolescents greatly benefit from regular physical activity. Thepresent results show that young male soccer players present adequate anthropometric conditionsand physical fitness prior to the initiation of formal training at soccer clubs.
Fabrícia Geralda Ferreira
Full Text Available The aim of this study was to investigate fluid replacement strategies of young soccer players and their level of knowledge regarding hydration management. A total of 216 males (age: 18 ± 0.9 years playing soccer for 8.7 ± 2.6 years were studied. The participants were members of four elite and subelite Brazilian soccer clubs. An exploratory descriptive study was conducted using a self-administered questionnaire consisting of 18 objective questions. The main results indicated that 32.3% and 30.1% of the athletes do not have an appropriate strategy for fluid replacement during competitions and training, respectively. In addition, 1.4% and 4.6% of the subjects reported to ingest no fluids during these exercise conditions. When asked about the type of solution (water or isotonic solution consumed before, during and after exercise, water was the main fluid ingested during these periods. Approximately 80 athletes only ingest fluids when feeling thirsty. Coca-Cola® accounted for 11.1% of ingested fluids. Only 27.8% of the participants measure their body weight and 54.2% were unaware of the adequate strategy for fluid replacement. The most common symptoms reported by the athletes were cramps (53.2%, intense thirst (37.5%, and headache (33.8%. These results suggest that young soccer players have inappropriate fluid replacement habits, a fact that may lead to low performance during training or competition.
Alvarez-Díaz, Pedro; Alentorn-Geli, Eduard; Steinbacher, Gilbert; Rius, Marta; Pellisé, Ferran; Cugat, Ramón
The purpose of this study was to report the functional outcomes of young active soccer players with lumbar spondylolysis undergoing conservative treatment. Between 2002 and 2004, all soccer players diagnosed with spondylolysis with a minimum 2-year follow-up were retrospectively reviewed. All patients were treated nonoperatively with cessation of sports activity and rehabilitation for 3 months. The rehabilitation protocol was identical for all patients and emphasized strengthening of abdominal muscles, stretching of the hamstrings, "core" stability exercises, and trunk rotational movements in a pain-free basis. Those patients with pain at rest and with daily life activities were also treated with a thoracolumbar orthosis. Symptomatic patients or those with positive SPECT were not allowed to return to sports and continued the rehabilitation protocol for 3 more months. The mean time of cessation of sports activity was 3.9 months (SD 0.8) and 5.2 months (SD 2.1) for a complete return to sports. At the 2-year follow-up, 28 patients (82%) obtained excellent results, 4 (12%) good results, 1 patient (3%) a fair result, and 1 patient (3%) a poor result. Conservative treatment of spondylolysis in young soccer players with cessation of sports and rehabilitation, with or without thoracolumbar orthosis, was associated with excellent functional results in terms of return to sports and level of achievable physical activity.
Pau, Massimiliano; Ibba, Gianfranco; Attene, Giuseppe
Although balance is generally recognized to be an important feature in ensuring good performance in soccer, its link with functional performance remains mostly unexplored, especially in young athletes. To investigate changes in balance induced by fatigue for unipedal and bipedal static stances in young soccer players. Crossover study. Biomechanics laboratory and outdoor soccer field. Twenty-one male soccer players (age = 14.5 ± 0.2 years, height = 164.5 ± 5.6 cm, mass = 56.8 ± 6.8 kg). Static balance was assessed with postural-sway analysis in unipedal and bipedal upright stance before and after a fatigue protocol consisting of a repeated sprint ability (RSA) test (2 × 15-m shuttle sprint interspersed with 20 seconds of passive recovery, repeated 6 times). On the basis of the center-of-pressure (COP) time series acquired during the experimental tests, we measured sway area, COP path length, and COP maximum displacement and velocity in the anteroposterior and mediolateral directions. Fatigue increased all sway values in bipedal stance and all values except COP velocity in the mediolateral direction in unipedal stance. Fatigue index (calculated on the basis of RSA performance) was positively correlated with fatigue/rest sway ratio for COP path length and COP velocity in the anteroposterior and mediolateral directions for nondominant single-legged stance. Fatigued players exhibited reduced performance of the postural-control system. Participants with better performance in the RSA test appeared less affected by balance impairment, especially in single-legged stance.
Galanti, Giorgio; Stefani, Laura; Scacciati, Irene; Mascherini, Gabriele; Buti, Gabriella; Maffulli, Nicola
The study evaluated the dietary habits in two groups of young athletes, practicing two different sports: soccer players and cycling. The dietary habits of 47 athletes were investigated by questionnaire. Body Mass Index, Fat Mass, Free Fat Mass, Total Body, Intracellular, Extracellular Water and Phase Angle were measured by bioimpedance. The t-Student test for unpaired data was used. Significance was set at P soccer player group (soccer players: 63.8±1.96%; cyclists : 59.8 ± 8.7%; and soccer players 43.9±3.1%, cyclists 43.8 ±2.1%, respectively). Fatty mass of the soccer player group (14.5±2.9%) was significantly lower than that of the cyclist group (19.5±3.6%). Daily food intake was similar between the two groups (2844 kCal/die for soccer players /2630 kcal/die for cyclists), and lower than recommended. There was a low intake of Calcium (soccer players 1120±128.9 mg/die, cyclists 718±309 mg/die) for both groups, and a low intake of Potassium for soccer player (2576 mg/die ± 52.4) The caloric intake of adolescent athletes is lower than recommended. Body composition is significantly different between soccer players and cyclists.
Manuel Jacob Sierra-Díaz
Full Text Available Grouping people according to chronological age is popular in fields such as education and sport. Athletes who are born in the first months of the year usually have cognitive and physical development differences in contrast to those born in the last months of the same year. That is why competitive teams tend to select older players more often than youngsters. Age differences between athletes born in the same year as well as an over-representation of older players are known as the Relative Age Effect. This effect is extensively described in young and elite team sports such as basketball, volleyball or, ice-hockey, as well as in soccer. The purpose of this study is to examine the state-of-the-art of the Relative Age Effect in youth and elite soccer players. This review summarizes recent research articles on the Relative Age Effect related to competitive soccer from 2010 to 2016. The systematic literature search was conducted in four databases: SPORTDiscus, Medline, EBSCO host and Google Scholar. Although causes and final solutions have not been clearly achieved yet, it is necessary to continue investigating this phenomenon in order to provide a starting point for future research.
Garcia-Mas, Alexandre; Palou, Pere; Gili, Margarita; Ponseti, Xavier; Borras, Pere A; Vidal, Josep; Cruz, Jaume; Torregrosa, Miquel; Villamarín, Francisco; Sousa, Catarina
Building upon Deci's and Ryan (1985) Self-determination theory as well as the sportive behavioral correlates of the model of Commitment (Scanlan et al., 1976), this study tries to establish the relationship between motivation and commitment in youth sport. For this purpose 454 young competitive soccer players answered the Sport Motivation Scale (SMS) and the Sport Commitment Questionnaire (SCQ) during the regular season. The SMS measures the three dimensions of the Motivational continuum (the Amotivation, the Extrinsic Motivation and the Intrinsic Motivation). The SCQ measures the Sportive Commitment and its composing factors such as the Enjoyment, the Alternatives to the sport, and the Social Pressure. Our findings provided a clear pattern of the influence of motivation in sport enjoyment and commitment, outlining the positive contribution of intrinsic and extrinsic motivation to enjoyment and commitment. Amotivation, contributes positively to alternatives to sport and negatively to enjoyment and commitment, It should be noted that extrinsic motivation has a higher contribution to enjoyment whereas intrinsic motivation has a higher contribution to commitment.
Arroyo, Marta; Gonzalez-de-Suso, Jose Manuel; Sanchez, Celia; Ansotegui, Laura; Rocandio, Ana M
The purpose of this study was to evaluate body composition and body image (perception and satisfaction) in a group of young elite soccer players and to compare the data with those of a control group (age and BMI matched). Participants were 56 volunteer males whose mean age and BMI were 19.6 (SD 1.3) years and 23.3 (SD 1.1) kg/m2, respectively. Results showed that soccer players have a higher lean mass and lower fat mass than controls. Moreover, body perception (difference between current and actual image) was more accurate in controls than in soccer players, and the results suggest a tendency for soccer players to aspire to have more muscle mass and body fat. Soccer players perceived an ideal image with significantly higher body-fat percentage than their current and actual images. There were no body-dissatisfaction differences between groups, however. Although the results are necessarily limited by the small sample size, the findings should be of interest to coaches of young elite soccer teams.
Full Text Available The aim of this study was to compare the plasma concentration of high sensitive C-reactive protein (hs-CRP, white blood cells (WBC, uric acid, and total cholesterol (TC between soccer players and non-athletes. We also intended to evaluate the relations of blood markers with ·VO2max and body composition variables. This cross-sectional study involved professional soccer players (n=40 and sedentary young men (n=60, aged 18-22 years. Blood markers such as CRP, WBC, uric acid, and TC were determined by laboratory tests. Cardiorespiratory fitness (VO2max, body mass index (BMI and fat tissue (FM were determined by the standard test protocols. There were no significant differences between CRP levels of soccer players and non-athletes (0.32±0.13 vs. 0.34±0.19 mg/dl. CRP correlated significantly with FM among soccer players (r=0.482, p≤0.002. Our results also showed a significant correlation between TC and VO2max in soccer players (r=0.469, p≤0.002. Our results showed that long-term soccer training may have no significant effect on the CRP level
Koertz, Rune; Andersen, T. Bull
. METHODS: Participants were 23 male elite soccer players, 13-16 years of age. They trained 6 times a week. The participants, who were randomly divided into a training group (N.=12) and a control group (N.=11), completed a pre and post test, which for each player consisted of 16 shots with their non......AIM: The purpose of the present study was to evaluate if players and coaches should focus more on the non-preferred foot. The hypothesis of this study is that a small amount of training focusing on the non-preferred foot will improve the performance of the non-preferred foot for young elite players......-preferred foot towards a goal corner in a soccer goal. Velocity and accuracy were measured. The training intervention for the training group consisted of 7-13 training sessions. RESULTS: The result showed only few statistic significant differences (P
Katis, Athanasios; Kellis, Eleftherios
The purpose of this study was to examine, first, the movement actions performed during two different small-sided games and, second, their effects on a series of field endurance and technical tests. Thirty-four young soccer players (age: 13 ± 0.9 yrs; body mass: 62.3 ± 15.1 kg; height: 1.65 ± 0.06 m) participated in the study. Small-sided games included three-a-side (3 versus 3 players) and six-a-side (6 versus 6 players) games consisting of 10 bouts of 4 min duration with 3 min active recovery between bouts. Soccer player performance was evaluated using five field tests: a) 30m sprint, b) throw-in for distance, c) Illinois Agility Test, d) dribbling the ball and e) horizontal jump before, in the middle and after the implementation of both game situations. Heart rate was monitored during the entire testing session. Each game was also filmed to measure soccer movements within the game. The ANOVA analysis indicated that the three-a- side games displayed significantly higher heart rate values compared with the six-a-side games (p players performed more long passes and headed the ball more often during the six-a-side (p performance (p performance were observed (p physical conditioning and technical improvement than six-a-side games and their use for training young soccer players is recommended. Key pointsThree-a-side games display higher HR compared with six-a-side games.In the three-a-side games players performed more short passes, kicks, dribbles, tackles and scored more goals compared with the six-a-side games.Impairment in endurance and field test performance was observed mainly after three-a-side games.The use of the three-a-side games to develop physical fitness and technique in young soccer players is recommended.
Barbero-Alvarez, José C; Gómez-López, Maite; Castagna, Carlo; Barbero-Alvarez, Verónica; Romero, David V; Blanchfield, Anthony W; Nakamura, Fábio Y
Barbero-Alvarez, JC, Gómez-López, M, Castagna, C, Barbero-Alvarez, V, Romero, DV, Blanchfield, AW, and Nakamura, FY. Game demands of seven-a-side soccer in young players. J Strength Cond Res 31(7): 1771-1779, 2017-The aim of this study was to examine the activity patterns and physiological demands of 7-a-side youth soccer matches across 2 chronological age categories (U12 and U14). Twenty-two soccer players of a national youth soccer academy were investigated. Players of each age category performed 2 training matches (2 × 25 minutes) and were monitored by global positioning system and heart rate monitor units. Players of both categories covered similar total distance (5,348 ± 307 m), at similar mean heart rate values (86 ± 4% of maximum). However, the number of high-intensity runs (82.5 ± 17.4 vs. 69.7 ± 15.2) and total distance covered during sprints (264 ± 207 vs. 128 ± 74 m) were significantly (p ≤ 0.05) higher in U14 compared with U12. The results suggest a highly demanding nature of 7-a-side soccer for skilled players, with physical maturity possibly influencing the match-related high-intensity performance at these ages.
Van Yperen, N.W.
This study of 65 highly skilled young male soccer players (mean age = 16.6 years) employed a 7-month longitudinal design to examine the causal relationship between performance level and interpersonal stress within the team. Particular attention was paid to the moderating effect of parental support.
The objective of this study is to investigate the effects of teaching core exercises on some motoric parameters in young soccer players. 32 amateur male football players from Afjet Afyonspor and Muglaspor football team; 16 experimental group (average age 13.75 ± 0.46 years; mean body height 1.65.± 0.09 cm; mean body mass 52.88 ± 8.04 kg) and 16…
Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n3p367 In soccer, the relative age effect (RAE was observed in both adult and young players. The RAE appears to be more pronounced in elite sports, probably by the need to select the best players to compete internationally. This study review: (1 the prevalence of RAE in soccer players, (a considering competitive level (b and specific position and (2 association between RAE (a and anthropometric characteristics, (b physical fitness components and technical skills. A total of 12 studies met all inclusion criteria for this review. One trial (meta-analysis was included after the eligibility process. Overall, 77675 young soccer players were analysed. In all studies, significance level of 0.05 was set for the type I error. There is a consensus about the presence of an RAE in men’s soccer, and the percentage of players born in the first quarter in the selection year for professionals is high, with peak values found for elite young athletes, and a large decrease is evident throughout the regional and school representation. The relationship between RAE and the specific position is controversial, according to few studies. It is likely that players born in the first quarter differ in a variety of anthropometric characteristics and physical fitness components compared with peers born in the last quarter. Researchers need to understand the mechanisms by which RAE increase and decrease in order, to reduce and eliminate this social inequality that influence the experiences of athletes, especially in periods of development. Organizational and practical intervention is required.
Marcelo de Oliveira Matta
Full Text Available The purpose of the present study is to describe the association between chronological age, morphology, biological maturation and sport experience in relation to technical performance in young Brazilian soccer players. Technical, maturation and anthropometric variables were assessed in 119 soccer players, 74 and 45 in the under-15 and under-17 categories, respectively. Data were analyzed using a multiple linear regression model. Adiposity was negatively associated with technical performance regardless the age-category. Weight was negatively associated with technical performance in under-15 and positively with the under-17 category, respectively. In under-17 biological maturation was negatively related to the dribbling test and positively associated with the ball control test. Years of experience proved to be positively associated with technique taught to soccer player in the under-17 category. The explained variance was different between categories. The technical performance of Brazilian soccer players aged 14-to-17 seems to be related to biological maturation, adiposity, weight and years of experience.
Aquino, Rodrigo L; Gonçalves, Luiz G; Vieira, Luiz H; Oliveira, Lucas P; Alves, Guilherme F; Santiago, Paulo R; Puggina, Enrico F
The objectives of this study were to describe and compare the displacement patterns and the tactical performance of the players in the first to the second game time and verify possible associations between indirect markers of muscle damage with displacement patterns in a simulated game played by young soccer players. Eighteen young soccer players were submitted to a simulated game and two blood collections, one before and another 30 minutes post-game to analyze the behavior of creatine kinase and lactate dehydrogenase enzymes. The patterns of displacement and tactics variables were obtained through functions developed in MATLAB environment (MathWorks, Inc., Natick, MA, USA). It is observed a significant increase in average speed (P=0.05), number of sprints (Ptactical variables (team surface area: P=0.002; spreading: P=0.001) in the second period of the simulated game. In addition, there was significant reduction in the percentage of the total distance at low intensity (P≤0.05) in the second period, and there was a strong association between the percentage of change delta of creatine kinase and lactate dehydrogenase with the displacement patterns in the simulated game. The results show that indirect markers of muscle damage have great association with displacement patterns in game performed in training conditions for young soccer players, evidencing a need for reflection on the post-training recovery sessions strategies, contributing to better planning of sessions throughout the macrocycle.
Full Text Available Physical capacity and coordination cannot alone predict success in team sports such as soccer. Instead, more focus has been directed towards the importance of cognitive abilities, and it has been suggested that executive functions (EF are fundamentally important for success in soccer. However, executive functions are going through a steep development from adolescence to adulthood. Moreover, more complex EF involving manipulation of information (higher level EF develop later than simple executive functions such as those linked to simple working memory capacity (Core EF. The link between EF and success in young soccer players is therefore not obvious. In the present study we investigated whether EF are associated with success in soccer in young elite soccer players. We performed tests measuring core EF (a demanding working memory task involving a variable n-back task; dWM and higher level EF (Design Fluency test; DF. Color-Word Interference Test and Trail Making Test were performed on an exploratory level as they contain a linguistic element. The lower level EF test (dWM was taken from CogStateSport computerized concussion testing and the higher level EF test (DF was from Delis-Kaplan Executive Function System test battery (D-KEFS. In a group of young elite soccer players (n = 30; aged 12-19 years we show that they perform better than the norm in both the dWM (+0.49 SD and DF (+0.86 SD. Moreover, we could show that both dWM and DF correlate with the number of goals the players perform during the season. The effect was more prominent for dWM (r = 0.437 than for DF (r = 0.349, but strongest for a combined measurement (r = 0.550. The effect was still present when we controlled for intelligence, length and age in a partial correlation analysis. Thus, our study suggests that both core and higher level EF may predict success in soccer also in young players.
Hashim, Hairul Anuar; Hanafi Ahmad Yusof, Hazwani
This study was designed to compare the effects of two different relaxation techniques, namely progressive muscle relaxation (PMR) and autogenic relaxation (AGR) on moods of young soccer players. sixteen adolescent athletes (mean age: 14.1 ± 1.3) received either PMR or AGR training. Using Profile of Mood States- Adolescents, their mood states were measured one week before relaxation training, before the first relaxation session, and after the twelfth relaxation session. Mixed ANOVA revealed no significant interaction effects and no significant main effects in any of the subscales. However, significant main effects for testing sessions were found for confusion, depression, fatigue, and tension subscales. Post hoc tests revealed post-intervention reductions in the confusion, depression, fatigue, and tension subscale scores. These two relaxation techniques induce equivalent mood responses and may be used to regulate young soccer players' mood states.
de Putter, C E; van Beeck, E F; Burdorf, A; Borsboom, G J J M; Toet, H; Hovius, S E R; Selles, R W
Young male soccer players have been identified as a target group for injury prevention, but studies addressing trends and determinants of injuries within this group are scarce. The goal of this study was to analyze age-specific trends in hospital-treated upper extremity fractures (UEF) among boys playing soccer in the Netherlands and to explore associated soccer-related factors. Data were obtained from a national database for the period 1998-2009. Rates were expressed as the annual number of UEF per 1000 soccer players. Poisson's regression was used to explore the association of UEF with the number of artificial turf fields and the number of injuries by physical contact. UEF rates increased significantly by 19.4% in boys 5-10 years, 73.2% in boys 11-14 years, and 38.8% in boys 15-18 years old. The number of injuries by physical contact showed a significant univariate association with UEF in boys 15-18 years old. The number of artificial turf fields showed a significant univariate association with UEF in all age groups, and remained significant for boys aged 15-18 years in a multivariate model. This study showed an increase of UEF rates in boys playing soccer, and an independent association between artificial turf fields and UEF in the oldest boys. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
The study evaluated the dietary habits in two groups of young athletes, practicing two different sports: soccer players and cycling. The dietary habits of 47 athletes were investigated by questionnaire. Body Mass Index, Fat Mass, Free Fat Mass, Total Body, Intracellular, Extracellular Water and Phase Angle were measured by bioimpedance. The t-Student test for unpaired data was used. Significance was set at P < 0.05. Body Mass Index was similar between the groups, wh...
Mantini, S; Bruner, E; Colaiacomo, B; Ciccarelli, A; Redaelli, A; Ripani, M
The plantar support and its modifications are widely studied because of their bearing on posture. In particular, past studies have focused on the support modification during specific athletic tasks to highlight the eventual correlations between foot type and the most frequent sport injuries, due to intrinsic and extrinsic components that involve the structural and functional dynamics that act on the plantar vault during static and dynamic condition. These studies have been conducted by analyzing the morphological variation of the footprint during the performance. In the present study the variation in shape of the baropodometrical footprint of young soccer players, has been analyzed using geometric morphometrics. This approach permits a quantification of the morphological variation of the subjects using Cartesian coordinates placed at specific points on the footprint outline, and to correlate them with physical variables. In the present study the young soccer players displayed a narrowing of the footprint due to a transversal variation on the isthmus, when compared to children of the same age who did not play soccer. These results suggest a physiological and biomechanical organization of the foot type in soccer due to the specific athletic tasks involved. As the foot type, in sport, is strictly associated to recurrent injuries, the result obtained in this study should be considered as indicative for future analysis. In fact, a clear and univocal knowledge of this phenomenon would be useful in the planning of a training protocol to reduce the incidence of sport related injuries.
Marcos Vaz De Lima
Full Text Available Objective: To demonstrate the safety of soccer for adolescents in terms of chronic lesions of the lumbar spine, particularly spondylolysis. Methods: 54 young players underwent a pre-season assessment. The athletes were submitted to radiography of the lumbosacral spine. Players complaining of chronic low back pain were later submitted to more specific tests. Results: only 1 athlete (1.85 % of our sample had complaints of chronic low back pain. In this case, the radiograph showed olisthesis grade I spondylolysis at the L5 level. Conclusion: Soccer proved to be a very safe sport in terms of the risk of developing chronic lesions of the lumbosacral spine. However, the actual incidence of spondylolysis in these athletes was not determined because only plain radiographs were used in this study.
Russell, Mark; Pennock, Anthony
Limited data exist concerning the dietary practices of young professional soccer players that compete within the United Kingdom. Therefore, the purpose of this study was to investigate the nutritional and activity habits of professional male soccer players (n = 10; age: 17 ± 1 years, height: 1.72 ± 0.01 m, mass: 67.5 ± 1.8 kg, estimated maximal aerobic capacity: 57.8 ± 0.9 ml·kg·min) who played for the youth team of a UK-based Championship club. All players recorded their 7-day dietary intake and activity habits during a competitive week that included a match day, 4- training days, and 2 rest days in the first half of the 2009/2010 playing season. The intake of carbohydrates (5.9 ± 0.4 g·kg·d), proteins (1.7 ± 0.1 g·kg·d), and fats (1.5 ± 0.1 g·kg·d) represented 56 ± 1, 16 ± 1, and 31 ± 1% of the mean daily energy intake respectively. The intake of fiber was found to be significantly lower than Recommended Nutrient Intake (RNI) values (67% of RNI, p nutritional practices of the sampled group of professional youth soccer players were inadequate to sustain optimized performance throughout training and match play. Youth soccer players should therefore seek to ensure that their diets contain adequate energy through increased total caloric intake, while also optimizing the proportion of energy derived from carbohydrates and ensuring that enough fiber-rich foods are consumed.
Freitas Camila G.
Full Text Available The purpose of the present study was to examine SIgA responses (concentration [SIgAabs] and a secretion rate [SIgArate] to official and simulated competitive matches in young soccer players. The sample was composed of 26 male soccer players (age 15.6 ± 1.1 yrs, stature 177.0 ± 6.1 cm, body mass 70.5 ± 5.7 kg. Four soccer matches (two simulated matches [SM] and two official matches [OM] were conducted. The matches consisted of two halves of 35 min with a 10 min rest interval. Each assessed player participated in only one SM and one OM. All matches were performed in the same week, during the competitive season, and at the same time of the day (9:00 am, separated by 48 h. Saliva samples were collected before and after every match. The session rating of perceived exertion was reported 30 min after each match in order to determine the internal training load (ITL. A significant decrease in SIgAabs and SIgArate after OM was observed when compared to the pre-match value. In addition, the SIgArate was higher at pre-OM when compared to pre-SM. A higher ITL for OM was observed compared to SM. The current findings indicate that OM may lead to a decrease in the main mucosal immunity function parameter of young soccer players that could increase the risk of URTI. Coaches should be aware of it in order to plan appropriate training loads and recovery procedures to avoid or minimize the likelihood of upper respiratory tract infection occurrences.
Chtara, Moktar; Rouissi, Mehdi; Bragazzi, Nicola L; Owen, Adam L; Haddad, Monoem; Chamari, Karim
Soccer requires maintaining unilateral balance when executing movement with the contralateral leg. Despite the fact that balance requires standing with maintaining isometric posture with the support leg, currently there is a lack of studies regarding the implication of isometric strength on dynamic balance's performance among young soccer players. Therefore, the aim of this study was to examine the relationship between the Y-Balance Test and 12 lower limbs isometric strength tests. Twenty-six right footed soccer players (mean±SD, age=16.2±1.6 years, height=175±4.2 cm, body mass=68.8±6.1 kg) performed a dynamic balance test (star excursion balance-test with dominant- (DL) and nondominant-legs (NDL). Furthermore, maximal isometric contraction tests of 12 lower limb muscle groups were assessed in DL and NDL. Correlations analysis reported a significant positive relationship between some of isometric strength tests (with DL and NDL) and the Y-Balance Test. Furthermore, stepwise multiple regression analysis showed that maximal isometric strength explained between 21.9% and 49.4% of the variance of the Y-Balance Test. Moreover, maximal isometric strength was dependent upon the reaching angle of the Y-Balance Test and the leg used to support body weight. This study showed a significant implication of maximal isometric strength of the lower limb and the Y-Balance Test. Moreover, the present investigation suggests the implementation of specific lower limb strengthening exercises depending on players' deficit in each reaching direction and leg. This result suggests that further studies should experiment if increasing lower limbs isometric strength could improve dynamic balance ability among young soccer players.
Hammami, Mohamed Ali; Ben Abderrahman, Abderraouf; Hackney, Anthony C; Kebsi, Wiem; Owen, Adam L; Nebigh, Amar; Racil, Ghazi; Tabka, Zouhair; Zouhal, Hassane
Hammami, MA, Ben Abderrahman, A, Hackney, AC, Kebsi, W, Owen, AL, Nebigh, A, Racil, G, Tabka, Z, and Zouhal, H. Hormonal (cortical-gonadotropic axis) and physical changes with two years intense exercise training in elite young soccer players. J Strength Cond Res 31(9): 2388-2397, 2017-The aim of this study was to investigate the effects of 2 soccer-training seasons on physical fitness and hormone concentrations in elite youth soccer players. Twenty male elite soccer players (SP, age 14.5 ± 0.4 years) and 20 male control subjects (CS, age 14.3 ± 0.3 years) participated in the study. Anthropometric measurements, aerobic (Yo-Yo Intermittent Recovery Test Level 1 [YYIRT1]) and anaerobic soccer relevant performances (jump and sprint tests), blood testosterone (T), cortisol (C), sex hormone binding globulin (SHBG), and T/C ratio were assessed 5 times (from T0 to T4) during 2 competitive seasons. Significant differences from basal values (Δ) of T, SHBG, and C between SP and CS were observed (p soccer players group compared with controls. Our findings also show that the T concentrations and power performance outcomes co-vary positively over the 2 soccer seasons in soccer players.
Oh, Seong Hwan; Joo, Chang Hwa
The aims of this study were to examine the differences in technical aspects and physical demands between small-size games (SSG; 8 vs. 8) and regular-size games (RSG; 11 vs. 11) in young Korean soccer players. Seventy-nine young soccer players from 6 teams (U-12) volunteered to participate in the study. The players completed 4 games (2 SSG, 62×51 m, and 2 RSG, 80×54 m) in 2 days. Each game was filmed to evaluate technical actions. Physical demand variables were measured using global positioning system technology. SSG showed significantly greater numbers of technical plays among 17 variables when compared to RSG ( P game format for Korean young soccer players, resulting in significantly greater exposure to technical plays without excessive physical demands.
Joo, Chang H; Hwang-Bo, Kwan; Jee, Haemi
Joo, CH, Hwang-Bo, K, and Jee, H. Technical and physical activities of small-sided games in young Korean soccer players. J Strength Cond Res 30(8): 2164-2173, 2016-The aim of this study was to examine the technical aspects and physical demands during small-sided games (SSGs) with different sized pitches in young Korean soccer players. Participants were randomly selected during a nationally held youth competition. Three different game formats were used: SSG8 (8 vs. 8 played on a small-sized field [68 × 47 m]), RSG8 (8 vs. 8 played on a regular-sized field [75 × 47 m]), and RSG11 (11 vs. 11 played on a regular-sized field). Eleven technical (ball touches, passes, and shots) and 6 physical demand variables (exercise frequency by intensity) were observed and analyzed. Same variables were also analyzed for the goalkeepers. As a result, SSG8 and RSG8 showed significantly greater numbers of technical plays in 5 and 4 variables in comparison to RSG11, respectively. In addition, although the exercise intensities increased slightly in both SSG formats, the amount was within the similar range as previous reports. In conclusion, the SSGs with reduced number of players may be referred in young players to effectively train them in technical aspects of the game by allowing greater ball exposure time without excessive physical demands. Various confounding factors such as pitch dimension should be carefully considered for training specific technical and physical variables in young Korean players.
Full Text Available The purpose of this study was to examine, first, the movement actions performed during two different small-sided games and, second, their effects on a series of field endurance and technical tests. Thirty-four young soccer players (age: 13 ± 0.9 yrs; body mass: 62.3 ± 15.1 kg; height: 1.65 ± 0.06 m participated in the study. Small-sided games included three-a-side (3 versus 3 players and six-a-side (6 versus 6 players games consisting of 10 bouts of 4 min duration with 3 min active recovery between bouts. Soccer player performance was evaluated using five field tests: a 30m sprint, b throw-in for distance, c Illinois Agility Test, d dribbling the ball and e horizontal jump before, in the middle and after the implementation of both game situations. Heart rate was monitored during the entire testing session. Each game was also filmed to measure soccer movements within the game. The ANOVA analysis indicated that the three-a- side games displayed significantly higher heart rate values compared with the six-a-side games (p < 0.05. The number of short passes, kicks, tackles, dribbles and scoring goals were significantly higher during the three-a-side compared with the six-a-side game condition (p < 0. 05 while players performed more long passes and headed the ball more often during the six-a-side (p < 0.05. After the three-a-side games, there was a significant decline in sprint and agility performance (p < 0.05, while after both game conditions significant alterations in the throw-in and the horizontal jump performance were observed (p < 0.05. The results of the present study indicated that three-a-side games provide higher stimulus for physical conditioning and technical improvement than six-a-side games and their use for training young soccer players is recommended
Full Text Available The purpose of this study was to investigate the effects of loaded and unloaded plyometric training strategies on speed and power performance of elite young soccer players. Twenty-three under-17 male soccer players (age: 15.9 ± 1.2 years, height: 178.3 ± 8.1 cm, body-mass (BM: 68.1 ± 9.3 kg from the same club took part in this study. The athletes were pair-matched in two training groups: loaded vertical and horizontal jumps using an haltere type handheld with a load of 8% of the athletes' body mass (LJ; n = 12 and unloaded vertical and horizontal plyometrics (UJ; n = 11. Sprinting speeds at 5-, 10-, and 20-m, mean propulsive power (MPP relative to the players' BM in the jump squat exercise, and performance in the squat jump (SJ and countermovement jump (CMJ were assessed pre- and post-training period. During the experimental period, soccer players performed 12 plyometric training sessions across a 6-week preseason period. Magnitude based inferences and standardized differences were used for statistical analysis. A very likely increase in the vertical jumps was observed for the LJ group (99/01/00 and 98/02/00 for SJ and CMJ, respectively. In the UJ group a likely increase was observed for both vertical jumps (83/16/01 and 90/10/00, for SJ and CMJ, respectively. An almost certainly decrease in the sprinting velocities along the 20-m course were found in the LJ group (00/00/100 for all split distances tested. Meanwhile, in the UJ likely to very likely decreases were observed for all sprinting velocities tested (03/18/79, 01/13/86, and 00/04/96, for velocities in 5-, 10-, and 20-m, respectively. No meaningful differences were observed for the MPP in either training group (11/85/04 and 37/55/08 for LJ and UJ, respectively. In summary, under-17 professional soccer players increased jumping ability after a 6-week preseason training program, using loaded or unloaded jumps. Despite these positive adaptations, both plyometric strategies failed to
Pereira Santiago, Paulo Roberto; Palucci Vieira, Luiz Henrique; Barbieri, Fabio Augusto; Moura, Felipe Arruda; Exel Santana, Juliana; de Andrade, Vitor Luiz; de Souza Bedo, Bruno Luiz; Cunha, Sergio Augusto
Background Kicking performance is the most studied technical action in soccer and lower limbs kinematics is closely related to success in kicking, mainly because they are essential in imparting high velocity to the ball. Previous studies demonstrated that soccer leagues in different countries exhibit different physical demands and technical requirements during the matches. However, evidencewhether nationality has any influence in the kinematics of soccer-related skills has not yet been reported. The nationality of the players is an aspect that might be also relevant to the performance in kicking. Objectives The aim of this study was to compare the lower limbs kinematic patterns during kicking, between Brazilian and Japanese young top soccer players. Patients and Methods Seven Brazilian (GA) and seven Japanese (GB) U-17 players performed 15 side-foot kicks each, with a distance of 20 m away from the goal, aiming a target of 1 × 1 m in upper corner, constrained by a defensive wall (1.8 × 2 m). Four digital video cameras (120 Hz) recorded the performance for further 3D reconstruction of thigh, shank and foot segments of both kicking and support limbs. The selected kicking cycle was characterized by the toe-off of the kicking limb to the end of the kicking foot when it came in contact with the ball. Stereographical projection of each segment was applied to obtain the representative curves of kicking as function of time for each participant in each trial. Cluster analysis was performed to identify the mean GA and GB curves for each segment. Silhouette coefficient (SC) was calculated, in order to determine the degree of separation between the two groups’ curves. Results Comparison between the median confidence intervals of the SC showed no differences between groups as regards lower limb patterns of movements. Task accuracy was determined by the relative frequency that the ball reached the target for all attempts and no differences were found (GA: 10.48 ± 14.33%; GB
Forsman, Hannele; Gråstén, Arto; Blomqvist, Minna; Davids, Keith; Liukkonen, Jarmo; Konttinen, Niilo
The objective of this 1-year, longitudinal study was to examine the development of perceived competence, tactical skills, motivation, technical skills, and speed and agility characteristics of young Finnish soccer players. We also examined associations between latent growth models of perceived competence and other recorded variables. Participants were 288 competitive male soccer players ranging from 12 to 14 years (12.7 ± 0.6) from 16 soccer clubs. Players completed the self-assessments of perceived competence, tactical skills, and motivation, and participated in technical, and speed and agility tests. Results of this study showed that players' levels of perceived competence, tactical skills, motivation, technical skills, and speed and agility characteristics remained relatively high and stable across the period of 1 year. Positive relationships were found between these levels and changes in perceived competence and motivation, and levels of perceived competence and speed and agility characteristics. Together these results illustrate the multi-dimensional nature of talent development processes in soccer. Moreover, it seems crucial in coaching to support the development of perceived competence and motivation in young soccer players and that it might be even more important in later maturing players.
Ramirez-Campillo, Rodrigo; Alvarez, Cristian; Gentil, Paulo; Loturco, Irineu; Sanchez-Sanchez, Javier; Izquierdo, Mikel; Moran, Jason; Nakamura, Fabio Y; Chaabene, Helmi; Granacher, Urs
To compare the effects of short-term (i.e., 7 week) plyometric training applied before (PJT-B) or after (PJT-A) soccer practice on components of physical fitness in young soccer players, a single-blind randomized controlled trial was conducted. Post-pubertal boys aged 17.0±0.5 years were allocated to three groups: PJT-B (n=12), PJT-A (n=14), and control (CON; n=12). The outcome measures included tests to evaluate 20-m speed, standing long jump [SLJ], squat jump [SJ], countermovement jump [CMJ], and drop jump [DJ], 20-m multistage shuttle running speed [MSSRT], and Illinois change of direction speed [ICODT]. While the CON performed soccer-specific training, the PJT-A and PJT-B groups conducted the same soccer-specific sessions but replaced ∼11% of their time with plyometric training. The PJT-B group performed plyometric exercises after a warm-up program, and the PJT-A group conducted plyometric exercises ∼10 minutes after the completion of soccer training. Analyses of variance (ANOVAs) were used to detect differences between groups in all variables for pre- and post-training tests. Main effects of time (all pplyometric training is effective in improving measures of physical fitness in young male soccer players when combined with regular soccer training. More specifically, larger training induced effects on physical fitness were registered if plyometric training was conducted prior to soccer specific training.
Mohamad Ali Mohamadi
Full Text Available Objective: To investigating the effect of different Warm-up Protocols on young Soccer Players' Explosive Power. Methods: Twenty male soccer players (17.4 0.685 years volunteered to participate in this study. The participants were randomly selected, and in order to remove the effects of transmission and to observe the sequence of warm-up methods, they were cross-matched randomly e.g. 20 players in four categories; that is, 5 players in each category. The participants in each category experienced the 4 warm-up ways in four consecutive so that at the end 20 players performed each method of warm-up. Warm-up methods: 1. Static warm-up; 2. Dynamic warm-up plus 2 min active rest; 3. Dynamic warm-up plus 5 min passive rest and finally Dynamic warm-up plus 15 min passive rest. Participants in each category performed different warm-up methods which had been designed based on scientific and research-based sources in 48 hours intervals After performing each warm-up method, they were given a Long Jump. Results: Based on the results of analysis of variance between the effect of different warm-up methods on Explosive Power participants, significant difference was observed (p?0/05 so that Dynamic warm-up plus 5 min passive rest was more effective in Explosive Power performance than other methods(p?0/05. Discussion: The results of this study are in line with those of Roger (2008 and Faigenbaum et al (2006 who indicated in their studies that Dynamic or mixed method of warm-up are more effective than static ones. Conclusion: Therefore, with regard to the results of the study presented here and also the nature of football enjoying explosive power than the air blows, it is recommended that these types of protocols during warm-up program be employed. Keywords: Warm up, Explosive Power , Soccer Players', Young
Rodríguez-Rosell, David; Franco-Márquez, Felipe; Mora-Custodio, Ricardo; González-Badillo, Juan José
Rodríguez-Rosell, D, Franco-Márquez, F, Mora-Custodio, R, and González-Badillo, JJ. Effect of high-speed strength training on physical performance in young soccer players of different ages. J Strength Cond Res 31(9): 2498-2508, 2017-The aim of the present study was to compare the effectiveness of low-load, low-volume weight training combined with plyometrics on strength, sprint, and jump performance in soccer players of different ages. Eighty-six soccer players from the same academy were categorized into 3 groups by age (under 13 years, U13, n = 30; under 15, U15, n = 28; and under 17, U17, n = 28) and then randomly assigned into 2 subgroups: a strength training group (STG) and a control group (CG). The strength training program was performed twice a week for 6 weeks and consisted of full squats (load: 45-60% 1 repetition maximum; volume: 3 set of 8-4 repetitions), jumps, and straight line sprint exercises. After training intervention, the STGs showed significant improvements in maximal strength (7.5-54.5%; p soccer players in most variables, whereas U15 showed higher improvements in jump and strength parameters than U17 (ES: 0.25-0.90) soccer players. Thus, although our results indicates that a combined weight training and plyometrics program may be effective in eliciting gains in strength, jump, and sprint in soccer players of different ages, the training program used appears to be generally less effective as the age of the soccer players increased. Therefore, it appears that training characteristics (mainly volume, intensity, and type of exercise) should be modified in relation to maturity status and initial strength level.
Hendley, Alexandra; Bielby, Denise D.
Our research examines the relationship among identity, age, gender and athleticism through a study of the association between sports clothing and the identity work of pre-adolescent female soccer players. Based on participant-observation and interviews conducted at three co-ed youth soccer camps, we find that age is an important element of…
Full Text Available The aim of this study was to investigate changes in the linear running speed (LRS for 30 m, change of direction speed (CODS, and endurance in young elite Czech soccer players. The following tests were conducted to assess CODS and endurance: Agility 505 turning toward the dominant (A505DL and non-dominant lower limb (A505NL; Illinois Agility Test (IAT; and intermittent test (Yo-Yo IRT1. During the soccer season, we investigated performance at the following time periods: the start (t1 and the end of the pre-season period (t2; during (t3 and at the end of the competitive period (t4. Repeated measurement analysis of variance revealed a significant effect of time period on selected fitness parameters (p < 0.05. Post hoc analysis for test A505DL revealed significant improvements of performance at t3 (2.71 ± 0.08 s and t4 (2.72 ± 0.06 s compared to t1 (2.81 ± 0.09 s. A505NL was significantly different between t1 (2.83 ± 0.09 s and t2 (2.76 ± 0.09 s, t3 (2.7 ± 0.07 s and t4 (2.71 ± 0.09 s. Performance of CODS at t1 for the IAT (18.82 ± 0.56 s was significantly lower (p < 0.05 than any other time period (t2 = 18.52 ± 0.63 s, t3 = 17.94 ± 0.51 s, t4 = 17.89 ± 0.66 s. The power of LRS was significantly different at t3 (4.99 ± 0.15 s, and t4 (4.98 ± 0.17 s compared to t1 (5.15 ± 0.21 s, and t2 (5.07 ± 0.14 s. For the Yo-Yo IRT1 test, we observed a significant increase in performance between t1 (625.26 ± 170.34 m, t2 (858.95 ± 210.55 m, and t3 (953.68 ± 229.88 m. These results show the impact of soccer season time period on young soccer player performance and may further serve as a basis for comparison with similar research conducted by peers. These results may aid sports practice for clinicians, conditioning coaches, soccer coaches and physiotherapeutic coaches.
Alvarez, María Sol; Balaguer, Isabel; Castillo, Isabel; Duda, Joan L
Based on the self-determination theory (Ryan & Deci, 2000), this study tested a model of the assumed sequential relationships between perceived autonomy support, psychological need satisfaction, self-determined motivation, and enjoyment/boredom. The hypothesized mediational roles of psychological need satisfaction and self-determined motivation were also studied. In a sample of 370 young male soccer players, path analysis results offered support for the proposed model. Total mediation was supported in the case of the psychological need satisfaction in the relationship between autonomy support and self-determined motivation, and partial mediation for self-determined motivation in the links between psychological need satisfaction and enjoyment (positive) and boredom (negative). Implications of autonomy-supportive behaviors provided by coaches for the quality of sport involvement among young athletes are discussed.
Chtara, M; Rouissi, M; Haddad, M; Chtara, H; Chaalali, A; Owen, A; Chamari, K
The aim of the present study was to compare the effects of 3 training protocols (plyometric [PLYO], agility [AG], or repeated shuttle sprints [RS]) on physical performance in the same population of young soccer players. Forty-two youth-level male players (13.6±0.3-years; 1.65±0.07 m; 54.1±6.5 kg; body fat: 12.8±2.6%) participated in a short-term (6-week) randomized parallel fully controlled training study (pre-to-post measurements): PLYO group, n=10; AG group, n=10; RS group, n=12; and control group [CON] n=10. PLYO training = 9 lower limb exercises (2-3 sets of 8-12 repetitions). The AG group performed planned AG drills and direction changes. RS training consisted of 2-4 sets of 5-6x 20 to 30 m shuttle sprints (20 seconds recovery in between). Progressive overload principles were incorporated into the programme by increasing the number of foot contacts and varying the complexity of the exercises. Pre/post-training tests were: bilateral standing horizontal jump, and unilateral horizontal jumps, sprint (30 m with 10 m lap time), agility (20 m zigzag), and repeated sprint ability (RSA) (i.e. 6x30 m shuttle sprints: 2x15 m with 180° turns). Significant main effects for time (i.e. training application) and group (training type) were detected. Improvements in horizontal jumping were higher (pperformances. Significantly greater increases in 20 m zigzag performance were observed following AG and RS training (4.0 and 3.8%, respectively) compared with PLYO (2.0%) and CON training (0.8%). No significant differences were reported in the RSA dec between groups. Elite young male soccer players' physical performances can be significantly and specifically improved either using PLYO or AG or RSA training over short-term in-season training.
Full Text Available The aim of the study was to assess changes in the anaerobic threshold of young soccer players in an annual training cycle. A group of highly trained 15-18 year old players of KKS Lech Poznań were tested. The tests included an annual training macrocycle, and its individual stages resulted from the time structure of the sports training. In order to assess the level of exercise capacities of the players, a field exercise test of increasing intensity was carried out on a soccer pitch. The test made it possible to determine the 4 millimolar lactate threshold (T LA 4 mmol · l-1 on the basis of the lactate concentration in blood [LA], to establish the threshold running speed and the threshold heart rate [HR]. The threshold running speed at the level of the 4 millimolar lactate threshold was established using the two-point form of the equation of a straight line. The obtained indicators of the threshold running speed allowed for precise establishment of effort intensity used in individual training in developing aerobic endurance. In order to test the significance of differences in mean values between four dates of tests, a non-parametric Friedman ANOVA test was used. The significance of differences between consecutive dates of tests was determined using a post-hoc Friedman ANOVA test. The tests showed significant differences in values of selected indicators determined at the anaerobic threshold in various stages of an annual training cycle of young soccer players. The most beneficial changes in terms of the threshold running speed were noted on the fourth date of tests, when the participants had the highest values of 4.01 m · s-1 for older juniors, and 3.80 m · s-1 for younger juniors. This may be indicative of effective application of an individualized programme of training loads and of good preparation of teams for competition in terms of players’ aerobic endurance.
Balaguer, Isabel; González, Lorena; Fabra, Priscila; Castillo, Isabel; Mercé, Juan; Duda, Joan L
This study entailed a longitudinal test of basic psychological needs theory, a sub-theory in the self-determination framework (Deci & Ryan, 2000), in young soccer players. We examined whether changes in soccer players' perceptions of the coaches' interpersonal style (autonomy supportive and controlling) predicted changes in the players' need satisfaction/need thwarting, and in turn, variability in their reported subjective vitality and burnout over the course of a season. Young male soccer players (M = 12.58 ± 0.54 years) completed a questionnaire at two time points in the season [n(T1) = 725; n(T2) = 597]. Changes in the players' perceptions of an autonomy supportive environment significantly predicted changes in psychological need satisfaction (positively) and in psychological need thwarting (negatively). Changes in psychological need satisfaction positively predicted changes in subjective vitality and negatively related to cross-time variation in global burnout scores. In contrast, changes in the players' perceptions of a controlling coach-created environment were positively associated with changes in psychological need thwarting that corresponded to increases in player burnout. Finally, results provided support for the assumed mediational roles of psychological need satisfaction and need thwarting in the social environment to well- and ill-being relationships.
Asier Los Arcos
Full Text Available The purpose of this study was to compare the effects of Small-Sided Games (SSG vs. Interval Training (IT in soccer training on aerobic fitness and physical enjoyment in youth elite soccer players during the last 8 weeks of the season. Seventeen U-16 male soccer players (age = 15.5 ± 0.6 years, and 8.5 years of experience of a Spanish First Division club academy were randomized to 2 different groups for 6 weeks: SSG group (n = 9 and IT group (n = 8. In addition to the usual technical and tactical sessions and competitive games, the SSG group performed 11 sessions with different SSGs, whereas the IT group performed the same number of sessions of IT. Players were tested before and after the 6-week training intervention with a continuous maximal multistage running field test and the counter movement jump test (CMJ. At the end of the study, players answered the physical activity enjoyment scale (PACES. During the study, heart rate (HR and session perceived effort (sRPE were assessed. SSGs were as effective as IT in maintaining the aerobic fitness in elite young soccer players during the last weeks of the season. Players in the SSG group declared a greater physical enjoyment than IT (P = 0.006; ES = 1.86 ± 1.07. Coaches could use SSG training during the last weeks of the season as an option without fear of losing aerobic fitness while promoting high physical enjoyment.
Brink, Michel; Visscher, Chris; Coutts, A.J.; Lemmink, Koen
The aim of this study was to prospectively monitor sport-specific performance and assess the stress-recovery balance in overreached (OR) soccer players and controls. During two competitive seasons, 94 players participated in the study. The stress-recovery balance (RESTQ-Sport) and sport-specific
Brink, M. S.; Visscher, C.; Coutts, A. J.; Lemmink, K. A. P. M.
The aim of this study was to prospectively monitor sport-specific performance and assess the stressrecovery balance in overreached (OR) soccer players and controls. During two competitive seasons, 94 players participated in the study. The stressrecovery balance (RESTQ-Sport) and sport-specific
C. Visscher; Koen A.P.M. Lemmink; M.S. Brink; A.J. Coutts
Abstract: The aim of this study was to prospectively monitor sport-specific performance and assess the stress-recovery balance in overreached (OR) soccer players and controls. During two competitive seasons, 94 players participated in the study. The stress-recovery balance (RESTQ-Sport) and
Fraga, Cesar G; Actis-Goretta, Lucas; Ottaviani, Javier I; Carrasquedo, Fernando; Lotito, Silvina B; Lazarus, Sheryl; Schmitz, Harold H; Keen, Carl L
The consumption of a diet rich in certain flavonoids, including the flavanol sub-class, has been associated with a reduced risk for vascular disease. We evaluated the effects of the regular consumption (14 d) of a flavanol-containing milk chocolate (FCMC) or cocoa butter chocolate (CBC) on variables related to vascular disease risk, oxidative stress and physical activity. Twenty-eight free-living, young (18-20 years old) male soccer players consumed daily 105 g of FCMC (168 mg of flavanols) or CBC (cardiovascular health and oxidant stress. The presence of significant quantities of flavanols in FCMC is likely to have been one of the contributing factors to these results.
Da Silva, Rafael P; Mündel, Toby; Natali, Antonio J; Bara Filho, Mauricio G; Alfenas, Rita C G; Lima, Jorge R P; Belfort, Felipe G; Lopes, Priscila R N R; Marins, João C B
In this study, we assessed the pre-game hydration status and fluid balance of elite young soccer players competing in a match played in the heat (temperature 31.0 ± 2.0 ° C, relative humidity 48.0 ± 5.0%) for an official Brazilian soccer competition. Fluid intake was measured during the match, as were urine specific gravity and body mass before and after the game to estimate hydration status. Data were obtained from 15 male players (age 17.0 ± 0.6 years, height 1.78 ± 0.06 m, mass 65.3 ± 3.8 kg); however, data are only analysed for 10 players who completed the full game. The mean (± s) sweat loss of players amounted to 2.24 ± 0.63 L, and mean fluid intake was 1.12 ± 0.39 L. Pre-game urine specific gravity was 1.021 ± 0.004, ranging from 1.010 to 1.025. There was no significant correlation between sweat loss and fluid intake (r = 0.504, P = 0.137) or between urine specific gravity and fluid intake (r = -0.276, P = 0.440). We conclude that young, native tropical soccer players started the match hypohydrated and replaced about 50% of the sweat lost. Thus, effective strategies to improve fluid replacement are needed for players competing in the heat.
Rouissi, M; Haddad, M; Chtara, H; Chaalali, A; Owen, A; Chamari, K
The aim of the present study was to compare the effects of 3 training protocols (plyometric [PLYO], agility [AG], or repeated shuttle sprints [RS]) on physical performance in the same population of young soccer players. Forty-two youth-level male players (13.6±0.3-years; 1.65±0.07 m; 54.1±6.5 kg; body fat: 12.8±2.6%) participated in a short-term (6-week) randomized parallel fully controlled training study (pre-to-post measurements): PLYO group, n=10; AG group, n=10; RS group, n=12; and control group [CON] n=10. PLYO training = 9 lower limb exercises (2-3 sets of 8-12 repetitions). The AG group performed planned AG drills and direction changes. RS training consisted of 2-4 sets of 5-6x 20 to 30 m shuttle sprints (20 seconds recovery in between). Progressive overload principles were incorporated into the programme by increasing the number of foot contacts and varying the complexity of the exercises. Pre/post-training tests were: bilateral standing horizontal jump, and unilateral horizontal jumps, sprint (30 m with 10 m lap time), agility (20 m zigzag), and repeated sprint ability (RSA) (i.e. 6x30 m shuttle sprints: 2x15 m with 180° turns). Significant main effects for time (i.e. training application) and group (training type) were detected. Improvements in horizontal jumping were higher (pperformances. Significantly greater increases in 20 m zigzag performance were observed following AG and RS training (4.0 and 3.8%, respectively) compared with PLYO (2.0%) and CON training (0.8%). No significant differences were reported in the RSAdec between groups. Elite young male soccer players’ physical performances can be significantly and specifically improved either using PLYO or AG or RSA training over short-term in-season training. PMID:28566807
Marcelo de Oliveira Matta
The objectives of this study were to describe and compare the anthropometric profile, physical fitness and soccer-specific skills between under-15 and under-17 Brazilian soccer players, as well as to evaluate possible differences in these variables according to biological maturation in the age categories. The sample consisted of 245 male soccer players (under-15: n=161; under-17: n=84. Anthropometric measures included weight, height and skinfolds. Biological maturation was assessed based on pubic hair development. The following tests were used for functional assessment: static and countermovement jump, Yo-Yo intermittent endurance test (level 2, RAST, 5- and 30-meter running speed, and agility T-test. Soccer-specific skills were assessed using three tests: ball control, dribbling, and kick accuracy. Descriptive statistics, t-test and analysis of variance (ANOVA were used for statistical analysis. The results showed a larger body size (stature and body mass, longer sports experience (years of formal training and better performance in most of the functional tests for under-17 soccer players compared to under-15 players. There were no significant differences in adiposity or soccer-specific skills between levels of competition. Significant differences as a function of maturation stage were observed in anthropometric and functional variables only in the under-15 category. In conclusion, the under-17 category differs from the under-15 category in terms of anthropometric and physical fitness characteristics. However, no difference was observed in two of the three soccer-specific skills. Physical fitness components and soccer-specific skills were associated with maturity only in the under-15 category.
Pietsch, Stefanie; Jansen, Petra
This study investigates the influence of specific soccer training with the non-dominant leg on mental rotation performance of 20 adolescent soccer players between 10 and 11 years of age. While the experimental group performed soccer specific tasks only with the non-dominant foot once a week for 10 weeks, the control group absolved the same exercises with the dominant foot for the same period of time. Both groups performed a mental rotation task and shot, dribbling and ball control tests before and after the 10 week intervention. The most relevant result was that the experimental group showed a significantly larger increase in mental rotation ability than the control group.
Castagna, Carlo; Francini, Lorenzo; Krustrup, Peter
The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test considering 5 line sprints of 30-m interspersed with 30-s of active recovery in non-elite outfield young male soccer players. Twenty-six (age 14.9±1.2 years, height 1.72±0.12 cm......, body mass 62.2±5.1 kg) players were tested 48 hours and 7 days apart for 5x30-m performance over 5 trials (T1-T5). Short- (T1-T2) and long-term reliability (T1-T3-T4-T5) were assessed with Intraclass Correlation Coefficient (ICC) and with typical error for measurement (TEM). Short- and long...... study revealed that the 5x30-m sprint test is a reliable field test in the short and long-term when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decrements variables showed large variability across trials....
Chauvin, Alan; Chassot, Steve; Chenevière, Xavier; Taube, Wolfgang
The cognitive-motor performance (CMP), defined here as the capacity to rapidly use sensory information and transfer it into efficient motor output, represents a major contributor to performance in almost all sports, including soccer. Here, we used a high-technology system (COGNIFOOT) which combines a visual environment simulator fully synchronized with a motion capture system. This system allowed us to measure objective real-time CMP parameters (passing accuracy/speed and response times) in a large turf-artificial grass playfield. Forty-six (46) young elite soccer players (including 2 female players) aged between 11 and 16 years who belonged to the same youth soccer academy were tested. Each player had to pass the ball as fast and as accurately as possible towards visual targets projected onto a large screen located 5.32 meters in front of him (a short pass situation). We observed a linear age-related increase in the CMP: the passing accuracy, speed and reactiveness of players improved by 4 centimeters, 2.3 km/h and 30 milliseconds per year of age, respectively. These data were converted into 5 point-scales and compared to the judgement of expert coaches, who also used a 5 point-scale to evaluate the same CMP parameters but based on their experience with the players during games and training. The objectively-measured age-related CMP changes were also observed in expert coaches’ judgments although these were more variable across coaches and age categories. This demonstrates that high-technology systems like COGNIFOOT can be used in complement to traditional approaches of talent identification and to objectively monitor the progress of soccer players throughout a cognitive-motor training cycle. PMID:28953958
Hicheur, Halim; Chauvin, Alan; Chassot, Steve; Chenevière, Xavier; Taube, Wolfgang
The cognitive-motor performance (CMP), defined here as the capacity to rapidly use sensory information and transfer it into efficient motor output, represents a major contributor to performance in almost all sports, including soccer. Here, we used a high-technology system (COGNIFOOT) which combines a visual environment simulator fully synchronized with a motion capture system. This system allowed us to measure objective real-time CMP parameters (passing accuracy/speed and response times) in a large turf-artificial grass playfield. Forty-six (46) young elite soccer players (including 2 female players) aged between 11 and 16 years who belonged to the same youth soccer academy were tested. Each player had to pass the ball as fast and as accurately as possible towards visual targets projected onto a large screen located 5.32 meters in front of him (a short pass situation). We observed a linear age-related increase in the CMP: the passing accuracy, speed and reactiveness of players improved by 4 centimeters, 2.3 km/h and 30 milliseconds per year of age, respectively. These data were converted into 5 point-scales and compared to the judgement of expert coaches, who also used a 5 point-scale to evaluate the same CMP parameters but based on their experience with the players during games and training. The objectively-measured age-related CMP changes were also observed in expert coaches' judgments although these were more variable across coaches and age categories. This demonstrates that high-technology systems like COGNIFOOT can be used in complement to traditional approaches of talent identification and to objectively monitor the progress of soccer players throughout a cognitive-motor training cycle.
Full Text Available The cognitive-motor performance (CMP, defined here as the capacity to rapidly use sensory information and transfer it into efficient motor output, represents a major contributor to performance in almost all sports, including soccer. Here, we used a high-technology system (COGNIFOOT which combines a visual environment simulator fully synchronized with a motion capture system. This system allowed us to measure objective real-time CMP parameters (passing accuracy/speed and response times in a large turf-artificial grass playfield. Forty-six (46 young elite soccer players (including 2 female players aged between 11 and 16 years who belonged to the same youth soccer academy were tested. Each player had to pass the ball as fast and as accurately as possible towards visual targets projected onto a large screen located 5.32 meters in front of him (a short pass situation. We observed a linear age-related increase in the CMP: the passing accuracy, speed and reactiveness of players improved by 4 centimeters, 2.3 km/h and 30 milliseconds per year of age, respectively. These data were converted into 5 point-scales and compared to the judgement of expert coaches, who also used a 5 point-scale to evaluate the same CMP parameters but based on their experience with the players during games and training. The objectively-measured age-related CMP changes were also observed in expert coaches' judgments although these were more variable across coaches and age categories. This demonstrates that high-technology systems like COGNIFOOT can be used in complement to traditional approaches of talent identification and to objectively monitor the progress of soccer players throughout a cognitive-motor training cycle.
Ramírez-Campillo, Rodrigo; Meylan, César M P; Álvarez-Lepín, Cristian; Henriquez-Olguín, Carlos; Martinez, Cristian; Andrade, David C; Castro-Sepúlveda, Mauricio; Burgos, Carlos; Baez, Eduardo I; Izquierdo, Mikel
The purpose of this study was to determine the effects of short-term plyometric training interposed with 24 or 48 hours of rest between training sessions on explosive and endurance adaptations in young soccer players. A total of 166 players, between 10 and 17 years of age, were randomly divided into 3 groups: a control group (CG; n = 55) and 2 plyometric training groups with 24 hours (PT24; n = 54) and 48 hours (PT48; n = 57) of rest between training sessions. Before and after intervention, players were measured in squat jump, countermovement jump, 20 (RSI20) cm drop jump reactive strength index, broad long jump, 20-m sprint time, 10 × 5-m agility time, 20-m multistage shuttle run test, and sit-and-reach test. The plyometric training program was applied during 6 weeks, 2 sessions per week, with a load from 140 to 260 jumps per session, replacing some soccer-specific drills. After intervention, the CG did not show significant performance changes. PT24 and PT48 groups showed a small-to-moderate significant improvement in all performance tests (p plyometric drills should not be conducted on consecutive days, the study shows that plyometric training applied twice weekly on consecutive or nonconsecutive days results in similar explosive and endurance adaptations in young male soccer players.
Van Yperen, Nico W.; Duda, Joan L.
Extending past work testing goal perspective theory in sport, one purpose of this study was to examine, via a longitudinal design, the relationship of goal orientations to the beliefs about the causes of success in the case of elite male Dutch soccer players. A second purpose was to determine the
Brink, Michel S.; Visscher, Chris; Schmikli, Sandor L.; Nederhof, E.; Lemmink, Koen A. P. M.
The aim of the present study was to find early markers for overreaching that are applicable in sport practice. In a group of elite soccer players aged 1518, the stressrecovery balance and reaction times before and after exercise were assessed. Overreaching was indicated by an elevated submaximal
Koen A.P.M. Lemmink; E. Nederhof; C. Visscher; S.L. Schmikli; Michel S. Brink
Abstract The aim of the present study was to find early markers for overreaching that are applicable in sport practice. In a group of elite soccer players aged 15–18, the stress–recovery balance and reaction times before and after exercise were assessed. Overreaching was indicated by an elevated
Full Text Available Considering the limited knowledge regarding the effects of n-3 and n-6 PUFAs on the inflammatory response during physical activity, we aimed to evaluate the level of pro- and anti-inflammatory cytokines in young soccer players before and after a maximal physical load test at the beginning and end of a two-month training process. The study included 75 young footballers from Football School “Kragujevac,” who were followed during the two-month training programme. The subjects were divided into the following groups: 1 control group (consumed a standard diet; 2 group that consumed fish oil (2500 mg of n-3 PUFAs per day; 3 group that consumed nutritional sunflower oil (2500 mg of n-6 PUFAs daily. The maximal progressive exercise test was performed using a treadmill belt. Venous blood samples were drawn 4 times for the determination of cytokine levels (IL-6 and TNF-α: before and after the exercise load test before the two-month training programme (initial measurement and immediately before and after the exercise load test after the two-month training programme (control measurement. Supplementation with fish oil (n-3 has been associated with reduced levels of IL-6 compared with the initial values. After an acute bout of exercise, n-3 PUFAs did not show a significant effect on inflammatory marker dynamics, whereas n-6 PUFAs slightly stimulated the production of TNF-α.
Full Text Available The aim of the present study was to compare the effects of 3 training protocols (plyometric [PLYO], agility [AG], or repeated shuttle sprints [RS] on physical performance in the same population of young soccer players. Forty-two youth-level male players (13.6±0.3-years; 1.65±0.07 m; 54.1±6.5 kg; body fat: 12.8±2.6% participated in a short-term (6-week randomized parallel fully controlled training study (pre-to-post measurements: PLYO group, n=10; AG group, n=10; RS group, n=12; and control group [CON] n=10. PLYO training = 9 lower limb exercises (2-3 sets of 8-12 repetitions. The AG group performed planned AG drills and direction changes. RS training consisted of 2-4 sets of 5-6x 20 to 30 m shuttle sprints (20 seconds recovery in between. Progressive overload principles were incorporated into the programme by increasing the number of foot contacts and varying the complexity of the exercises. Pre/post-training tests were: bilateral standing horizontal jump, and unilateral horizontal jumps, sprint (30 m with 10 m lap time, agility (20 m zigzag, and repeated sprint ability (RSA (i.e. 6x30 m shuttle sprints: 2x15 m with 180° turns. Significant main effects for time (i.e. training application and group (training type were detected. Improvements in horizontal jumping were higher (p<0.01: ES=large in PLYO. The RS group improved significantly more (p<0.01; ES=large than other groups: 30 m sprint, RSAbest and RSAmean performances. Significantly greater increases in 20 m zigzag performance were observed following AG and RS training (4.0 and 3.8%, respectively compared with PLYO (2.0% and CON training (0.8%. No significant differences were reported in the RSAdec between groups. Elite young male soccer players’ physical performances can be significantly and specifically improved either using PLYO or AG or RSA training over short-term in-season training.
Full Text Available PURPOSE: To compare the lateral abdominal muscle thickness and other possible functional risk factors in young soccer players with and without low back pain (LBP.METHOD: In total, 30 young soccer players between 16 and 20 years old, with and without LBP, from the premier league participated in this study. The thicknesses of external oblique, internal oblique and transversus abdominis on both sides were measured via ultrasound imaging. In addition, hamstring flexibility, active lumbar forward flexion, and isometric muscle endurance of trunk extensors were measured and were compared regarding the history of LBP.RESULTS: Mean ± SD age of the subjects was 17.4 ± 1.1 years. There was no statistically significant difference regarding age, BMI, weekly training hours and age of starting to compete between groups. Subjects with sports-life, last year and last month history ofLBP had a statistically significant lower external oblique muscle thickness in both right and left side, and both dominant and non-dominant feet (p<0.05. Subjects with sportslife history of LBP had lower internal oblique muscle thickness in both side and both feet (p<0.05. Moreover, those with a sports-life history of LBP had a significantly higher degree of hamstring muscle tightness than non-LBP group on the dominant foot (p <0.05.CONCLUSION: In this sample group of young soccer players, abdominal muscles seem to have an important role in the stability of the spine and prevention of LBP. Further longitudinal studies are needed to evaluate the role of these muscles as a risk factor for soccer players.
Full Text Available It is recognized that much of the dietary data on adolescents and athletes is prone to reporting error, mostly through under-reporting. Nevertheless, in the majority of studies assessing the nutritional intake of young soccer players under-reporting has not been taken into consideration. The purpose of this study was to assess the dietary intake of a sample of young male Italian high-level soccer players on two time points to evaluate the degree of under- reporting. Seventy-five male high level soccer players (age range: 15-17 years completed 4-day food records on two separate occasions (T0; T1, 3 months after T0. Under-reporting was assessed by the ratio of reported estimated energy intake (EEI to estimated energy expenditure (EEE. Forty- three subjects, whose food records were judged accurate enough both at T0 and T1, were included in the data analysis (inclusion rate 57.3%. No significant weight changes were documented between T0 and T1 and in the two weeks preceding both T0 and T1. Reported mean daily energy intake was significantly lower than mean estimated daily energy expenditure both at T0 and T1 (p < 0.001. The average EEI/EEE ratio was 0.75 + 0.2 both at T0 and T1. It was < 80% in 27 subjects (62.8% at T0 and in 23 (53.4% at T1; it reached 50% in 4 subjects both at T0 and T1. The degree of under- reporting of the young soccer players was in line with the available data on this age group. This study emphasizes that under-reporting is a critical issue in the evaluation of young athletes dietary intake, which should be considered in the interpretation of data, particularly when energy inadequacies are reported. Further studies with uniformed methods are needed, in order to reduce the degree of under-reporting, obtain reliable data on the dietary intake of young soccer players and evaluate the efficacy of targeted nutrition education programs
Cesar G. Fraga
Full Text Available The consumption of a diet rich in certain flavonoids, including the flavanol sub-class, has been associated with a reduced risk for vascular disease. We evaluated the effects of the regular consumption (14 d of a flavanol-containing milk chocolate (FCMC or cocoa butter chocolate (CBC on variables related to vascular disease risk, oxidative stress and physical activity. Twenty-eight free-living, young (18–20 years old male soccer players consumed daily 105 g of FCMC (168 mg of flavanols or CBC (<5 mg of flavanols, as part of their normal diet. The consumption of FCMC was significantly associated with a decrease in diastolic blood pressure (-5 mm Hg, mean blood pressure (-5 mm Hg, plasma cholesterol (-11%, LDL-cholesterol (-15%, malondialdehyde (-12%, urate (-11% and lactate dehydrogenase (LDH activity (-11%, and an increase in vitamin E/cholesterol (+12%. No relevant changes in these variables were associated with CBC consumption. No changes in the plasma levels of (--epicatechin were observed following analysis of fasting blood samples. In conclusion, FCMC consumption was associated with changes in several variables often associated with cardiovascular health and oxidant stress. The presence of significant quantities of flavanols in FCMC is likely to have been one of the contributing factors to these results.
Full Text Available This study investigates the influence of specific soccer training with the non-dominant leg on mental rotation performance of 20 adolescent soccer players between 10 and 11 years of age. While the experimental group performed soccer specific tasks only with the non-dominant foot once a week for 10 weeks, the control group absolved the same exercises with the dominant foot for the same period of time. Both groups performed a mental rotation task and shot, dribbling and ball control tests before and after the 10 week intervention. The most relevant result was that the experimental group showed a significantly larger increase in mental rotation ability than the control group.
Sæther, Stig A; Aspvik, Nils P
'Practise makes perfect' is a well-known expression in most sports, including top-level soccer. However, a high training and match load increases the risk for injury, overtraining and burnout. With the use of accelerometers and a self-report questionnaire, the aim of this study was to describe talented players' physical activity (PA) level. Data were collected three times during the 2011 Norwegian Football season (March, June and October). The accelerometer output, counts·min(-1) (counts per unit time registered), reports the daily PA-level for young talented soccer players. Results showed a stable PA-level across the season (March: 901.2 counts·min(-1), June: 854.9 counts·min(-1), October: 861.5 counts·min(-1)). Furthermore, comparison of five different training sessions across the season showed that the PA-level ranged from 2435.8 to 3745.4 counts·min(-1). A one-way ANOVA showed no significant differences between the three measured weeks during the soccer season (p≤0.814). However, the training sessions in January had a significantly higher PA-level than those in June and October (p≤0.001). Based on these results, we discuss how potential implications of PA-level affect factors such as risk of injury, overtraining and burnout. We argue that player development must be seen as part of an overall picture in which club training and match load should be regarded as one of many variables influencing players' PA-level. Key pointsIt is well established that to achieve a high performance level in sport, one must implement a high training and match load in childhood and youth.With the use of accelerometers and a self-reported questionnaire, the aim of this study was to describe talented players' total physical activity (PA) load.These results indicate that young talented soccer players must overcome large doses of PA on a weekly basis, exposing them to a high risk of injury, overtraining and burnout.
Buchheit, Martin; Horobeanu, Cosmin; Mendez-Villanueva, Alberto; Simpson, Ben M; Bourdon, Pitre C
The aim of this study was to examine the effect of age and spa treatment (i.e. combined sauna, cold water immersion, and jacuzzi) on match running performance over two consecutive matches in highly trained young soccer players. Fifteen pre- (age 12.8 ± 0.6 years) and 13 post- (15.9 ± 1 y) peak height velocity (PHV) players played two matches (Matches 1 and 2) within 48 h against the same opposition, with no specific between-match recovery intervention (control). Five post-PHV players also completed another set of two consecutive matches, with spa treatment implemented after the first match. Match running performance was assessed using a global positioning system with very-high-intensity running (> 16.1-19.0 km · h(-1)), sprinting distance (>19 km · h(-1)), and peak match speed determined. Match 2 very-high-intensity running was "possibly" impaired in post-PHV players (-9 ± 33%; ± 90% confidence limits), whereas it was "very likely" improved for the pre-PHV players (+27 ± 22%). The spa treatment had a beneficial impact on Match 2 running performance, with a "likely" rating for sprinting distance (+30 ± 67%) and "almost certain" for peak match speed (+6.4 ± 3%). The results suggest that spa treatment is an effective recovery intervention for post-PHV players, while its value in pre-PHV players is questionable.
Grégory Hallé Petiot
Full Text Available Abstract Aim The aim of this research is to identify the mechanisms that lead soccer players to make quality tactical decisions, and how these mechanisms evolve over time. Methods Ninety male youth players training in a professional club in Brazil were submitted to a soccer video test which consists in making tactical decisions when the image freezes. These participants were divided in five groups with 18 players in each of following age levels: Under-11, Under-13, Under-15, Under-17 and Under-20. The dominant statements of verbal reports were distributed in categories that reflect key mechanisms. The frequency of correct tactical answers was calculated for each statement types and Standard Residuals (e were calculated to verify the influence of the mechanisms on the quality of tactical decision for each age level. Results Results revealed that evaluation statement was related to accurate tactical decisions from Under-15 age level. Conclusion In conclusion, evaluation of perceived information makes better decision makers.
Chamorro, José L; Torregrosa, Miquel; Sánchez Oliva, David; García Calvo, Tomás; León, Benito
Within the context of the transition from junior-to-senior sport, this study aims in first place to explore differences in young Spanish elite soccer players based on the importance given to getting different achievements in their future (including sport, studies and private life) and, in second place, to explore differences among those players in levels of passion, motivation and basic psychological need. 478 elite youth soccer filled out a questionnaire based on the presented theoretical models. A cluster analysis shows a sport oriented group (N = 98) only interested in becoming a professional, a life spheres balance group (N = 288) characterized by balancing the importance of achievements in the sport sphere, as well as in education and a private life and a group (N = 91) only interested in private life achievements. The life spheres balance group shows higher levels of harmonious passion (η2 = .06, F(2, 475) = 9.990, p passion and motivation, to cope with the transition to professional soccer.
Koertz, Rune; Andersen, T. Bull
AIM: The purpose of the present study was to evaluate if players and coaches should focus more on the non-preferred foot. The hypothesis of this study is that a small amount of training focusing on the non-preferred foot will improve the performance of the non-preferred foot for young elite playe...
García Quinteiro, Eva María; Rodríguez Casal, Mauro; Andrade, Elena M; Arce, Constantino
This work describes the Spanish adaptation and studies the psychometric properties of Yukelson, Weinberg, and Jackson's Multidimensional Sport Cohesion Instrument (MSCI) with a sample of 173 soccer players. The Spanish version is composed of 22 items grouped in four factors: quality of teamwork (performance aspects), attraction to the group, valued roles and quality of teamwork (interpersonal relationships), that accounted for 53.30% of the total variance. Reliability coefficients (Cronbach's Alphas) for the factors ranged from .84 (factor 1) to .56 (factor 4). Suggestions are made for future research on the validity of the scale, mainly in terms of convergence with other multidimensional measures of sport cohesion.
Full Text Available The aim of the study was to investigate test reliability of the Yo-Yo intermittent recovery test level 1 (YYIR1 in 36 high-level youth soccer players, aged between 13 and 18 years. Players were divided into three age groups (U15, U17 and U19 and completed three YYIR1 in three consecutive weeks. Pairwise comparisons were used to investigate test reliability (for distances and heart rate responses using technical error (TE, coefficient of variation (CV, intra-class correlation (ICC and limits of agreement (LOA with Bland-Altman plots. The mean YYIR1 distances for the U15, U17 and U19 groups were 2024 ± 470 m, 2404 ± 347 m and 2547 ± 337 m, respectively. The results revealed that the TEs varied between 74 and 172 m, CVs between 3.0 and 7.5%, and ICCs between 0.87 and 0.95 across all age groups for the YYIR1 distance. For heart rate responses, the TEs varied between 1 and 6 bpm, CVs between 0.7 and 4.8%, and ICCs between 0.73 and 0.97. The small ratio LOA revealed that any two YYIR1 performances in one week will not differ by more than 9 to 28% due to measurement error. In summary, the YYIR1 performance and the physiological responses have proven to be highly reliable in a sample of Belgian high-level youth soccer players, aged between 13 and 18 years. The demonstrated high level of intermittent endurance capacity in all age groups may be used for comparison of other prospective young soccer players.
Full Text Available The aim of the study was to compare the effects of plyometric training using 30, 60, or 120 s of rest between sets on explosive adaptations in young soccer players. Four groups of athletes (age 10.4 ± 2.3 y; soccer experience 3.3 ± 1.5 y were randomly formed: control (CG; n = 15, plyometric training with 30 s (G30; n = 13, 60 s (G60; n = 14, and 120 s (G120; n = 12 of rest between training sets. Before and after intervention players were measured in jump ability, 20-m sprint time, change of direction speed (CODS, and kicking performance. The training program was applied during 7 weeks, 2 sessions per week, for a total of 840 jumps. After intervention the G30, G60 and G120 groups showed a significant (p = 0.0001 – 0.04 and small to moderate effect size (ES improvement in the countermovement jump (ES = 0.49; 0.58; 0.55, 20 cm drop jump reactive strength index (ES = 0.81; 0.89; 0.86, CODS (ES = -1.03; -0.87; -1.04, and kicking performance (ES = 0.39; 0.49; 0.43, with no differences between treatments. The study shows that 30, 60, and 120 s of rest between sets ensure similar significant and small to moderate ES improvement in jump, CODS, and kicking performance during high-intensity short-term explosive training in young male soccer players.
Otero-Esquina, Carlos; de Hoyo Lora, Moisés; Gonzalo-Skok, Óliver; Domínguez-Cobo, Sergio; Sánchez, Hugo
The aim of this study was to analyse the effects of a combined strength-training programme (full-back squat, YoYo TM leg curl, plyometrics and sled towing exercises) on performance in elite young soccer players and to examine the effects when this training programme was performed one or two days per week. Thirty-six male soccer players (U-17 to U-19) were recruited and assigned to experimental groups (EXP1: 1 s w -1 ; EXP2: 2 s w -1 ) or a control group (CON). Performance was assessed through a countermovement jump (CMJ) test (relative peak power [CMJ PP ] and CMJ height [CMJ H ]), a 20-m linear sprint test with split-times at 10-m, and a change of direction test (V-cut test) 1 week before starting the training programme and also 1 week after performing such training programme. Within-group analysis showed substantial improvements in CMJ variables (ES: 0.39-0.81) and COD (ES: 0.70 and 0.76) in EXP1 and EXP2, while EXP2 also showed substantial enhancements in all linear sprinting tests (ES: 0.43-0.52). Between-group analysis showed substantially greater improvements in CMJ variables (ES: 0.39-0.68) in experimental groups in comparison to CON. Furthermore, EXP2 achieved a substantial better performance in 20-m (ES: 0.48-0.64) than EXP1 and CON. Finally, EXP2 also showed greater enhancements in 10-m (ES: 0.50) and V-cut test (ES: 0.52) than EXP1. In conclusion, the combined strength-training programme improved jumping ability, independently of training frequency, though the achievement of two sessions per week also enhanced sprinting abilities (linear and COD) in young soccer players.
Ruscello, B; Briotti, G; Tozzo, N; Partipilo, F; Taraborelli, M; Zeppetella, A; Padulo, J; D'Ottavio, S
The aim of this paper was to investigate the acute effects of two different initial heart rates intensities when testing the repeated sprint ability (RSA) performances in young soccer players. Since there are many kinds of pre-match warm-ups, we chose to take as an absolute indicator of internal load the heart rate reached at the end of two different warm-up protocols (60 vs. 90% HRmax) and to compare the respective RSA performances. The RSA tests were performed on fifteen male soccer players (age: 17.9±1.5 years) with two sets of ten shuttle-sprints (15+15 m) with a 1:3 exercise to rest ratio, in different days (randomized order) with different HR% (60 & 90% HRmax). In order to compare the different sprint performances a Fatigue Index (FI%) was computed, while the blood lactate concentrations (BLa-) were measured before and after testing, to compare metabolic demand. Significant differences among trials within each sets (Psoccer player operates during a real match. This background may be partially reproduced by warming up protocols that, by duration and metabolic commitment, can reproduce conveniently the physiological conditions encountered in a real game (e.g. HRmax≈85-95%; BLa->4 mmol/L(-1)).
Kato, Yoshihiko; Koga, Michiaki; Taguchi, Toshihiko
A 17-year-old male soccer player presented with numbness in the upper- and lower-left extremities of 6 months' duration. He had no apparent history of trauma but experienced neck pain during heading of the ball 5 years prior. A high-signal intensity area was seen on T2-weighted magnetic resonance imaging (MRI) of the cervical spine. No muscle weakness was observed. Hypoesthesia was observed in bilateral forearms, hands, and extremities below the inguinal region. Plain radiographs in the neutral position showed local kyphosis at C3/4. A small protrusion of the C3/4 disk was observed on T1-weighted MRI. A high-signal area in the spinal cord at the C3/4 level was observed on T2-weighted MRI, but this was not enhanced by gadolinium. Multiple sclerosis, intramedullary spinal cord tumor, sarcoidosis and malignant lymphoma, and spinal cord injury were all considered in the differential diagnosis. However, in view of the clinical, laboratory, and radiological investigations, we concluded that repeated impacts to the neck caused by heading of the ball during soccer induced a chronic, minor spinal cord injury. This contributed to the high-signal intensity change of the spinal cord in T2-weighted MRI. The present case demonstrates that repeated impact may cause chronic spinal cord injury. Soccer, American football, or rugby players presenting with neck or extremity symptoms should not be overlooked for the possibility of latent spinal cord injury, as this could present later development of more severe or unrecoverable spinal cord injuries. Copyright 2010, SLACK Incorporated.
Castagna, Carlo; Krustrup, Peter; D'Ottavio, Stefano
The purpose of this study was to examine the reliability and the association with relevant match activities (ecological validity) of an age-adapted field test for intermittent high-intensity endurance known as Yo-Yo intermittent recovery level 1 children test (YYIR1C) in young male soccer players......-intensity metabolic power (r=0.46) distances. Match total distance was largely associated with YYIR1C (r=0.30). The results of this study showed that YYIR1C may be considered a valid and reliable field test for assessing intermittent high-intensity endurance in young male soccer players. Due to the relevance...... performance showed an excellent relative (ICC=0.94) and a good absolute reliability (TEM as %CV=5.1%). Very large and significant associations were found between YYIR1C performance and match high-intensity activity (r=0.53). Large correlations were found between YYIR1C and match sprinting (r=0.42) and high...
Karakilcik, A Z; Halat, R; Zerin, M; Celik, H; Nazligul, Y
Exercise may increase production of reactive oxygen species (ROS) enhancing oxidative stress. Antioxidants can efficiently scavenge ROS before they initiate oxidative damage of biomolecules such as enzymes, nucleic acids, lipids and lipoproteins in the body. Vitamin C, an important antioxidant, may affect oxidative stress in living organism. Therefore, this study was carried out to investigate the effects of exercise and vitamin C on thiobarbituric acid-reactive substance (TBARS), lipid profile, erythrocyte and platelet indices in young soccer players. This investigation was carried out on twenty two male volunteer players in three groups. The first group was examined as a control. The second group was only exposed to exercise. The third group was exposed to exercise plus vitamin C (500 mg/day) administered per oral. The players were 23.50±0.59 year-old, 67.66±1.52 kg body weight and 1.74±0.03 m height. Blood samples were collected in vacutainer tubes for analysis of biochemical and hematological parameters. While the levels of high density lipoprotein-cholesterol (HDL-C) were significantly increased (PC) were decreased (Pvitamin C treatment. While TBARS levels were increased (Pvitamin C treatment. The platelet counts (PLT), mean platelet volume (MPV), plateletcrit (PCT) and red blood cell distribution width (RDW) were significantly decreased (Pvitamin C. There were significantly correlations (PC and in increasing of HDL-C. In addition, exercise plus vitamin C may diminish TBARS-levels and may affect the values of PLT, MPV, PCT and RDW in young soccer players.
Ramírez-Campillo, Rodrigo; Henríquez-Olguín, Carlos; Burgos, Carlos; Andrade, David C; Zapata, Daniel; Martínez, Cristian; Álvarez, Cristian; Baez, Eduardo I; Castro-Sepúlveda, Mauricio; Peñailillo, Luis; Izquierdo, Mikel
The purpose of the study was to compare the effects of progressive volume-based overload with constant volume-based overload on muscle explosive and endurance performance adaptations during a biweekly short-term (i.e., 6 weeks) plyometric training intervention in young soccer players. Three groups of young soccer players (age 13.0 ± 2.3 years) were divided into: control (CG; n = 8) and plyometric training with (PPT; n = 8) and without (NPPT; n = 8) a progressive increase in volume (i.e., 16 jumps per leg per week, with an initial volume of 80 jumps per leg each session). Bilateral and unilateral horizontal and vertical countermovement jump with arms (CMJA), 20-cm drop jump reactive strength index (RSI20), maximal kicking velocity (MKV), 10-m sprint, change of direction speed (CODS), and Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1) were measured. Although both experimental groups significantly increased CMJA, RSI20, CODS, and endurance performance, only PPT showed a significant improvement in MKV and 10-m sprint time. In addition, only PPT showed a significantly higher performance improvement in jumping, MKV, and Yo-Yo IR1 compared with CG. Also, PPT showed higher meaningful improvement compared with NPPT in all (except 1) jump performance measures. Furthermore, although PPT involved a higher total volume compared with NPPT, training efficiency (i.e., percentage change in performance/total jump volume) was similar between groups. Our results show that PPT and NPPT ensured significant improvement in muscle explosive and endurance performance measures. However, a progressive increase in plyometric training volume seems more advantageous to induce soccer-specific performance improvements.
Moreira, Alexandre; Massa, Marcelo; Thiengo, Carlos R; Rodrigues Lopes, Rafael Alan; Lima, Marcelo R; Vaeyens, Roel; Barbosa, Wesley P; Aoki, Marcelo S
The aim of this study was to examine the influence of hormonal status, anthropometric profile, sexual maturity level, and physical performance on the technical abilities of 40 young male soccer players during small-sided games (SSGs). Anthropometric profiling, saliva sampling, sexual maturity assessment (Tanner scale), and physical performance tests (Yo-Yo and vertical jumps) were conducted two weeks prior to the SSGs. Salivary testosterone was determined by the enzyme-linked immunosorbent assay method. Technical performance was determined by the frequency of actions during SSGs. Principal component analyses identified four technical actions of importance: total number of passes, effectiveness, goal attempts, and total tackles. A multivariate canonical correlation analysis was then employed to verify the prediction of a multiple dependent variables set (composed of four technical actions) from an independent set of variables, composed of testosterone concentration, stage of pubic hair and genitalia development, vertical jumps and Yo-Yo performance. A moderate-to-large relationship between the technical performance set and the independent set was observed. The canonical correlation was 0.75 with a canonical R 2 of 0.45. The highest structure coefficient in the technical performance set was observed for tackles (0.77), while testosterone presented the highest structure coefficient (0.75) for the variables of the independent set. The current data suggest that the selected independent set of variables might be useful in predicting SSG performance in young soccer players. Coaches should be aware that physical development plays a key role in technical performance to avoid decision-making mistakes during the selection of young players.
McKinlay, Brandon John; Wallace, Phillip; Dotan, Raffy; Long, Devon; Tokuno, Craig; Gabriel, David; Falk, Bareket
This study examined the effect of 8-weeks of free-weight-resistance (RT) and plyometric (PLYO) training on maximal strength, explosiveness and jump performance compared with no added training (CON), in young male soccer players. Forty-one 11[FIGURE DASH]13-year-old soccer players were divided into three groups (RT, PLYO, CON). All participants completed isometric and dynamic (240°/s) knee extensions pre- and post-training. Peak torque (pT), peak rate of torque development (pRTD), electromechanical-delay (EMD), rate of muscle activation (Q50), m. vastus-lateralis thickness (VLT), and jump performance were examined. pT, pRTD and jump performance significantly improved in both training groups. Training resulted in significant (pplyometric training resulted in significant improvements in muscle strength and jump performance. Training resulted in similar muscle hypertrophy in the two training modes, with no clear differences in muscle performance. Plyometric training was more effective in improving jump performance, while free-weight resistance training was more advantageous in improving peak torque, where the stretch reflex was not involved.
Full Text Available Gunnar Mathisen, Svein Arne Pettersen School of Sport Sciences, UiT The Arctic University of Norway, Tromsø, Norway Objective: To investigate the relationship between anthropometrics and sprint and agility performance and describe the development of sprint (acceleration and agility performance in 10- to 16-year-old male soccer players. Methods: One hundred and thirty-two participants were divided into three age groups, 10–12 years (mean 10.8±0.50, 13–14 years (mean 13.9±0.50, and 15–16 years (mean 15.5±0.24, with assessment of 20 m sprint with 10 m split time and agility performance related to body height and body mass within groups. Results: In the 10- to 12-year-olds, there were no significant correlations between height, weight, and the performance variables, except for body mass, which was correlated to 10–20 m sprint (r=0.30. In the 13- to 14-year-olds, body height was significantly correlated with 10 m sprint (r=0.50 and 20 m sprint (r=0.52, as well as 10–20 m sprint (r=0.50 and agility performance (r=0.28. In the 15- to 16-year-old group, body height was correlated to 20 m (r=0.38 and 10–20 m (r=0.45 sprint. Body mass was significantly correlated to 10 m spring (r=0.35 in the 13- to 14-year-olds, as well as 20 m (r=0.33 and 10–20 m (r=0.35 sprint in the 15- to 16-year-olds. Conclusion: Height and body mass were significantly correlated with sprint performance in 13- to 16-year-old male soccer players. However, the 10- to 12-year-olds showed no significant relationship between sprint performance and anthropometrics, except for a small correlation in 10–20 m sprint. This may be attributed to maturation, with large differences in body height and body mass due to different patterns in the growth spurt. The agility performance related to anthropometrics was insignificant apart from a moderate correlation in the 13- to 14-year-olds. Keywords: youth soccer, running speed, development, football, puberty, skills
Stig A. Sæther, Nils P. Aspvik
Full Text Available ‘Practise makes perfect’ is a well-known expression in most sports, including top-level soccer. However, a high training and match load increases the risk for injury, overtraining and burnout. With the use of accelerometers and a self-report questionnaire, the aim of this study was to describe talented players’ physical activity (PA level. Data were collected three times during the 2011 Norwegian Football season (March, June and October. The accelerometer output, counts·min–1 (counts per unit time registered, reports the daily PA-level for young talented soccer players. Results showed a stable PA-level across the season (March: 901.2 counts·min–1, June: 854.9 counts·min–1, October: 861.5 counts·min–1. Furthermore, comparison of five different training sessions across the season showed that the PA-level ranged from 2435.8 to 3745.4 counts·min–1. A one-way ANOVA showed no significant differences between the three measured weeks during the soccer season (p≤0.814. However, the training sessions in January had a significantly higher PA-level than those in June and October (p≤0.001. Based on these results, we discuss how potential implications of PA-level affect factors such as risk of injury, overtraining and burnout. We argue that player development must be seen as part of an overall picture in which club training and match load should be regarded as one of many variables influencing players’ PA-level.
Full Text Available The aim of this study was to identify the physiological responses of 3 forms of players’ numbers during two different games rules of small-sided games (SSG: stop-ball vs. small-goals rules. Eighteen youth amateur soccer players (age 13.5±0.7 years; height 168.9±6.1cm; body mass 63.1±7.7 kg participated in this study and performed 3 SSGs with varying players’ number (2vs.2; 3vs.3 and 4vs.4: stop-ball SSG (SB-SSG vs. small-goals SSG (SG-SSG in a randomized and counter-balanced order on a constant pitch dimension (20×25m. The players performed 4×4 min SSG with 2-min of passive recovery in-between. Heart rate (HR, (expressed in bpm and % HRmax, lactate ([La-], and rating of perceived exertion (RPE were collected during each session. SB-SSG induced the higher HR values in comparison with the SG-SSG for the 3 game formats (2vs.2; 3vs.3 and 4vs.4. Also, compared with SG-SSG, SB-SSG induced the higher HR values during 2vs.2 compared with 4vs.4 games rules (178 vs. 174 and 175 vs. 171 bpm, respectively. However, the SB-SSG was more intense compared with SG-SSG in the 2 vs. 2 game rule compared with the two others (3 vs.3 and 4 vs. 4 for [La-] and RPE (7.58 vs. 7; 7.25 vs. 6.75 and 6.5 vs. 6.16 mmol ∙ L-1, and 7.75 vs. 7.33; 7.41 vs. 7.08 and 7.16 vs. 6.83, respectively. Therefore, the use of 2 vs. 2 and 3 vs. 3 SSG with SB-SSG seems to represent an alternative to coaches to increase cardiovascular and metabolic demands in youth soccer players.
Chtourou, H; Dellal, A; Chaouachi, A; Chamari, K
The aim of this study was to identify the physiological responses of 3 forms of players’ numbers during two different games rules of small-sided games (SSG: stop-ball vs. small-goals rules). Eighteen youth amateur soccer players (age 13.5±0.7 years; height 168.9±6.1cm; body mass 63.1±7.7 kg) participated in this study and performed 3 SSGs with varying players’ number (2vs.2; 3vs.3 and 4vs.4): stop-ball SSG (SB-SSG) vs. small-goals SSG (SG-SSG) in a randomized and counter-balanced order on a constant pitch dimension (20×25m). The players performed 4×4 min SSG with 2-min of passive recovery in-between. Heart rate (HR), (expressed in bpm and % HRmax), lactate ([La-]), and rating of perceived exertion (RPE) were collected during each session. SB-SSG induced the higher HR values in comparison with the SG-SSG for the 3 game formats (2vs.2; 3vs.3 and 4vs.4). Also, compared with SG-SSG, SB-SSG induced the higher HR values during 2vs.2 compared with 4vs.4 games rules (178 vs. 174 and 175 vs. 171 bpm, respectively). However, the SB-SSG was more intense compared with SG-SSG in the 2 vs. 2 game rule compared with the two others (3 vs.3 and 4 vs. 4) for [La-] and RPE (7.58 vs. 7; 7.25 vs. 6.75 and 6.5 vs. 6.16 mmol ∙ L-1, and 7.75 vs. 7.33; 7.41 vs. 7.08 and 7.16 vs. 6.83, respectively). Therefore, the use of 2 vs. 2 and 3 vs. 3 SSG with SB-SSG seems to represent an alternative to coaches to increase cardiovascular and metabolic demands in youth soccer players. PMID:28566810
Prieske, Olaf; Maffiuletti, Nicola A; Granacher, Urs
High-intensity muscle actions have the potential to temporarily improve muscle contractile properties (i.e., postactivation potentiation, PAP) thereby inducing acute performance enhancements. There is evidence that balance training can improve performance during strength exercises. Taking these findings together, the purpose of this study was to examine the acute effects of a combined balance and strength (B+S) exercise vs. a strength only (S) exercise on twitch contractile properties, maximum voluntary strength, and jump performance in young athletes. Female elite young soccer players ( N = 12) aged 14-15 years conducted three experimental conditions in randomized order: S included 3 sets of 8-10 dynamic leg extensions at 80% of the 1-repetition maximum, B+S consisted of 3 sets of 40 s double-leg stances on a balance board prior to leg extensions (same as S), and a resting control period. Before and 7 min after exercise, participants were tested for their electrically-evoked isometric twitches (i.e., twitch peak torque, twitch rate of torque development) and maximal voluntary contraction (MVC) torque of the plantar flexor muscles. Additionally, countermovement (CMJ) and drop jump (DJ) performances (i.e., CMJ/DJ height, DJ ground contact time) were assessed. Significant effects of condition on twitch contractile properties ( p jump performance outputs ( p jump performance. It is concluded that PAP effects in the plantar flexors may not directly translate to improved jump performance in female elite young soccer players. Therefore, the observed gains in jump performance following B+S are most likely related to neuromuscular changes (e.g., intramuscular coordination) rather than improved contractile properties.
Arnaoutis, Giannis; Kavouras, Stavros A; Kotsis, Yiannis P; Tsekouras, Yiannis E; Makrillos, Michalis; Bardis, Costas N
There is a lack of studies concerning hydration status of young athletes exercising in the heat. To assess preexercise hydration status in young soccer players during a summer sports camp and to evaluate body- water balance after soccer training sessions. Initial hydration status was assessed in 107 young male soccer players (age 11-16 yr) during the 2nd day of the camp. Seventy-two athletes agreed to be monitored during 2 more training sessions (3rd and 5th days of the camp) to calculate dehydration via changes in body weight, while water drinking was allowed ad libitum. Hydration status was assessed via urine specific gravity (USG), urine color, and changes in total body weight. Mean environmental temperature and humidity were 27.2 ± 2 °C and 57% ± 9%, respectively. According to USG values, 95 of 107 of the players were hypohydrated (USG ≥ 1.020) before practice. The prevalence of dehydration observed was maintained on both days, with 95.8% and 97.2% of the players being dehydrated after the training sessions on the 3rd and 5th days, respectively. Despite fluid availability, 54 of the 66 (81.8%) dehydrated players reduced their body weight (-0.35 ± 0.04 kg) as a response to training, while 74.6% (47 out of the 63) further reduced their body weight (-0.22 ± 0.03 kg) after training on the 5th day. Approximately 90% of the young soccer players who began exercising under warm weather conditions were hypohydrated, while drinking ad libitum during practice did not prevent further dehydration in already dehydrated players.
Verburgh, Lot; Scherder, Erik J. A.; van Lange, Paul A.M.; Oosterlaan, Jaap
Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer. PMID:24632735
Full Text Available Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9, and forty-two age-matched amateur soccer players (mean age 11.8 in the age range 8 to 16 years performed a Stop Signal task (motor inhibition, the Attention Network Test (alerting, orienting, and executive attention and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer.
Buchheit, Martin; Hammond, Kristal; Bourdon, Pitre C; Simpson, Ben M; Garvican-Lewis, Laura A; Schmidt, Walter F; Gore, Christopher J; Aughey, Robert J
To compare relative match intensities of sea-level versus high-altitude native soccer players during a 2-week camp at 3600 m, data from 7 sea-level (Australian U17 National team, AUS) and 6 high-altitude (a Bolivian U18 team, BOL) native soccer players were analysed. Two matches were played at sea-level and three at 3600 m on Days 1, 6 and 13. The Yo-Yo Intermittent recovery test (vYo-YoIR1) was performed at sea-level, and on Days 3 and 10. Match activity profiles were measured via 10-Hz GPS. Distance covered >14.4 km.h(-1) (D>14.4 km·h(-1)) and >80% of vYo-YoIR1 (D>80%vYo-YoIR1) were examined. Upon arrival at altitude, there was a greater decrement in vYo-YoIR1 (Cohen's d +1.0, 90%CL ± 0.8) and D>14.4 km·h(-1) (+0.5 ± 0.8) in AUS. D>14.4 km.h(-1) was similarly reduced relative to vYo-YoIR1 in both groups, so that D>80%vYo-YoIR1 remained similarly unchanged (-0.1 ± 0.8). Throughout the altitude sojourn, vYo-YoIR1 and D>14.4 km·h(-1) increased in parallel in AUS, so that D>80%vYo-YoIR1 remained stable in AUS (+6.0%/match, 90%CL ± 6.7); conversely D>80%vYo-YoIR1 decreased largely in BOL (-12.2%/match ± 6.2). In sea-level natives competing at high-altitude, changes in match running performance likely follow those in high-intensity running performance. Bolivian data confirm that increases in 'fitness' do not necessarily translate into greater match running performance, but rather in reduced relative exercise intensity. Key pointsWhen playing at high-altitude, players may alter their activities during matches in relation to their transient maximal physical capacities, possibly to maintain a 'tolerable' relative exercise intensity.While there is no doubt that running performance per se in not the main determinant of match outcomes (Carling, 2013), fitness levels influence relative match intensity (Buchheit et al., 2012, Mendez-Villanueva et al., 2013), which in-turn may impact on decision making and skill performance (Rampinini et al., 2008).In the context of
Ramirez-Campillo, Rodrigo; Sanchez-Sanchez, Javier; Gonzalo-Skok, Oliver; Rodríguez-Fernandez, Alejandro; Carretero, Manuel; Nakamura, Fabio Y
The aim of this study was to compare changes in young soccer player's fitness after traditional bilateral vs. unilateral combined plyometric and strength training. Male athletes were randomly divided in two groups; both received the same training, including strength training for knee extensors and flexors, in addition to horizontal plyometric training drills. The only difference between groups was the mode of drills technique: unilateral (UG; n = 9; age, 17.3 ± 1.1 years) vs. bilateral (TG; n = 9; age, 17.6 ± 0.5 years). One repetition maximum bilateral strength of knee muscle extensors (1RM_KE) and flexors (1RM_KF), change of direction ability (COD), horizontal and vertical jump ability with one (unilateral) and two (bilateral) legs, and limb symmetry index were measured before and after an 8-week in-season intervention period. Some regular soccer drills were replaced by combination of plyometric and strength training drills. Magnitude-based inference statistics were used for between-group and within-group comparisons. Beneficial effects ( p plyometric training should be complemented with unilateral drills, in order to maximize adaptations.
Waldenmeier, Leonie; Evers, Christoph; Uder, Michael; Janka, Rolf; Hennig, Frank Friedrich; Pachowsky, Milena Liese; Welsch, Götz Hannes
Objective To evaluate and characterize the appearance of articular cartilage in the tibiofemoral joint of young professional soccer players using T2-relaxation time evaluation on magnetic resonance imaging (MRI). Design In this study, we included 57 male adolescents from the youth academy of a professional soccer team. The MRI scans were acquired of the knee joint of the supporting leg. An "early unloading" (minute 0) and "late unloading" (minute 28) T2-sequence was included in the set of images. Quantitative T2-analysis was performed in the femorotibial joint cartilage in 4 slices with each 10 regions of interest (ROIs). Statistical evaluation, using Wilcoxon signed-rank tests, was primarily performed to compare the T2 values of the "early unloading" and "late unloading." Results When comparing "early unloading" with "late unloading," our findings showed a significant increase of T2-relaxation times in the weightbearing femoral cartilage of the medial ( P cartilage of the medial compartment ( P cartilage were found with a maximum in the medial condyle where the biomechanical load of the knee joint is highest, as well as where most of the chronic cartilage lesions occur. To avoid chronic damage, special focus should be laid on this region.
Valente-Dos-Santos, J; Coelho-E-Silva, M J; Vaz, V; Figueiredo, A J; Capranica, L; Sherar, L B; Elferink-Gemser, M T; Malina, R M
The purpose of the current study was to assess the developmental changes in change of direction and dribbling speed in youth soccer players taking into account skeletal age (SA), maturity status, body size, estimated fat mass, aerobic endurance, lower limb explosive strength and annual volume of training. Eighty-three male soccer players aged 10-15 years (SA) at baseline were annually followed over 5 years, resulting in an average 4.4 observations per player. After testing for multicollinearity, multi-level regression modeling was used to examine the longitudinal developmental changes on change of direction and dribbling speed. Maturity-associated variability was significant in change of direction and also dribbling speed among young soccer players aged 12-14 years with better scores being performed by late maturers. Moreover, the predicted longitudinal scores for change of direction and dribbling speed improved with SA (Psoccer-specific skill, dibbling speed, was also explained by annual volume of training (Pperformances with and without the ball possession at early ages of participation in competitive soccer. The effects tend to persist across ages combined with longitudinal changes in body composition and functional fitness. In the particular case of the ball test, annual volume of training was also a longitudinal performance predictor.
Full Text Available The purpose of this study was to examine the effect of maturation on post-exercise hemodynamic and autonomic responses. Fifty-five highly-trained young male soccer players (12-18 yr classified as pre-, circum- or post-peak height velocity (PHV performed a graded running test to exhaustion on a treadmill. Before (Pre and after (5th-10th min, Post exercise, heart rate (HR, stroke volume (SV, cardiac ouput (CO, arterial pressure (AP and total peripheral resistance (TPR were monitored. Parasympathetic (high-frequency [HFRR] of HR variability (HRV and baroreflex sensitivity [Ln BRS] and sympathetic activity (low-frequency [LFSAP] of systolic AP variability were estimated. Post-exercise blood lactate [La]b, the HR recovery (HRR time constant and parasympathetic reactivation (time varying HRV analysis were assessed. In all three groups, exercise resulted in increased HR, CO, AP and LFSAP (P<0.001, decreased SV, HFRR and Ln BRS (all P<0.001, and no change in TPRI (P=0.98. There was no ‘maturation x time’ interaction for any of the hemodynamic or autonomic variables (all P>0.22. After exercise, pre-PHV players displayed lower SV, CO and [La]b, faster HRR and greater parasympathetic reactivation compared with circum- and post-PHV players. Multiple regression analysis showed that lean muscle mass, [La]b and Pre parasympathetic activity were the strongest predictors of HRR (r2=0.62, P<0.001. While pre-PHV players displayed a faster HRR and greater post-exercise parasympathetic reactivation, maturation had little influence on the hemodynamic and autonomic responses following maximal running exercise. HRR relates to lean muscle mass, blood acidosis and intrinsic parasympathetic function, with less evident impact of post-exercise autonomic function.
Ramírez-Campillo, Rodrigo; Meylan, César; Alvarez, Cristian; Henríquez-Olguín, Carlos; Martínez, Cristian; Cañas-Jamett, Rodrigo; Andrade, David C; Izquierdo, Mikel
Integrating specific training methods to improve explosive actions and endurance in youth soccer is an essential part of players' development. This study investigated the efficiency of short-term vertical plyometric training program within soccer practice to improve both explosive actions and endurance in young soccer players. Seventy-six players were recruited and assigned either to a training group (TG; n = 38; 13.2 ± 1.8 years) or a control group (CG; n = 38; 13.2 ± 1.8 years) group. All players trained twice per week, but the TG followed a 7-week plyometric program implemented within soccer practice, whereas the CG followed regular practice. Twenty-meter sprint time (20-m), Illinois agility test time, countermovement jump (CMJ) height, 20- (RSI20) and 40- (RSI40) cm drop jump reactive strength index, multiple 5 bounds distance (MB5), maximal kicking test for distance (MKD), and 2.4-km time trial were measured before and after the 7-week period. Plyometric training induced significant (p ≤ 0.05) and small to moderate standardized effect (SE) improvement in the CMJ (4.3%; SE = 0.20), RSI20 (22%; SE = 0.57), RSI40 (16%; SE = 0.37), MB5 (4.1%; SE = 0.28), Illinois agility test time (-3.5%, SE = -0.26), MKD (14%; SE = 0.53), 2.4-km time trial (-1.9%; SE = -0.27) performances but had a trivial and nonsignificant effect on 20-m sprint time (-0.4%; SE = -0.03). No significant improvements were found in the CG. An integrated vertical plyometric program within the regular soccer practice can substitute soccer drills to improve most explosive actions and endurance, but horizontal exercises should also be included to enhance sprinting performance.
Full Text Available High-intensity muscle actions have the potential to temporarily improve muscle contractile properties (i.e., postactivation potentiation, PAP thereby inducing acute performance enhancements. There is evidence that balance training can improve performance during strength exercises. Taking these findings together, the purpose of this study was to examine the acute effects of a combined balance and strength (B+S exercise vs. a strength only (S exercise on twitch contractile properties, maximum voluntary strength, and jump performance in young athletes. Female elite young soccer players (N = 12 aged 14–15 years conducted three experimental conditions in randomized order: S included 3 sets of 8–10 dynamic leg extensions at 80% of the 1-repetition maximum, B+S consisted of 3 sets of 40 s double-leg stances on a balance board prior to leg extensions (same as S, and a resting control period. Before and 7 min after exercise, participants were tested for their electrically-evoked isometric twitches (i.e., twitch peak torque, twitch rate of torque development and maximal voluntary contraction (MVC torque of the plantar flexor muscles. Additionally, countermovement (CMJ and drop jump (DJ performances (i.e., CMJ/DJ height, DJ ground contact time were assessed. Significant effects of condition on twitch contractile properties (p < 0.05, d = 1.1 and jump performance outputs (p < 0.05, 1.1 ≤ d ≤ 1.2 were found. Post-hoc tests revealed that S compared to control produced larger PAP for twitch peak torques by trend (p = 0.07, d = 1.8, 33 vs. 21% and significantly larger PAP for twitch rate of torque development (p < 0.05, d = 2.4, 55 vs. 43%. Following B+S compared to control, significant improvements in CMJ height (p < 0.01, d = 1.9, 3% and DJ contact time were found (p < 0.01, d = 2.0, 10%. This study revealed protocol-specific acute performance improvements. While S resulted in significant increases in twitch contractile properties, B+S produced
Sargent, Charli; Schmidt, Walter F; Aughey, Robert J; Bourdon, Pitre C; Soria, Rudy; Claros, Jesus C Jimenez; Garvican-Lewis, Laura A; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Gore, Christopher J; Roach, Gregory D
Background Altitude training is used by elite athletes to improve sports performance, but it may also disrupt sleep. The aim of this study was to examine the effects of 2 weeks at high altitude on the sleep of young elite athletes. Methods Participants (n=10) were members of the Australian under-17 soccer team on an 18-day (19-night) training camp in Bolivia, with six nights at near sea level in Santa Cruz (430 m) and 13 nights at high altitude in La Paz (3600 m). Sleep was monitored using polysomnography during a baseline night at 430 m and three nights at 3600 m (immediately after ascent, 1 week after ascent and 2 weeks after ascent). Data were analysed using effect size statistics. Results All results are reported as comparisons with baseline. Rapid eye movement (REM) sleep was likely lower immediately upon ascent to altitude, possibly lower after 1 week and similar after 2 weeks. On all three nights at altitude, hypopneas and desaturations were almost certainly higher; oxygen saturation was almost certainly lower; and central apnoeas, respiratory arousals and periodic breathing were very likely higher. The effects on REM sleep were common to all but one participant, but the effects on breathing were specific to only half the participants. Conclusions The immediate effects of terrestrial altitude of 3600 m are to reduce the amount of REM sleep obtained by young elite athletes, and to cause 50% of them to have impaired breathing during sleep. REM sleep returns to normal after 2 weeks at altitude, but impaired breathing does not improve. PMID:24282215
Full Text Available The aim of the present study was to determine the effects of three weeks of hyperbaric oxygen (HBO2 training on oxidative stress markers and endurance performance in young soccer players. Participants (18.6±1.6 years were randomized into hyperbaric-hyperoxic (HH training (n=6 and normobaric normoxic (NN training (n=6 groups. Immediately before and after the 5th, 10th, and 15th training sessions, plasma oxidative stress markers (lipid hydroperoxides and uric acid, plasma antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [TROLOX], arterial blood gases, acid-base balance, bases excess (BE, and blood lactate analyses were performed. Before and after intervention, maximal oxygen uptake (VO2max and peak power output (PPO were determined. Neither HH nor NN experienced significant changes on oxidative stress markers or antioxidant capacity during intervention. VO2max and PPO were improved (moderate effect size after HH training. The results suggest that HBO2 endurance training does not increase oxidative stress markers and improves endurance performance in young soccer players. Our findings warrant future investigation to corroborate that HBO2 endurance training could be a potential training approach for highly competitive young soccer players.
Abeln, Vera; Kleinert, Jens; Strüder, Heiko K; Schneider, Stefan
The effect of sleep deprivation on psychophysical performance and well-being is comprehensively investigated. Research investigating the effect of improved sleep is rare. Just as little exists about attempts to support athletic mental state and performance by improving sleep quality. This study aims to investigate whether sleep quality of top athletes can be improved by auditory brainwave entrainment and whether this leads to enhancements of post-sleep psychophysical states. In a pilot study, 15 young elite soccer players were stimulated for eight weeks during sleep with binaural beats around 2-8 Hz. Once a week after wake-up, participants completed three different questionnaires: a sleep diary, an adjective list for psychophysical and motivational state, and a self-assessment questionnaire for sleep and awakening quality. Fifteen sport students executed the same protocol sleeping on the same pillow, but without stimulation. Subjective ratings of sleep and awakening quality, sleepiness and motivational state were significantly improved only in the intervention group, but did not impact their perceived physical state. In summary, eight weeks of auditory stimulation with binaural beats improved perceived sleep quality and the post-sleep state of athletes, whereas the effect on physical level is assumed to occur in a time-delayed fashion. It seems to be worthwhile - to further elaborate long-time effects and consequences on physical and mental performance.
Bricout, Véronique-Aurélie; Dechenaud, Simon; Favre-Juvin, Anne
The use of heart rate variability (HRV) in the management of sport training is a practice which tends to spread, especially in order to prevent the occurrence of states of fatigue. To estimate the HRV parameters obtained using a heart rate recording, according to different loads of sporting activities, and to make the possible link with the appearance of fatigue. Eight young football players, aged 14.6 years+/-2 months, playing at league level in Rhône-Alpes, training for 10 to 20 h per week, were followed over a period of 5 months, allowing to obtain 54 recordings of HRV in three different conditions: (i) after rest (ii) after a day with training and (iii) after a day with a competitive match. Under the effect of a competitive match, the HRV temporal indicators (heart rate, RR interval, and pNN50) were significantly altered compared to the rest day. The analysis of the sympathovagal balance rose significantly as a result of the competitive constraint (0.72+/-0.17 vs. 0.90+/-0.20; pHRV is an objective and non-invasive monitoring of management of the training of young sportsmen. HRV analysis allowed to highlight any neurovegetative adjustments according to the physical loads. Thus, under the effect of an increase of physical and psychological constraints that a football match represents, the LF/HF ratio rises significantly; reflecting increased sympathetic stimulation, which beyond certain limits could be relevant to prevent the emergence of a state of fatigue. 2009 Elsevier B.V. All rights reserved.
Ramírez-Campillo, Rodrigo; Gallardo, Francisco; Henriquez-Olguín, Carlos; Meylan, Cesar M P; Martínez, Cristian; Álvarez, Cristian; Caniuqueo, Alexis; Cadore, Eduardo L; Izquierdo, Mikel
The aim of this study was to compare the effects of 6 weeks of vertical, horizontal, or combined vertical and horizontal plyometric training on muscle explosive, endurance, and balance performance. Forty young soccer players aged between 10 and 14 years were randomly divided into control (CG; n = 10), vertical plyometric group (VG; n = 10), horizontal plyometric group (HG; n = 10), and combined vertical and horizontal plyometric group (VHG; n = 10). Players performance in the vertical and horizontal countermovement jump with arms, 5 multiple bounds test (MB5), 20-cm drop jump reactive strength index (RSI20), maximal kicking velocity (MKV), sprint, change of direction speed (CODS), Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1), and balance was measured. No significant or meaningful changes in the CG, apart from small change in the Yo-Yo IR1, were observed while all training programs resulted in meaningful changes in explosive, endurance, and balance performance. However, only VHG showed a statistically significant (p ≤ 0.05) increase in all performance test and most meaningful training effect difference with the CG across tests. Although no significant differences in performance changes were observed between experimental groups, the VHG program was more effective compared with VG (i.e., jumps, MKV, sprint, CODS, and balance performance) and HG (i.e., sprint, CODS, and balance performance) to small effect. The study demonstrated that vertical, horizontal, and combined vertical and horizontal jumps induced meaningful improvement in explosive actions, balance, and intermittent endurance capacity. However, combining vertical and horizontal drills seems more advantageous to induce greater performance improvements.
Yamaner, Faruk; Gumusdag, Hayrettin; Kartal, Alparslan; Gumus, M.; Gullu, A.; Imamoglu, O.
Study aim: To assess the prevalence and anatomical sites of injuries in professional soccer players in one game season. Material and methods: A cohort of 510 professional male soccer players consisting of 48 goalkeepers, 194 defence players, 189 mid-field players and 79 forward players of the 1st and 2nd Turkish Professional Soccer Leagues in…
Noelia Belando Pedreño
Full Text Available The aim of this study was to contribute to the postulates of the self-determination theory, the hierarchical model of intrinsic and extrinsic motivation by Vallerand, and social goals. A structural regression model was estimated to analyze the relations between social goals (responsibility and relationships, praise for autonomous behavior, satisfaction of the basic psychological needs and intrinsic motivation in commitment to sport. A sample of 264 young Spanish soccer players aged between 14 and 16 (M =14.74, SD =.77 participated in the study. Structural Equation Modeling results showed that the social responsibility goal, the social relationship goal and praise for autonomous behavior predicted perceived competence. Furthermore, the relationship goal also predicted the need for relatedness. Satisfaction of the basic psychological needs for competence and relatedness predicted intrinsic motivation. Intrinsic motivation positively predicted future commitment to sport. These results highlighted the importance of social goals, praise for autonomous behavior and psychological mediators in encouraging greater commitment in young soccer players. Future research should focus on the coach’s role in generating greater commitment to sport through the development of intervention methodologies based on social goals.
Full Text Available The purpose of this study was to investigate the association between offensive tactical knowledge and the soccer-specific motor skills performance. Fifteen participants were submitted to two evaluation tests, one to assess their technical and tactical analysis. The motor skills performance was measured through four tests of technical soccer skills: ball control, shooting, passing and dribbling. The tactical performance was based on a tactical assessment system called FUT-SAT (Analyses of Procedural Tactical Knowledge in Soccer. Afterwards, technical and tactical evaluation scores were ranked with and without the use of the cluster method. A positive, weak correlation was perceived in both analyses (rho = 0.39, not significant p = 0.14 (with cluster analysis; and rho = 0.35; not significant p = 0.20 (without cluster analysis. We can conclude that there was a weak association between the technical and the offensive tactical knowledge. This shows the need to reflect on the use of such tests to assess technical skills in team sports since they do not take into account the variability and unpredictability of game actions and disregard the inherent needs to assess such skill performance in the game.
van Beijsterveldt, A.M.C.
Soccer causes the largest number of injuries each year (18% of all sports injuries) in the Netherlands. The aim of this dissertation is to contribute to the body of evidence on injury prevention for adult male soccer players. Chapter 1 is a general introduction and presents the “sequence of
Full Text Available The aim of this study was to compare changes in young soccer player's fitness after traditional bilateral vs. unilateral combined plyometric and strength training. Male athletes were randomly divided in two groups; both received the same training, including strength training for knee extensors and flexors, in addition to horizontal plyometric training drills. The only difference between groups was the mode of drills technique: unilateral (UG; n = 9; age, 17.3 ± 1.1 years vs. bilateral (TG; n = 9; age, 17.6 ± 0.5 years. One repetition maximum bilateral strength of knee muscle extensors (1RM_KE and flexors (1RM_KF, change of direction ability (COD, horizontal and vertical jump ability with one (unilateral and two (bilateral legs, and limb symmetry index were measured before and after an 8-week in-season intervention period. Some regular soccer drills were replaced by combination of plyometric and strength training drills. Magnitude-based inference statistics were used for between-group and within-group comparisons. Beneficial effects (p < 0.05 in 1RM_KE, COD, and several test of jumping performance were found in both groups in comparison to pre-test values. The limb symmetry index was not affected in either group. The beneficial changes in 1RM_KE (8.1%; p = 0.074 and 1RM_KF (6.7%; p = 0.004, COD (3.1%; p = 0.149, and bilateral jump performance (from 2.7% [p = 0.535] to 10.5% [p = 0.002] were possible to most likely beneficial in the TG than in the UG. However, unilateral jump performance measures achieved likely to most likely beneficial changes in the UG compared to the TG (from 4.5% [p = 0.090] to 8.6% [p = 0.018]. The improvements in jumping ability were specific to the type of jump performed, with greater improvements in unilateral jump performance in the UG and bilateral jump performance in the TG. Therefore, bilateral strength and plyometric training should be complemented with unilateral drills, in order to maximize adaptations.
Full Text Available In some team sports such as soccer which is interval, athletes need to prepare themselves immediatelyfor the next activity. Therefore it is very important to have enough information on characteristics of recovery phase and quick recovery to the first situation and to have the minimum speed reduction. The purpose of this study was to determine the relationship between aerobic power and repeated sprint ability (RSA or decrementindex in young soccer players in three different levels of Vo2max. Methods: For this reason 41 volunteers were divided in to three groups with different levels of Vo2max ml.kg-1.min-1 low 37.22 ± 2.3 (n= 18, age 17.1 ± 0.9 year, height 170.6 ± 0.76 cm, weight 67.1 ± 5.05 kg medium 46.46± 1.97 ml.kg-1.min-1 (n= 13, age 17.6± 0.76year, height 173.8 ± 4.84 cm, weight 65.9 ± 4.92 kg and high 55.63 ± 1.52 ml.kg-1.min-1 (n=10, age 17.4 ±0.69 year, height 177 ± 3.23 cm, weight 71.4 ± 3.94 kg. To determine Vo2max a graded exercise test until volitional exhaustion on treadmill was used, and also RAST was used to measure RSA. The lactate accumulation was measured before and after RSA protocol. Pearson's correlation was used to determine the correlation between the aerobic power and RSA. The results indicated that there are significant relationship between Vo2max anddecremental index in low Vo2max group (r= 0.86, p= 0.001, no significant relationship medium Vo2max group (r= 0.14, p= 0.63 and negative significant relationship in high Vo2max group (r= - 0.64, p= 0.04. There are no significant relationship between Lactate accumulation and decremental index in medium (r= 0.005, p= 0.98 and high Vo2max groups (r=0.27, p= 0.45. Discussion: It is possible that the recovery of inter muscular resources relates to aerobic ability, but there are other factors effective in RSA rather than Vo2max and Lactate accumulation. The current study showed a normal curved relationship between Vo2max and RSA.
Ersoy, Nesli; Ersoy, Gulgun; Kutlu, Mehmet
The purpose of the study is to determine and compare the hydration status with different methods and determine fluid intake, dehydration percentages and sweat rate of 26 young male soccer players (15 ± 1.2 years) before an important competition. More specifically, the study aims at validating the urine strip and advising the players to use it as an easy and practical method. Measurements of urine analysis were taken from the urine sample of the participants before breakfast and conducted for 3 consecutive days before the competition. Hydration status was assessed through analysis of urine color, urine specific gravity (USG) (laboratory, strip, refractometry), and osmolality. The players' dehydration percentages and sweat ratio were calculated. The average values for all samples were 3 ± 1 for color, and 1.021 ± 4 g/cm(3) for USG (laboratory), and 1.021 ± 3 g/cm(3) for USG (strip), and 1.021 ± 4 for USG (refractometry), and 903 ± 133 mOsm/kg for osmolality. USG (strip) was highly correlated with USG (laboratory), USG (refractometry) (r = 0.8; P soccer players were observed as 0.5 % and 582.3 ± 232.0 mL/h, respectively. We found that youth soccer players are under a slight risk of dehydration under moderate weather conditions. As indicated by the research results, determination of hydration status of athletes must be taken into account more carefully under moderate and hot weather conditions. In addition, hydration methods were compatible with one another as measured in this study.
Bakker, A.B.; Oerlemans, Wido; Demerouti, E.; Bruins Slot, B.; Karamat Ali, D.
Objective: The present study examines the relationship between environmental resources (autonomy,social support from the coach, and performance feedback), flow, and performance among young talented soccer players. Design: The design was non-experimental and involved both self- and coach-rated
Full Text Available Introduction: We report a case of a young female soccer player affected by congenital medial bilateral malleolus pseudoarthrosis and os subfibulare. Congenital pseudoarthrosis is the failure of the bones to fuse prior or at birth. The etiology is still unknown, although frequency is high in subjects affected by neurofibromatosis or correlated syndromes, so it has been suggested that these congenital disorders may be the cause of congenital pseudoarthrosis. Case Report: Our patient, a 16-year-old female, high level soccer player, was referred to us following a right ankle sprain during a match. She reported no medical history of tibia-tarsus joint injuries or disease. Pain, swelling and functional impairment were noted immediately after the accident. Standard radiographs in the emergency department revealed a displaced fracture of the medial malleolus and the presence of os subfibularis. The patient was transferred to our Traumatology and Orthopaedic Department to undergo malleolus ostheosynthesis. Before surgery swelling, functional impairment and intense pain at the medial malleolus level were confirmed. However, there was no radiological opening of ankle, instability or pronation pain; furthermore the flexion-extension was preserved with slight pain. Twenty-four hours later a considerable remission of symptoms was evident with increased range of motion and reduction in the swelling and post-traumatic edema. A radiograph on the left ankle to compare with that of the right ankle was necessary to overcome the discrepancy between the radiological diagnosis and the clinical examination. The radiographic results of both medial malleoli were comparable although on the left the os subfibularis was absent. Since the diagnosis of fracture by the association between the radiographs and the symptomatology was doubtful, a bilateral CT was performed. The scan revealed a medial bilateral malleolus pseudoarthrosis and an accessory right subfibularis nucleus
Jastrzebska, Maria; Kaczmarczyk, Mariusz; Suárez, Arturo Diaz; Sánchez, Guillermo Felipe López; Jastrzebska, Joanna; Radziminski, Lukasz; Jastrzebski, Zbigniew
Vitamin D deficiency has been associated with increased risk for cardiovascular disease and anemia. Vitamin D-related changes in lipid profile have been studied extensively but the relationship between vitamin D and lipid metabolism is not completely understood. As both vitamin D and intermittent training may potentially affect iron and lipid metabolism, the aim of the study was to evaluate whether a daily supplementation of vitamin D can modulate the response of hematological and lipid parameters to high-intensity interval training (HIIT) in soccer players. Thirty-six young elite junior soccer players were included in the placebo-controlled, double-blind study. Participants were non-randomly allocated into either a supplemented group (SG, n=20, HIIT and 5,000 IU of vitamin D daily) or placebo group (PG, n=16, HIIT and sunflower oil). Hematological parameters were ascertained before and after the 8-wk training. The change score (post- and pre-training difference) was calculated for each individual and the mean change score (MCS) was compared between SG and PG using the t test and analysis of covariance. There were no differences between SG and PG at baseline. The red and white cell count, hemoglobin, hematocrit, MCHC, ferritin, and HDL-cholesterol changed significantly over the 8-wk HIIT. However, no significant differences in MCS were observed between SG and PG for any variable. A daily vitamin D supplement did not have any impact on alteration in hematological or lipid parameters in young soccer players in the course of high-intensity interval training.
Palucci Vieira, Luiz H; de Andrade, Vitor L; Aquino, Rodrigo L; Moraes, Renato; Barbieri, Fabio A; Cunha, Sérgio A; Bedo, Bruno L; Santiago, Paulo R
The main aim of this study was to verify the relationship between the classification of coaches and actual performance in field tests that measure the kicking performance in young soccer players, using the K-means clustering technique. Twenty-three U-14 players performed 8 tests to measure their kicking performance. Four experienced coaches provided a rating for each player as follows: 1: poor; 2: below average; 3: average; 4: very good; 5: excellent as related to three parameters (i.e. accuracy, power and ability to put spin on the ball). The scores interval established from k-means cluster metric was useful to originating five groups of performance level, since ANOVA revealed significant differences between clusters generated (Pperformance. The Wall Volley Test seems to be a good predictor of other tests. Five tests showed reasonable construct validity and can be used to predict the accuracy (penalty kick, free kick, kicking a rolling ball and Wall Volley Test) and ability to put spin on the ball (free kick and corner kick tests) when kicking in soccer. In contrast, the goal kick, kicking the ball when airborne and the vertical kick tests exhibited low power of discrimination and using them should be viewed with caution.
Leskošek, Bojan; Vodičar, Janez; Topič, Mojca Doupona
Abstract The purpose of this study was to identify factors that constituted the cultural capital among soccer players. We assumed that in the increasingly globalized world of professional soccer, a player’s success would often depend on migrating and adjusting to life in other countries. Willingness to migrate and successful adjustment are tied to player’s previous attitudes and/or behaviours (habitus), significant support from others, including family members, and previous experiences and success in sports and education. Our hypothesised model of the cultural capital was based on the Pierre Bourdieu’s theoretical framework. It consisted of 26 variables related to three sets of factors: soccer experiences, a family context and support, and educational achievements of the players and their parents. The model was tested using a sample of 79 current soccer coaches who also had been players at the elite level. A factor analysis was used to empirically verify the content of the hypothetical model of the soccer players’ cultural capital. Nine latent factors were extracted and together, they accounted for 55.01% of the total model variance. Individual factors obtained showed a sufficient level of substantial connection. The Cronbach’s alpha value of 0.77 confirmed the internal consistency of the operationalised variables in the hypothetical model. In addition, the impact of these aforementioned life dimensions on the migration of soccer players was studied. The results of the binary logistic regression analysis showed that the first factor of the hypothetical model (F1) had 2.2 times and the second factor (F8) had 3.9 times higher odds for migration abroad. Sociocultural findings using this new assessment approach could help create better “success conditions” in the talent development of young players. PMID:28031770
Full Text Available The purpose of this study was to identify factors that constituted the cultural capital among soccer players. We assumed that in the increasingly globalized world of professional soccer, a player’s success would often depend on migrating and adjusting to life in other countries. Willingness to migrate and successful adjustment are tied to player’s previous attitudes and/or behaviours (habitus, significant support from others, including family members, and previous experiences and success in sports and education. Our hypothesised model of the cultural capital was based on the Pierre Bourdieu’s theoretical framework. It consisted of 26 variables related to three sets of factors: soccer experiences, a family context and support, and educational achievements of the players and their parents. The model was tested using a sample of 79 current soccer coaches who also had been players at the elite level. A factor analysis was used to empirically verify the content of the hypothetical model of the soccer players’ cultural capital. Nine latent factors were extracted and together, they accounted for 55.01% of the total model variance. Individual factors obtained showed a sufficient level of substantial connection. The Cronbach’s alpha value of 0.77 confirmed the internal consistency of the operationalised variables in the hypothetical model. In addition, the impact of these aforementioned life dimensions on the migration of soccer players was studied. The results of the binary logistic regression analysis showed that the first factor of the hypothetical model (F1 had 2.2 times and the second factor (F8 had 3.9 times higher odds for migration abroad. Sociocultural findings using this new assessment approach could help create better “success conditions” in the talent development of young players.
Olmedilla-Zafra, Aurelio; Rubio, Victor J; Ortega, Enrique; García-Mas, Alexandre
Several attempts to reduce the incidence of sport injuries using psychosocial interventions produced fruitful, although inconclusive results. This paper presents the effectiveness and implementation issues of a pilot 3-month stress-management and muscle relaxation program aimed at reducing sport injury incidence. Pre-post treatment-non treatment group comparison. The program was administered by a trained psychologist on a once-a-week, 1-h session basis. Seventy-four male soccer players from four National Youth league teams voluntarily participated. Teams were randomly assigned to either treatment/non-treatment group. Injury protocol, Self-monitoring cards, Athletes' satisfaction and commitment survey, Coaches' interview. Group main effect and Time-Group interaction effect were both statistically significant, F(1,60) = 8.30, p = 0.005, η 2 p = 0.121, with the average number of injuries larger in the post-treatment phase of non-treatment group (p = 0.005, η 2 p = 0.077). There was a significant decrease in the average number of injuries for the intervention group before and after implementing the program (p youth soccer sport injuries, with a high level of satisfaction and commitment from the athletes, as well as high acceptance from the coaches. Copyright © 2016 Elsevier Ltd. All rights reserved.
Juan Del Coso
Full Text Available Background: Epidemiologic research to learn the incidence, type, location, and severity of female soccer injuries and the risk factors for sustaining a sport injury is the first step in developing preventive policies. The aim of this study was to analyze the incidence of injuries in the population of female soccer players in Spain. Methods: The injuries incurred by 25,397 female soccer players were registered by the medical staff of the Spanish Football Federation during 1 season. A standardized medical questionnaire was used to classify the injury according to type, severity, location, and injury mechanism. A total of 2108 injuries was reported with an incidence of 0.083 injuries per player per season. Most injuries were in the lower limbs (74.0%, mainly affecting knee (30.4% and ankle joints (17.9%. Results: The proportion of injuries derived from contact with another player was higher during matches (33.7% than during training (11.4%; p 0.05. Conclusion: Most female soccer injuries were located at the knee and ankle; the injury mechanism determined the playing time lost; and the player's age did not affect injury characteristics. Keywords: Ankle, Epidemiology, Knee, Sport injuries, Women
... commonly injured. Keywords: Epidemiology, soccer injuries, youth ... fun and enjoyment while burning up calories especially when electronic devices ... ture on female soccer players has also grown significant- ly9,10. In the last decade, ...
Beijsterveldt, A.M. van; Steffen, K.; Stubbe, J.H.; Frederiks, J.E.; Port, I.G.L. van de; Backx, F.J.G.
OBJECTIVE:: To describe characteristics of outdoor soccer injury and recovery among Dutch soccer players. DESIGN:: Prospective cohort study. SETTING:: The 2009-2010 competitive season (33 weeks). PARTICIPANTS:: Four hundred fifty-six Dutch male soccer players of 23 amateur teams. MAIN OUTCOME
Hidalgo y Teran Elizondo, Roberto; Martín Bermudo, Francisco Manuel; Peñaloza Mendez, Ricardo; Berná Amorós, Genoveva; Lara Padilla, Eleazar; Berral de la Rosa, Francisco José
nutritional intake and status of soccer players has attracted not much research attention. Many soccer players follow an inadequate nutritional intake and have a poor nutritional status. This is relevant in youngsters soccer players, in order to improve performance and promote healthy dietary practices. analyze anthropometric characterizes, evaluate nutritional intake and status, dietary habits and pre- and post-exercise meals in elite teenagers soccer players. seventy-two young male soccer players (15-20 years) from four junior teams of a soccer Club from the Mexican National Soccer League were measured for height, seat height, weight, 6 skinfolds, 6 diameters and 7 circumferences, height-for-age and BMI-for-age values. Skin, adipose, muscle, bone and residual tissue masses were calculated with the Ross and Kerr equation. Resting energy expenditure and intake was also measured. Daily dietary intake was self-recorded for 4 consecutive days (excluding the match day) using a digital food-weighing scale and a food record questionnaire. Dietary analysis was performed using the NutriBase 7 Clinical software. Several biochemical values were determined. One-way analysis of variance (ANOVA) and post hoc testing was performed using t-tests with a Bonferroni correction. all soccer players were within the normal range values for anthropometric parameters studies, when compared with other adolescent elite soccer teams. Values of plasma glucose, urea, creatinine, uric acid, lipid profile and total proteins were within normal range for young adult population, although albumin levels were high. Moreover, 14% and 20% of soccer players presented hyperuricemia and elevated total cholesterol levels respectively. Energy expenditure and intake were within normal range for all teenager elite soccer players. However, two teams shower significant lower intakes than demands. All macronutrient intakes were within recommendations, except protein that was higher. Micronutrient intake exceeded
This study focused on coping strategies used by soccer (football) players by exploring the role of the environment, ethnicity and culture in players' response to stressful situations. An interpretive-qualitative research methodology was applied with a sample of 33 professional soccer players. The subjects were representative ...
Valente-Dos-Santos, J.; Coelho-E-Silva, M. J.; Vaz, V.; Figueiredo, A. J.; Capranica, L.; Sherar, L. B.; Elferink-Gemser, M. T.; Malina, R. M.
Aim. The purpose of the current study was to assess the developmental changes in change of direction and dribbling speed in youth soccer players taking into account skeletal age (SA), maturity status, body size, estimated fat mass, aerobic endurance, lower limb explosive strength and annual volume
Giagazoglou, Paraskevi; Katis, Athanasios; Kellis, Eleftherios; Natsikas, Christos
The purpose of the current study was to examine the kinematic differences during instep soccer kicks between players who were blind and sighted controls. Eleven male soccer players who were blind and nine male sighted performed instep kicks under static and dynamic conditions. The results indicated significantly higher (p less than 0.05) ball…
De Ste Croix, Mark B A; Hughes, Jonathan D; Lloyd, Rhodri S; Oliver, Jon L; Read, Paul J
De Ste Croix, MBA, Hughes, JD, Lloyd, RS, Oliver, JL, and Read, PJ. Leg stiffness in female soccer players: intersession reliability and the fatiguing effects of soccer-specific exercise. J Strength Cond Res 31(11): 3052-3058, 2016-Low levels of leg stiffness and reduced leg stiffness when fatigue is present compromise physical performance and increase injury risk. The purpose of this study was to (a) determine the reliability of leg stiffness measures obtained from contact mat data and (b) explore age-related differences in leg stiffness after exposure to a soccer-specific fatigue protocol in young female soccer players. Thirty-seven uninjured female youth soccer players divided into 3 subgroups based on chronological age (under 13 [U13], under 15 [U15], and under 17 [U17] year-olds) volunteered to participate in the study. After baseline data collection, during which relative leg stiffness, contact time, and flight time were collected, participants completed an age-appropriate soccer-specific fatigue protocol (SAFT). Upon completion of the fatigue protocol, subjects were immediately retested. Intersession reliability was acceptable and could be considered capable of detecting worthwhile changes in performance. Results showed that leg stiffness decreased in the U13 year-olds, was maintained in the U15 age group, and increased in the U17 players. Contact times and flight times did not change in the U13 and U15 year-olds, but significantly decreased and increased, respectively, in the U17 age group. The data suggest that age-related changes in the neuromuscular control of leg stiffness are present in youth female soccer players. Practitioners should be aware of these discrepancies in neuromuscular responses to soccer-specific fatigue, and should tailor training programs to meet the needs of individuals, which may subsequently enhance performance and reduce injury risk.
Boone, Jan; Vaeyens, Roel; Steyaert, Adelheid; Vanden Bossche, Luc; Bourgois, Jan
The purpose of this study was to gain an insight into the physical and physiological profile of elite Belgian soccer players with specific regard to the player's position on the field. The sample consisted of 289 adult players from 6 different first division teams. The players were divided into 5 subgroups (goalkeepers, center backs, full backs, midfielders, and strikers) according to their self-reported best position on the field. The subjects performed anaerobic (10-m sprint, 5 × 10-m shuttle run [SR], squat jump [SJ], and countermovement jump [CMJ]) and aerobic (incremental running protocol) laboratory tests. The strikers had significantly shorter sprinting times (5-, 5- to 10-m time, and SR) compared with the midfielders, center backs, and goalkeepers, whereas the full backs were also significantly faster compared with the goalkeepers and the center backs. The goalkeepers and the center backs displayed higher jumping heights (total mean SJ = 40.7 ± 4.6 cm and CMJ = 43.1 ± 4.9 cm) compared with the other 3 positions, whereas the strikers also jumped higher than the full backs and the midfielders did. Regarding the aerobic performance, both full backs and the midfielders (61.2 ± 2.7 and 60.4 ± 2.8 ml · min(-1) · kg(-1), respectively) had a higher VO2max compared with the strikers, center backs, and goalkeepers (56.8 ± 3.1, 55.6 ± 3.5, and 52.1 ± 5.0 ml · min(-1) · kg(-1), respectively). From this study, it could be concluded that players in different positions have different physiological characteristics. The results of this study might provide useful insights for individualized conditional training programs for soccer players. Aside from the predominant technical and tactical skills, a physical profile that is well adjusted to the position on the field might enhance game performance.
Nebigh, Ammar; Abed, Mohamed Elfethi; Borji, Rihab; Sahli, Sonia; Sellami, Slaheddine; Tabka, Zouhair; Rebai, Haithem
The aim of this study was to examine the relationship between bone mass and bone turnover markers with lean mass (LM) in pubescent soccer players. Two groups participated in this study, which included 65 elite young soccer players who trained for 6-8 hours per week and 60 controls. Bone mineral density; bone mineral content in the whole body, lower limbs, lumbar spine, and femoral neck; biochemical markers of osteocalcin; bone-specific alkaline phosphatase; C-telopeptide type I collagen; and total LM were assessed. Young soccer players showed higher bone mineral density and bone mineral content in the whole body and weight-bearing sites (P soccer players compared with the control group, but no significant difference in C-telopeptide type I collagen was observed between the 2 groups. This study showed a significant positive correlation among bone-specific alkaline phosphatase, osteocalcin, and total LM (r = .29; r = .31; P soccer players. Findings of this study highlight the importance of soccer practice for bone mineral parameters and bone turnover markers during the puberty stage.
Pfirrmann, Daniel; Herbst, Mark; Ingelfinger, Patrick; Simon, Perikles; Tug, Suzan
The incidence of injury for elite youth and professional adult soccer players is an important concern, but the risk factors for these groups are different. To summarize and compare the injury incidences and injury characteristics of male professional adult and elite youth soccer players. We searched MEDLINE and Web of Science using the search terms elite, international, European, soccer, football, injury, injuries, epidemiology, incidence, prevalence, not female, not American football, and not rugby. We also used the search terms professional for studies on professional adult soccer players and high-level, soccer academy, youth, adolescent, and young for studies on elite youth soccer players. Eligible studies were published in English, had a prospective cohort design, and had a minimum study period of 6 months. To ensure that injury data were assessed in relationship to the athlete's individual exposure, we included only studies that reported on injuries and documented exposure volume. Two independent reviewers applied the selection criteria and assessed the quality of the studies. A total of 676 studies were retrieved from the literature search. Eighteen articles met the inclusion criteria: 6 for elite youth and 12 for professional adult soccer players. Injury rates were higher for matches than for training for both youth and adult players. Youth players had a higher incidence of training injuries than professionals. Efforts must be made to reduce the overall injury rate in matches. Therefore, preventive interventions, such as adequately enforcing rules and focusing on fair play, must be analyzed and developed to reduce match-related injury incidences. Reducing training injuries should be a particular focus for youth soccer players.
Gyarmati, Laszlo; Hefeeda, Mohamed
It is challenging to get access to datasets related to the physical performance of soccer players. The teams consider such information highly confidential, especially if it covers in-game performance.Hence, most of the analysis and evaluation of the players' performance do not contain much information on the physical aspect of the game, creating a blindspot in performance analysis. We propose a novel method to solve this issue by deriving movement characteristics of soccer players. We use eve...
Maughan, R J
OBJECTIVE: To examine the dietary habits of professional soccer players at two Scottish Premier League clubs during the competitive season. METHODS: A study of the dietary intake of 51 professional soccer players with two different clubs was carried out by the seven day weighed intake method. RESULTS: Physical characteristics of the two groups of players were similar, with only small differences in age and body mass but no difference in height and body fat. Mean (SD) daily energy intake for c...
Charles F. Babbs
Full Text Available To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton�s second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player�s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater “touch” and “playability”, measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.
Wagner-Egger, Pascal; Gygax, Pascal; Ribordy, Farfalla
This experiment investigated challenge evaluations in soccer and their relation to prejudice: more precisely, whether skin colour may influence judgments of soccer tackles. Three groups of participants (soccer players, referees,and soccer fans) were asked to evaluate challenges, featuring Black and White players as aggressors and victims in a mixed-design study. Results showed that participants made some differentiations between Black and White players in a challenge evaluation task. Participants were more likely to consider within-group challenges as fouls and were faster to consider challenges made by Black players as fouls. On the other hand, fouls made by White players were seen as more severe. There were no major differences between the participating groups, suggesting that the observed effects were independent of how good players were or whether the participants were referees or not.
Iaia, F Marcello; Fiorenza, Matteo; Perri, Enrico
In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players...... different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles' ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short......-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in trained young soccer players....
Soccer is one of the most widely played and complex sports in the world, where success depends on technical, tactical and physical skills of the players. Studies to improve performance in soccer have often focused on technique and tactics. However, nutrition is one of the most important factors influencing athletic performance of the players. The duration of matches is long and the training is intense. This leads to increased requirements for energy and nutrients, as well as increased reactive oxygen radicals and hence increased muscle damage. Vitamins are micronutrients that a living organism requires in trace quantities for health. As these assume crucial functions in the body, the performance of the player is negatively affected particularly during long-term deficiency. Beta-carotene, C and E vitamins are antioxidants that protect against oxygen radicals. In case of their deficiency, oxidative stress and muscle fatigue increases. Vitamin D is involved in maintaining mineral balance, and it increases absorption of dietary calcium and phosphorus. In case of vitamin D deficiency, injuries resulting from the musculoskeletal system might increase. B Vitamins (B1, B2, niacin, B6, B12, biotin, folic acid and pantothenic acid) perform duties such as energy production, absorption and transport of iron and blood cell production. Athletes who follow an energy-restricted and imbalanced diet might develop vitamin deficiency. In such a case, supplements can be used as recommended by the doctor/dietician. It is further reported that supplement use by athletes who have an adequate and balanced nutrition does not increase performance.
Soccer is one of the most popular sports in the world. There is still much uncertainty and debate surrounding its physiological requirements because emphasis is on skills to the neglect of fitness, conservative training methods and the difficulty of studying the sport scientifically. The frequently found values for total distance covered in a game of about 10 km and an above-average, though not outstanding, maximum oxygen uptake of 60 ml/kg/min suggest a moderate overall aerobic demand. A comparison of top teams and players with less able participants indicates that the components of anaerobic fitness-speed, power, strength and the capacity of the lactic acid system may differentiate better between the 2 groups. Generally, there is a reduction in the level of activity in the second half of games compared with the first. There is some evidence that increased aerobic fitness may help counteract this. Progressively lower muscle glycogen stores are one likely cause of reduction in activity, and nutrition also appears to be a key factor in minimising performance deterioration, both in terms of overall diet and, more particularly, the ingestion of carbohydrates immediately before, during and after a game. There are evolutionary trends in the sport such as greater frequency of games, changes in the roles of players, and new strategies and tactics which are placing increasing demands on the all-round fitness of players. Many studies indicate scope for improvement in player fitness. The challenge for coaches and players is to meet these fitness requirements without sacrificing the skill work which makes the sport unique.
Background: Sport is a compulsory activity in schools in South Africa. Female learners participating in soccer are more vulnerable to injuries than males. Objective: This study determined the epidemiology of injuries in female high school soccer players. Methods: A cross sectional survey captured the epidemiology of ...
Castro-Sepúlveda, Mauricio; Astudillo, Sebastian; Álvarez, Cristian; Zapata-Lamana, Rafael; Zbinden-Foncea, Hermann; Ramírez-Campillo, Rodrigo; Jorquera, Carlos
there is a lack of studies concerning hydration status before training in professional soccer player. to describe hydration status before regular training practices in professional soccer players. a total of 156 male soccer players (age 25.4 ± 5.2 y) from six professional Chilean clubs were included. No hydration or food intake recommendations were made before experiment, with the aim to assess hydration status under athlete's regular "real" conditions. Body mass, height and urine specific gravity (USG) measurements were performed before training practices. 98% of athletes showed dehydration (between moderate and severe) before regular training practices. dehydration is the most prevalent hydration status in professional Chilean soccer players before training, which may negatively affect athlete's performance and may increase their risk of heat-related injuries. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
Abdullah, M. R; Maliki, A. B. H. M; Musa, R. M; Kosni, N. A; Juahir, H
This study aims to predict the potential pattern of soccer technical skill on Malaysia youth soccer players relative performance using multivariate analysis and artificial neural network techniques. 184 male youth soccer players were recruited in Malaysia soccer academy (average age = 15.2±2.0) underwent to, physical fitness test, anthropometric, maturity, motivation and the level of skill related soccer. Unsupervised pattern recognition of principal component analysis (PCA) was used to ident...
Puspaningtyas, Desty Ervira; Afriani, Yuni; Mahfida, Silvi Lailatul; Kushartanti, Wara; Farmawati, Arta
Training is conducted to improve physiological functions that can support improvementof cardio-respiratory function (O2max). However, intensive training can lead to oxidativestress, which can contribute to health problems. The purpose of this study was to evaluatethe effect of training on serum lipid peroxidation levels in student soccer players. Thestudy was pre-experimental study with a one-shot case design conducted in April 2014.Twelve student soccer players from UGM who chosen by purposi...
Avhandling (doktorgrad) - Norges idrettshøgskole, 2015 Background: High performance in soccer depends on various physical qualities and skills, including tactical and technical skills as the two most import factors that contribute to success. These skills could be more important than small differences in physical performance abilities. Nevertheless, to be able to utilize the tactical and technical skills during a top soccer match, a soccer player has to cope with the physical demands...
Proietti, Riccardo; di Fronso, Selenia; Pereira, Lucas A; Bortoli, Laura; Robazza, Claudio; Nakamura, Fabio Y; Bertollo, Maurizio
Heart rate variability (HRV) has been increasingly used to monitor team sports athletes. Besides the traditional time domain indices (i.e., the SD of successive RR intervals [SDNN] and the root mean square difference of successive normal RR intervals [RMSSD]), recently the use of the stress score (SS), which is an inverse function of the SD2 index derived from the Poincaré plot, and the sympathetic/parasympathetic ratio (S/PS) to monitor soccer players has been proposed. However, the reliability of these new indices and the ability of HRV to differentiate between soccer competitive levels are unknown. The aim of this study was to analyze the reliability of the different HRV-derived indices in professional soccer players during the competitive period and to compare HRV of professional soccer players from 3 teams of distinct competitive levels (i.e., Italian Second Division [2D], European League [EL], and Champions League [CL]). Fifty-four male professional soccer players from 3 different teams of 2 European countries (Italy and Germany) participated in the study. The intraclass correlation coefficient values of the HRV indices varied from 0.78 (very large) to 0.90 (near perfect). The coefficient of variation (CV) values for RMSSD and SDNN were all soccer players and is able to differentiate between international- and national-level players.
Julio Francisco Kleinpaul
Full Text Available O objetivo deste estudo foi verificar a incidência de lesões, os principais desvios posturais e a possível associação entre lesões e desvios posturais em jogadores de futebol. Foram avaliados 21 voluntários do sexo masculino tendo entre 17 e 19 anos, jogadores de futebol de uma equipe profissional, que foram divididos em dois grupos: G1 formado por 15 jogadores que sofreram lesões relacionadas à prática de futebol; e G2 composto por 6 atletas que não tiveram lesões. Foram coletados dados sobre características antropométricas, posição de jogo, tempo de prática de futebol, freqüência de prática e histórico de lesões relacionadas à prática de futebol. O alinhamento postural foi verificado utilizando um protocolo específico para detectar alterações. Os resultados mostram alterações no alinhamento corporal em ambos os grupos. Os maiores desvios posturais encontrados foram assimetria das escápulas, no alinhamento horizontal da cabeça e no da pelve, em ambos os grupos. Considerando as lesões no G1, a mais comum foi no tornozelo (35% e a segunda mais freqüente, no joelho (23%. Embora não tenha sido encontrada associação entre desvios posturais e ocorrência de lesões, a incidência de ambos é importante, sugerindo a necessidade de intervenções de prevenção na formação de jogadores de futebol.The purpose of this study was to assess the incidence of injuries, deviations in postural alignment, and possible associations between injuries and postural deviations in soccer players. Twenty-one male professional soccer players, aged 17 to 19 years old, were assessed as to anthropometric features, playing position, length and frequency of soccer practice, and history of injuries linked to soccer practicing. Athletes were divided into two groups: G1 made up by 15 players who had suffered soccer-related injuries; and G2 composed by 6 players with no such injuries. Postural alignment was assessed using a specific protocol
Martin, Louise; Lambeth, Anneliese; Scott, Dawn
The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day(-1)) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key pointsFemale soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study.Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer playersFluid requirements should be addressed on an individual basis and matched to player requirements.The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV.
Martin, Louise; Lambeth, Anneliese; Scott, Dawn
The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day-1) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key points Female soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study. Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer players Fluid requirements should be addressed on an individual basis and matched to player requirements. The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV. PMID:24198690
A Los Arcos
Full Text Available The aim of this study was to quantify the seasonal perceived respiratory and muscular training loads (i.e., sRPEres-TL and sRPEmus-TL completed by elite-oriented young professional soccer players. Twentyfour players (20.3 ± 2.0 years belonging to the same reserve team of a Spanish La Liga club participated in this study. Only the players that were available to train for a whole week with the team and also to play the weekly game were considered: Starters, players that participated in the match for at least 45 min and Non- Starters, players that did not participate or played less than 45 minutes in the match. The competitive period was analysed after the division into 5x6-8 week blocks and 35x1 week microcycles. Data were also analysed with respect to number of days before the immediate match. Weekly TL variation across the in-season blocks was trivial-small for both groups except between Block 2 and Block 3 (ES= moderate. Substantial TL differences (ES= small–very likely were found between training days, the TL pattern being a progressive increase up to MD-3 followed by a decrease until MD-1. Except for the match, sRPEres-/sRPEmus-TL was very similar between Starters and Non-Starters. In summary, perceived TL across the season displayed limited variation. Coaches periodized training contents to attain the highest weekly TL 72 hours before the match to progressively unload the players between MD-3 and the match day. The data revealed that the TL arising from the weekly game was solely responsible for the observed higher weekly TL of Starters in comparison with Non-Starters.
Heisterberg, Mette F; Fahrenkrug, Jan; Krustrup, Peter
of the season. Leucocytes decreased with increased physical training. Lymphocytes decreased at the end of the season. VO2max decreased towards the end of the season whereas no significant changes were observed in the IE2 test.The regular blood samples from elite soccer players reveal significant changes......ABSTRACT: The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players, and to analyze different blood parameters in relation to seasonal changes in training and match exposure.Blood samples were collected five times during a six...... months period and analyzed for 37 variables in 27 professional soccer players from the best Danish league. Additionally, players were tested for body composition, VO2max and physical performance by the Yo-Yo intermittent endurance sub-max test (IE2).Multiple variations in blood parameters occurred during...
Wieczorek, Marta; Wiliński, Wojciech; Struzik, Artur; Rokita, Andrzej
Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 - 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.
Full Text Available Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.
Full Text Available Plyometric training is an important training program in improving physical fitness and soccer skills of players. The study was conducted to find out the effects of plyometric training on soccer related physical fitness variables of Haramaya University intercollegiate female soccer players. For this study forty female (age, 20±1.5 years; height, 1.61±0.7 m; BMI, 20.41±0.7Kg/cm2 soccer players were selected through purposive sampling. Experimental group (n= 20 participants were engaged in a supervised plyometric training program 3 days/week for 12 weeks. The control group (n= 20 did not participate in any of the program except regular soccer training however, the tests were conducted for them. The physical fitness and soccer skill variables selected for the study were: Speed, Explosive power, Agility, Dribbling, Kicking Right and Left Feet. Tests were taken three times at pre training, during training and post training. Comparison of mean was done by paired t-test. The results obtained in this study indicated that there was significant improvement in selected physical fitness and soccer skill variables due to the effects of plyometric training. After 12 weeks of plyometric training participant’s speed (0.78 m/sec., agility (2.64 sec, and explosive power (7.85 cm were changed significantly (p<0.05. Participant’s dribbling soccer skill (1.92 sec., kicking right foot for distance (2.19 m and kicking left foot for distance (2.91 m were significantly improved through plyometric training. This study proved that plyometric training was significantly better in improving the physical fitness variables and soccer skills of female soccer players.
Phillips, Saun M; Sykes, Dave; Gibson, Neil
The objective of the study was to investigate the hydration status and fluid balance of elite European youth soccer players during three consecutive training sessions. Fourteen males (age 16.9 ± 0.8 years, height 1.79 ± 0.06 m, body mass (BM) 70.6 ± 5.0 kg) had their hydration status assessed from first morning urine samples (baseline) and pre- and post-training using urine specific gravity (USG) measures, and their fluid balance calculated from pre- to post-training BM change, corrected for fluid intake and urine output. Most participants were hypohydrated upon waking (USG >1.020; 77% on days 1 and 3, and 62% on day 2). There was no significant difference between first morning and pre-training USG (p = 0.11) and no influence of training session (p = 0.34) or time (pre- vs. post-training; p = 0.16) on USG. Significant BM loss occurred in sessions 1-3 (0.69 ± 0.22, 0.42 ± 0.25, and 0.38 ± 0.30 kg respectively, p sessions 1-3 was 425 ± 185, 355 ± 161, and 247 ± 157 ml, respectively (p sessions. Body mass loss, fluid intake, and USG measures showed large inter-individual variation. Elite young European soccer players likely wake and present for training hypohydrated, when a USG threshold of 1.020 is applied. When training in a cool environment with ad libitum access to fluid, replacing ~71% of sweat losses results in minimal hypohydration (training appears to prevent excessive (≥2% BM) dehydration, as advised by current fluid intake guidelines. Current fluid intake guidelines appear applicable for elite European youth soccer players training in a cool environment. Key PointsThe paper demonstrates a notable inter-participant variation in first morning, pre- and post-training hydration status and fluid balance of elite young European soccer players.On average, elite young European soccer players are hypohydrated upon waking and remain hypohydrated before and after training.Elite young European soccer players display varied fluid intake volumes during training
Full Text Available The primary goal of this research is to compare the accuracy of the collision of the ball to players of both age groups U-17 and U-19. The research was conducted on a sample of 100 young soccer players Kosovo divided into two groups: the first group comprised of 50 young players U17 and second group comprised of 50 young soccer players U-19. To assess the precision of the attack on the ball all the players they have subjected technical demonstration testing in four tests: (T-JUGGL, T-PASI, T-KROS, T-SHOOT. Through T-test method are proven differences in favor of players U-19 to U-17 in all tests of precision technical movements with the ball, but statistically significant differences are shown in the collision test at the gateway (T-SHOOT and the test ball juggling (T-JUGGL . The results obtained show us that more experienced players U-19 have a better precision in demonstrating the technical movements with the ball, compared to U-17 players. Assuming that the training process is very important to voice learning, mastering demonstration, acquisition, and precise technical movements with the ball, because the precision peak levels is very significant.
Full Text Available The aims of the present study were to assess gender differences regarding lactate threshold and intermittent shuttle run performance in female and male soccer players as well as to investigate the relationships between both endurance characteristics in both genders. Fourteen female (1st division and thirteen male (4th division soccer players completed an incremental test (IT to determine running velocities at 2 and 4 mmol · l-1 blood lactate (v2 and v4 and maximum velocity (vmax as well as an interval shuttle run test (ISRT to determine running distance. Based on v2 and v4 and their percentages in relation to vmax, three intensity zones were calculated: a low lactate zone (v4. Female soccer players have a lower v4 (8.2%, vmax (11.3% and ISRT distance (31.6%. No gender difference was found in v2. In contrast to males, ISRT distance correlates with vmax as well as with v2 and v4 in female soccer players. The intensity zones v4 differ between genders. The present study revealed that gender differences increase when the running performance is intermittent including change of directions. In both genders, different relationships between lactate threshold and intermittent shuttle run performance exist. During incremental testing, the running performances of female and male players reflect different distributions of aerobic and anaerobic metabolic pathways. The revealed gender differences should be considered for soccer endurance training.
Hidalgo y Terán Elizondo, Roberto; Martín Bermudo, Francisco Manuel; Peñaloza Méndez, Ricardo; Berná Amorós, Genoveva; Lara Padilla, Eleazar; Berral de la Rosa, Francisco José
Introduction: nutritional intake and status of soccer players has attracted not much research attention. Many soccer players follow an inadequate nutritional intake and have a poor nutritional status. This is relevant in youngsters soccer players, in order to improve performance and promote healthy dietary practices. Aims: analyze anthropometric characterizes, evaluate nutritional intake and status, dietary habits and pre- and post-exercise meals in elite teenagers soccer players. Methods: se...
Afyon, Yakup Akif
Core trainings have been widely used by trainers recently in order to improve performance of soccer players. In this context, the aim of this study is to examine the effect of core training on some motoric capabilities of 16 years old soccer players. Thirty certified soccer players who were 16 years old from B.B. Bodrumspor Club in 2013-2014…
Full Text Available The main goal of this research was to determine inter and intra positional differences in ball kicking speed between U-16 Croatian soccer players. 44 young soccer players (15.7 ± 1.5 years were tested with 8 specific soccer field tests that evaluate kicking velocity by using Pocket radar that was reading the ball velocity in km/h. The tests took place two days in a row; beginning at 8 A.M. Prior to the tests, players warmed up and stretched for 20 minutes (13 minutes of running with and without the ball, 7 minutes of dynamic stretching. Inter positional differences were significant (p ≤ 0.05 between midfielders and defenders in all tests and in one test midfielders scored better than strikers. The fastest kicks were instep kicks when stationary and non-stationary ball was kicked. Shots were taken by midfielders with 106.94±7.07 and 101.61±7.88 km/h respectively. Similar to dominant leg, midfielders also achieved the fastest instep kicks with non-dominant leg (91.44±9.56 km/h. Intra positional differences revealed that soccer kick velocity is one of possible selection tools, because more efficient players in all playing lines shoot faster kicks than less efficient players.
Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders
PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects...... in type I and II fibers did not change. CONCLUSION: In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers...
Full Text Available Purpose. The aim of the study was to compare the morphological characteristics of experienced futsal players with professional soccer players. Methods. The research sample included 22 university futsal players and 22 professional soccer players. Parameters including body height and mass, skinfold thicknesses of the trunk and extremities, lower limb length, trunk width, humerus and femur bone breadths, and the circumferences of the chest, hips, thighs, and calves were used to calculate various somatic indices. Somatotyping was performed using the Heath–carter method. Differences in the characteristics between the futsal and soccer players were analyzed using Student’s t test. Intragroup analysis was also performed on futsal players depending on player position and compared with the arithmetic means and standard deviations of all variables of the entire sample. Results. compared with their soccer-playing peers, the futsal players were shorter, weighed less, had shorter lower limbs, narrower hips, and smaller hip circumference and bone breadth values. In contrast, higher levels of body fat and endomorphy were noted in this group. The proportion of mesomorphs and ectomorphs were similar in both groups. Futsal goalkeepers were differentiated by greater subcutaneous adiposity and body mass. Defenders had the slimmest body shape, with relatively narrower shoulders and hips, smaller bone breadths, and lower levels of adiposity. The body build of wingers was slightly larger. Pivoters were characterized by greater body height and larger values for the characteristics measuring the lateral trunk dimensions. Conclusions. The observed morphological differences between futsal and soccer players were mainly in body height and height-associated characteristics. This indicates that no specialized approach in futsal recruitment is currently used. This points to the need to develop a specialized approach in the player recruitment stage, as the tactical and
Full Text Available Introduction. The aims of the present study were to determine the activity profiles of a large sample of Polish Premier League soccer players during elite-standard soccer matches depending on their position on the pitch and the intensity range of physical activity. Material and methods. The study sample comprised 1,178 players in 5 outfield positions: external defenders (ED, n = 289, central defenders (CD, n = 307, central midfield players (CM, n = 327, external midfield players (EM, n = 152, and forwards (F, n = 103. Altogether, 81 Polish League games held during four domestic seasons (2010-2011, 2011-2012, 2012-2013, and 2013-2014 were used in the analysis. A semi-automatic computerised player tracking system (Amisco Pro®, version 1.0.2, Nice, France was applied to create the match activity profiles of the teams. Results. The results of statistical analysis revealed that the average total distance covered by all the players (n = 1,178 was 11,313 ± 852 m. With respect to the players’ position on the pitch, the central midfielders travelled the longest average distance (11,894 ± 765 m during the game. The longest distance was covered in the V1 intensity range (62%, followed by V2 (15%, V3 (10%, V4 (8%, V5 (3%, and V6 (2%. Conclusions. The objective of this study was to verify the differences among playing positions and to quantify the demands placed on elite Polish soccer players in each individual position during match play. While analysing elite-level match play in terms of the overall distance covered in different categories of intensity, we found a number of statistically significant differences between different playing positions. The data presented in this study can be regarded as norms for elite soccer players, serve for present and future comparison, and represent the scientific basis for developing position-specific conditioning/training protocols in soccer.
Athos Trecroci, Luca Cavaggioni, Riccardo Caccia, Giampietro Alberti
Full Text Available General physical practice and multidimensional exercises are essential elements that allow young athletes to enhance their coordinative traits, balance, and strength and power levels, which are linked to the learning soccer-specific skills. Jumping rope is a widely-used and non-specific practical method for the development of athletic conditioning, balance and coordination in several disciplines. Thus, the aim of this study was to investigate the effects of a short-term training protocol including jumping rope (JR exercises on motor abilities and body balance in young soccer players. Twenty-four preadolescent soccer players were recruited and placed in two different groups. In the Experimental group (EG, children performed JR training at the beginning of the training session. The control group (CG, executed soccer specific drills. Harre circuit test (HCT and Lower Quarter Y balance test (YBT-LQ were selected to evaluate participant’s motor ability (e.g. ability to perform rapidly a course with different physical tasks such as somersault and passages above/below obstacles and to assess unilateral dynamic lower limb balance after 8 weeks of training. Statistical analysis consisted of paired t-test and mixed analysis of variance scores to determine any significant interactions. Children who performed jumping rope exercises showed a significant decrease of 9% (p 0.05, ES = 0.05-0.2 from pre- to post-training. A training-by-group interaction was found for the composite score in both legs (p 0.14. Our findings demonstrated that JR practice within regular soccer training enhanced general motor coordination and balance in preadolescent soccer players. Therefore, the inclusion of JR practice within regular soccer training session should encouraged to improve children’s motor skills.
Conclusion: The study revealed that soccer players with osteitis pubis may have concomitant inguinal hernia, and that osteitis pubis may develop in soccer players who have undergone hernia repair. In addition, more severe osteitis pubis findings on the same side with hernia indicate that the two pathologies occur with common mechanisms. It should not be forgotten that inguinal hernia be considered in the differential diagnosis of osteitis pubis, which it may accompany. Conservative methods are mostly used in the treatment of osteitis pubis, whereas the treatment of inguinal hernia is surgery. If only one entity is diagnosed when both are present, the success of treatment will decrease.
Visscher, C; Elferink-Gemser, MT; Lemmink, KAPM
The purpose of this study, in which 113 talented Youth soccer players (M = 16.0 yr., SD = 15), selected by their age and level of performance participated, was to investigate interval endurance capacity needed to play at the highest level of competition in the age-category 12 through 18.
Strategies for a nutrition education as applied to individual soccer players provide a key to guiding them towards appropriate food selection. Scientific investigations have associated energy requirements, composition of the diet and carbohydrate intake with muscle glycogen storage, and adequacy of fluids with optimal athletic performance. In general, soccer players appear to consume adequate energy but low carbohydrate diets. The training diet should be comprised of 55-65% carbohydrate, 12-15% protein and less than 30% fat. The goal of the training diet is to provide adequate energy for weight maintenance, and 7-10 g of carbohydrate per kg body weight for maximizing glycogen storage. Nutritional needs for competition include eating prior to and after matches. Consumption of carbohydrate-rich foods for energy needs and glycogen resynthesis are key behaviours soccer players need to focus on daily. Qualified dietitians should be on hand to provide personal nutrition counselling, carbohydrate resource lists and education on food labels as simple and quick nutrition education strategies to guide soccer players, their parents, coaches and trainers towards improved food selections.
Doncaster, Greg; Unnithan, Viswanath
To assess the between-game variation in measures of physical performance during 11 v 11 soccer match-play, over a short period of time, in highly trained youth soccer players. A single cohort observational study design was employed. Physical match performance data were collected from 17 male, highly trained youth soccer players (age: 13.3 ± 0.4 y) over three, 2 x 20min, 11 v 11 matches. Using 10 Hz GPS, the variables selected for analyses were total distance (TD), high-speed running (HSR), very high-speed running (VHSR), number of high-speed running efforts (HSReff) and number of very high-speed running efforts (VHSReff). Match data was also separated into cumulative 5 min epochs, to identify the peak 5 min epoch and the mean of the cumulative 5 min epochs for each match. Variability was quantified using the coefficient of variation (CV), Standard error of measurement (SEM) and intra-class correlation coefficient (ICC). Between- and within-player smallest worthwhile changes (SWC) were also calculated for each variable to aid in the interpretation of the data. Analysis of the variance between games reported a low CV for TD (3.8%) but larger CVs for HSR (33.3%), HSReff (35.4%) and VHSR and VHSReff (59.6 and 57.4 %, respectively). Analysis of 5 min epochs (peak and average) found an increase in the CVs beyond that of the values reported for the whole match. Between-player SWC in high intensity physical performance data ranged from 24.7 - 42.4 %, whereas within-player SWC ranged from 1.2 - 79.9%. The between-game variability of high and very high intensity activities in youth soccer players, across three soccer matches over a short period of time (2 weeks), is relatively 'large' and specific to the individual, thus highlighting the need for caution when interpreting physical performance data between games and players.
Full Text Available This research is aimed at examining sensitivity of the speed evaluation tests while carrying the ball. The research included 76 male examinees, aged 17 years (+/- 6 months, who were divided into two qualitatively different subgroups. For determining the speed while carrying the ball, the tests of M type of carrying the ball between cones and slalom ball carrying with a pass were performed. The obtained results proved that the examinees from the group of more successful soccer players (Group 1 scored better on the applied tests when compared to the results of the group consisting of the soccer players from lower ranked clubs and who are not national team members (Group 2. High values of the result homogeneity in the two groups (for the Groups 1 and 2 it was 75% and 68.75% respectively lead to the conclusion that this ability is essential characteristics of young soccer players. The coefficient of discrimination of 0.269 for the results of M type test and 0.197 for the results of the test of carrying the ball with a pass indicate that the results of the two tests provide possibility to qualitatively distinguish youth players. Therefore, it can be concluded that as a technical element, carrying the ball significantly affects the quality of players' performance.
Maughan, R J
To examine the dietary habits of professional soccer players at two Scottish Premier League clubs during the competitive season. A study of the dietary intake of 51 professional soccer players with two different clubs was carried out by the seven day weighed intake method. Physical characteristics of the two groups of players were similar, with only small differences in age and body mass but no difference in height and body fat. Mean (SD) daily energy intake for club A was 11.0 (2.6) MJ, and for club B 12.8 (2.2) MJ. The higher energy intake at club B was largely accounted for by a higher (P macronutrients to total energy intake was broadly similar to that of the general population.
Serner, Andreas; Jakobsen, Markus Due; Andersen, Lars Louis
INTRODUCTION: Exercise programmes are used in the prevention and treatment of adductor-related groin injuries in soccer; however, there is a lack of knowledge concerning the intensity of frequently used exercises. OBJECTIVE: Primarily to investigate muscle activity of adductor longus during six...... traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals. MATERIALS AND METHODS: 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally...
Iaia, F. Marcello; Fiorenza, Matteo; Perri, Enrico; Alberti, Giampietro; Millet, Grégoire P.; Bangsbo, Jens
In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg) reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6) or speed endurance maintenance (SEM; n = 7) training, three times per wk. SEP training consisted of 6–8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6–8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (pstrategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles’ ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in trained young soccer players. PMID:26394225
García-Rovés, Pablo M.; García-Zapico, Pedro; Patterson, Ángeles M.; Iglesias-Gutiérrez, Eduardo
Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of thes...
Vigh-Larsen, Jeppe F; Dalgas, Ulrik; Andersen, Thomas B
Vigh-Larsen, JF, Dalgas, U, and Andersen, TB. Position-specific acceleration and deceleration profiles in elite youth and senior soccer players. J Strength Cond Res 32(4): 1114-1122, 2018-The purpose of the study was to characterize and compare the position-specific activity profiles of young and senior elite soccer players with special emphasis put on accelerations and decelerations. Eight professional senior matches were tracked using the ZXY tracking system and analyzed for the number of accelerations and decelerations and running distances within different speed zones. Likewise, 4 U19 and 5 U17 matches were analyzed for comparison between youth and senior players. In senior players, the total distance (TD) was 10,776 ± 107 m with 668 ± 28 and 143 ± 10 m being high-intensity running (HIR) and sprinting, respectively. Number of accelerations and decelerations were 81 ± 2 and 84 ± 3, respectively, with central defenders performing the lowest and wide players the highest number. Declines were found between first and second halves for accelerations and decelerations (11 ± 3%), HIR (6 ± 4%), and TD (5 ± 1%), whereas sprinting distance did not differ. U19 players performed a higher number of accelerations, decelerations, and TD compared with senior players. In conclusion, differences in the number and distribution of accelerations and decelerations appeared between player positions, which is of importance when monitoring training and match loads and when prescribing specific training exercises. Furthermore, youth players performed as much high-intensity activities as senior players, indicating that this is not a discriminating physiological parameter between these players.
Song, In Sup; Lee, Jong Ik; Kwak, Byeung Kook; Shim, Hyung Jin; Lee, Jong Beum; Lee, Yong Chul; Kim, Kun Sang; Seo, Kyung Mook
We aimed to know the prevalence of abnormal meniscal signal on MR imaging in asymptomatic soccer players and its radiologic significance. Using T1 and gradient echo T2 weighted sagittal and coronal MR image, 48 knees in twenty-four full time soccer players were evaluated for the meniscal abnormalities, the status of ligament and existence of joint effusion. Meniscal abnormalities were interpreted using grading system of Lotysch. By using Chi-square method. We analyzed the existence of joint effusion could divide the healing state and healed state of the meniscus. The prevalence of Grade 2 and more and Grade 3 were 42% and 39% of asymptomatic knees. In the 24 knees with meniscus tear, nine of the 14 asymptomatic knee showed effusion while eight of the 10 symptomatic knee did. Of 24 knees with meniscal tear, only eleven knees were related to previous history of major knee trauma. The prevalence of meniscal abnormalities on MR imaging in asymptomatic soccer players was higher (grade 3: 39%) than we expected. The joint effusion was not helpful to divide the healing state and healed state of the meniscus. So we suggest baseline MR imaging in the athletes who have been using the knee vigorously could give decisive information for the interpretation of subsequent MRI that may be performed when the players wounded
Full Text Available We investigated the level of dehydration after a match in 20 soccer players (mean ± SD, 17.9 ± 1.3 years old, height 1.75 ± 0.05 m, body mass 70.71± 7.65 kg from two teams that participate in a Brazilian Championship game performed at a temperature of 29 ± 1.1 C and a relative humidity of 64 ± 4.2%. Body mass, urine specific gravity and urinary protein were measured before and after the match, and self-perception measurements were performed during the match. Body mass loss was 1.00 ± 0.39 kg, corresponding to a dehydration percentage of 1.35 ± 0.87%. The mean sweating rate during the match was 866 ± 319 ml · h[sup]-1[/sup] and total fluid intake was 1265.00 ± 505.45 ml. The sweating rate and the quantity of ingested fluids correlated positively (r = 0.98; P<0.05. Protein occurred in the urine in 18 soccer players. The players showed no perception of thirst and considered themselves as comfortable during the match. At the end of the match the soccer players replaced 57.7 ± 15% of the water loss and presented a condition of significant to severe dehydration based on the post-match urine specific gravity data (1.027 ± 6 g · ml[sup]-1[/sup]. The results of this study demonstrate that most of the soccer players began the match with some degree of dehydration that worsened during the match.
Jonge, M.C. de; Maas, M.; Kuijk, C. van
Soccer is one of the most popular sports worldwide. There is a high incidence of injuries in soccer in which several intrinsic and extrinsic factors play a part. Most injuries are minor, self-limiting and do not need extensive medical treatment or imaging. Imaging can be required for several reasons e.g. when the clinical findings are doubtful, to replace arthroscopy (i. e. of the knee) or for prognostic reasons. All imaging modalities available to the radiologist can be used but MRI is the most valuable imaging modality with its superior contrast resolution and multiplanar capabilities. Basically, injuries in the soccer player can occur anywhere in the body like in every sport. The lower extremities, more specific the knee and ankle, are however the most injured parts. (orig.) [de
Cumming, Sean P; Brown, Daniel J; Mitchell, Siobhan; Bunce, James; Hunt, Dan; Hedges, Chris; Crane, Gregory; Gross, Aleks; Scott, Sam; Franklin, Ed; Breakspear, Dave; Dennison, Luke; White, Paul; Cain, Andrew; Eisenmann, Joey C; Malina, Robert M
Individual differences in the growth and maturation have been shown to impact player performance and development in youth soccer. This study investigated Premier League academy players' experiences of participating in a tournament bio-banded for biological maturation. Players (N = 66) from four professional soccer clubs aged 11 and 14 years and between 85-90% of adult stature participated in a tournament. Players competed in three 11 vs 11 games on a full size pitch with 25-min halves. Sixteen players participated in four 15-min focus groups and were asked to describe their experiences of participating in the bio-banded tournament in comparison to age group competition. All players described their experience as positive and recommended the Premier League integrate bio-banding into the existing games programme. In comparison to age-group competitions, early maturing players described the bio-banded games more physically challenging, and found that they had to adapt their style of play placing a greater emphasis on technique and tactics. Late maturing players considered the games to be less physically challenging, yet appreciated the having more opportunity to use, develop and demonstrate their technical, physical, and psychological competencies. Bio-banding strategies appear to contribute positively towards the holistic development of young soccer players.
Heisterberg, Mette F; Fahrenkrug, Jan; Krustrup, Peter; Storskov, Anders; Kjær, Michael; Andersen, Jesper L
The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players and to analyze different blood parameters in relation to seasonal changes in training and match exposure. Blood samples were collected 5 times during a 6-month period and analyzed for 37 variables in 27 professional soccer players from the best Danish league. Additionally, the players were tested for body composition, V[Combining Dot Above]O2max and physical performance by the Yo-Yo intermittent endurance submax test (IE2). Multiple variations in blood parameters occurred during the observation period, including a decrease in hemoglobin and an increase in hematocrit as the competitive season progressed. Iron and transferrin were stable, whereas ferritin showed a decrease at the end of the season. The immunoglobulin A (IgA) and IgM increased in the period with basal physical training and at the end of the season. Leucocytes decreased with increased physical training. Lymphocytes decreased at the end of the season. The V[Combining Dot Above]O2max decreased toward the end of the season, whereas no significant changes were observed in the IE2 test. The regular blood samples from elite soccer players reveal significant changes that may be related to changes in training pattern, match exposure, or length of the match season. Especially the end of the preparation season and at the end of the competitive season seem to be time points were the blood-derived values indicate that the players are under excessive physical strain and might be more subjected to a possible overreaching-overtraining conditions. We suggest that regular analyses of blood samples could be an important initiative to optimize training adaptation, training load, and game participation, but sampling has to be regular, and a database has to be built for each individual player.
Full Text Available Many sports (for instance soccer are stereotypically perceived as a male activity. Even so, more and more women decide to become competitive athletes. Since the theory of sport requires comprehensive explanations and the practice of sport needs clear guidelines, interdisciplinary studies into the nature of sport, including its psychological aspects, are necessary. Analysing the psychological profile of female soccer players, particularly those who are about to become professional athletes, can provide many interesting insights into the specific character of female youth sport and show where improvements can be made in athletic training programmes (especially in mental training. It is therefore important to study psychological gender that determines social behaviours and to analyse female athletes’ emotional intelligence. Emotional intelligence is defined as a set of emotional competencies that determine the effectiveness of human behaviours. Psychological gender and emotional intelligence have a significant effect on human adaptability and the efficiency of psychosocial functioning. This research was undertaken with the dual purpose of identifying the psychological gender and emotional intelligence of female soccer players. It involved 54 secondary-school girls, some of whom attended a sports class and others played on the Polish national team. The following tools were used to carry out the research: the Gender Assessment Inventory (IPP [This and the other acronyms derive from the Polish language]-developed by Kuczyńska and the Emotional Intelligence Questionnaire (INTE; created by Jaworowska and Matczak. As shown by the analysis of the results, most female soccer players in the study were androgynous and the level of their emotional intelligence was significantly higher than in other participants. This also seems to point to their significantly greater adaptability. At the same time, the level of emotional intelligence in many players was
Thorborg, Kristian; Serner, Andreas; Petersen, Jesper
An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....
Raizel, Raquel; da Mata Godois, Allan; Coqueiro, Audrey Yule; Voltarelli, Fabrício Azevedo; Fett, Carlos Alexandre; Tirapegui, Julio; de Paula Ravagnani, Fabricio Cesar; de Faria Coelho-Ravagnani, Christianne
Despite the well-documented importance of nutrition in optimizing performance and health, the dietary intake of soccer players has attracted little attention. We aimed to assess the pre-season dietary intake of professional soccer players and its adequacy in macro and micronutrients. The pre-season dietary intake of 19 male athletes was assessed using a semi-structured 3-day food record. To determine dietary adequacy and excess, energy and macronutrient intake were compared with the Brazilian dietary reference values for athletes, and micronutrients were compared with the Estimated Average Requirement - EAR (minimum recommendation) and Tolerable Upper Intake Level - UL (maximum recommendation). Mean daily energy intake (40.74±12.81 kcal/kg) was adequate. However, there was a low carbohydrate intake (5.44±1.86 g/kg/day) and a high amount of protein and fat (1.91±0.75 and 1.27±0.50 g/kg/day, respectively). Sodium intake (3141.77±939.76 mg/day) was higher than UL (2300 mg/day), while the majority of players showed daily intake of vitamin A (74%), vitamin D (100%), folate (58%), calcium and magnesium (68%) below the EAR (625, 10 and 320 µg/day, 800 and 330 mg/day, respectively). The dietary intake of professional soccer players was adequate in energy, but inadequate in macro and micronutrients, which suggests the need to improve nutritional practices to sustain the physical demands of soccer during pre-season.
Rutkowska, Katarzyna; Bergier, Józef
Many sports (for instance soccer) are stereotypically perceived as a male activity. Even so, more and more women decide to become competitive athletes. Since the theory of sport requires comprehensive explanations and the practice of sport needs clear guidelines, interdisciplinary studies into the nature of sport, including its psychological aspects, are necessary. Analysing the psychological profile of female soccer players, particularly those who are about to become professional athletes, can provide many interesting insights into the specific character of female youth sport and show where improvements can be made in athletic training programmes (especially in mental training). It is therefore important to study psychological gender that determines social behaviours and to analyse female athletes' emotional intelligence. Emotional intelligence is defined as a set of emotional competencies that determine the effectiveness of human behaviours. Psychological gender and emotional intelligence have a significant effect on human adaptability and the efficiency of psychosocial functioning. This research was undertaken with the dual purpose of identifying the psychological gender and emotional intelligence of female soccer players. It involved 54 secondary-school girls, some of whom attended a sports class and others played on the Polish national team. The following tools were used to carry out the research: the Gender Assessment Inventory (IPP [This and the other acronyms derive from the Polish language]-developed by Kuczyńska) and the Emotional Intelligence Questionnaire (INTE; created by Jaworowska and Matczak). As shown by the analysis of the results, most female soccer players in the study were androgynous and the level of their emotional intelligence was significantly higher than in other participants. This also seems to point to their significantly greater adaptability. At the same time, the level of emotional intelligence in many players was average or low
Full Text Available This study analyzed soccer players’ retention of coaches’ feedback during training sessions. We intended to determine if the retention of information was influenced by the athletes’ personal characteristic (age, gender and the sports level, the quantity of information included in coach’s feedback (the number of ideas and redundancy, athletes’ perception of the relevance of the feedback information and athletes’ motivation as well as the attention level. The study that was conducted over the course of 18 sessions of soccer practice, involved 12 coaches (8 males, 4 females and 342 athletes (246 males, 96 females, aged between 10 and 18 years old. All coach and athlete interventions were transposed to a written protocol and submitted to content analysis. Descriptive statistics and multiple linear regression were calculated. The results showed that a substantial part of the information was not retained by the athletes; in 65.5% of cases, athletes experienced difficulty in completely reproducing the ideas of the coaches and, on average, the value of feedback retention was 57.0%. Six variables with a statistically significant value were found: gender, the athletes’ sports level, redundancy, the number of transmitted ideas, athletes’ perception of the relevance of the feedback information and the athletes’ motivation level.
Full Text Available The aims of this study were to verify the occurrence of dental injuries in 343 amateur Turkish soccer players in İzmir and the level of knowledge of the teams’ soccer players about mouthguards. The soccer players were interviewed to determine the occurrence of dental trauma during soccer and mouthguard usage level. The data were analyzed with descriptive analysis to determine absolute and relative frequencies of answers for each one of the questions. Only 35 (10.2% soccer players reported the occurrence of some type of dental injury during soccer practice. Regarding emergency conducts, approximately 84 players (24.48% answered that replantation could be obtained after teeth avulsion, 23 players (27.38% answered that successful replantation could be obtained within 2 hours immediately after injury, and 60.71% were not able to answer this question. Regarding mouthguard use, 61.8% of soccer players did not know about mouthguards. It was possible to conclude that dental injuries are common during amateur soccer practice and that there is a lack of information in the soccer players related to the emergency conducts and prevention of dental trauma.
Full Text Available The aim of this study was to compare the physical performance profile among young soccer players of different competitive levels. Two teams of elite (n = 22 and sub-elite (n = 22 soccer players at national (highly skilled and regional (moderately skilled level were recruited in the study. All participants were tested using a modified Illinois change of direction speed test, a T-drill with and without a ball, a countermovement jump, and a 10-m sprint. The analysis revealed significant differences in favor of elite players in sprint (d = 1.54, large and vertical jump (d = 2.03, very large outcomes, while no differences were observed in both modified Illinois change of direction speed (d = 0.16, trivial and T-drill (d = 0.20, small tests between the groups. The ability to change direction and speed with and without a ball was found not to be suitable enough to highlight the difference among youth players with moderate-to-high level of play. In conclusion, multi-testing approach based on task-related power should include vertical jump and sprint performance to delineate players of a higher level.
Mara, Jocelyn K; Thompson, Kevin G; Pumpa, Kate L; Ball, Nick B
To investigate the variation in training demands, physical performance, and player well-being across a women's soccer season. Seventeen elite female players wore GPS tracking devices during every training session (N=90) throughout 1 national-league season. Intermittent high-speed-running capacity and 5-, 15-, and 25-m-sprint testing were conducted at the beginning of preseason, end of preseason, midseason, and end of season. In addition, subjective well-being measures were self-reported daily by players over the course of the season. Time over 5 m was lowest at the end of preseason (mean 1.148 s, SE 0.017 s) but then progressively deteriorated to the end of the season (Pperformance over 15 m improved by 2.8% (P=.013) after preseason training, while 25-m-sprint performance peaked at midseason, with a 3.1% (P=.05) improvement from the start of preseason, before declining at the end of season (P=.023). Training demands varied between phases, with total distance and high-speed distance greatest during preseason before decreasing (Pphysical performance in elite female soccer players allow coaches to ensure that training periodization goals are being met and related positive training adaptations are being elicited.
Stubbe, J.H.; Beijsterveldt, A.M. van; Knaap, S. van der; Stege, J.; Verhagen, E.; Mechelen, W. van; Backx, F.J.G.
Context : Injuries are a major adverse event in a soccer player's career. Reducing injury incidence requires a thorough knowledge of the epidemiology of soccer injuries. Objective : To investigate the incidence and characteristics of injuries in the Dutch premier soccer league. Design : Cohort
Stubbe, J.H.; van Beijsterveldt, A.M.M.C.; van der Knaap, S.; Stege, J.; Verhagen, E.A.L.M.; van Mechelen, W.; Backx, F.J.G.
Context: Injuries are a major adverse event in a soccer player's career. Reducing injury incidence requires a thorough knowledge of the epidemiology of soccer injuries. Objective: To investigate the incidence and characteristics of injuries in the Dutch premier soccer league. Design: Cohort study.
Toering, Tynke; Elferink-Gemser, Marije; Jordet, Geir; Jorna, Casper; Pepping, Gert-Jan; Visscher, Chris
This study aimed to measure behavioral correlates of self-regulation in elite youth soccer players. Behaviors regarded as indicative of self-regulated learning were identified by interviewing six expert youth soccer coaches. These behaviors were observed during practice of eight elite youth soccer
Noda, Yuka; Iide, Kazuhide; Masuda, Reika; Kishida, Reina; Nagata, Atsumi; Hirakawa, Fumiko; Yoshimura, Yoshitaka; Imamura, Hiroyuki
The purpose of this study was: 1) to collect baseline data on nutrient intake in order to advise athletes about nutrition practices that might enhance performance, and 2) to evaluate the dietary iron intake and blood iron status of Japanese collegiate soccer players. The subjects were 31 soccer players and 15 controls. Dietary information was obtained with a food frequency questionnaire. The mean carbohydrate (6.9 g.kg-1 BW) and protein (1.3 g/kg) intakes of the soccer players were marginal in comparisons with recommended targets. The mean intakes of calcium, magnesium, vitamin A, B1, B2, and C were lower than the respective Japanese recommended dietary allowances (RDAs) or adequate dietary intakes in the soccer players. The mean intakes of green and other vegetables, milk and dairy products, fruits, and eggs were lower than the recommended targets. Thus, we recommended athletes to increase the intake of these foodstuffs along with slight increase in carbohydrate and lean meat. The mean intake of iron was higher than the respective RDA in the soccer players. A high prevalence of hemolysis (71%) in the soccer players was found. None of the soccer players and controls had anemia. Two soccer players had iron depletion, while none was found in the controls. In those players who had iron deficiency, the training load need to be lowered and/or iron intake may be increased.
Nikolaos E Koundourakis
Full Text Available The current study had two aims. The primary purpose was to examine the association between serum vitamin D levels and the ergometric evaluation of muscle strength, aerobic capacity, and speed in professional soccer players. The secondary aim was to evaluate the effects of the soccer off-season period on serum vitamin D levels.Sixty-seven Caucasian male soccer players (age 25.6 ± 6.2 and height 1.81 ± 0.08 m, members of two Greek Superleague Soccer teams and one Football-league championship team participated in this study. Exercise performance testing for the determination of squat jump (SJ, countermovement jump (CMJ, 10 (10 m and 20 meters (20 m sprint performance, maximal oxygen consumption (VO2max, anthropometry, and blood sampling were performed before (pre and after (post the six-week off-season period.Analysis of our results showed the following: (a a significant correlations between serum vitamin D levels and performance parameters in both pre (SJ; P < 0.001, CMJ; P < 0.001, VO2max; P < 0.001, 10 m; P < 0.001, and 20 m; P < 0.001 and post (SJ; P < 0.001, CMJ; P<0.001, VO2max; P = 0.006, 10 m; P < 0.001, and 20 m; P < 0.001 experimental sessions. (b Vitamin D concentration increased significantly (P < 0.001 following the six-week off-season period compared to baseline, while at the same time all measured performance parameters decreased (SJ; P < 0.001, CMJ; P < 0.001, 10 m; P < 0.001, 20 m; P < 0.001, VO2max; P<0.001.Our findings suggest that vitamin D levels are associated with the ergometric evaluation of muscle strength, as expressed by SJ and CMJ, sprinting capacity, and VO2max in professional soccer players, irrespective the levels of performance. Furthermore, our data reaffirm the importance of UVB on serum vitamin D levels. Moreover, reductions in exercise training stress may also have beneficial effects on vitamin D levels, suggesting a possible association of its levels and the training-induced stress. Our results indicate a
Yanci, Javier; Los Arcos, Asier; Camara, Jesús; Castillo, Daniel; García, Alberto; Castagna, Carlo
The aim of this study was to examine the dose response effect of strength and conditioning programmes, involving horizontally oriented plyometric exercises, on relevant soccer performance variables. Sixteen soccer players were randomly allocated to two 6-week plyometric training groups (G1 and G2) differing by imposed (twice a week) training volume. Post-training G1 (4.13%; d = 0.43) and G2 (2.45%; d = 0.53) moderately improved their horizontal countermovement jump performance. Significant between-group differences (p 0.05, d = trivial or small) post-training improvements in sprint, change of direction ability (CODA) and horizontal arm swing countermovement jump were reported in either group. Horizontal plyometric training was effective in promoting improvement in injury prevention variables. Doubling the volume of a horizontal plyometric training protocol was shown to have no additional effect over functional aspects of soccer players' performance.
Full Text Available The aim of the present study was to analyse the parameters that characterize the vertical ground reaction force during the landing phase of a jump, and to determine the relationship among these parameters in elite soccer players with cerebral palsy (CP. Thirteen male members of the Spanish national soccer team for people with CP (mean age: 27.1 ± 4.7 years volunteered for the study. Each participant performed three counter movement jumps. The characteristics of the first peak of the vertical ground reaction force during the landing phase of a jump, which corresponds to the forefoot contact with the ground, were similar to the results obtained in previous studies. However, a higher magnitude of rearfoot contact with the ground (F2 was observed in participants with CP than in participants without CP. Furthermore, a significant correlation between F2 magnitude and the elapsed time until its production (T2 was not observed (r = -0.474 for p = 0.102. This result implies that a landing technique based on a delay in the production of F2 might not be effective to reduce its magnitude, contrary to what has been observed in participants without CP. The absence of a significant correlation between these two parameters in the present study, and the high magnitude of F2, suggest that elite soccer players with CP should use footwear with proper cushioning characteristics.
Malina, Robert M; Figueiredo, António J; Coelho-E-Silva, Manuel J
Studies of the body size and proportions of athletes have a long history. Comparisons of athletes within specific sports across time, though not extensive, indicate both positive and negative trends. To evaluate secular variation in heights and weights of male youth soccer players reported in studies between 1978 and 2015. Reported mean ages, heights, and weights of male soccer players 9-18 years of age were extracted from the literature and grouped into two intervals: 1978-99 and 2000-15. A third-order polynomial was fitted to the mean heights and weights across the age range for each interval, while the Preece-Baines model 1 was fitted to the grand means of mean heights and mean weights within each chronological year to estimate ages at peak height velocity and peak weight velocity for each time interval. Third-order polynomials applied to all data points and estimates based on the Preece-Baines model applied to grand means for each age group provided similar fits. Both indicated secular changes in body size between the two intervals. Secular increases in height and weight between 1978-99 and 2000-15 were especially apparent between 13 and 16 years of age, but estimated ages at peak height velocity (13.01 and 12.91 years) and peak weight velocity (13.86 and 13.77 years) did not differ between the time intervals. Although the body size of youth soccer players increased between 1978-99 and 2000-15, estimated ages at peak height velocity and peak weight velocity did not change. The increase in height and weight likely reflected improved health and nutritional conditions, in addition to the selectivity of soccer reflected in systematic selection and retention of players advanced in maturity status, and exclusion of late maturing players beginning at about 12-13 years of age. Enhanced training programs aimed at the development of strength and power are probably an additional factor contributing to secular increases in body weight.
Barfield, J P; Malone, Laurie A
Lack of exercise is a major risk factor for secondary conditions among persons dependent upon motorized wheelchairs. Power wheelchair soccer is a unique exercise opportunity for this population, and understanding factors that influence exercise decision-making is necessary for clinicians to help those in motorized chairs reduce their secondary risk. Therefore, this study examined differences in perceived benefits and barriers to exercise among power wheelchair soccer players using a mixed-methods analysis. The most common perceived benefit to exercise was "Exercising lets me have contact with friends and persons I enjoy." Post hoc comparisons of quantitative data indicated that persons with muscular dystrophy perceived exercise to be significantly less important than did other disability groups (p Exercise is hard work for me," "Exercise tires me," and "There are too few places for me to exercise" were the most common perceived barriers. These findings can assist with development of exercise opportunities for power wheelchair users.
Göksu, Ömer Can; Yüksek, Selami; Ölmez, Cengiz
This study was conducted to examine the effects of sports activities other than soccer on 10-15-year-old soccer players' motor skills. The sample included 146 registered soccer players in the U category (U10-U15) of the Turkish Football Federation's Aslantepe, Çeliktepe and Seyrantepe clubs. The players participated in this study on a voluntary…
van der Sluis, A; Elferink-Gemser, Marije; Brink, M S; Visscher, C
The purpose of this study was to identify differences in traumatic and overuse injury incidence between talented soccer players who differ in the timing of their adolescent growth spurt. 26 soccer players (mean age 11.9 ± 0.84 years) were followed longitudinally for 3 years around Peak Height
Verbeek, Jan; Elferink-Gemser, Marije T.; Jonker, Laura; Huijgen, Barbara C. H.; Visscher, Chris
In the general population, estimates of left-foot preference are around 20%. In soccer, specific tasks create positional demands, requiring 40% of the players to be left-footed. Whether and how this is related to the selection of players is unknown. To examine the successive selection of soccer
Teixeira, Luis Augusto; de Oliveira, Dalton Lustosa; Romano, Rosangela Guimaraes; Correa, Sonia Cavalcanti
To examine the effect of long lasting practice on pedal behavior in sport, we compared experienced adult soccer players and nonsoccer players on leg preference in motor tasks requiring general mobilization, soccer related mobilization, and body balance stabilization. We also evaluated performance asymmetry between the right and left legs in static…
The purpose of this study was to determine the effect of core training program on speed, acceleration, vertical jump, and standing long jump in female soccer players. A total of 40 female soccer players volunteered to participate in this study. They were divided randomly into 1 of 2 groups: core training group (CTG; n = 20) and control group (CG;…
Anne-Marie van Beijsterveldt, A. M C; Stubbe, J. H.; Schmikli, S. L.; Van De Port, I. G L; Backx, F. J G
Objectives To compare the incidence and characteristics of injuries between Dutch amateur and professional male soccer players during one entire competition season. Design A prospective two-cohort design. Methods During the 2009–2010 season, 456 Dutch male amateur soccer players and 217 professional
Fransson, Dan; Nielsen, Tobias Schmidt; Olsson, Karl
PURPOSE: To examine the skeletal muscle and performance responses across two different exercise training modalities which are highly applied in soccer training. METHODS: Using an RCT design, 39 well-trained male soccer players were randomized into either a speed endurance training (SET; n = 21...... pronouncedly than small-sided game training, but comparable responses were in muscle ion transporters and antioxidative capacity in well-trained male soccer players....
Alentorn-Geli, Eduard; Álvarez-Díaz, Pedro; Doblas, Jesús; Steinbacher, Gilbert; Seijas, Roberto; Ares, Oscar; Boffa, Juan José; Cuscó, Xavier; Cugat, Ramón
To report the return to sports and recurrence rates in competitive soccer players after arthroscopic capsulolabral repair using knotless suture anchors at a minimum of 5 years of follow-up. All competitive soccer players with anterior glenohumeral instability treated by arthroscopic capsulolabral repair using knotless suture anchors between 2002 and 2009 were retrospectively identified through the medical records. Inclusion criteria were: no previous surgical treatment of the involved shoulder, absence of glenoid or tuberosity fractures, absence of large Hill-Sachs or glenoid bone defect, minimum follow-up of 5 years, instability during soccer practice or games, and failure of non-surgical treatment. The charts of included players were reviewed, and a phone call was performed in a cross-sectional manner to obtain information on: current soccer, return to soccer, recurrence of instability, shoulder function (Rowe score), and disability [Quick-Disability of the Arm, Shoulder, and Hand (DASH) score and Quick-DASH Sports/Performing Arts Module]. Fifty-seven young male soccer players were finally included with a median (range) follow-up of 8 (5-10) years. Forty-nine (86 %) of the soccer players were able to return to soccer and 36 of them (73 %) at the same pre-injury level. There were 6 (10.5 %) re-dislocations in the 57 players, all of them of traumatic origin produced during soccer and other unrelated activities. The main reasons to not return to soccer were: knee injuries (two players), changes in personal life (two players), and job-related (three players). None of the players quit playing soccer because of their shoulder instability injury. The median (range) Rowe score, Quick-DASH score, and Quick-DASH sports score were 80 (25-100), 2.3 (0-12.5), and 0 (0-18.8), respectively. Competitive soccer players undergoing arthroscopic capsulolabral repair with knotless suture anchors for shoulder instability without significant bone loss demonstrate excellent return to
Bruno Fles Mazuquin
Full Text Available ABSTRACTIntroduction:Muscle activity in soccer players can be measured by isokinetic dynamometer, which is a reliable tool for assessing human performance.Objectives:To perform isokinetic analyses and to determine which variables differentiate the under-17 (U17 soccer category from the professional (PRO.Methods:Thirty four players were assessed (n=17 for each category. The isokinetic variables used for the knee extension-flexion analysis were: peak torque (Nm, total work (J, average power (W, angle of peak torque (deg., agonist/ antagonist ratio (%, measured for three velocities (60°/s, 120°/s and 300°/s, with each series containing five repetitions. Three Wilks' Lambda discriminant analyses were performed, to identify which variables were more significant for the definition of each of the categories.Results:The discriminative variables at 60°/s in the PRO category were: extension peak torque, flexion total work, extension average power and agonist/antagonist ratio; and for the U17s were: extension total work, flexion peak torque and flexion average power. At 120°/s for the PRO category the discriminant variables were: flexion peak torque and extension average power; for the U17s they were: extension total work and flexion average power. Finally at 300°/s, the variables found in the PRO and U17 categories respectively were: extension average power and extension total work.Conclusion:Isokinetic variables for flexion and extension knee muscles were able to significantly discriminate between PRO and U17 soccer players.
Full Text Available The basic goal of this study was to analysis of the results of the 30-m running speed test in soccer players in third soccer leagues. The study examined the group of randomly selected seventy athletes from two soccer teams from the Ekstraklasa league, two teams from the first league and two teams from the second leagues were randomized into the study group. All the measurements were performed in indoor arenas. The temperature in the arenas ranged from 22 to 24 C. Measurements were recorded in the morning (between 10:00 am and 12:00 am. The Running Speed Test was used in the study to diagnose speed potential in the athletes. The running speed was measured by means of a set of photocells located at 0m, 5m, 20m, 30m. The results obtained demonstrated that the elite-level matches are more dynamic since the players show higher values of speed parameters. Apart from starting speed, the results obtained for the distance of 5 m provide information for coaches concerning their work on special strength. The speed is indicated by the results obtained for 20 and 30 m distances, whereas flying measurements between 5/20m and 20/30m reflect inherited speed aptitudes.
Thorborg, Kristian; Serner, Andreas; Petersen, Jesper
An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain.......An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side...
Segers, V; De Clercq, D; Janssens, M; Bourgois, J; Philippaerts, R
The aim of this study was to investigate the influence of maturity on running economy in a population of young soccer players. 13 boys (mean age 14.3 years) active in soccer were divided into two groups: 6 early and 7 late maturers. Anthropometrical characteristics, respiratory exchange ratio, heart rate and maximal oxygen uptake were measured. Running economy was assessed at three submaximal running speeds (8, 9.5 and 11 km/h). Allometric coefficients were calculated and used to diminish the effect of body mass. In addition, running style was analysed biomechanically (stride length and meaningful kinematic values). There was no significant difference in the running economy of early and late maturing soccer players, nor any significant differences in mass adjusted physiological values. Therefore physiological differences cannot explain why late maturers succeed in keeping up with early maturers. Late maturing boys take longer relative strides, and have more anteversion of the thigh at heel contact, a smaller knee-angle during swing-phase and a lower mass moment of inertia. Running style seems to be an important determinant in running economy of children.
Sporis, Goran; Vucetić, Vlatko; Jovanović, Mario; Milanović, Zoran; Rucević, Marijan; Vuleta, Dinko
The aim of the study was to analyze differences in power performance and morphological characteristics of young Croatian soccer players with respect to their team positions and to establish correlations between the power performance variables. Anthropometric characteristics and jumping and sprint performances were analyzed for 45 soccer players (age 14-15; mean body height 175.4 +/- 6.61 cm; body weight 63.6 +/- 8.06 kg) according to their team positions (defender, midfielder, forward). Pearsons coefficient of correlation was used to determine the relationship between the power performance variables. There were no significant differences (p > 0.05) in the power performance of players according to their team position. The only significant differences between players were in some of the anthropometric characteristics, such as height and weight linear relationship was determined between almost all the power performance variables. Since the players in this study were very young and their sports careers have not reached their peak performance, it is possible that their nominal team positions may change during their soccer careers.
Baláková, Veronika; Boschek, Petr; Skalíková, Lucie
The identification of talent in soccer is critical to various programs. Although many research findings have been presented, there have been only a few attempts to assess their validity. The aim of this study was to determine the relationship between talent and achievement variables in the Vienna Test System. The participants were 91 Czech soccer players, representing four youth soccer teams, who were born in the year 2000. These boys were divided into two groups according to their coaches' assessments using a TALENT questionnaire. A two-factor model (component 1: "kinetic finesse"; component 2: "mental strength") was designed to interpret the responses of the coaches on the questionnaire. The Vienna Test System was used to determine the level of players' cognitive abilities. In total, the subjects performed seven tests in the following order: Raven's Standard Progressive Matrices (SPM), a reaction test (RT), a determination test (DT), a visual pursuit test (LVT), a Corsi Block-Tapping Test (CORSI), a time/movement anticipation test (ZBA), and a peripheral perception test (PP). To analyze the relationship between talent and achievement variables within the Vienna Test System, correlation analyses were performed. The results revealed that the talented group attained significantly better results on only 1 of the 16 variables, which was ZBA2: movement anticipation - deviation of movement median (r = .217, p = .019). A comparison of the two talent components showed that component 1 ("kinetic finesse") was a more significant factor than component 2 ("mental strength"). Although we observed statistically significant correlations, their actual significance remains questionable; thus, further research is required.
Full Text Available This study examined the effects of mental fatigue and additional corridor and pitch sector lines on players' physical and tactical performances during soccer small-sided games. Twelve youth players performed four Gk+6vs6+Gk small-sided games. Prior to the game, one team performed a motor coordination task to induce mental fatigue, while the other one performed a control task. A repeated measures design allowed to compare players' performances across four conditions: (a with mental fatigue against opponents without mental fatigue in a normal pitch (MEN, (b with mental fatigue on a pitch with additional reference lines (#MEN; (c without mental fatigue against mentally fatigued opponents on a normal pitch (CTR; and (d without mental fatigue on a pitch with reference lines (#CTR. Player's physical performance was assessed by the distance covered per minute and the number of accelerations and decelerations (0.5–3.0 m/s2; > −3.0 m/s2. Positional data was used to determine individual (spatial exploration index, time synchronized in longitudinal and lateral directions and team-related variables (length, width, speed of dispersion and contraction. Unclear effects were found for the physical activity measures in most of the conditions. There was a small decrease in time spent laterally synchronized and a moderate decrease in the contraction speed when MEN compared to the CTR. Also, there was a small decrease in the time spent longitudinally synchronized during the #MEN condition compared to MEN. The results showed that mental fatigue affects the ability to use environmental information and players' positioning, while the additional reference lines may have enhanced the use of less relevant information to guide their actions during the #MEN condition. Overall, coaches could manipulate the mental fatigue and reference lines to induce variability and adaptation in young soccer players' behavior.
Huijgen, Barbara C H; Leemhuis, Sander; Kok, Niels M; Verburgh, Lot; Oosterlaan, Jaap; Elferink-Gemser, Marije T; Visscher, Chris
Soccer players are required to anticipate and react continuously in a changing, relatively unpredictable situation in the field. Cognitive functions might be important to be successful in soccer. The current study investigated the relationship between cognitive functions and performance level in elite and sub-elite youth soccer players aged 13-17 years. A total of 47 elite youth soccer players (mean age 15.5 years, SD = 0.9) and 41 sub-elite youth soccer players (mean age 15.2 years, SD = 1.2) performed tasks for "higher-level" cognitive functions measuring working memory (i.e., Visual Memory Span), inhibitory control (i.e., Stop-Signal Task), cognitive flexibility (i.e., Trail Making Test), and metacognition (i.e., Delis-Kaplan Executive Function System Design Fluency Test). "Lower-level" cognitive processes, i.e., reaction time and visuo-perceptual abilities, were also measured with the previous tasks. ANOVA's showed that elite players outscored sub-elite players at the "higher-level" cognitive tasks only, especially on metacognition (p soccer players on inhibitory control (p = .001), and cognitive flexibility (p = .042), but not on metacognition (p = .27). No differences were found concerning working memory nor the "lower-level" cognitive processes (p > .05). In conclusion, elite youth soccer players have better inhibitory control, cognitive flexibility, and especially metacognition than their sub-elite counterparts. However, when training hours are taken into account, differences between elite and sub-elite youth soccer players remain apparent on inhibitory control and cognitive flexibility in contrast to metacognition. This highlights the need for longitudinal studies to further investigate the importance of "higher-level" cognitive functions for talent identification, talent development and performance in soccer.
Den Hartigh, Ruud J R; Van Der Steen, Steffie; Hakvoort, Bas; Frencken, Wouter G P; Lemmink, Koen A P M
Applying an established theory of cognitive development-Skill Theory-the current study compares the game-reading skills of youth players selected for a soccer school of a professional soccer club (n = 49) and their non-selected peers (n = 38). Participants described the actions taking place in videos of soccer game plays, and their verbalisations were coded using Skill Theory. Compared to the non-selected players, the selected players generally demonstrated higher levels of complexity in their game-reading, and structured the information of game elements-primarily the player, teammate and field-at higher complexity levels. These results demonstrate how Skill Theory can be used to assess, and distinguish game-reading of youth players with different expertise, a skill important for soccer, but also for other sports.
Full Text Available The aim of this investigation was to assess whether the demands of the modern English competitive soccer season would be reflected in the mood states of professional soccer players. Sixty-nine male participants either activity competing in English soccer leagues or resident in England were recruited and grouped accordingly as professional soccer players, university level soccer players, Sunday league soccer players, or non-sporting controls. On three separate occasions; at the beginning, at the middle, and finally towards the end of the English soccer season, participants completed both the Profile of Mood States (POMS questionnaire as well as a questionnaire related to their teams’ performance in addition to their perceived life stress. Results showed the POMS scores to differ over the season in relation to the groups’ standard of competition. ANOVAs demonstrated this pattern to be significant for the dependent measures of tension, depression, and confusion with significant group by time interactions (95% level of confidence. At the outset of the season professionals had the most positive POMS profile, however, as the season progressed they showed the greatest change towards a negative profile. These results indicate that English soccer is placing professional players at a predisposition of demonstrating POMS commensurate with negative adaptation to training, having important implications for their long-term performance and health.
Branci, Sonia; Thorborg, Kristian; Bech, Birthe Højlund; Boesen, Mikael; Nielsen, Michael Bachmann; Hölmich, Per
Soccer players are commonly affected by long-standing adductor-related groin pain (ARGP), but the clinical significance of MRI findings in these athletes is largely unknown. Our aims were (1) to evaluate whether MRI findings are associated with long-standing ARGP in soccer players, (2) to assess MRI findings in asymptomatic soccer players and non-soccer playing controls. This cross-sectional study included 28 male soccer players with long-standing ARGP, 17 male asymptomatic soccer players and 20 male asymptomatic non-soccer playing athletes of matching age and athletic exposure. Participants underwent identical standardised and reliable clinical examination, and MRI scans (3 T) of the pelvis performed by a blinded observer. Images were consensus rated by three blinded radiologists according to a standardised MRI evaluation protocol. The associations between clinical adductor-related findings and pathological MRI findings were investigated with χ(2) statistics and OR. Central disc protrusion (p=0.027) and higher grades of pubic bone marrow oedema (BMO; p=0.027) were significantly more present in symptomatic players than asymptomatic players. However, up to 71% of asymptomatic soccer players displayed different positive MRI findings, and asymptomatic soccer players had significantly higher odds (OR ranging from 6.3 to 13.3) for BMO, adductor tendinopathy and degenerative changes than non-soccer players. ARGP in soccer players was associated with central disc protrusion and higher grades of pubic BMO. Moreover, positive MRI findings were significantly more frequent in soccer players compared with non-soccer players irrespective of symptoms, suggesting that these MRI changes may be associated with soccer play itself rather than clinical symptoms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G
We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12) participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated...
García-Rovés, Pablo M; García-Zapico, Pedro; Patterson, Angeles M; Iglesias-Gutiérrez, Eduardo
Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player's career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.
Full Text Available The purpose of the study was to find out the relationship between psychological variables and soccer playing ability among the university level male players. 42 soccer players representing different universities who participated in inter university competitions were selected as the subjects of the study. The dependent variable was soccer playing ability and independent variables were the selected psychological variables. Soccer playing ability was determined through a 10 point scale at the time of competitions. Psychological variables included achievement motivation, anxiety, self-concept and aggression. The data was statistically analyzed using Karl Pearson’s correlation coefficient and multiple regression analysis using SPSS. It was concluded that soccer playing ability has a positive correlation with achievement motivation and self-concept whereas anxiety and aggression have a negative correlation with soccer playing ability.
Silva, Rafael P; Mündel, Toby; Natali, Antônio J; Bara Filho, Maurício G; Lima, Jorge R P; Alfenas, Rita C G; Lopes, Priscila R N R; Belfort, Felipe G; Marins, João C B
In this study we investigated pre-training hydration status, fluid intake, and sweat loss in 20 elite male Brazilian adolescent soccer players (mean ± s: age 17.2 ± 0.5 years; height 1.76 ± 0.05 m; body mass 69.9 ± 6.0 kg) on three consecutive days of typical training during the qualifying phase of the national soccer league. Urine specific gravity (USG) and body mass changes were evaluated before and after training sessions to estimate hydration status. Players began the days of training mildly hypohydrated (USG > 1.020) and fluid intake did not match fluid losses. It was warmer on Day 1 (33.1 ± 2.4°C and43.4 ± 3.2% relative humidity; P < 0.05) and total estimated sweat losses (2822 ± 530 mL) and fluid intake (1607 ± 460 mL) were significantly higher (P < 0.001) compared with Days 2 and 3. Data also indicate a significant correlation between the extent of sweat loss and the volume of fluid consumed (Day 1: r = 0.560, P = 0.010; Day 2: r = 0.445, P = 0.049; Day 3: r = 0.743, P = 0.0001). We conclude that young, native tropical soccer players arrive hypohydrated to training and that they exhibit voluntary dehydration; therefore, enhancing athletes' self-knowledge of sweat loss during training might help them to consume sufficient fluid to match the sweat losses.
Vazini Taher, Amir; Parnow, Abdolhossein
Different methods of warm-up may have implications in improving various aspects of soccer performance. The present study aimed to investigate acute effects of soccer specific warm-up protocols on functional performance tests. This study using randomized within-subject design, investigated the performance of 22 collegiate elite soccer player following soccer specific warm-ups using dynamic stretching, static stretching, and FIFA 11+ program. Post warm-up examinations consisted: 1) Illinois Agility Test; 2) vertical jump; 3) 30 meter sprint; 4) consecutive turns; 5) flexibility of knee. Vertical jump performance was significantly lower following static stretching, as compared to dynamic stretching (P=0.005). Sprint performance declined significantly following static stretching as compared to FIFA 11+ (P=0.023). Agility time was significantly faster following dynamic stretching as compared to FIFA 11+ (P=0.001) and static stretching (P=0.001). Knee flexibility scores were significantly improved following the static stretching as compared to dynamic stretching (P=016). No significant difference was observed for consecutive turns between three warm-up protocol. The present finding showed that a soccer specific warm-up protocol relied on dynamic stretching is preferable in enhancing performance as compared to protocols relying on static stretches and FIFA 11+ program. Investigators suggest that while different soccer specific warm-up protocols have varied types of effects on performance, acute effects of dynamic stretching on performance in elite soccer players are assured, however application of static stretching in reducing muscle stiffness is demonstrated.
Harøy, Joar; Clarsen, Ben; Thorborg, Kristian
surveillance method developed to capture acute and overuse problems. STUDY DESIGN: Descriptive epidemiology study. METHODS: We registered groin problems during a 6-week period of match congestion using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A total of 240 players from 15 teams......BACKGROUND: The majority of surveillance studies in soccer have used a time-loss injury definition, and many groin problems result from overuse, leading to gradually increasing pain and/or reduced performance without necessarily causing an absence from soccer training or match play. Thus......, the magnitude of groin problems in soccer has probably been underestimated in previous studies based on traditional injury surveillance methods. PURPOSE: To investigate the prevalence of groin problems among soccer players of both sexes and among male soccer players at different levels of play through a new...
This study explores the ways in which a group of young Muslim refugee women in Adelaide, South Australia, draw upon their experiences of playing in a soccer team as a way of establishing and embellishing a particular cultural identity that both affirms and challenges many of the traditions of Islam. Based primarily on qualitative interviews with the players, this study examines some of the ways in which they construct notions of self, sameness and difference as young Muslim women growing up i...
Full Text Available The identification of talent in soccer is critical to various programs. Although many research findings have been presented, there have been only a few attempts to assess their validity. The aim of this study was to determine the relationship between talent and achievement variables in the Vienna Test System. The participants were 91 Czech soccer players, representing four youth soccer teams, who were born in the year 2000. These boys were divided into two groups according to their coaches’ assessments using a TALENT questionnaire. A two-factor model (component 1: “kinetic finesse”; component 2: “mental strength” was designed to interpret the responses of the coaches on the questionnaire. The Vienna Test System was used to determine the level of players’ cognitive abilities. In total, the subjects performed seven tests in the following order: Raven’s Standard Progressive Matrices (SPM, a reaction test (RT, a determination test (DT, a visual pursuit test (LVT, a Corsi Block-Tapping Test (CORSI, a time/movement anticipation test (ZBA, and a peripheral perception test (PP. To analyze the relationship between talent and achievement variables within the Vienna Test System, correlation analyses were performed. The results revealed that the talented group attained significantly better results on only 1 of the 16 variables, which was ZBA2: movement anticipation - deviation of movement median (r = .217, p = .019. A comparison of the two talent components showed that component 1 (“kinetic finesse” was a more significant factor than component 2 (“mental strength”. Although we observed statistically significant correlations, their actual significance remains questionable; thus, further research is required.
Schmikli, Sándor L; de Vries, Wouter R; Brink, Michel S; Backx, Frank Jg
To verify if in male elite junior soccer players a minimum 1-month performance decrease is accompanied by a mood profile and hormone levels typical of non-functional over-reaching (NFOR). A prospective case-control study using a monthly performance monitor with a standardised field test to detect the performance changes. Players with a performance decrease lasting at least 1 month were compared with control players without a performance decrease on mood scores and pre-exercise and postexercise levels of stress hormones. Sporting field and sports medical laboratory. Ninety-four young elite soccer players were monitored during the 2006-2008 seasons. Twenty-one players were invited to the laboratory, seven of whom showed a significant performance decrease. Performance change over time, scores on the profile of mood states and premaximal and postmaximal exercise serum levels of adrenocorticotropic hormone (ACTH), growth hormone (GH) and cortisol. Players with a performance decrease showed psychological and hormonal changes typical of the non-functional state of over-reaching. Scores were higher on depression and anger, whereas the resting GH levels and ACTH levels after maximal exercise were reduced. ACTH and GH were capable of classifying all but one player correctly as either NFOR or control. Performance-related criteria in field tests are capable of identifying players with worsened mood and adaptations of the endocrine system that fit the definition of NFOR. Performance, mood and hormone levels may therefore be considered as valid instruments to diagnose NFOR in young elite soccer players.
Vincent, John; Glamser, Francis D
A large body of research has shown that a disproportionate number of elite youth male soccer players competing in age-segmented competition are born early in the selection year. The advantage of being born early in a cohort has been termed the "relative age effect". Although there has been an exponential growth in women's soccer, few studies have examined the relative age effect in female youth soccer. This study compared the relative age effect of 1,344 female and male youth soccer players considered by the US Olympic Development Program (ODP), in 2001, to be the most talented soccer players born in 1984. The birth dates were taken from the women's state and regional ODP, and national team rosters, and were analysed using basic descriptive statistics and chi-square tests. Results revealed only a marginal relative age effect for female ODP regional and national team players and no relative age effect for female ODP state team players. In comparison, a strong relative age effect was found in male state, regional and national team players. The results suggest that there are gender differences in the relative age effect of 17-year-old elite female and male soccer players. The gender differences may be explained by a complex interaction of biological and maturational differences with socialization influences.
Tojima, Michio; Torii, Suguru
Many adolescent soccer players experience low back pain (LBP). However, there are no reports studying the kick motion of adolescent soccer players experiencing LBP. This study aimed to clarify the kick motion of adolescent soccer players in the presence and absence of LBP. We recruited 42 adolescent soccer players and divided them into two groups according to the presence of LBP (LBP group, n=22) and absence of LBP (NBP group, n=20). We measured real-time kick motion using a three-dimensional motion analysis system. We placed 65 spherical markers on each anatomical landmark and calculated the angle of the lumbar spine, center of mass (COM) of the whole body, and displacement of the support foot. We used an unpaired t-test to compare the data between the groups. Compared with the NBP group, the LBP group showed a lateral shift in COM, which increased the duration of kick motion. The presence of LBP affected the posterior positioning of the support foot and restricted the player's lumbar spine from bending laterally. A lateral shift in COM and larger rotation of the lumbar spine could stress the lumbar spine during kick motion. Therefore, coaches and athletic trainers should pay attention to soccer players' lumbar spine rotation and the COM shift during kick motion. This would be important for preventing LBP in adolescent soccer players. Copyright © 2017 Elsevier B.V. All rights reserved.
Suzue, Naoto; Iwame, Toshiyuki; Kato, Kenji; Takao, Shoichiro; Tateishi, Tomohiko; Takeda, Yoshitsugu; Hamada, Daisuke; Goto, Tomohiro; Takata, Yoichiro; Matsuura, Tetsuya; Sairyo, Koichi
We report the case of a 29-year-old male professional soccer player who presented with symptoms of plantar fasciitis. His symptoms occurred with no remarkable triggers and gradually worsened despite conservative treatments including taping, use of insoles, and physical therapy. Local corticosteroid injection was given twice as a further intervention, but his plantar fascia partially ruptured 49 days after the second injection. He was treated conservatively with platelet-rich plasma, and magnetic resonance imaging showed regenerative change of the ruptured fascia. Five months after the rupture, he returned to his original level of training. If professional athletes find it difficult to refrain from athletic activity, as in the present case, the risk of rupture due to corticosteroid injection should not be overlooked.
huijgen, b.c.h.; Leemhuis, s.; kok, n.m.; Verburgh, L.; Oosterlaan, J.; Buitelaar, J.K.
Soccer players are required to anticipate and react continuously in a changing, relatively unpredictable situation in the field. Cognitive functions might be important to be successful in soccer. The current study investigated the relationship between cognitive functions and performance level in
Van Yperen, N.W.
This study investigated whether the perception of disadvantageous inequity makes athletes more vulnerable to dropping out. Sixty five talented youth male soccer players (mean age = 16.6 years), attending a prestigious soccer school, completed a questionnaire at the beginning and at the end of the
Beijsterveldt, A.M.C. van
Soccer causes the largest number of injuries each year (18% of all sports injuries) in the Netherlands. The aim of this dissertation is to contribute to the body of evidence on injury prevention for adult male soccer players. Chapter 1 is a general introduction and presents the “sequence of
Rafn, Bolette S; Tang, Lars; Nielsen, Peter Martin
OBJECTIVE: To investigate whether self-reported pain during hip strength testing correlates to a large degree with hip muscle strength in soccer players with long-standing unilateral hip and groin pain. DESIGN: Cross-sectional study. SETTING: Clinical assessments at Sports Orthopaedic Research...... Center-Copenhagen (SORC-C), Arthroscopic Centre Amager, Copenhagen University Hospital, Denmark. PARTICIPANTS: Twenty-four male soccer players with unilateral long-standing hip and groin pain. INTERVENTIONS: The soccer players performed 5 reliable hip muscle strength tests (isometric hip flexion...... strength (Spearman rho = -0.44, P = 0.016). CONCLUSIONS: Self-reported pain during testing does not seem to correlate with the majority of hip muscle strength tests used in soccer players with long-standing hip and groin pain....
Landahl, Göran; Adolfsson, Peter; Börjesson, Mats; Mannheimer, Clas; Rödjer, Stig
The objective of the study was to determine the prevalence of iron deficiency and iron deficiency anemia among elite women soccer players. Hemoglobin, serum iron, serum total iron binding capacity, and ferritin were determined in 28 female soccer players called up for the national team. Of the investigated female soccer players, 57% had iron deficiency and 29% iron deficiency anemia 6 months before the FIFA Women's World Cup. It is concluded that iron deficiency and iron deficiency anemia is common in female soccer players at the top international level. Some might suffer from relative anemia and measurement of hemoglobin alone is not sufficient to reveal relative anemia. Regular monitoring of hemoglobin concentration and iron status is necessary to institute iron supplementation when indicated.
Pablo M. García-Rovés
Full Text Available Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player’s career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.
García-Rovés, Pablo M.; García-Zapico, Pedro; Patterson, Ángeles M.; Iglesias-Gutiérrez, Eduardo
Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player’s career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players. PMID:25045939
Zago, Matteo; Piovan, Andrea Gianluca; Annoni, Isabella; Ciprandi, Daniela; Iaia, F Marcello; Sforza, Chiarella
Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s(-1), P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.
Barbara C H Huijgen
Full Text Available Soccer players are required to anticipate and react continuously in a changing, relatively unpredictable situation in the field. Cognitive functions might be important to be successful in soccer. The current study investigated the relationship between cognitive functions and performance level in elite and sub-elite youth soccer players aged 13-17 years. A total of 47 elite youth soccer players (mean age 15.5 years, SD = 0.9 and 41 sub-elite youth soccer players (mean age 15.2 years, SD = 1.2 performed tasks for "higher-level" cognitive functions measuring working memory (i.e., Visual Memory Span, inhibitory control (i.e., Stop-Signal Task, cognitive flexibility (i.e., Trail Making Test, and metacognition (i.e., Delis-Kaplan Executive Function System Design Fluency Test. "Lower-level" cognitive processes, i.e., reaction time and visuo-perceptual abilities, were also measured with the previous tasks. ANOVA's showed that elite players outscored sub-elite players at the "higher-level" cognitive tasks only, especially on metacognition (p .05. In conclusion, elite youth soccer players have better inhibitory control, cognitive flexibility, and especially metacognition than their sub-elite counterparts. However, when training hours are taken into account, differences between elite and sub-elite youth soccer players remain apparent on inhibitory control and cognitive flexibility in contrast to metacognition. This highlights the need for longitudinal studies to further investigate the importance of "higher-level" cognitive functions for talent identification, talent development and performance in soccer.
The ecliptic elongation of the moon with respect to the sun does not show uniform distribution on the birth dates of the 704 soccer players selected for the 1998 World Cup. However, a uniform distribution is expected on astronomical grounds. The World Cup players show a very pronounced tendency (p = 0.00001) to be born on days when the sun and moon are in adjacent zodiacal signs. Key Words: soccer; World Cup; astrology; moon PMID:11131239
Huijgen, Barbara C. H.; Leemhuis, Sander; Kok, Niels M.; Verburgh, Lot; Oosterlaan, Jaap; Elferink-Gemser, Marije T.; Visscher, Chris
Soccer players are required to anticipate and react continuously in a changing, relatively unpredictable situation in the field. Cognitive functions might be important to be successful in soccer. The current study investigated the relationship between cognitive functions and performance level in elite and sub-elite youth soccer players aged 13–17 years. A total of 47 elite youth soccer players (mean age 15.5 years, SD = 0.9) and 41 sub-elite youth soccer players (mean age 15.2 years, SD = 1.2) performed tasks for “higher-level” cognitive functions measuring working memory (i.e., Visual Memory Span), inhibitory control (i.e., Stop-Signal Task), cognitive flexibility (i.e., Trail Making Test), and metacognition (i.e., Delis-Kaplan Executive Function System Design Fluency Test). “Lower-level” cognitive processes, i.e., reaction time and visuo-perceptual abilities, were also measured with the previous tasks. ANOVA’s showed that elite players outscored sub-elite players at the “higher-level” cognitive tasks only, especially on metacognition (p .05). In conclusion, elite youth soccer players have better inhibitory control, cognitive flexibility, and especially metacognition than their sub-elite counterparts. However, when training hours are taken into account, differences between elite and sub-elite youth soccer players remain apparent on inhibitory control and cognitive flexibility in contrast to metacognition. This highlights the need for longitudinal studies to further investigate the importance of “higher-level” cognitive functions for talent identification, talent development and performance in soccer. PMID:26657073
Sanchis-Moysi, Joaquin; Idoate, Fernando; Izquierdo, Mikel; Calbet, Jose A. L.; Dorado, Cecilia
Purpose To determine the volume and degree of asymmetry of iliopsoas (IL) and gluteal muscles (GL) in tennis and soccer players. Methods IL and GL volumes were determined using magnetic resonance imaging (MRI) in male professional tennis (TP) and soccer players (SP), and in non-active control subjects (CG) (n = 8, 15 and 6, respectively). Results The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, Psoccer players had similar volumes in both sides (P = 0.87). The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = −0.97, PSoccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively). GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (Psoccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury. PMID:21829539
Iglesias-Gutiérrez, Eduardo; García, Angela; García-Zapico, Pedro; Pérez-Landaluce, Javier; Patterson, Angeles M; García-Rovés, Pablo Miguel
Many authors have proposed the necessity of the design and implementation of dietary and nutrition education programs for soccer players, although little information is available about the determinants of food selection and nutrient intake. The aim of this study was to evaluate the nutritional intake and eating patterns of soccer players according to their playing position in the team. Eighty-seven young male soccer players (aged 16-21 years) were recruited from the junior teams of a Spanish First Division Soccer League Club and divided into 6 positional categories (goalkeepers, full-backs, centre-backs, midfielders, wingers, and forwards). Body composition (height, weight, and body fat), performance in soccer-specific tests (jumping, sprinting, and intermittent endurance), and dietary intake (weighed food intake method) were assessed. A spontaneous higher carbohydrate intake was observed for full-backs, midfielders, and wingers (g·kg(-1) body mass: 4.9 ± 1.0, 4.9 ± 1.3, 4.9 ± 0.8; % of energy intake: 47 ± 5, 46 ± 6, 46 ± 4), compared with goalkeepers and centre-backs (g·kg(-1) of body mass: 3.9 ± 1.0, 4.3 ± 1.1; % of energy intake: 44 ± 3, 42 ± 4). These differences were related to food selection patterns, and a higher contribution to daily energy intake of cereals, derivatives, and potatoes was observed between full-backs compared with goalkeepers and centre-backs (33% vs. 27% and 25%). The magnitude of these differences is limited considering the whole diet, and an inadequate nutrient intake were observed in most individuals of every group. The design and implementation of nutrition intervention programs, taking into consideration positional differences in nutritional intake, would be useful for these players.
Grosdent, Stéphanie; Demoulin, Christophe; Rodriguez de La Cruz, Carlos; Giop, Romain; Tomasella, Marco; Crielaard, Jean-Michel; Vanderthommen, Marc
This study aimed to investigate the relationship between the history of low back pain and quality of lumbopelvic motor control in soccer players. Forty-three male elite soccer players (mean age, 18.2 ± 1.4 years) filled in questionnaires related to low back pain and attended a session to assess lumbopelvic motor control by means of five tests (the bent knee fall out test, the knee lift abdominal test, the sitting knee extension test, the waiter's bow and the transversus abdominis test). A physiotherapist, blinded to the medical history of the participants, scored (0 = failed, 1 = correct) the performance of the players for each of the tests resulting in a lumbopelvic motor control score ranging from 0 to 5. Forty-seven per cent of the soccer players reported a disabling low back pain episode lasting at least two consecutive days in the previous year. These players scored worse lumbopelvic motor control than players without a history of low back pain (lumbopelvic motor control score of 1.8 vs. 3.3, P soccer players with a history of low back pain had an altered lumbopelvic motor control. Further research should examine whether lumbopelvic motor control is etiologically involved in low back pain episodes in soccer players.
Nashirudin, M.; Kusnanik, N. W.
Soccer players are required to have good physical fitness in order to achieve optimum accomplishment; physical fitness stands as the foundation of technical and tactical proficiency as well as the mental maturity during the matches. The purpose of this study was to identify the physiological profile of junior soccer players of SSB Surabaya Bhakti age 16-17. The research was conducted at 20 junior soccer players. This research was quantitative with descriptive analysis. Data were collected by testing of physiological (anaerobic power and capacity including explosive leg power, speed, agility; aerobic capacity: cardiovascular endurance). Data was analyzed using percentage. The result showed that the percentage of explosive leg power of junior soccer players were 30% (good category), speed was 85% (average category), right agility was 90% (average category), left agility was 75% (average category). On the other hand, the aerobic power and capacity of the junior soccer players in this study was 50% (average category). The conclusion of this research is that the physiological profile of junior soccer players at SSB Surabaya Bhakti age 16-17 was majority in average category.
Full Text Available Abstract Exercise training is known to induce an increase in free radical production potentially leading to enhanced muscle injury. Vitamins C and E are well known antioxidants that may prevent muscle cell damage. The purpose of this study was to determine the effects of these supplemental antioxidant vitamins on markers of oxidative stress, muscle damage and performance of elite soccer players. Ten male young soccer players were divided into two groups. Supplementation group (n = 5 received vitamins C and E supplementation daily during the pre-competitive season (S group, while the placebo group (PL group, n = 5 received a pill containing maltodextrin. Both groups performed the same training load during the three-month pre-season training period. Erythrocyte antioxidant enzymes glutathione reductase, catalase and plasma carbonyl derivatives did not show any significant variation among the experimental groups. Similarly, fitness level markers did not differ among the experimental groups. However, S group demonstrated lower lipid peroxidation and muscle damage levels (p
Full Text Available The popularity of female soccer is increasing as well as the number of females playing soccer. Similarly, over the last twenty or so years, research in soccer has increased significantly, but a large disparity exists in the volume of studies involving male and female players. As a consequence of this, female players remain less well understood compared to males. The purpose of the present narrative review was to describe morphological characteristics, physiological demands, physical abilities and injuries in female soccer players. Physiological demands are similar between men’s and women’s soccer, but competitive women’s matches were characterized by nearly 33% less distance covered, although at higher intensity levels (maximum speeds greater than 15 km/h than typically found in the men’s game. Sub-elite female players also tended to run less at higher intensity levels at the end of both halves in comparison with elite female players. High intensity running is an important factor of success in soccer since many critical moments of the game occur under this condition. The ability to rapidly change direction also determined elite, sub-elite and amateur levels. The implementation of functional training, which focused on soccer-specific drills and plyometric exercises, to improve explosive power, may improve conditioning in female soccer players as well as decrease the risk of injuries which was 3-8 times higher in females compared to males. This review presents an in-depth overview of the most influential factors for determining success in female soccer.
Full Text Available Purpose. The aim of the study was to determine differences in anteroposterior spine curvatures between futsal players, soccer players, and non-training students. The results may contribute to the development of present-day knowledge of posturometry, and its implementation in training can help reduce the risk of body posture disorders in athletes. Methods. The examined group consisted of 48 athletes and 38 non-training college students. Body posture parameters were measured with the use of Posturometr-S. The normality of distribution was checked with the Shapiro-Wilk test, and the differences between the groups were measured with ANOVA and the Bonferroni post-hoc test. The level of statistical significance was set at p < 0.05. Results. The analysis of angle values revealed the widest and most similar measurements in the group of futsal players and soccer players. The analysis of variance proved statistically significant differences between the soccer players and futsal players (p = 0.003. The difference between the soccer players and non-training students was statistically significant. The highest γ angular value was measured in non-training students, followed by futsal players and soccer players. The statistical analysis revealed significant differences between the non-training students and futsal players, as well as non-training students and soccer players (p < 0.001. Conclusions. A complex assessment of athletes’ body posture is crucial in injury prevention. Training overloads may often lead to disorders of the organ of locomotion and affect the correct body posture in athletes. This, in turn, may result in pains and injuries.
David Gutierrez Diaz Del Campo
Full Text Available The purpose of this study was to identify the existence of Relative Age Effect (RAE at youth level in both elite and amateur Spanish soccer clubs, and also to carry out an analysis providing with information on how this effect has evolved in recent years. We have obtained information on the youth teams of the 20 clubs belonging to the Spanish Professional Football League (LFP in two separate seasons (2005-2006 and 2008-2009 as well as data on five youth academies belonging to amateur clubs. The collected data revealed an over- representation of players born in the first months of the selection year in all groups of analysis (Elite 2005-2006, Elite 2008-2009 and Amateurs, although only the Elite groups showed significant variations in birth-date distribution in relation to the Spanish population. The results showed a reduction in RAE from the 2005-2006 season to the 2008-2009 season. The following variables - playing position, the number of years each player has spent in their specific age group and the category of the team at each club were shown not to have influence on the extent of RAE
Chrisman, Sara P.; O'Kane, John W.; Polissar, Nayak L.; Tencer, Allan F.; Mack, Christopher D.; Levy, Marni R.; Schiff, Melissa A.
Context Most researchers investigating soccer injuries have studied elite athletes because they have greater athletic-exposure hours than other athletes, but most youth participate at the recreational level. If risk factors for injury vary by soccer level, then recommendations generated using research with elite youth soccer players might not generalize to recreational players. Objective To examine injury risk factors of strength and jump biomechanics by soccer level in female youth athletes and to determine whether research recommendations based on elite youth athletes could be generalized to recreational players. Design Cross-sectional study. Setting Seattle Youth Soccer Association. Patients or Other Participants Female soccer players (N = 92) aged 11 to 14 years were recruited from 4 randomly selected elite (n = 50; age = 12.5 years, 95% confidence interval [95% CI]) = 12.3, 12.8 years; height = 157.8 cm, 95% CI = 155.2, 160.3 cm; mass = 49.9 kg, 95% CI = 47.3, 52.6 kg) and 4 randomly selected recreational (n = 42; age = 13.2 years, 95% CI = 13.0, 13.5 years; height = 161.1 cm, 95% CI = 159.2, 163.1 cm; mass = 50.6 kg, 95% CI = 48.3, 53.0 kg) soccer teams. Main Outcome Measure(s) Players completed a questionnaire about demographics, history of previous injury, and soccer experience. Physical therapists used dynamometry to measure hip strength (abduction, adduction, extension, flexion) and knee strength (flexion, extension) and Sportsmetrics to measure vertical jump height and jump biomechanics. We compared all measurements by soccer level using linear regression to adjust for age and mass. Results Elite players were similar to recreational players in all measures of hip and knee strength, vertical jump height, and normalized knee separation (a valgus estimate generated using Sportsmetrics). Conclusions Female elite youth players and recreational players had similar lower extremity strength and jump biomechanics. This suggests that recommendations generated from
Luiz Carlos Moraes
Full Text Available This study investigated the role of parents in the development of soccer players. Twenty parents and 12 soccer players, between 15 and 18 years old participated in the study. Both quantitative and qualitative approaches were used by administrating questionnaires forms and interviews. It was observed that few changes occurred in the family routines and that parents were minimally involved in their sons' sport activities. This did not appear to be a constraint for their sons' development because of their passion for soccer, the total amount of practice, and a potential lucrative professional career. Researchers should carefully adopt important paradigms from first world countries to another country with contextual differences.
Edholm, P; Krustrup, Peter; Randers, Morten Bredsgaard
This study investigated the acute effects of a half-time re-warm up on performance and movement patterns in soccer match play. Using a crossover design, 22 professional male players performed traditional passive rest (CON) or a low-intensity re-warm up (RW) during the half-time period of two soccer.......01). Moreover, RW had more possession of the ball in the beginning of the second half. In conclusion, traditional passive half-time rest leads to impaired sprint and jump performance during the initial phase of the second half in professional soccer players whereas a re-warm up effectively attenuates...
Ranchordas, Mayur K; King, George; Russell, Mitchell; Lynn, Anthony; Russell, Mark
The purpose of this study was to determine whether caffeinated gum influenced performance in a battery of soccer-specific tests used in the assessment of performance in soccer players. In a double blind, randomised, cross-over design, ten male university-standard soccer players (age 19 ± 1 y, stature 1.80 ± 0.10 m, body mass 75.5 ± 4.8 kg) masticated a caffeinated (200 mg; caffeine) or control (0 mg; placebo) gum on two separate occasions. After a standardised warm-up, gum was chewed for 5 min and subsequently expectorated 5 min before players performed a maximal countermovement jump, a 20 m sprint test and the Yo-Yo intermittent recovery test level 1 (Yo-YoIR1). Performance on 20 m sprints were not different between trials (caffeine: 3.2 ± 0.3 s, placebo: 3.1 ± 0.3 s; p = 0.567; small effect size: d = 0.33), but caffeine did allow players to cover 2.0% more distance during Yo-YoIR1 (caffeine: 1754 ± 156 m, placebo: 1719 ± 139 m; p = 0.016; small effect size: d = 0.24) and increase maximal countermovement jump height by 2.2% (caffeine: 47.1 ± 3.4 cm, placebo: 46.1 ± 3.2 cm; p = 0.008; small effect size: d = 0.30). Performance on selected physical tests (Yo-YoIR1 and countermovement jump) was improved by the chewing of caffeinated gum in the immediate period before testing in university-standard soccer players but the sizes of such effects were small. Such findings may have implications for the recommendations made to soccer players about to engage with subsequent exercise performance.
Verbeek, Jan; Elferink-Gemser, Marije T; Jonker, Laura; Huijgen, Barbara C H; Visscher, Chris
In the general population, estimates of left-foot preference are around 20%. In soccer, specific tasks create positional demands, requiring 40% of the players to be left-footed. Whether and how this is related to the selection of players is unknown. To examine the successive selection of soccer players for Dutch national youth teams in relation to foot preference, 280 youth players (age = 16.2 ± 1.08 years) were monitored from the U16 through the U19 teams over the last 5 years. No difference in successive selection between left- and right-footed players was found (p soccer teams.
Hjort, Anders; Henriksen, Kristoffer; Elbæk, Lars
consistent video analyses and tagging; coaches are important as role models and providers of feedback; and that the use of the platform primarily stimulated deliberate practice activities. PU can be seen as a source of inspiration for soccer players and clubs as to how analytical platforms can motivate......In the present article, we investigate the introduction of a cloud-based video analysis platform called Player Universe (PU). Video analysis is not a new performance-enhancing element in sports, but PU is innovative in how it facilitates reflective learning. Video analysis is executed in the PU...... platform by involving the players in the analysis process, in the sense that they are encouraged to tag game actions in video-documented soccer matches. Following this, players can get virtual feedback from their coach. Findings show that PU can improve youth soccer players' reflection skills through...
Fiorilli, Giovanni; Mitrotasios, Michalis; Iuliano, Enzo; Pistone, Eugenio M; Aquino, Giovanna; Calcagno, Giuseppe; DI Cagno, Alessandra
The goal of this study was to compare the changes of direction speed (CODS) and reactive agility (RA) in soccer players of different ages, in order to optimize the best training of these skills. One hundred eighty-seven players, divided into bi-annual age-groups, U12, U14, U16 and U18, performed two tests: Y-Agility Test, carried out in planned and reactive mode (Y-PLAN and Y-REAC) and Illinois for Change of Direction Test (ICODT). Difference between Y-REAC minus Y-PLAN represents the index of reactivity (REAC-INDEX). MANOVA showed significant differences among groups (F3,182=14.591; Pplayers (0.398 Pperformance of Y-PLAN and ICODT, through age, depends on physical skill level, whereas the best RA results depend on technique and experience that help the players to use anticipatory skill. The high correlations between CODS and RA performances, differently than adult athletes, suggest that an effective work program for young players may include RA and CODS training at the same time.
Gutierrez Diaz Del Campo, David; Pastor Vicedo, Juan Carlos; Gonzalez Villora, Sixto; Contreras Jordan, Onofre Ricardo
The purpose of this study was to identify the existence of Relative Age Effect (RAE) at youth level in both elite and amateur Spanish soccer clubs, and also to carry out an analysis providing with information on how this effect has evolved in recent years. We have obtained information on the youth teams of the 20 clubs belonging to the Spanish Professional Football League (LFP) in two separate seasons (2005-2006 and 2008-2009) as well as data on five youth academies belonging to amateur clubs. The collected data revealed an over- representation of players born in the first months of the selection year in all groups of analysis (Elite 2005-2006, Elite 2008-2009 and Amateurs), although only the Elite groups showed significant variations in birth-date distribution in relation to the Spanish population. The results showed a reduction in RAE from the 2005-2006 season to the 2008-2009 season. The following variables - playing position, the number of years each player has spent in their specific age group and the category of the team at each club were shown not to have influence on the extent of RAE. Key pointsThere was RAE in all groups analyzed, although only the Elite groups showed significant variations in birth-date distribution in relation to the general population.RAE is more evident in the Elite groups than in the Amateur probably because of the detection process, which is more thorough in the Elite groups.Playing position, number of years in their specific age group and category of the team did not have any influence on the extent of RAE.Any attempts to prevent RAE should be based on a stable sport policy and the implication of all the stakeholders in the system. All of them should think in the development of a player as a long-term project.
Full Text Available Objective: To determine the morphological characteristics, fat mass, somatotype and dietary patterns of youth soccer players from an amateur Spanish team. Method: Height, weight, diameters, circumferences and skinfolds from sixteen youth soccer players were measured. Body fat percentage and somatotype were calculated. They completed the Kidmed questionnaire to analyze dietary patterns. Descriptive statistics (mean ± standard deviation were used. Results: The global body fat percentage was 9.16 ± 2.12 and the somatotype (2.56-3.73-2.77. The sum of the six skinfolds was 62.6 ± 2.7 mm. The sum of the eight skinfolds was 80.7 ± 3.1 mm. 75% of athletes consumed a fruit daily, 18.75% took a second fruit each day. 43.75% of players took vegetables once a day, 18.75% ate vegetables more than once a day. Conclusion: Body fat percentage, the sum of the six skinfolds, the sum of the eight skinfolds and somatotype results are in agreement with previous studies where youth non-professional soccer players were analyzed. Other studies have obtained lower values in body fat percentage or in sum of six skinfolds due to they have evaluated professional soccer players. Anthropometric measures would be important to prescribed personalized diet and training plans. Resumen: Objetivo: Determinar las características morfológicas, la masa grasa, el somatotipo y los patrones alimentarios de jugadores de fútbol jóvenes de un equipo amateur. Método: Se midieron la altura, el peso, los diámetros corporales, las circunferencias y los pliegues cutáneos de 16 jugadores. Se calcularon el porcentaje de grasa corporal y el somatotipo. Se administró el cuestionario Kidmed con objeto de conocer el patrón alimentario. Se utilizaron métodos estadísticos descriptivos (media ± desviación estándar. Resultados: El porcentaje global de grasa corporal fue 9.16 ± 2.12 y el somatotipo (2.56-3.73-2.77. El sumatorio de 6 pliegues fue 62.6 ± 2.7 mm y el
Sáez de Villarreal, Eduardo; Suarez-Arrones, Luis; Requena, Bernardo; Haff, Gregory G; Ferrete, Carlos
To determine the influence of a short-term combined plyometric and sprint training (9 weeks) within regular soccer practice on explosive and technical actions of pubertal soccer players during the in-season. Twenty-six players were randomly assigned to 2 groups: control group (CG) (soccer training only) and combined group (CombG) (plyometric + acceleration + dribbling + shooting). All players trained soccer 4 times per week and the experimental groups supplemented the soccer training with a proposed plyometric-sprint training program for 40 minutes (2 days per weeks). Ten-meter sprint, 10-m agility with and without ball, CMJ and Abalakov vertical jump, ball-shooting speed, and Yo-Yo intermittent endurance test were measured before and after training. The experimental group followed a 9-week plyometric and sprint program (i.e., jumping, hurdling, bouncing, skipping, and footwork) implemented before the soccer training. Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the CG; however, meaningful improvement was found in all variables in the experimental group: CMJ (effect size [ES] = 0.9), Abalakov vertical jump (ES = 1.3), 10-m sprint (ES = 0.7-0.9), 10-m agility (ES = 0.8-1.2), and ball-shooting speed (ES = 0.7-0.8). A specific combined plyometric and sprint training within regular soccer practice improved explosive actions compared with conventional soccer training only. Therefore, the short-term combined program had a beneficial impact on explosive actions, such as sprinting, change of direction, jumping, and ball-shooting speed which are important determinants of match-winning actions in soccer performance. Therefore, we propose modifications to current training methodology for pubertal soccer players to include combined plyometric and speed training for athlete preparation in this sport.
Nansseu, Jobert Richie; Ama Moor, Vicky Jocelyne; Takam, Ruth Danielle M; Zing-Awona, Bertrand; Azabji-Kenfack, Marcel; Tankeu, Francine; Tchoula, Corinne M; Moukette, Bruno M; Ngogang, Jeanne Y
Elevated titers of antibodies against oxidized low-density lipoproteins-cholesterol (ox-LDL-Ab) have been reported among professional athletes, paradoxically reflecting an increased risk of developing atherogenic and/or cardiovascular events. This study aimed to determine titers of ox-LDL-Ab in a group of Cameroonian professional soccer players, and evaluate their evolution during part of a competition season as well as the plasmatic antioxidant status to find out if this latter correlates with ox-LDL-Ab . We conducted a descriptive cohort study in 2012 including 18 healthy male soccer players. Three samplings were performed in March (T1), May (T2), and July 2012 (T3) to assess the lipid profile, titers of ox-LDL-Ab, and plasmatic concentrations of four antioxidants: the ferric reducing antioxidant power (FRAP), reduced glutathione (GSH), superoxide dismutase (SOD), and uric acid. Ages ranged from 16 to 28 years with a median (interquartile range) of 19.5 (19-23) years. Total cholesterol, high-density lipoproteins-cholesterol (HDL-C), low-density lipoproteins-cholesterol (LDL-C) and triglycerides varied within normal ranges throughout the three samplings. While total cholesterol and LDL-C titers increased significantly (p = 0.003 and p = 0.006, respectively), triglycerides and HDL-C values varied non-significantly throughout the measurements (p = 0.061 and p = 0.192, respectively). The median ox-LDL-Ab titers were respectively: 653.3 (468.2-838.8) mIU/ml at T1, 777.7 (553.7-1150.7) mIU/ml at T2, and 1037.7 (901.7-1481.5) mIU/ml at T3. Overall, ox-LDL-Ab titers increased significantly from T1 to T3 (p = 0.006). Concomitantly, uric acid and FRAP concentrations decreased significantly (p = 0.001 and p = 0.003, respectively); on the contrary, GSH and SOD values increased, but insignificantly (p = 0.115 and p = 0.110, respectively). There was a positive and significant correlation between ox-LDL-Ab and HDL-C (ρ = 0.519, p = 0.027), and between ox
F Marcello Iaia
Full Text Available In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6 or speed endurance maintenance (SEM; n = 7 training, three times per wk. SEP training consisted of 6-8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6-8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (p<0.01 the total time in a repeated sprint ability test (RSAt by 2.5%. SEM training improved the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, p<0.01 and had a likely beneficial impact on the percentage decrement score of the RSA test (from 4.07±1.28 to 3.55±1.01% but induced a very likely impairment in RSAt (from 83.81±2.37 to 84.65±2.27 s. The distance covered in the Yo-Yo Intermittent Recovery test level 2 was 10.1% (p<0.001 and 3.8% (p<0.05 higher after SEP and SEM training, respectively, with possibly greater improvements following SEP compared to SEM. No differences were observed in the 20- and 40-m sprint performances. In conclusion, these two training strategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles' ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in
Horst, Nick Van Der; Priesterbach, Annique; Backx, Frank; Smits, Dirk-Wouter
Objective: This study investigated the hamstring-and-lower-back flexibility (HLBF) of male adult amateur soccer players, using the sit-and-reach test (SRT), with a view to obtaining population-based reference values and to determining whether SRT scores are associated with player characteristics.
Taylor, Jeffrey B; Ford, Kevin R; Schmitz, Randy J; Ross, Scott E; Ackerman, Terry A; Shultz, Sandra J
Anterior cruciate ligament injury prevention programs are less successful in basketball than soccer and may be due to distinct movement strategies that these athletes develop from sport-specific training. The purpose of this study was to identify biomechanical differences between female basketball and soccer players during multi-directional jump landings. Lower extremity biomechanics of eighty-nine female athletes who played competitive basketball (n=40) or soccer (n=49) at the middle- or high-school level were analyzed with three-dimensional motion analysis during a drop vertical jump (DVJ), double- (SAG-DL) and single-leg forward jump (SAG-SL), and double- (FRONT-DL) and single-leg (FRONT-SL) lateral jump. Basketball players landed with less hip and/or knee excursion during all tasks (pbasketball players landed with greater peak hip flexion angles (p=.04). The FRONT-SL task elicited the most distinct sport-specific differences, including decreased hip adduction (pbasketball players. Additionally, the FRONT-SL task elicited greater forces in knee abduction (p=.003) and lesser forces in hip adduction (p=.001) and knee external rotation (pbasketball players. Joint energetics were different during the FRONT-DL task, as basketball players exhibited less sagittal plane energy absorption at the hip (pjump landing tasks, such that soccer players exhibited a more protective landing strategy than basketball players, justifying future efforts toward sport-specific ACL injury prevention programs.
Elferink-Gemser, Marije; Huijgen, Barbara C.; Coelho e Silva, M.; Lemmink, Koen; Visscher, Chris
Talent development programmes for professional soccer clubs aim to guide players towards professional level performance. We identify whether the intermittent endurance capacity of these players may have changed over time. Since the 2000/2001 competition season, the intermittent endurance capacity of
Taylor, Jeffrey B; Ford, Kevin R; Schmitz, Randy J; Ross, Scott E; Ackerman, Terry A; Shultz, Sandra J
Taylor, JB, Ford, KR, Schmitz, RJ, Ross, SE, Ackerman, TA, and Shultz, SJ. Biomechanical differences of multidirectional jump landings among female basketball and soccer players. J Strength Cond Res 31(11): 3034-3045, 2017-Anterior cruciate ligament (ACL) injury prevention programs are less successful in basketball than soccer and may be due to distinct movement strategies that these athletes develop from sport-specific training. The purpose of this study was to identify biomechanical differences between female basketball and soccer players during multidirectional jump landings. Lower extremity biomechanics of 89 female athletes who played competitive basketball (n = 40) or soccer (n = 49) at the middle- or high-school level were analyzed with 3-dimensional motion analysis during a drop vertical jump, double- (SAG-DL) and single-leg forward jump (SAG-SL), and double- (FRONT-DL) and single-leg (FRONT-SL) lateral jump. Basketball players landed with either less hip or knee, or both hip and knee excursion during all tasks (p ≤ 0.05) except for the SAGSL task, basketball players landed with greater peak hip flexion angles (p = 0.04). The FRONT-SL task elicited the most distinct sport-specific differences, including decreased hip adduction (p soccer players exhibited a more protective landing strategy than basketball players, justifying future efforts toward sport-specific ACL injury prevention programs.
Nicole M. Sauls
Full Text Available Objective: The purpose of this investigation was to determine the differences in collegiate and recreationally trained soccer players in sprint, vertical jump, and balance performance. Methods: Twenty-one soccer players, twelve Division II collegiate and nine recreationally trained volunteered to participate. Session one acted as a familiarization day, where the participants were familiarized with testing day protocols. During testing day, participants performed a dynamic warm-up, followed by balance measurements, three countermovement vertical jumps, and pro-agility shuttle test. Results: There were no significant (p>0.05 differences between groups in the all balance variables. Collegiate soccer players had a significantly (p0.05 differences in groups in all other variables. Conclusion: These results indicate that collegiate, Division II, soccer players had greater vertical jumping and sprinting velocities when compared to recreationally trained soccer players. These results may have been impacted by the lack of resistance training background in either of the two groups. With the addition of more time on a collegiate resistance training program, it is very likely the Division II athletes will see a significant increase in all balance, sprint, and vertical jump performance measures compared to recreationally trained players who receive little to no specialized resistance training.
Full Text Available The purposes of the present study were to investigate if a shuttle-run sprint training performed in a normobaric hypoxia chamber of limited size (4.75x2.25m is feasible, in terms of producing the same absolute training load, when compared to training in normoxia, and b if such training improves the repeated sprint ability (RSA and the Yo-Yo intermittent recovery (YYIR test outcome in young elite soccer players. Players of an elite soccer training Centre (age: 15.3 ± 0.5 years, height: 1.73 ± 0.07 m, body mass: 62.6 ± 6.6 kg were randomly assigned to a hypoxia or a normoxia training group. Within a 5-week period, players, who were not informed about the hypoxia intervention, performed at least 7 sessions of identical shuttle-run sprint training either in a normal training room (FiO2 = 20.95% or in a hypoxic chamber (FiO2 = 14.8%; approximately 3300m, both equipped with the same floor. Each training session comprised 3 series of 5x10s back and forth sprints (4.5m performed at maximal intensity. Recovery time between repetitions was 20s and between series 5min. Before and after the training period the RSA (6 x 40m shuttle sprint with 20 s rest between shuttles and the YYIR test were performed. The size of the chamber did not restrict the training intensity of the sprint training (both groups performed approximately 8 shuttles during 10s. Training in hypoxia resulted in a lower fatigue slope which indicates better running speed maintenance during the RSA test (p = 0.024. YYIR performance increased over time (p = 0.045 without differences between groups (p > 0.05. This study showed that training intensity of the shuttle-run sprint training was not restricted in a hypoxic chamber of limited size which indicates that such training is feasible. Furthermore, hypoxia compared to normoxia training reduced the fatigue slope during the RSA test in youth soccer players.
Petersen, Jesper; Thorborg, Kristian; Nielsen, Michael Bachmann
BACKGROUND: An injury to the hamstring muscle complex is the most common injury in soccer. Ultrasound of acute hamstring injuries is often used as a clinical tool for diagnosing hamstring injuries and guiding players in when they can return to play. PURPOSE: To (1) investigate the characteristic......) to investigate if ultrasonography can be used as a prognostic indicator of time to return to play. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Players from 50 teams participating in 1 of the top 5 Danish soccer divisions were followed in the period from January to December 2008. Of 67 players...
Emmonds, S; Nicholson, G; Beggs, CB; Jones, B; Bissas, A
The purpose of this study was to determine the importance of physical qualities for speed and change of direction (CoD) ability in female soccer players. Data were collected on 10 female soccer players who were part of a professional English Women’s Super League team. Player assessments included anthropometric (stature and body mass), body composition (dual-energy X-ray absorptiometry), speed (10m, 30m sprint), CoD ability (505 agility), aerobic (Yo-Yo Intermittent Recovery Test), lower-body ...
Mara, Jocelyn K; Thompson, Kevin G; Pumpa, Kate L
The aim of this study was to assess the total and exercise energy expenditure of elite female soccer players during a training week. Eight elite female soccer players wore SenseWear Mini Armbands (SWAs) for 7 consecutive days during the preseason phase of a national league competition. In addition, players wore 15-Hz GPSports tracking devices during 4 training sessions and a friendly game. Total energy expenditure, exercise energy expenditure, and training and game demands were collected from the SWA and GPSports devices. Mean daily energy expenditure for the game day, training days, and rest days were 12,242 kJ (SD = 603 kJ), 11,692 (SD = 274 kJ), and 9,516 (SD = 369 kJ), respectively, with significant differences shown between activities (p soccer players. Nutritional intake should be adjusted accordingly to avoid energy imbalances for optimal performance and recovery.
Full Text Available The relative age effect (RAE in the selection of young soccer players is a well-known phenomenon. The purpose of this study was to examine the relative age effect existing despite strategies that have been implemented to avoid its presence in the selection process. We also aimed to investigate the RAE during the three different selection stages for B13, B14 (boys, and G13, G14 (girls, and gender differences in the RAE. This was achieved by collecting data from everyone who played soccer in Troendelag, and data that would illuminate the RAE during the three stages of selection for the regional teams of the 2015/2016 season. Mann–Whitney U-tests and Chi-square tests were used as statistical methods. The main finding of this study is that, despite the intention to reduce RAE in the selection process according to the criterion that at least 40% of the players should be born in the second half of the year, both the early-born boys and girls are more likely to be selected. The results also show that the RAE occurs gradually, and the longer the players are in the selection process the more prominent it is. This study highlights the importance of being aware of the RAE when selecting young players.
Vandenbroucke, Nicolas; Macaire, Ludovic; Postaire, Jack-Gerard
Soccer is a very popular sport all over the world, Coaches and sport commentators need accurate information about soccer games, especially about the players behavior. These information can be gathered by inspectors who watch the soccer match and report manually the actions of the players involved in the principal phases of the game. Generally, these inspectors focus their attention on the few players standing near the ball and don't report about the motion of all the other players. So it seems desirable to design a system which automatically tracks all the players in real- time. That's why we propose to automatically track each player through the successive color images of the sequences acquired by a fixed color camera. Each player which is present in the image, is modelized by an active contour model or snake. When, during the soccer match, a player is hidden by another, the snakes which track these two players merge. So, it becomes impossible to track the players, except if the snakes are interactively re-initialized. Fortunately, in most cases, the two players don't belong to the same team. That is why we present an algorithm which recognizes the teams of the players by pixels representing the soccer ground which must be withdrawn before considering the players themselves. To eliminate these pixels, the color characteristics of the ground are determined interactively. In a second step, dealing with windows containing only one player of one team, the color features which yield the best discrimination between the two teams are selected. Thanks to these color features, the pixels associated to the players of the two teams form two separated clusters into a color space. In fact, there are many color representation systems and it's interesting to evaluate the features which provide the best separation between the two classes of pixels according to the players soccer suit. Finally, the classification process for image segmentation is based on the three most
McCunn, Robert; Fünten, Karen Aus der; Whalan, Matthew; Sampson, John A; Meyer, Tim
Study Design Prospective cohort. Background The association between movement quality and injury is equivocal. No soccer-specific movement assessment has been prospectively investigated in relation to injury risk. Objectives To investigate the association between a soccer-specific movement quality assessment and injury risk among semi-professional soccer players. Methods Semi-professional soccer players (n=306) from 12 clubs completed the Soccer Injury Movement Screen (SIMS) during the pre-season period. Individual training/match exposure and non-contact time loss injuries were recorded prospectively for the entirety of the 2016 season. Relative risks (RR) were calculated, and presented with 90% confidence intervals (CI), for the SIMS composite and individual sub-test scores from generalized linear models with Poisson distribution offset for exposure. Results When considering non-contact time loss lower extremity injuries (primary level of analysis), there was a most likely trivial association with the SIMS composite score. Similarly, SIMS composite score demonstrated most likely to likely trivial associations to all injury categories included in the secondary level of analysis (non-contact time loss hip/groin, thigh, knee and ankle injuries). When considering hamstring strains and ankle sprains specifically (tertiary level of analysis) the SIMS composite score, again, demonstrated very likely trivial associations. A total of 262 non-contact time loss injuries were recorded. The overall (training and match exposure combined) incidence of non-contact time loss injury was 12/1000 hours. Conclusion The SIMS composite score demonstrated no association to any of the investigated categories of soccer-related injury. The SIMS composite score should not be used to group players into 'high' or 'low' risk groups. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther, Epub 8 May 2018. doi:10.2519/jospt.2018.8037.
Munguia-Izquierdo, Diego; Suarez-Arrones, Luis; Di Salvo, Valter; Paredes-Hernandez, Victor; Alcazar, Julian; Ara, Ignacio; Kreider, Richard; Mendez-Villanueva, Alberto
This study determined the most effective field method for quantifying body fat percentage in male elite youth soccer players and developed prediction equations based on anthropometric variables. Forty-four male elite-standard youth soccer players aged 16.3-18.0 years underwent body fat percentage assessments, including bioelectrical impedance analysis and the calculation of various skinfold-based prediction equations. Dual X-ray absorptiometry provided a criterion measure of body fat percentage. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses were used to develop soccer-specific prediction equations. The equations from Sarria et al. (1998) and Durnin & Rahaman (1967) reached very large correlations and the lowest biases, and they reached neither the practically worthwhile difference nor the substantial difference between methods. The new youth soccer-specific skinfold equation included a combination of triceps and supraspinale skinfolds. None of the practical methods compared in this study are adequate for estimating body fat percentage in male elite youth soccer players, except for the equations from Sarria et al. (1998) and Durnin & Rahaman (1967). The new youth soccer-specific equation calculated in this investigation is the only field method specifically developed and validated in elite male players, and it shows potentially good predictive power. © Georg Thieme Verlag KG Stuttgart · New York.
Koerte, Inga K; Lin, Alexander P; Muehlmann, Marc; Merugumala, Sai; Liao, Huijun; Starr, Tyler; Kaufmann, David; Mayinger, Michael; Steffinger, Denise; Fisch, Barbara; Karch, Susanne; Heinen, Florian; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E
Soccer is played by more than 250 million people worldwide. Repeatedly heading the ball may place soccer players at high risk for repetitive subconcussive head impacts (RSHI). This study evaluates the long-term effects of RSHI on neurochemistry in athletes without a history of clinically diagnosed concussion, but with a high exposure to RSHI. Eleven former professional soccer players (mean age 52.0±6.8 years) and a comparison cohort of 14 age- and gender-matched, former non-contact sport athletes (mean age 46.9±7.9 years) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation. In the soccer players a significant increase was observed in both choline (Cho), a membrane marker, and myo-inositol (ml), a marker of glial activation, compared with control athletes. Additionally, ml and glutathione (GSH) were significantly correlated with lifetime estimate of RSHI within the soccer group. There was no significant difference in neurocognitive tests between groups. Results of this study suggest an association between RSHI in soccer players and MRS markers of neuroinflammation, suggesting that even subconcussive head impacts affect the neurochemistry of the brain and may precede neurocognitive changes. Future studies will need to determine the role of neuroinflammation in RSHI and the effect on neurocognitive function.
Fousekis, Konstantinos; Tsepis, Elias; Vagenas, George
Ankle sprain is an extremely common injury in soccer players. Despite extensive research, the intrinsic cause of this injury under noncontact conditions remains unclear. To identify intrinsic risk factors for noncontact ankle sprains in professional soccer players. Cohort study; Level of evidence, 2 One hundred professional soccer players were assessed in the preseason for potential risk factors of noncontact ankle sprains. The assessment included (A) ankle joint asymmetries (right-left) in isokinetic muscle strength, flexibility, proprioception, and stability; (B) somatometric asymmetries; (C) previous injuries; and (D) lateral dominance traits. Noncontact ankle sprains were prospectively recorded and diagnosed for a full competition period (10 months). Seventeen of the players sustained at least 1 noncontact ankle sprain. Logistic regression revealed that players with (A) eccentric isokinetic ankle flexion strength asymmetries (odds ratio [OR] = 8.88; 95% confidence interval [CI], 1.95-40.36, P = .005), (B) increased body mass index (OR = 8.16; 95% CI, 1.42-46.63, P = .018), and (C) increased body weight (OR = 5.72; 95% CI, 1.37-23.95, P = .017 ) each had a significantly higher risk of a noncontact ankle sprain. A trend for younger players (OR = 0.28; 95% CI, 0.061-1.24, P = .092) and for players with ankle laxity asymmetries (OR = 3.38; 95% CI, 0.82-14.00, P = .093) to be at greater risk for ankle sprain was also apparent to the limit of statistical significance (.05 ankle flexors and increased body mass index and body weight raise the propensity for ankle sprains in professional soccer players. Age and asymmetries in ankle laxity are potential factors worth revisiting, as there was an indication for younger players and players with ankle instability to be at higher risk for ankle injury. Proper preseason evaluation may improve prevention strategies for this type of injury in soccer.
Mohr, Magni; Krustrup, Peter; Andersson, Helena
, (2) fatigue develops temporarily during and towards the end of a game, and (3) defenders have lower work rates than midfielders and attackers. The difference in high-intensity running between the 2 levels demonstrates the importance of intense intermittent exercise for match performance in women......We sought to study the physical demands and match performance of women soccer players. Nineteen top-class and 15 high-level players were individually videotaped in competitive matches, and time-motion analysis were performed. The players changed locomotor activity >1,300 times in a game...... fewer (P women soccer players (1) top-class international players perform more intervals of high-intensity running than elite players at a lower level...
Zago, Matteo; Codari, Marina; Grilli, Massimo; Bellistri, Giuseppe; Lovecchio, Nicola; Sforza, Chiarella
We explored the biomechanics of the 180° change-of-direction with the ball (half-turn) in soccer. We aimed at identifying movement strategies which enhance the players' half-turning performance, by characterising technique kinematics and understanding the structure of biomechanical and anthropometrics variables. Ten Under-13 sub-elite male players were recorded with an optoelectronic motion analyser while performing a 5-m straight dribbling followed by a half-turn with the sole. Joints kinematics differences between faster and slower trials were found in support-side hip rotation, driving-side hip adduction, trunk flexion and rotation, and arms abduction. To unveil the data-set structure, a principal component (PC) analysis and a stepwise linear discriminant analysis were performed using 30 biomechanical parameters and four anthropometric variables for each trial. Seven retained PCs explained 79% of the overall variability, featuring combinations of original variables that help in understanding the factors facilitating fast half-turns: keeping short steps, minimising lateral and forward body movements, and centre-of-mass lowering, even with ample lower limbs ranges of motion (RoM); abducting the upper limbs while limiting trunk flexion and pelvic inclination RoM. Balance and task-constrained exercises may be proposed to improve this technique. Moreover, a quantitative knowledge of the movement structure could give coaches objective insights to better instruct young players.
Naughton, Robert J; Drust, Barry; O'Boyle, Andy; Abayomi, Julie; Mahon, Elizabeth; Morton, James P; Davies, Ian G
It is recommended that soccer players consume a high carbohydrate diet to augment performance. However, growing evidence suggests that there is a link between high free-sugar (FS) intake (>5% total energy intake; TEI) and metabolic diseases. Furthermore, foods that are often high in sugar, such as processed foods, are typically lacking in nutrient quality. We therefore analysed total-sugar, FS, dietary fibre, and micronutrient intake of players from an English Premier League academy under (U) 18 (n = 13), U15/16 (n = 25), and U13/14 (n = 21) using a 7-day food diary. Data were compared with current United Kingdom (UK) dietary reference value (DRV) for FS via a t test. The U13/14s (10% ± 18%) and U15/16s (11% ± 30%) both consumed higher amounts of FS in comparison with the UK DRV of 5% TEI (P elite youth soccer players. We report an apparent "nutritional transition" from schoolboy to fulltime soccer player, with U18s showing a significantly lower intake of sugar in comparison with younger squads, and a similar intake of FS to the UK DRVs. Practitioners should target improving player education around sugar and fibre consumption.
Ruiz‐Cotorro, A; Balius‐Matas, R; Estruch‐Massana, A; Angulo, J Vilaró
The general aetiology, diagnosis, and treatment of spondylolysis, a bone defect in the pars interarticularis of the vertebra, are reviewed. A retrospective study of young tennis players diagnosed between 2000 and 2004 with spondylolysis with or without spondylolisthesis, assessed by radiography and planar bone scintigraphy, is described. If the radiographic results were negative, computed tomography was performed. Sixty six cases were evaluated: 53 L5 lesions, eight L4 lesions, two L3 lesions, and one bilateral lesion at the L2 level. Two more lesions at two levels were found (bilateral L5 and unilateral L4 and L3 on the right side). Classification, treatment, and outcome of the cases are reported. A combination of radiography, planar bone scintigraphy, and SPECT is useful for evaluating spondylolysis in tennis players and recommending treatment. Use of a brace did not appear to achieve significant results. PMID:16632576
Ingebrigtsen, Jørgen; Brochmann, Marit; Castagna, Carlo
after two and four minutes of the Yo-Yo IR tests by testing 57 high-level soccer players. All players played regularly in one of the three highest levels of Norwegian soccer and were tested during three sessions on three consecutive days. Large correlations were observed between Yo-Yo IR1 and IR2 test...... using only one of the Yo-Yo tests and a RSA test, in a general soccer-specific field test protocol. The sub-maximal heart rate measures during Yo-Yo tests are reproducible and may be utilized for frequent, time-efficient and non-exhaustive testing of intermittent exercise capacity of high-level soccer...
Full Text Available Purpose of the present study was to extrapolate intricate relationships between autonomic indices of emotionality in predicting changes in transient as well as dispositional emotionality. Performance excellence in sports and games, particularly in soccer has been referred to as resultant of mental toughness or more specifically the aspect of emotional flexibility and hardiness of the athlete. One hundred thirty five high-achiever young-adult male competitive soccer players, who were residents of Kota Bharu region volunteered as participants. All of them were subjected to evaluation of inner psychobiological status (decomposed indices of phasic skin conductance activity – viz. orienting recovery time; rise time and skin conductance adaptation levels; assessment of projective analyses of unconscious core of emotionality (employing Rorschach Ink-Blot Test in the form of evaluation indices of impulsivity, irritability, integrity. Results however revealed corroborative relationships between psychobiological autonomic indices in predicting differential aspects of inner core emotionality. Multiple linear regression analyses were done to identify differential possibilities of direct, inverse, moderating and supportive relationships between decomposition indices of autonomic orienting activity related to cognitive-affective and affective-motivational aspects of sports behaviour. Analyses of autonomic activation and arousal modulation and various indices habituation paradigm indices were found as significant predictors of changes in dispositional emotional constellation observed in the athletes. Orienting latency was observed as the most significant contributor in influencing recovery from autonomic arousal (orienting recovery in predicting changes in emotional hardiness as well as in flexibility.
Horcajo, Javier; de la Vega, Ricardo
The aim of this experiment was to analyse the consequences of changing attitudes related to doping through thoughtful versus non-thoughtful processes. Participants were young soccer players. They received a persuasive message either against or in favour of the legalisation of several doping behaviours in soccer (e.g., the use of anabolic androgenic steroid - AAS), and participants' level of elaboration (i.e., deliberative thinking) was manipulated in two different experimental (high vs. low) conditions. Attitudes towards the legalisation proposal were assessed immediately following the message and one week later. Results showed attitude change was a function of message direction and was relatively equivalent for both high and low elaboration participants immediately after reading the message. That is, those who received the message against legalisation showed significantly more unfavourable attitudes towards the proposal than did those who received the message in favour of legalisation regardless of the extent of elaboration. However, attitude change was found to be persistent only for high elaboration participants one week after message exposure. In the present paper, we discuss implications of changing attitudes related to doping depending on whether the change occurred through psychological processes that require either extensive or small amounts of deliberative thinking and elaboration.
Gokhan, Ismail; Kurkcu, Recep; Cekin, Resul
In this study, it was aimed to compare the investigate the effects of regular exercise on blood lipids, blood pressure and left ventricular cavity dimensions function between soccer players and non-athletes in football players. This study consisted included a total of 30 subjects, including an experimental group including 18 soccer players…
Stubbe, Janine H.; van Beijsterveldt, Anne-Marie M. C.; van der Knaap, Sissi; Stege, Jasper; Verhagen, Evert A.; van Mechelen, Willem; Backx, Frank J. G.
Context: Injuries are a major adverse event in a soccer player's career. Reducing injury incidence requires a thorough knowledge of the epidemiology of soccer injuries. Objective: To investigate the incidence and characteristics of injuries in the Dutch premier soccer league. Design: Cohort study. Setting: The Dutch premier soccer league. Patients or Other Participants: During the 2009–2010 soccer season, a total of 217 professional soccer players from 8 teams were prospectively followed. Main Outcome Measure(s): The medical staff recorded time-loss injuries, including information on injuries (ie, type, body part, duration) and exposure data for training sessions and matches. Results: A total of 286 injuries were recorded, affecting 62.7% of the players. The overall injury incidence was 6.2 injuries per 1000 player-hours, 2.8 in training sessions and 32.8 in matches. Most of the recorded injuries were acute (68.5%). Eight percent of the injuries were classified as recurrent. Injuries were most likely to be located in the lower extremities (82.9%). Injury time loss ranged from 1 to 752 days, with a median of 8 days. Knee injuries had the greatest consequences in terms of days of absence from soccer play (on average, 45 days). The most common diagnosis was muscle/tendon injury of the lower extremities (32.9%). Conclusions: Injury risk in the Dutch premier soccer league is high, especially during matches. Preventive measures should focus on the most common diagnoses, namely, muscle/tendon injuries of the lower extremities. PMID:25531144
Siegler, J; Robergs, R; Weingart, H
The application of performance testing for the evaluation of non-elite soccer players has received little attention. The purpose of this investigation was to use tests developed for elite soccer players to evaluate performance in non-elite soccer players and compare performance test results between elite (literature) and non-elite (data) players. Thirteen male soccer players volunteered to participate. The tests included a treadmill VO2max test, 20 m sprint, vertical jump (VJ), 30 s Wingate cycle ergometer test, the Loughborough Intermittent Shuttle Test (LIST), and 2 20-m multi-stage shuttle runs to exhaustion (fatigue test). Actual VO2max (absolute and relative) scores were correlated with the estimated VO2max scores (fatigue test), 20 m sprint, VJ, and 30 s Wingate using a Pearson's product-moment correlation. A paired t-test was conducted on the fatigue test trials. Non-significant relationships were observed between actual VO2max scores and estimated VO2max from the fatigue test (absolute and relative terms). Non-significant relationships were also observed between peak and average power output (Wingate), 20 m sprint, and VJ. Mean heart rates (HRs) throughout the LIST was 165+/-7 bpm, which represented 88% of HRmax. The results of this study demonstrate that to elicit physiological differences between elite and non-elite players, assessment must include both an aerobic and anaerobic component.
Metaxas, Thomas I; Koutlianos, Nikos; Sendelides, Thomas; Mandroukas, Athanasios
The purpose of this study was to examine and compare the cardiorespiratory performance and isokinetic muscle strength between Greek soccer and basketball players of different divisions before starting the training season. Study participants included 100 soccer players and 61 basketball players, who were assigned according to the kind of sport and division. All participants underwent anthropometric measurements and performed an exercise test on a treadmill to determine maximal oxygen uptake (VO2max). Peak torque for quadriceps and hamstring muscles was measured on isokinetic dynamometer at angular velocity of 60 degrees/s(-1), 180 degrees/s(-1), and 300 degrees/s(-1). The statistical p value was set at p duration of the maintenance period and to the effect of the training session on each sport, respectively. Finally, a higher level of muscle strength would be preferable in soccer and basketball and would reduce the risk for injuries in the maintenance and rebuilding training periods.
Vilas, Tiago; Rodrigues, J. M. F.; Cardoso, P. J. S.; Silva, Bruno
The current performance requirements in soccer make imperative the use of new technologies for game observation and analysis, such that detailed information about the teams' actions is provided. This paper summarizes a framework to collect the soccer players and ball positions using one or more Full HD Handycams, placed no more than 20cm apart in the stands, as well as how this framework connects to the FootData project. The system was based on four main modules: the detection and delimitation of the soccer pitch, the ball and the players detection and assignment to their teams, the tracking of players and ball and finally the computation of their localization (in meters) in the pitch.
Saeed Najafpour Bushehry
Full Text Available Exercise and nutrition have a significant impact on health. To evaluate nutrient consumption pattern of soccer players in city of Shiraz, 323 players were selected by proportional multi-stage cluster random sampling from 11 clubs in Shiraz. Anthropometric indices, socioeconomic status, 24 hours dietary recall and food frequency data were collected. Protein, carbohydrate and fat intake of the players were 73.73 gr (10.8%, 493.3 gr (72.4% and 50.8 gr (16.7%, respectively. Calcium (689.6 mg, phosphorus (734.4 mg, iron (20.3 mg, vitamin B1 (2 mg, vitamin B2 (1.6 mg, vitamin C (107.5 mg and vitamin A (962.4 mcg RE intake were lower than the desirable levels. The mean energy consumption of the players was 2723 Kcal per day. In conclusion, protein and micronutrients intakes are not desirable in Iranian soccer players in Shiraz.
van Doormaal, Mitchell C M; van der Horst, Nick; Backx, Frank J G; Smits, Dirk-Wouter; Huisstede, Bionka M A
In soccer, although hamstring flexibility is thought to play a major role in preventing hamstring injuries, the relationship between hamstring flexibility and hamstring injuries remains unclear. To investigate the relationship between hamstring flexibility and hamstring injuries in male amateur soccer players. Case-control study; Level of evidence, 3. This study included 450 male first-class amateur soccer players (mean age, 24.5 years). Hamstring flexibility was measured by performing the sit-and-reach test (SRT). The relationship between hamstring flexibility and the occurrence of hamstring injuries in the following year, while adjusting for the possible confounding effects of age and previous hamstring injuries, was determined with a multivariate logistic regression analysis. Of the 450 soccer players, 21.8% reported a hamstring injury in the previous year. The mean (±SD) baseline score for the SRT was 21.2 ± 9.2 cm. During the 1-year follow-up period, 23 participants (5.1%) suffered a hamstring injury. In the multivariate analysis, while adjusting for age and previous injuries, no significant relationship was found between hamstring flexibility and hamstring injuries ( P = .493). In this group of soccer players, hamstring flexibility (measured with the SRT) was not related to hamstring injuries. Age and previous hamstring injuries as possible confounders did not appear to influence this relationship. Other etiological factors need to be examined to further elucidate the mechanism of hamstring injuries.
Nikolaidis, P T; Theodoropoulou, E
Whereas nutrition has a crucial role on sport performance, it is not clear to what extent nutrition knowledge is associated with physical fitness. The aim of this study was to examine the current level of nutrition knowledge of soccer players and whether this level is associated with physical fitness. Soccer players (n = 185, aged 21.3 ± 4.9 yr, weight 72.3 ± 8.4 kg, and height 177.5 ± 6.4 cm) performed a battery of physical fitness tests (sit-and-reach test, SAR; physical working capacity in heart rate 170, PWC170; and Wingate anaerobic test, WAnT) and completed an 11-item nutrition knowledge questionnaire (NKQ). Low to moderate Pearson correlations (0.15 Soccer players with high score in NKQ were older (4.4 yr (2.2; 6.6), mean difference (95% confidence intervals)) and heavier (4.5 kg (0.6; 8.3)) with higher FFM (4.0 kg (1.1; 6.8)) and peak power (59 W (2; 116)) than their counterparts with low score. The moderate score in the NKQ suggests that soccer players should be targeted for nutrition education. Although the association between NKQ and physical fitness was low to moderate, there were indications that better nutrition knowledge might result in higher physical fitness and, consequently, soccer performance.
Moran, Jason; Parry, Dave A; Lewis, Ieuan; Collison, Jay; Rumpf, Michael C; Sandercock, Gavin R H
This study investigated the effects of a previously recommended dose of sprint training (ST) in young male soccer players of differing maturity status. Quasi-experimental design. Male soccer players from two professional academies were divided into Pre-PHV (Training: n=12; Control: n=13) and Mid-PHV (Training: n=7; Control=10) groups. The training groups completed 16 sprints of 20m with 90s recovery, once per week for 8weeks. Between-group effect sizes (ES) were substantially larger in Pre-PHV (10m [1.54, CI: 0.74-2.23]; 20m [1.49, CI: 0.75-2.23]; 5-10-5 [0.92, CI: 0.23-1.61]) than in Mid-PHV (10m [-0.00, CI: -0.81 to 0.81]; 20m [-0.12, CI: -0.93 to 0.69]; 5-10-5 [-0.41, CI: -1.22 to 0.41]). Within-group effects demonstrated a similar, though less accentuated, trend which revealed ST to be effective in both Pre-PHV (10m [0.44, CI: -0.24 to 1.12]; 20m [0.45, CI: -0.23 to 1.13]; 5-10-5 [0.69, CI: 0.00-1.38]) and Mid-PHV (10m [0.51, CI: -0.38 to 1.40]; 20m [0.33, CI: -0.56 to 1.21]; 5-10-5 [0.43, CI: -0.46 to 1.32]). ST, in the amount of 16 sprints over 20m with a 90s rest, may be more effective in Pre-PHV youths than in Mid-PHV youths. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Background. The physical demands of field hockey and soccer, based on match analysis, are comparable. As a consequence many exercise scientists and coaches have started to use the same type of field tests for hockey and soccer for the purposes of talent identification and training prescription. The validity of this ...
Nikolaidis, P. T.; Theodoropoulou, E.
Whereas nutrition has a crucial role on sport performance, it is not clear to what extent nutrition knowledge is associated with physical fitness. The aim of this study was to examine the current level of nutrition knowledge of soccer players and whether this level is associated with physical fitness. Soccer players (n = 185, aged 21.3 ± 4.9 yr, weight 72.3 ± 8.4 kg, and height 177.5 ± 6.4 cm) performed a battery of physical fitness tests (sit-and-reach test, SAR; physical working capacity in...
Raphael Mendes Ritti Dias
Full Text Available During a soccer match, countless movements involving muscular force are performed. While some studies have analyzed the force exerted by soccer players, their results have been divergent, particularly when force has been analyzed with respect to fi eld positions. The objective of this study was to compare peak torque, total muscular work, maximum power and isokinetic fatigue index of the knee fl exor and extensor muscles of soccer players in a variety of fi eld positions. Seventy-eight under-twenty soccer players were classifi ed according to the position they play: goalkeepers (n=7, full backs (n=14, wingers (n=16, defensive midfi elders (n=11, center midfi elders (n=14 and forwards (n=16. The concentric isokinetic force of knee fl exor and extensor muscles was evaluated using an isokinetic dynamometer, Cybex® brand Norm™ 6000 model (CSMI, USA. Data was analyzed in terms of non-parametric statistics and results expressed in medians and semi-interquartile range. The Kruskal-Wallis test was applied and when results were signifi cant to pRESUMO Durante uma partida de futebol são realizados inúmeros movimentos que envolvem a força muscular. Embora alguns estudos tenham analisado a força de jogadores de futebol, os resultados encontrados têm sido controversos, principalmente quando analisada a força em função da posição de jogo. O objetivo deste estudo foi comparar o pico de torque, trabalho muscular total, potência máxima e índice de fadiga isocinético dos músculos fl exores e extensores de joelho de jogadores de futebol que atuam em diferentes posições de jogo. Foram incluídos 78 atletas de futebol, pertencentes à categoria Sub-20, foram agrupados de acordo com a posição em campo de jogo: goleiros (n=7, zagueiros (n=14, laterais (n=16, volantes (n=11, meio campo (n=14 e atacantes (n=16. Foi realizada avaliação da força isocinética concêntrica dos músculos fl exores e extensores de joelho em dinamômetro isocin
Allen, Melissa M; Pareek, Ayoosh; Krych, Aaron J; Hewett, Timothy E; Levy, Bruce A; Stuart, Michael J; Dahm, Diane L
Female soccer players have a well-known risk for anterior cruciate ligament (ACL) injury, but few studies have reported on second ACL injuries in this population. To (1) report the rates of subsequent ACL injury (ipsilateral graft rupture or contralateral tear) in competitive female soccer players, (2) compare these rates with those of other female athletes of similar competitive level, (3) determine risk factors for second ACL injury, and (4) report clinical outcome scores in this population. Cohort study; Level of evidence, 3. The medical records at a single institution were reviewed for female patients who were injured during a competitive athletic event and treated with primary ACL reconstruction (ACLR) between 1998 and 2013. Patients were followed for a mean of 68.8 months postoperatively (range, 24-115.2 months). Clinical outcome was obtained via Lysholm and International Knee Documentation Committee (IKDC) scores. Soccer players were matched 1:1 to non-soccer athletes for age, activity level, and graft type. A total of 180 female ACLR patients with a mean ± SD age of 19.6 ± 6.9 years met the study inclusion and exclusion criteria (90 soccer players and 90 non-soccer players). Soccer players sustained more second ACL injuries, including both graft failures (11% vs 1%; P soccer players. Of the 67 patients who returned to soccer after ACLR (mean age, 17.5 years; range, 13-27 years), significantly more had graft tears compared with those who did not return to soccer (15% vs 0%, respectively; P = .04); however, the difference in contralateral ACL tears (19% for returning players vs 9% for those who did not return; P = .34) was not significant. Relatively older age (odds ratio, 1.5 per year; P = .03) was a significant risk factor for ACL graft tear but not for contralateral ACL injury. Both groups had similar mean Lysholm (96 vs 95) and IKDC scores (95 vs 96) at final follow-up. Twenty-eight percent of all female soccer players and 34% of those players who
Furley, Philip; Dicks, Matt; Memmert, Daniel
In the present article, we investigate the effects of specific nonverbal behaviors signaling dominance and submissiveness on impression formation and outcome expectation in the soccer penalty kick situation. In Experiment 1, results indicated that penalty takers with dominant body language are perceived more positively by soccer goalkeepers and players and are expected to perform better than players with a submissive body language. This effect was similar for both video and point-light displays. Moreover, in contrast to previous studies, we found no effect of clothing (red vs. white) in the video condition. In Experiment 2, we used the implicit association test to demonstrate that dominant body language is implicitly associated with a positive soccer player schema whereas submissive body language is implicitly associated with a negative soccer player schema. The implications of our findings are discussed with reference to future implications for theory and research in the study of person perception in sport.
Paillard, Thierry; Noé, Frédéric; Rivière, Terence; Marion, Vincent; Montoya, Richard; Dupui, Philippe
Sport training enhances the ability to use somatosensory and otolithic information, which improves postural capabilities. Postural changes are different according to the sport practiced, but few authors have analyzed subjects' postural performances to discriminate the expertise level among highly skilled athletes within a specific discipline. To compare the postural performance and the postural strategy between soccer players at different levels of competition (national and regional). Repeated measures with 1 between-groups factor (level of competition: national or regional) and 1 within-groups factor (vision: eyes open or eyes closed). Dependent variables were center-of-pressure surface area and velocity; total spectral energy; and percentage of low-, medium-, and high-frequency band. Sports performance laboratory. Fifteen national male soccer players (age = 24 +/- 3 years, height = 179 +/- 5 cm, mass = 72 +/- 3 kg) and 15 regional male soccer players (age = 23 +/- 3 years, height = 174 +/- 4 cm, mass = 68 +/- 5 kg) participated in the study. The subjects performed posturographic tests with eyes open and closed. While subjects performed static and dynamic posturographic tests, we measured the center of foot pressure on a force platform. Spatiotemporal center-of-pressure measurements were used to evaluate the postural performance, and a frequency analysis of the center-of-pressure excursions (fast Fourier transform) was conducted to estimate the postural strategy. Within a laboratory task, national soccer players produced better postural performances than regional players and had a different postural strategy. The national players were more stable than the regional players and used proprioception and vision information differently. In the test conditions specific to playing soccer, level of playing experience influenced postural control performance measures and strategies.
O'Kane, John W.; Gray, Kristen E.; Levy, Marni R.; Neradilek, Moni; Tencer, Allan F.; Polissar, Nayak L.; Schiff, Melissa A.
Objective Describe acute lower extremity injuries and evaluate extrinsic risk factors in female youth soccer Design Nested case-control study Setting Youth soccer clubs in Washington State, USA. Participants Female soccer players (N= 351) ages 11 to 15 years randomly selected from 4 soccer clubs from which 83% of their players were enrolled with complete follow-up for 92% of players. Interventions Injured players were interviewed regarding injury, field surface, shoe type, and position. Uninjured controls, matched on game or practice session, were also interviewed. Main Outcome Measures The association between risk factors and acute lower extremity injury using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). Results One hundred seventy-three acute lower extremity injuries occurred involving primarily the ankle (39.3%), knee (24.9%), and thigh (11.0%). Over half (52.9%) recovered within 1 week, while 30.2% lasted beyond 2 weeks. During practices, those injured were approximately 3-fold ( OR 2.83, 95% CI 1.49-5.31) more likely to play on grass than artificial turf and 2.4-fold (95% CI 1.03-5.96) more likely to wear cleats on grass than other shoe and surface combinations. During games injured players were 89% (95% CI 1.03-4.17) more likely to play defender compared to forward. Conclusions Half of the acute lower extremity injuries affected the ankle or knee. Grass surface and wearing cleats on grass increased training injuries. PMID:26327288
Helsen, Werner F; Starkes, Janet L; Van Winckel, Jan
The consistent asymmetry in the birth-date distribution of senior professional soccer players has led us to investigate whether similar asymmetries emerge throughout youth categories in soccer. Birth dates were considered for professional players, national youth teams, youth players transferred to top teams, and regular youth league players. Kolmogorov Smirnov tests assessed differences between observed and expected birth-date distributions. Regression analyses examined the relationship between month of birth and number of participants at various levels of play in soccer. Results indicated that youth players born from August to October (the early part of the selection year), beginning in the 6-8 year age group, are more likely to be identified as talented and to be exposed to higher levels of coaching. Eventually, these players are more likely to be transferred to top teams, to play for national teams, and to become involved professionally. In comparison, players born late in the selection year tended to dropout as early as 12 years of age. Recommendations suggest a review of the 24-month age band and current methods for talent detection and selection. Am. J. Hum. Biol. 10:791-798, 1998. © 1998 Wiley-Liss, Inc. Copyright © 1998 Wiley-Liss, Inc.
Volpi, Piero; Taioli, Emanuela
Injuries are a major adverse event during a soccer player's career; they require medical and surgical treatment and rehabilitation and thus may interrupt the player's activity, often with severe physical and psychological sequel. Specialists have tried to identify the risk factors for injuries, in an attempt to discover predictors that could be prevented and or eliminated before the injury occurs, but the results are scarce. This article reviews the epidemiology of the frequency and occurrence of injuries in Italian soccer players, reports a list of preventable risk factors that are associated with injuries, and identifies preventable risk factors. We have identified personal factors (age, previous traumatic events, physical and biological characteristics of the player, life style habits such as smoking, alcohol, and diet, changes in physical-athletic aspects of the players, such as increased muscle strength, and use of medications) as possible risk factors for injuries. However, environmental factors such as changes in training techniques, field composition, and shoes structure may also have a major influence. This summary indicates that appropriate preventive measures can be undertaken to prevent injuries in professional soccer players. Professionals who are in close contacts with the players should be informed of the predictors of injuries and should be trained to intervene and plan appropriate preventive measures.
Full Text Available Most studies on the identification and development of soccer talent have been one-dimensional in nature. Although some multi-dimensional analyses have been conducted, few research studies have assessed in any depth the socio-spatial factors influencing talent development. The aim of this particular study was to analyse variations in the international representation of clubs (n = 821 and countries (n = 59 in the development of players who took part in the 2014 FIFA Soccer World Cup. Clubs and countries were ranked and divided into quartiles according to the number of players developed between the ages of 15 and 21 (clubs and countries that developed players for at least three years between these ages and the number of official league matches played by these players up to the age of 23. Significant variations were observed between clubs in terms of the number of developed players who took part in the World Cup and the number of official league matches played by these players up to the age of 23 (p < .05, and also between countries (p < .05. The findings reveal the need to carry out more in-depth studies into the type of training and competition engaged in by elite players in the period of development between the ages of 15 and 21. It may be the case that these factors are potentially decisive socio-spatial constraints in the development of soccer talent.
Mohr, Magni; Krustrup, Peter
The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional...... during training were higher (psoccer players with superior...... speed endurance production (SEP) or speed endurance maintenance (SEM) training (two additional sessions/wk for 4 weeks) during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2) and a repeated sprint test (RST) pre- and postintervention. Yo-Yo IR2 performance...
Devlin, Brooke L; Kingsley, Michael; Leveritt, Michael D; Belski, Regina
Devlin, BL, Kingsley, M, Leveritt, MD, and Belski, R. Seasonal changes in soccer players' body composition and dietary intake practices. J Strength Cond Res 31(12): 3319-3326, 2017-The aims of this study were 2-fold: to determine seasonal changes in dietary intake and body composition in elite soccer players and to evaluate the influence of self-determined individual body composition goals on dietary intake and body composition. This longitudinal, observational study assessed body composition (total mass, fat-free soft tissue mass, and fat mass) using dual-energy x-ray absorptiometry and dietary intake (energy and macronutrients) via multiple-pass 24-hour recalls, at 4 time points over a competitive season in elite soccer players from one professional club in the Australian A-League competition. Self-reported body composition goals were also recorded. Eighteen elite male soccer players took part (25 ± 5 years, 180.5 ± 7.4 cm, 75.6 ± 6.5 kg). Majority (≥67%) reported the goal to maintain weight. Fat-free soft tissue mass increased from the start of preseason (55,278 ± 5,475 g) to the start of competitive season (56,784 ± 5,168 g; p nutrition recommendations. The self-reported body composition goals did not strongly influence dietary intake practices or changes in body composition. This study has demonstrated that body composition changes over the course of a soccer season are subtle in elite soccer players despite relatively low self-reported intake of energy and carbohydrate.
Hashim, Hairul Anuar; Hanafi@Ahmad Yusof, Hazwani
Purpose This study was designed to compare the effects of two different relaxation techniques, namely progressive muscle relaxation (PMR) and autogenic relaxation (AGR) on moods of young soccer players. Methods Sixteen adolescent athletes (mean age: 14.1 ± 1.3) received either PMR or AGR training. Using Profile of Mood States- Adolescents, their mood states were measured one week before relaxation training, before the first relaxation session, and after the twelfth relaxation session. Results Mixed ANOVA revealed no significant interaction effects and no significant main effects in any of the subscales. However, significant main effects for testing sessions were found for confusion, depression, fatigue, and tension subscales. Post hoc tests revealed post-intervention reductions in the confusion, depression, fatigue, and tension subscale scores. Conclusion These two relaxation techniques induce equivalent mood responses and may be used to regulate young soccer players’ mood states. PMID:22375225
Cross, Kevin M.; Saliba, Susan A.; Conaway, Mark; Gurka, Kelly K.; Hertel, Jay
Context Among US collegiate soccer players, the incidence rate and the event characteristics of hamstrings strains differ between sexes, but comparisons in the return-to-participation (RTP) time have not been reported. Objective To compare the RTP time between male and female collegiate soccer players and analyze the influence of event characteristics on the RTP time for each sex. Design Descriptive epidemiology study. Setting Data were collected from collegiate teams that voluntarily participated in the National Collegiate Athletic Association Injury Surveillance System. Patients or Other Participants Collegiate soccer athletes who sustained 507 hamstrings strains (306 men, 201 women) during the 2004 through 2009 fall seasons. Main Outcome Measure(s) Nonparametric statistics were used to evaluate RTP time differences between sexes and among categories of each event characteristic (ie, time of season, practice or competition, player position). Negative binomial regression was used to model the RTP time for each sex. All analyses were performed separately for first-time and recurrent strains. Results We found no differences in the RTP time between sexes for first-time (median: men = 7.0 days, women = 6.0 days; P = .07) or recurrent (median: men = 11 days, women = 5.5 days; P = .06) hamstrings strains. For male players with first-time strains, RTP time was increased when the strain occurred during competition or the in-season/postseason and varied depending on the division of play. Among female players with first-time strains, we found no differences in RTP time within characteristics. For male players with recurrent hamstrings strains, the RTP time was longer when the injury occurred during the in-season/postseason. Among female players with recurrent strains, RTP time was longer for forwards than for midfielders or defenders. Conclusions Although we found no differences in the RTP time after hamstrings strains in male and female collegiate soccer players, each sex
Mizuguchi, S; Gray, H; Calabrese, L S; Haff, G G; Sands, W A; Ramsey, M W; Cardinale, M; Stone, M H
The aim of the study was to investigate the applicability of a repeated change-of-direction (RCoD) test for NCAA Division-I male soccer players. The RCoD test consisted of 5 diagonal direction changes per repetition with a soccer ball to be struck at the end. Each player performed 15 repetitions with approximately 10 seconds to jog back between repetitions. Data were collected in two sessions. In the first session, 13 players were examined for heart rate responses and blood lactate concentrations. In the second session, 22 players were examined for the test's ability to discriminate the primary from secondary players (78.0±16.1 and 10.4±13.3 minutes per match, respectively). Heart rate data were available only from 9 players due to artifacts. The peak heart rate (200.2±6.6 beats∙min-1: 99.9±3.0% maximum) and blood lactate concentration (14.8±2.4 mmol∙L-1 immediately after) resulted in approximately 3.5 and 6.4-fold increases from the resting values, respectively. These values appear comparable to those during intense periods of soccer matches. In addition, the average repetition time of the test was found to discriminate the primary (4.85±0.23 s) from the secondary players (5.10±0.24 s) (P=0.02). The RCoD test appears to induce physiological responses similar to intense periods of soccer matches with respect to heart rate and blood lactate concentration. Players with better average repetition times tend to be those who play major minutes.
Adriano Lima Alves
Full Text Available OBJECTIVE: to determine the individual profile of blood concentration of creatine kinase CK in elite soccer players as well as to analyze the CK concentrations in different periods during the Professional Brazilian Championship. METHODS: resting CK of 17 soccer players was evaluated before the competition pre-season and after the matches 36 and 46 hours after the games CKGame for the individual blood CK. The Chi-square test was used to analyze the individual CK during the season. The competitive season was divided into three periods: initial, intermediate and final. The one-way ANOVA with repeated measurements followed by post hoc Student-Newman-Keuls test was used to compare the individual CK of each soccer player in each competitive period. The significance level was set at p<0.05. RESULTS: the highest frequency of individual CK was found in the second quartile 71 observations and the lowest frequency in the first 26 observations and the fourth quartile 40 observations compared to the expected number of 45.8 x2=22.21. CK concentrations were lower in the intermediate mean=66.99% and final mean=60.21% periods than in the initial period mean=89.33%. CONCLUSION: soccer players did not show elevated muscle damage and probably a muscle adaptation occurred in the competition, due to the reduction of CK concentrations observed.
Toering, Tynke; Elferink-Gemser, Marije T.; Jordet, Geir; Pepping, Gert-Jan; Visscher, Chris
This study examined the relationship between self-regulated learning and performance level of 256 elite youth soccer players aged 12 to 17 years (M-age = 14.2; SD = 1.2). As relative age may affect this relationship through its association with maturation, experience, and performance level, we
Kuijt, Marie-Therese K.; Inklaar, Han; Gouttebarge, Vincent; Frings-Dresen, Monique H. W.
Objectives: To investigate the prevalence of knee and/or ankle osteoarthritis in former elite soccer player. Design: Systematic review. Methods: Medline, Embase and SPORTDiscus (2000 to January 2012) were used. To be included, studies were required to be a primary study, written in English, Dutch,
Beijsterveldt, A.M.C. van; Port, L.G.L. van de; Vereijken, A.J.; Backx, F.J.C.
Hamstring injuries are common injuries in soccer players. In view of the high incidence and the serious consequences, identifying risk factors related to hamstring injuries is essential. The aim of this systematic review was therefore to identify risk factors for hamstring injuries in male adult
Gouttebarge, Vincent; Aoki, Haruhito; Kerkhoffs, Gino
To present time, scientific knowledge about symptoms of common mental disorders and adverse health behaviours among professional soccer players is lacking. Consequently, the aim of the study was to determine the prevalence of symptoms of common mental disorders (distress, anxiety/depression, sleep
Roca, André; Williams, A Mark; Ford, Paul R
We examined whether soccer players with varying levels of perceptual-cognitive expertise can be differentiated based on their engagement in various types and amounts of activity during their development. A total of 64 participants interacted with life-size video clips of 11 versus 11 dynamic situations in soccer, viewed from the first-person perspective of a central defender. They were required to anticipate the actions of their opponents and to make appropriate decisions as to how best to respond. Response accuracy scores were used to categorise elite players (n = 48) as high- (n = 16) and low-performing (n = 16) participants. A group of recreational players (n = 16) who had lower response accuracy scores compared to the elite groups acted as controls. The participation history profiles of players were recorded using retrospective recall questionnaires. The average hours accumulated per year during childhood in soccer-specific play activity was the strongest predictor of perceptual-cognitive expertise. Soccer-specific practice activity during adolescence was also a predictor, albeit its impact was relatively modest. No differences were reported across groups for number of other sports engaged in during development, or for some of the key milestones achieved. A number of implications for talent development are discussed.
The purpose of this study was to determine whether an ecological imagery intervention program would affect perception (i.e., exploratory activity and prospective control of future actions) in three elite soccer players. The imagery was adjusted to the unique action opportunities typically
Jonker, Laura; Elferink-Gemser, Marije T.; Toering, Tynke T.; Lyons, James; Visscher, Chris
Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning,
Full Text Available BACKGROUND: Agility is a determinant component in soccer performance. This study aimed to evaluate the reliability and sensitivity of a "Modified Illinois change of direction test" (MICODT in ninety-five U-14 soccer players. METHODS: A total of 95 U-14 soccer players (mean ± SD: age: 13.61 ± 1.04 years; body mass: 30.52 ± 4.54 kg; height: 1.57 ± 0.1 m from a professional and semi-professional soccer academy, participated to this study. Sixty of them took part in reliability analysis and thirty-two in sensitivity analysis. RESULTS: The intraclass correlation coefficient (ICC that aims to assess relative reliability of the MICODT was of 0.99, and its standard error of measurement (SEM for absolute reliability was <5% (1.24%. The MICODT's capacity to detect change is "good", it's SEM (0.10 s was ≤ SWC (0.33 s. The MICODT is significantly correlated to the Illinois change of direction speed test (ICODT (r = 0.77; p<0.0001. The ICODT's MDC95 (0.64 s was twice about the MICODT's MDC95 (0.28 s, indicating that MICODT presents better ability to detect true changes than ICODT. The MICODT provided good sensitivity since elite U-14 soccer players were better than non-elite one on MICODT (p = 0.005; dz = 1.01 [large]. This was supported by an area under the ROC curve of 0.77 (CI 95%, 0.59 to 0.89, p<0.0008. The difference observed in these two groups in ICODT was not statistically significant (p = 0.14; dz = 0.51 [small], showing poor discriminant ability. CONCLUSION: MICODT can be considered as more suitable protocol for assessing agility performance level than ICODT in U-14 soccer players.
Haugen, Thomas A; Tønnessen, Espen; Seiler, Stephen
The purpose of this investigation was to compare sprint and countermovement-jump (CMJ) performance among female competitive soccer players as a function of performance level, field position, and age. In addition, the authors wanted to quantify the evolution of these physical characteristics among elite players over a 15-y period. 194 female elite players (22± 4.1 y, 63 ± 5.6 kg), including an Olympic winning squad, tested 40-m sprint with electronic timing and CMJ on a force platform at the Norwegian Olympic training center from 1995 to 2010. Moderate to large velocity differences across performance levels and positions were observed. National-team players were 2% faster than 1st-division players (P = .027, d = 0.5) and 5% faster than 2nd-division players (P players jumped 8-9% higher than 1st-division players (P = .001, d = 0.6) and junior elite players (P = .023, d = 0.5). Forwards were 3-4% faster than midfielders (P Players from 2006-2010 were 2% faster (P players from 1995-1999 over 20 m, whereas no differences in 20- to 40-m velocity or CMJ performance were observed. This study provides effect-magnitude estimates for the influence of performance level, age, and player position on sprint and CMJ performance in female soccer players. While 20- to 40-m velocity and CMJ performance have remained stable over the time, there has been a moderate but positive development in 0- to 20-m velocity among elite performers.
Brito, João; Vasconcellos, Fabrício; Oliveira, José
This study aimed to analyse the short-term performance effects of three in-season low-volume strength-training programmes in college male soccer players. Fifty-seven male college soccer players (age: 20.31.6 years) were randomly assigned to a resistance-training group (n=12), plyometric training.......001) compared with the control group. No differences were observed in 5-m sprint and agility performances (p>0.05). Overall, the results suggest that in-season low-volume strength training is adequate for developing strength and speed in soccer players....
Kubayi, Alliance; Paul, Yvonne; Mahlangu, Prescott; Toriola, Abel
Soccer is the most popular sport worldwide. Despite its global acclaim, scientific studies of soccer have tended to focus on tactics and techniques, thereby neglecting the physical and physiological profile of the players. Therefore, the purpose of this study was to examine physical and anthropometric characteristics of male South African university soccer players. Twenty-seven male soccer players aged 19 to 24 (mean age: 22.1 years; s = 1.5 years) volunteered to participate in the study. The results showed that goalkeepers (77.5 ± 9.7 kg) and defenders (68.2 ± 6.5 kg) were the heaviest compared to players in other playing positions. The goalkeepers also had the highest percentage of body fat (11.3 ± 2.3%), in contrast to midfielders who had the lowest body fat content (9.1 ± 0.9%). With regard to flexibility, defenders (45.1 ± 4.9 cm) and midfielders (45.9 ± 5.4 cm) performed better than goalkeepers (37.1 ± 4.3 cm) and strikers (40.1 ± 3.4 cm). Midfielders (57.2 ± 3.1 ml 1 ·kg -1 ·min 1 ) and defenders (56.1 ± 5.1 ml 1 ·kg -1 ·min 1 ) had significantly higher values of maximal oxygen uptake (VO 2max ) than goalkeepers (47.9 ± 0.2 ml -1 ·kg -1 ·min -1 ) and strikers (49.8 ± 6.2 ml -1 ·kg -1 ·min -1 ). No significant (p > 0.05) differences were observed for all other variables, with the exception of body height, body mass, and VO 2max . It was therefore concluded that sports scientists and coaches should tailor conditioning programmes in soccer according to players' positions in view of the implications for successful performance.
Locks, Renato; Utsunomiya, Hajime; Briggs, Karen K; McNamara, Shannen; Chahla, Jorge; Philippon, Marc J
Arthroscopic hip surgery has been shown to be effective in returning professional athletes back to play at a high level of performance in different sports. Limited information exists regarding professional soccer players and their return to play. To determine the rate and time to return to sport for professional soccer players after hip arthroscopic surgery for the treatment of femoroacetabular impingement (FAI) and to identify possible risk factors associated with a delay in returning to play. Case series; Level of evidence, 4. Professional soccer players who underwent hip arthroscopic surgery for FAI by a single surgeon between 2005 and 2015 were evaluated. Data retrieved from www.mlssoccer.com , www.fifa.com , www.transfermarkt.co.uk , and www.wikipedia.org included information on each player's professional career, participation on the national team, length of professional career before surgery, number of appearances (games) before surgery, time between surgery and first appearance in a professional game, and number of appearances after surgery. Other data were obtained from the patient's medical records. Twenty-four professional soccer players (26 hips) were included. The mean age at surgery was 25.0 ± 4.0 years (range, 19-32 years). A total of 96% of patients were able to return to play at the professional level. The mean time between surgery and the first professional game played was 9.2 months (range, 1.9-24.0 months). On average, players played in 70 games after surgery (range, 0-224). National team players were able to return to play significantly earlier than the rest of the players (median, 5.7 months vs 11.6 months, respectively; P = .018). Severe chondral damage and microfracture did not interfere with return to play. The arthroscopic management of FAI in symptomatic professional soccer players allowed 96% of them to return to play. Players with national team experience were able to return to play earlier than those without it. Severe chondral damage
Fousekis, Konstantinos; Tsepis, Elias; Vagenas, George
Kicking and cutting skills in soccer are clearly unilateral, require asymmetrical motor patterns and lead to the development of asymmetrical adaptations in the musculoskeletal function of the lower limbs. Assuming that these adaptations constitute a chronicity-dependent process, this study examined the effects of professional training age (PTA) on the composite strength profile of the knee and ankle joint in soccer players. One hundred soccer players (n=100) with short (5-7 years), intermediate (8-10 years) and long (>11 years) PTA were tested bilaterally for isokinetic concentric and eccentric strength of the knee and ankle muscles. Knee flexion-extension was tested concentrically at 60°, 180° and 300 °/sec and eccentrically at 60° and 180 °/sec. Ankle dorsal and plantar flexions were tested at 60 °/sec for both the concentric and eccentric mode of action. Bilaterally averaged muscle strength [(R+L)/2] increased significantly from short training age to intermediate and stabilized afterwards. These strength adaptations were mainly observed at the concentric function of knee extensors at 60°/sec (p = 0. 023), knee flexors at 60°/sec (p = 0.042) and 180°/sec (p = 0.036), and ankle plantar flexors at 60o/sec (p = 0.044). A linear trend of increase in isokinetic strength with PTA level was observed for the eccentric strength of knee flexors at 60°/sec (p = 0.02) and 180°/sec (p = 0.03). Directional (R/L) asymmetries decreased with PTA, with this being mainly expressed in the concentric function of knee flexors at 180°/sec (p = 0.04) and at 300 °/sec (p = 0.03). These findings confirm the hypothesis of asymmetry in the strength adaptations that take place at the knee and ankle joint of soccer players mainly along with short and intermediate PTA. Players with a longer PTA seem to adopt a more balanced use of their lower extremities to cope with previously developed musculoskeletal asymmetries and possibly reduce injury risk. This has certain implications
Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej
The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players’ knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p soccer players. PMID:26630271
Cristian Javier Ramirez Lizana
Full Text Available AbstractConceptual small-sided games (CSSGs may be interesting as a methodology for training soccer players given its connection to the unpredictability that is inherent to soccer. Our aim was investigate, through videogrammetry, if the technical and tactical principles promoted through the adoption of distinct rules from two distinct CSSGs (maintaining ball possession; and progression to the target would actually be achieved. The study included 24 athletes assigned to 6-player teams. Our data showed that the CSSGs' organising principles create situations with differing levels of difficulty that obey the propositions of maintaining ball possession and progression to the target, i.e., CSSGs permit systematic training on technical and tactical components in order to emphasize the concepts adopted in this study in games context. Our data credit the CSSGs for teaching technical and tactical lessons that, when coupled with adequate physical conditioning, can facilitate a player's capacity to merge thoughts and events in different situations.
Emmonds, Stacey; Nicholson, G; Beggs, C; Jones, B; Bissas, A
The purpose of this study was to determine the importance of physical qualities for speed and change of direction (CoD) ability in female soccer players. Data were collected on 10 female soccer players who were part of a professional English Women's Super League team. Player assessments included anthropometric (stature and body mass), body composition (dual-energy X-ray absorptiometry), speed (10m, 30m sprint), CoD ability (505 agility), aerobic (Yo-Yo Intermittent Recovery Test), lower-body strength (bilateral knee extensions) and power (countermovement jump [CMJ], squat jump [SJ], 30cm drop jump [DJ]) measures. The relationships between the variables were evaluated using eigenvector analysis and Pearson correlation analysis. Multiple linear regression revealed that the performance variables (10 and 20m speed, mean 505, and CoD deficit mean) can be predicted with almost 100% accuracy (i.e. adjusted R > 0.999) using various combinations of the predictor variables (DJ height, CMJ height, SJ height, lean body mass). An increase of one standard deviation (SD) in DJ height was associated with reductions of -5.636 and -9.082 SD in 10 m and 20 m sprint times. A one SD increase in CMJ also results in a reduction of -3.317 and -0.922 SD respectively in mean 505 and CoD deficit mean values. This study provides comparative data for professional English female soccer players that can be used by strength and conditioning coaches when monitoring player development and assessing the effectiveness of training programmes. Findings highlight the importance of developing reactive strength to improve speed and CoD ability in female soccer players.
Lara, Beatriz; Gonzalez-Millán, Cristina; Salinero, Juan Jose; Abian-Vicen, Javier; Areces, Francisco; Barbero-Alvarez, Jose Carlos; Muñoz, Víctor; Portillo, Luis Javier; Gonzalez-Rave, Jose Maria; Del Coso, Juan
There is little information about the effects of caffeine intake on female team-sport performance. The aim of this study was to investigate the effectiveness of a caffeine-containing energy drink to improve physical performance in female soccer players during a simulated game. A double-blind, placebo controlled and randomized experimental design was used in this investigation. In two different sessions, 18 women soccer players ingested 3 mg of caffeine/kg in the form of an energy drink or an identical drink with no caffeine content (placebo). After 60 min, they performed a countermovement jump (CMJ) and a 7 × 30 m sprint test followed by a simulated soccer match (2 × 40 min). Individual running distance and speed were measured using GPS devices. In comparison to the placebo drink, the ingestion of the caffeinated energy drink increased the CMJ height (26.6 ± 4.0 vs 27.4 ± 3.8 cm; P 18 km/h (161 ± 99 vs 216 ± 103 m; P caffeine/kg might be an effective ergogenic aid to improve physical performance in female soccer players.
Fessi, Mohamed Saifeddin; Moalla, Wassim
The aim of this study was to assess post-match perceived exertion, feeling and wellness according to the match outcome (winning, drawing or losing) in professional soccer players. Twelve outfield players were followed during 52 official matches where the outcomes (win, draw or lose) were noted. Following each match players completed both a 10-point scale rating of perceived exertion (RPE) and an 11-point scale rating of perceived feeling. Rating of perceived sleep quality, stress, fatigue and muscle soreness were collected separately on a 7-point scale the day following each match. Player RPE was higher by a very largely magnitude following a loss compared to a draw or a win and higher by a small magnitude after a draw compared to a win. Players felt more pleasure after a win compared to a draw or loss and more displeasure after a loss compared to draw. The players reported a largely and moderately better-perceived sleep quality, less stress and fatigue following a win compared to draw or a loss, and a moderately bad-perceived sleep quality, higher stress and fatigue following a draw compared to a loss. In contrast, only a trivial-small change was observed in perceived muscle soreness between all outcomes. Matches outcomes moderately to largely affect RPE, perceived feeling, sleep quality, stress and fatigue whereas perceived muscle soreness remains high regardless of the match outcome. However, winning a match decreases the strain and improves both pleasure and wellness in professional soccer players.
To assess the validity of measuring locomotor activities and PlayerLoad using real-time (RT) data collection during soccer training. Twenty-nine English soccer players participated. Each player wore the same MEMS device (Micromechanical Electrical Systems; S5, Optimeye; CatapultSports, Melbourne, Australia) during 21 training sessions (N = 331 data sets) in the 2015-16 and 2016-17 seasons. An RT receiver (TRX; Catapultsports, Melbourne, Australia) was used to collect the locomotor activities and PlayerLoad data in RT and compared with the postevent downloaded (PED) data. PlayerLoad and locomotor activities (total distance covered; total high-speed running distance covered, >5.5#x00A0;m/s; total sprinting distance covered, >7 m/s; maximum velocity) were analyzed. Correlations were near perfect for all variables analyzed (r = .98-1.00), with a varied level of noise between RT and PED also (0.3-9.7% coefficient of variation). Locomotor activities and PlayerLoad can use both RT and PED concurrently to quantify a player's physical output during a training session. Caution should be taken with higher-velocity-based locomotor activities during RT compared to PED.
Full Text Available Abstract The complete isolated rupture of the popliteus tendon has been described as a rare injury and this report describes the case of a 31-year-old soccer player who sustained a partial rupture of the popliteus tendon during a game. The injury was suspected clinically and at MRI but confirmed only by the arthroscopic examination. The treatment consisted in open debridment with no tendon repair or augmentation. Seven weeks post-operation the patient was symptom-free and returned to competitive professional soccer at the same preinjury level. The clinical and arthroscopic findings of the case reported suggest a possible overuse disease with degenerative expression.
Hägglund, Martin; Zwerver, Johannes; Ekstrand, Jan
Background: Patellar tendinopathy is common among athletes in jumping sports and in sports with prolonged repetitive stress of the knee extensor apparatus. The epidemiology in soccer is not well described. Purpose: This study was undertaken to investigate and describe the epidemiology of patellar
Male teamsport athletes have traditionally been described as some of the most homophobic and femphobic men in North American culture. However, in this ethnographic research of an education-based soccer team at a small Catholic university in a rural part of Middle America, I use inclusive masculinity theory to highlight that a softer version of…
P. T. Nikolaidis
Full Text Available Whereas nutrition has a crucial role on sport performance, it is not clear to what extent nutrition knowledge is associated with physical fitness. The aim of this study was to examine the current level of nutrition knowledge of soccer players and whether this level is associated with physical fitness. Soccer players (n=185, aged 21.3±4.9 yr, weight 72.3±8.4 kg, and height 177.5±6.4 cm performed a battery of physical fitness tests (sit-and-reach test, SAR; physical working capacity in heart rate 170, PWC170; and Wingate anaerobic test, WAnT and completed an 11-item nutrition knowledge questionnaire (NKQ. Low to moderate Pearson correlations (0.15
Full Text Available Soccer is the most popular sport worldwide. Despite its global acclaim, scientific studies of soccer have tended to focus on tactics and techniques, thereby neglecting the physical and physiological profile of the players. Therefore, the purpose of this study was to examine physical and anthropometric characteristics of male South African university soccer players. Twenty-seven male soccer players aged 19 to 24 (mean age: 22.1 years; s = 1.5 years volunteered to participate in the study. The results showed that goalkeepers (77.5 ± 9.7 kg and defenders (68.2 ± 6.5 kg were the heaviest compared to players in other playing positions. The goalkeepers also had the highest percentage of body fat (11.3 ± 2.3%, in contrast to midfielders who had the lowest body fat content (9.1 ± 0.9%. With regard to flexibility, defenders (45.1 ± 4.9 cm and midfielders (45.9 ± 5.4 cm performed better than goalkeepers (37.1 ± 4.3 cm and strikers (40.1 ± 3.4 cm. Midfielders (57.2 ± 3.1 ml1·kg−1·min1 and defenders (56.1 ± 5.1 ml1·kg−1·min1 had significantly higher values of maximal oxygen uptake (VO2max than goalkeepers (47.9 ± 0.2 ml−1·kg−1·min−1 and strikers (49.8 ± 6.2 ml−1·kg−1·min−1. No significant (p > 0.05 differences were observed for all other variables, with the exception of body height, body mass, and VO2max. It was therefore concluded that sports scientists and coaches should tailor conditioning programmes in soccer according to players’ positions in view of the implications for successful performance.
Olthof, S. B. H.; Frencken, W. G. P.; Lemmink, K. A. P. M.
Small-sided games are an often used training tool in soccer practices. It has proven to provide a simultaneous physical, technical and tactical training stimulus for soccer players. Small-sided games replicate the tactical character of a match, but in a simplified format with reductions in number
Full Text Available The aim of this study was to determine the relationship of selected motor and functional abilities with dribbling and changing direction with the ball in 183 young soccer players between 10 and 17 years of age (age 13,0 ± 1,8 years; body height 161,8 ± 13,3 cm; body mass 53,3 ± 14,7 kg. Based on the obtained data and results it was found that after the age of 13, in addition to other skills important for soccer game, it would be necessary to emphasise the elastic power of lower extremities and after the age of 16 additional emphasis should be put on high-speed and quality of execution of specific speed and agility type soccer movements. The most important ability related to dribbling and changing direction with the ball at the age 10-11 is agility. At the age 12-13 these are agility, aerobic-anaerobic endurance and relative elastic power of lower extremities, at the age 14-15 mainly aerobicanaerobic endurance and at the age 16-17, in addition to agility also acceleration and maximum running speed.
Rössler, Roland; Junge, Astrid; Chomiak, Jiri; Dvorak, Jiri; Faude, Oliver
As part of a risk-management approach, sound epidemiological data are needed to develop prevention programs. A recent review on soccer injuries of players younger than 19 years concluded that prospective data concerning children are lacking. To analyze the incidence and characteristics of soccer injuries in children aged 7 to 12 years. Descriptive epidemiological study. The present survey was a prospective descriptive epidemiological study on soccer injuries over 2 seasons in the Czech Republic and Switzerland. Exposure of players during training and match play (in hours) and injury data were reported by coaches via an Internet-based registration system. Location, type, and severity of injuries were classified according to an established consensus. Injury characteristics are presented as absolute numbers and injury incidence rates (injuries per 1000 hours of soccer exposure). An injury was defined as any physical complaint sustained during a scheduled training session or match play resulting in at least 1 of the following: (1) inability to complete the current match or training session, (2) absence from subsequent training sessions or matches, and (3) injury requiring medical attention. In total, 6038 player-seasons with 395,295 hours of soccer exposure were recorded. The mean (±SD) age of the players was 9.5 ± 2.0 years, and 3.9% of the participants were girls. A total of 417 injuries were reported. Most (76.3%) injuries were located in the lower limbs, with 15.6% located in the upper limbs. Joint and ligament injuries comprised 30.5%, contusions 22.5%, muscle and tendon injuries 18.5%, and fractures and bone injuries 15.4% of all injuries; 23.7% of injuries led to more than 28 days of absence from sport participation. The overall injury incidence was 0.61 (95% CI, 0.53-0.69) injuries per 1000 hours of soccer exposure during training sessions and 4.57 (95% CI, 4.00-5.23) during match play. Injury incidence rates increased with increasing age. The observed injury
Musculus, Lisa; Lobinger, Babett H
Psychological characteristics, including personality traits and psychological skills, have been shown to be relevant predictors of soccer performance. In research, general and sport specific standardized self-report questionnaires have been applied in psychological diagnostics of sports talent. However, with regard to the assessment of psychological characteristics of talented soccer players, a gap between research and practice is apparent. While soccer clubs often ask their coaches to assess their players on self-designed, unevaluated scouting sheets, research widely neglects expert coaches' and clubs' perspectives on relevant performance characteristics. As we believe that expert coaches' assessments could be a valid predictor of a player's current performance and future success, we provide recommendations on how to improve coaches' assessment of psychological characteristics. As the quality of the assessment of psychological characteristics is crucial, we provide recommendations on how to ensure the central diagnostic standards: objectivity, reliability, and validity in talent assessment. Further, we argue that assessing psychological characteristics should combine self ratings of players and external ratings of coaches in talent development. Sport psychologists should assist clubs and coaches in improving the diagnostics of psychological characteristics as well as in embedding psychological diagnostics and interventions in the talent development process.
Inácio, Suelen Galante; de Oliveira, Gustavo Vieira; Alvares, Thiago Silveira
Caffeine and creatine are ingredients in the most popular dietary supplements consumed by soccer players. However, some products may not contain the disclosed amounts of the ingredients listed on the label, compromising the safe usage and the effectiveness of these supplements. Therefore, the aim of this study was to evaluate the content of caffeine and creatine in dietary supplements consumed by Brazilian soccer players. The results obtained were compared with the caffeine content listed on the product label. Two batches of the supplement brands consumed by ≥ 50% of the players were considered for analysis. The quantification of caffeine and creatine in the supplements was determined by a high-performance liquid chromatography system with UV detector. Nine supplements of caffeine and 7 supplements of creatine met the inclusion criteria for analysis. Eight brands of caffeine and five brands of creatine showed significantly different values (p soccer players present inaccurate values listed on the label, although most presented no difference among batches. To ensure consumer safety and product efficacy, accurate information on caffeine and creatine content should be provided on all dietary supplement labels.
Leo, Francisco M; Sánchez-Miguel, Pedro A; Sánchez-Oliva, David; Amado, Diana; García-Calvo, Tomás
The principal aims of the study were to define different profiles of cohesion and perceived efficacy in soccer players and to measure their differences in performance. The subjects were 235 soccer players in the under-18 category who played in the National League in Spain and 15 coaches whose ages ranged from 29 to 45 years. Diverse instruments to assess cohesion, perceived efficacy, and expectations of success were used in the study. Moreover, we measured playing time and performance. The results of the study proved the existence of four cohesion and efficacy profiles that presented significant differences in expectations of success, playing time, and performance. Furthermore, significant differences were found in the distribution of players in the teams as a function of performance. The main conclusion of this study is that soccer players with higher cohesion and collective efficacy levels belonged to teams that completed the season at the top-level classification. In contrast, athletes with low cohesion and collective efficacy usually played in unsuccessful teams. Coaches and sports psychologists are encouraged to promote both social and task cohesion and collective efficacy to enhance team performance.
Vescovi, J D; Rupf, R; Brown, T D; Marques, M C
Performance assessment has become an invaluable component of monitoring player development and within talent identification programs in soccer, yet limited performance data are available for female soccer players across a wide age range. The aim of this study was to describe the physical performance characteristics of female soccer players ranging in age from 12 to 21 years. High-level female soccer players (n=414) were evaluated on linear sprinting (36.6 m with 9.1 m splits), countermovement jump (CMJ), and two agility tests. Separate one-way ANOVAs were used to compare performance characteristics between (1) each year of chronological age and (2) three age groups: 12-13 years, n=78, 14-17 years, n=223, and 18-21 years, n=113. Mean linear sprint speed over 9.1 m was similar across all chronological ages, however sprint speed over the final 9.1 m, CMJ height and agility scores improved until approximately 15-16 years. Outcomes from the group data indicated better performance on all tests for the 14-17-year-old group compared with the 12-13-year-old group. Additionally, sprint speed on the second and fourth 9.1 m splits and 36.6 m sprint speed as well as performance on the Illinois agility test was better in the 18-21-year-old group compared with the 14-17-year-old group. The findings from this study indicate that marked improvements of high intensity short duration work occur up until 15-16 years. Smaller gains in performance were observed beyond 16 years of age as evidenced by better performance on 36.6 m sprint speed, several sprint splits and the Illinois agility test in the college aged players (i.e., 18-21-year-old group). © 2010 John Wiley & Sons A/S.
Matheus Machado Gomes
Full Text Available The aim of this study was to compare jump height and kinetic and kinematic com-ponents of countermovement vertical jumps between soccer and basketball players performed in two different arm swing conditions: with arm swing (WAS and without arm swing (NAS. Nine basketball players (21.2 ± 2.9 years; 101.64 ± 14.58 kg; 1.95 ± 0.06 m and nine soccer players (18.2 ± 0.7 years; 77.4 ± 7.58 kg; 1.81 ± 0.07 m performed 12 maximal countermo-vement vertical jumps, including 6 WAS jumps and 6 NAS jumps, on a force platform that recorded the ground reaction force (GRF. The vertical component of the GRF was used to estimate jump height and to calculate the kinematic (duration of eccentric phase, duration of concentric phase, and maximal downward displacement of center of mass and kinetic variables (mean power during the eccentric phase, mean power during the concentric, peak power, and peak force. The results showed no differences in jump height or in kinematic or kinetic variables between basketball and soccer players. In addition, the results showed that the participants of the two groups jumped higher in the WAS condition (0.41 m than in the NAS condition (0.36 m because of a higher peak power (WAS=276.8 W/kg0.67 and NAS=241.3 W/kg0.67 and a longer concentric phase duration (WAS=0.20 s/m0.5 and NAS=0.19 s/m0.5 during WAS jump. These results indicate that the basketball and soccer players studied here showed similar performance and the same kinematic and kinetic pattern in maximal vertical jumps and were comparably affected by the use of arm swing.
Alexandre Gomes de Almeida
Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n1p88 The aim of this study was to investigate whether a 300-m shuttle run test predicts anaerobic capacity, expressed as mean power output in the Wingate test, in a group of professional soccer players. Twenty-one soccer players (21 ± 2 years; 76.8 ± 7.0 kg; 179.8 ± 6.7 cm from a first division team of the São Paulo Soccer Federation participated in the study. In the first session, the players were submitted to the Wingate test for the determination of relative peak power output, relative mean power output and fatigue index. In the second session, the players underwent a shuttle run test which consisted of a maximum sprint of 20 m at the highest speed possible until completing a distance of 300 m. The total run time and mean velocity over the 20 m (V20m were recorded. Blood samples were collected before and after the 300-m shuttle run test for the determination of lactate concentration ([LAC]. Pearson’s correlation between the Wingate and 300-m shuttle run test variables showed that only relative mean power output was significantly correlated with total run time (r = - 0.75 and V20m (r = 0.72. [LAC] showed a significant increase (p < 0.05 when comparing the values obtained before (2.1 ± 1.0 mM and after (14.3 ± 2.4 mM the shuttle run test. In conclusion, this study demonstrated that the 300-m shuttle run test can predict anaerobic capacity in professional soccer players.
Ross Cloak, Andrew Lane, Matthew Wyon
Full Text Available Acute whole body vibration (WBV is an increasingly popular training technique amongst athletes immediately prior to performance and during scheduled breaks in play. Despite its growing popularity, evidence to demonstrate its effectiveness on acute neuromuscular responses is unclear, and suggestions that athlete ability impacts effectiveness warrant further investigation. The purpose of this study was to compare the neuromuscular effects of acute WBV and perceptions of whether WBV is an effective intervention between amateur and professional soccer players. Participants were 44 male soccer players (22 professional and 22 amateur; age: 23.1 ± 3.7 years, body mass: 75.6 ± 8.8 kg and height: 1.77 ± 0.05 m. Participants in each group were randomly assigned to either an intervention of 3 x 60 s of WBV at 40 Hz (8mm peak-to-peak displacement or control group. Peak knee isometric force, muscle activation and post activation potentiation (PAP of the knee extensors along with self-report questionnaire of the perceived benefits of using the intervention were collected. A three-way ANOVA with repeated measures revealed professional players demonstrated a significant 10.6% increase (p < 0.01, Partial Eta2 = 0.22 in peak knee isometric force following acute WBV with no significant differences among amateur players. A significant difference (p < 0.01, Partial Eta2 = 0.16 in PAP amongst professional players following acute WBVT was also reported. No significant differences amongst amateur players were reported across measurements. Results also indicated professional players reported significantly stronger positive beliefs in the effectiveness of the WBV intervention (p < 0.01, Partial Eta2 = 0.27 compared to amateur players. Acute WBV elicited a positive neuromuscular response amongst professional players identified by PAP and improvements in knee isometric peak force as well as perceived benefits of the intervention, benefits not found among amateur players.
Raphael Rodrigues Perim
Full Text Available INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n = 45. Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10% of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20% of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40% complete (p<.01. Although the slopes of the lines were similar (p = .25, the regression intercepts differed (p<.01 between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20% of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.
van Beijsterveldt, Anna M C; van de Port, Ingrid G L; Krist, Mark R; Schmikli, Sandor L; Stubbe, Janine H; Frederiks, Janet E; Backx, Frank J G
Background The incidence rate of soccer injuries is among the highest in sports, particularly for adult male soccer players. Purpose To investigate the effect of the ‘The11’ injury prevention programme on injury incidence and injury severity in adult male amateur soccer players. Study design Cluster-randomised controlled trial. Methods Teams from two high-level amateur soccer competitions were randomly assigned to an intervention (n=11 teams, 223 players) or control group (n=12 teams, 233 players). The intervention group was instructed to perform The11 in each practice session during one soccer season. The11 focuses on core stability, eccentric training of thigh muscles, proprioceptive training, dynamic stabilisation and plyometrics with straight leg alignment. All participants of the control group continued their practice sessions as usual. Results In total, 427 injuries were recorded, affecting 274 of 456 players (60.1%). Compliance with the intervention programme was good (team compliance=73%, player compliance=71%). Contrary to the hypothesis, injury incidences were almost equal between the two study groups: 9.6 per 1000 sports hours (8.4–11.0) for the intervention group and 9.7 (8.5–11.1) for the control group. No significant differences were found in injury severity, but a significant difference was observed in the location of the injuries: players in the intervention group sustained significantly less knee injuries. Conclusions This study did not find significant differences in the overall injury incidence or injury severity between the intervention and control group of adult male soccer players. More research is recommended, focusing on injury aetiology and risk factors in adult male amateur soccer players. PMID:22878257
Thorborg, Kristian; Branci, Sonia; Nielsen, Martin Peter; Tang, Lars; Nielsen, Michael Bachmann; Hölmich, Per
Background: Adductor-related pain is the most common clinical finding in soccer players with groin pain and can be a long-standing problem affecting physical function and performance. Hip adductor weakness has been suggested to be associated with this clinical entity, although it has never been investigated. Purpose: To investigate whether isometric and eccentric hip strength are decreased in soccer players with adductor-related groin pain compared with asymptomatic soccer controls. The hypothesis was that players with adductor-related groin pain would have lower isometric and eccentric hip adduction strength than players without adductor-related groin pain. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Male elite and subelite players from 40 teams were contacted. In total, 28 soccer players with adductor-related groin pain and 16 soccer players without adductor-related groin pain (asymptomatic controls) were included in the study. In primary analysis, the dominant legs of 21 soccer players with adductor-related groin pain (≥4 weeks duration) were compared with the dominant legs of 16 asymptomatic controls using a cross-sectional design. The mean age of the symptomatic players was 24.5 ± 2.5 years, and the mean age of the asymptomatic controls was 22.9 ± 2.4 years. Isometric hip strength (adduction, abduction, and flexion) and eccentric hip strength (adduction) were assessed with a handheld dynamometer using reliable test procedures and a blinded assessor. Results: Eccentric hip adduction strength was lower in soccer players with adductor-related groin pain in the dominant leg (n = 21) compared with asymptomatic controls (n = 16), namely 2.47 ± 0.49 versus 3.12 ± 0.43 N·m/kg, respectively (P strength differences were observed between symptomatic players and asymptomatic controls for the dominant leg (P = .35-.84). Conclusion: Large eccentric hip adduction strength deficits were found in soccer players with adductor-related groin pain
Bode, Gerrit; Hammer, Thorsten; Karvouniaris, N; Feucht, M J; Konstantinidis, L; Südkamp, N P; Hirschmüller, A
The prevalence of patellar tendinopathy is elevated in elite soccer compared to less explosive sports. While the burden of training hours and load is comparably high in youth elite players (age soccer academy. One hundred nineteen male youth soccer players (age 15,97 ± 2,24 years, height 174, 60 ± 10,16 cm, BMI 21, 24 ± 2,65) of the U-13 to U-23 teams were part of the study. Data acquisition included sport specific parameters such as footwear, amount of training hours, leg dominance, history of tendon pathologies, and clinical examination for palpatory pain, indurations, muscular circumference, and range of motion. Subjective complaints were measured with the Victorian Institute of Sport Assessment Patellar (VISA-P) Score. Furthermore, sonographical examinations (Aplio SSA-770A/80; Toshiba, Tokyo, Japan) with 12-MHz multifrequency linear transducers (8-14 MHz) of both patellar tendons were performed with special emphasis on hyper- and hypo echogenic areas, diameter and neovascularization. The prevalence of patellar tendinopathies was 13.4%. Seventy-five percent of the players complained of pain of their dominant leg with onset of pain at training in 87.5%. The injured players showed a medium amount of 10.34 ± 3.85 training hours and a medium duration of symptoms of 11.94 ± 18.75 weeks. Two thirds of players with patellar tendinopathy were at the age of 15-17 (Odds ratio 1.89) while no differences between players of the national or regional league were observed. In case of patellar tendinopathy, VISA-P was significantly lower in comparison to healthy players (mean ± SD 76.80 ± 28.56 points vs. 95.85 ± 10.37). The clinical examination revealed local pain at the distal patella, pain at stretching, and thickening of the patellar tendon (p = 0.02). The mean tendon diameter measured 2 cm distally to the patella was 4.10 ± 0.68 mm with a significantly increased diameter of 0.15 mm in case of an underlying tendinopathy (p = 0.00). The
Lesinski, Melanie; Prieske, Olaf; Helm, Norman; Granacher, Urs
The objectives of this study were to (i) describe soccer training (e.g., volume, types), anthropometry, body composition, and physical fitness and (ii) compute associations between soccer training data and relative changes of anthropometry, body composition, and physical fitness during a soccer season in female elite young athletes. Seasonal training (i.e., day-to-day training volume/types) as well as variations in anthropometry (e.g., body height/mass), body composition (e.g., lean body/fat mass), and physical fitness (e.g., muscle strength/power, speed, balance) were collected from 17 female elite young soccer players (15.3 ± 0.5 years) over the training periods (i.e., preparation, competition, transition) of a soccer season that resulted in the German championship title in under-17 female soccer. Training volume/types, anthropometrics, body composition, and physical fitness significantly varied over a soccer season. During the two preparation periods, higher volumes in resistance and endurance training were performed (2.00 ≤ d ≤ 18.15; p < 0.05), while higher sprint and tactical training volumes were applied during the two competition periods (2.22 ≤ d ≤ 11.18; p < 0.05). Body height and lean body mass increased over the season (2.50 ≤ d ≤ 3.39; p < 0.01). In terms of physical fitness, significant performance improvements were found over the soccer season in measures of balance, endurance, and sport-specific performance (2.52 ≤ d ≤ 3.95; p < 0.05). In contrast, no statistically significant changes were observed for measures of muscle power/endurance, speed, and change-of-direction speed. Of note, variables of muscle strength (i.e., leg extensors) significantly decreased (d = 2.39; p < 0.01) over the entire season. Our period-specific sub-analyses revealed significant performance improvements during the first round of the season for measures of muscle power/endurance, and balance (0.89 ≤ d ≤ 4.01; p < 0.05). Moreover, change
Full Text Available The objectives of this study were to (i describe soccer training (e.g., volume, types, anthropometry, body composition, and physical fitness and (ii compute associations between soccer training data and relative changes of anthropometry, body composition, and physical fitness during a soccer season in female elite young athletes. Seasonal training (i.e., day-to-day training volume/types as well as variations in anthropometry (e.g., body height/mass, body composition (e.g., lean body/fat mass, and physical fitness (e.g., muscle strength/power, speed, balance were collected from 17 female elite young soccer players (15.3 ± 0.5 years over the training periods (i.e., preparation, competition, transition of a soccer season that resulted in the German championship title in under-17 female soccer. Training volume/types, anthropometrics, body composition, and physical fitness significantly varied over a soccer season. During the two preparation periods, higher volumes in resistance and endurance training were performed (2.00 ≤ d ≤ 18.15; p < 0.05, while higher sprint and tactical training volumes were applied during the two competition periods (2.22 ≤ d ≤ 11.18; p < 0.05. Body height and lean body mass increased over the season (2.50 ≤ d ≤ 3.39; p < 0.01. In terms of physical fitness, significant performance improvements were found over the soccer season in measures of balance, endurance, and sport-specific performance (2.52 ≤ d ≤ 3.95; p < 0.05. In contrast, no statistically significant changes were observed for measures of muscle power/endurance, speed, and change-of-direction speed. Of note, variables of muscle strength (i.e., leg extensors significantly decreased (d = 2.39; p < 0.01 over the entire season. Our period-specific sub-analyses revealed significant performance improvements during the first round of the season for measures of muscle power/endurance, and balance (0.89 ≤ d ≤ 4.01; p < 0.05. Moreover, change
Fenner, Jonathan S J; Iga, John; Unnithan, Viswanath
The aim of this study was to evaluate physiological and technical attributes of prepubertal soccer players during multiple small-sided games (SSGs), and determine if SSGs can act as a talent identification tool. Sixteen highly trained U10 soccer players participated and separated into two groups of eight. Each group played six small-sided (4 vs. 4) matches of 5-min duration. Each player was awarded total points for the match result and goals scored. A game technical scoring chart was used to rate each player's performance during each game. Time-motion characteristics were measured using micromechanical devices. Total points had a very large significant relationship with game technical scoring chart (r = 0.758, P talented prepubertal soccer players.
Full Text Available The purpose of this study was to verify the effects of a carbohydrate-electrolyte drink on soccer performance. Twenty soccer players volunteered to participate in the study. Players were allocated to two assigned trials according to their positional roles in the team: CHO group (ingesting a 6% carbohydrate-electrolyte solution at regular 15 minutes intervals and NCHO (ingesting no fluid during 75 min on-field soccer game. During the trials, body mass loss, heart rate, time spent running, number of sprints and core temperature were measured. There were statistically significant changes (p < 0.05 in body mass loss (CHO: 1.14 ± 0.37 kg vs. NCHO: 1.75 ± 0.47 kg and number of sprints performed (CHO: 14.70 ± 4.38 vs. NCHO: 10.70 ± 5.80 between groups. The main finding of the present study indicates that supplementation with a carbohydrate-electrolyte drink during a soccer match is beneficial in helping to prevent deterioration in performance.
Rubley, Mack D; Haase, Amaris C; Holcomb, William R; Girouard, Tedd J; Tandy, Richard D
The purpose of this study was to measure the effects of low-frequency, low-impact plyometric training on vertical jump (VJ) and kicking distance in female adolescent soccer players. Sixteen adolescent soccer players were studied (age 13.4 ± 0.5 years) across 14 weeks. The control group (general soccer training only) had 6 subjects, and the plyometric training (general soccer training plus plyometric exercise) group had 10 subjects. All subjects were tested for VJ and kicking distance on 3 occasions: pre-test, 7 weeks, and 14 weeks. Data were analyzed using a 2 (Training) × 3 (Test) analysis of variance (ANOVA) with repeated measures on the factor test. No significant difference in kicking distance was found between groups at pre-test (p = 0.688) or 7 weeks (p = 0.117). The plyometric group had significantly greater kicking distance after 14 weeks (p plyometric group had a significantly higher VJ after 14 weeks (p = 0.014). These results provide strength coaches with a safe and effective alternative to high-intensity plyometric training. Based on these findings, to increase lower-body power resulting in increased VJ and kicking distance, strength coaches should implement once-weekly, low-impact plyometric training programs with their adolescent athletes.
Carling, Christopher; Bloomfield, Jonathan
The aim of this study was to examine the effects of an early dismissal (after 5-min play) on work-rate in a professional soccer match. A computerised player tracking system was used to assess the work-rates of seven players who completed the match on a team with 10 players. A minute-by-minute analysis of the remaining 91min following the dismissal was performed for the total distance covered, the distance covered in five categories of movement intensity and the recovery time between high-intensity efforts for each player. The data were calculated for each half and for three equal intervals within each half and profiled against normative data for the same players obtained from the analysis of 15 games in the same season. Following the dismissal, the players covered a greater total distance than normal (pplayers may not always utilise their full physical potential as this match illustrated an increase in overall work-rate when reduced to 10 players. However, as a team with 10 players is likely to incur higher levels of fatigue, tactical alterations may be necessary and/or players may adopt a pacing strategy to endure the remainder of the match. Copyright (c) 2008 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Christensen, Peter Møller; Krustrup, Peter; Gunnarsson, Thomas P.
18 elite soccer players were, for a two-week period, assigned to a high intensity training group (HI, n=7) performing 10 training sessions mainly consisting of aerobic high intensity training (8×2 min) and speed endurance training (10-12×30-s sprints) or a training cessation group (TC, n=11......PURPOSE:: To examine the effects of a short-term period with intensified training or training cessation of trained soccer players on VO2 kinetics at 75% maximal aerobic speed (MAS), oxidative enzymes and performance in repeated high intensity exercise. METHODS:: After the last match of the season......) that refrained from training. RESULTS:: For TC, VO2 kinetics became slower (P...
Jensen, Jesper; Hölmich, Per; Bandholm, Thomas
programme, including one hip-adduction exercise, on eccentric and isometric hip-adduction strength, using elastic bands as external load. METHODS: Thirty-four healthy, sub-elite soccer players, mean (±SD) age of 22.1 (±3.3) years, were randomised to either training or control. During the mid-season break......BACKGROUND: Soccer players with weak hip-adductor muscles are at increased risk of sustaining groin injuries. Therefore, a simple hip-adductor strengthening programme for prevention of groin injuries is needed. OBJECTIVE: We aimed to investigate the effect of an 8-week hip-adductor strengthening...... sessions per week (weeks 7-8) with 3×8 RM. Eccentric hip-adduction (EHAD), isometric hip-adduction (IHAD) and isometric hip-abduction (IHAB) strength, and the IHAD/IHAB ratio were measured assessor-blinded preintervention and postintervention, using reliable hand-held dynamometry procedures. RESULTS...
Bidaurrazaga-Letona, Iraia; Lekue, José Antonio; Amado, Markos; Gil, Susana Maria
Since age-groups in soccer often comprise children born within a two-year timeframe, characteristics that define the profile of a successful player may not be appropriate for the oldest or youngest players of the same age group. Therefore, this study aimed to determine to what extent performance was influenced by age, maturation and body size in elite soccer players with barely one year age gap. Anthropometry, 15-m sprint test, modified Barrow´s agility test, Yo-Yo intermittent recovery test level 1, countermovement jump, and handgrip test were conducted in players aged twelve and under (n=82, 11.1 ± 0.6 years; Mean ± SD) and between twelve and thirteen (n=79, 12.8 ± 0.6 years; Mean ± SD). A total score of performance, chronological age and age at peak height velocity were calculated. Descriptive statistics, Student's t-tests, and multiple linear regressions were performed. The explained variance in composite score was greater in the older (54%) than in the younger (30%) players. Sum of skinfolds was the primary predictor of 15-m sprint and countermovement jump in the younger group whereas in the older group chronological age and body size appeared as predictors of performance (41%). Body size explained the variance in most tests in older players. In the younger group biological maturity status explained the variance in endurance (35%) and handgrip (59%) tests. In summary, chronological age and sum of skinfolds influenced most tests; however, predictors differed between age groups. These findings highlight the importance of assessing individual differences in young male soccer players regardless of their similarity in age.
Prieto-Mondragón, Laura del Pilar; Camargo-Rojas, Diana Alexandra; Quiceno, Christian Alexander
Abstract Introduction: Soccer is the sport with the highest risk of muscle injury for players. Eccentric exercise is fundamental for reducing injury rates and isoinertial technology devices cause an increase in eccentric demands after a concentric contraction. Objective: To identify the use of isoinertial technology in the fields of physical activity and sports for rehabilitation and prevention of muscle injuries reported in scientific literature. Materials and methods: A search of scienti...
Manore, Melinda M.; Patton-Lopez, Megan M.; Meng, Yu; Wong, Siew Sun
For adolescent athletes (14–18 years), data on sport nutrition knowledge, behaviors and beliefs are limited, especially based on sex, race/ethnicity and socioeconomic status. High school soccer players (n = 535; 55% female; 51% White, 41% Latino; 41% National School Lunch Program (NSLP) participants (80% Latino)) completed two questionnaires (demographic/health history and sport nutrition). The sport nutrition knowledge score was 45.6% with higher scores in NSLP-Whites vs. NSLP-Latinos (p <...
Morales, Anderson Pontes; Sampaio-Jorge, Felipe; da Cruz Rangel, Luiz Felipe; de Souza Menezes, Jackson; Leite, Tiago Costa; Ribeiro, Beatriz Gonçalves
The aim of this study was to evaluate the curves of cardiorespiratory variables during cardiopulmonary exercise testing (CPET) in soccer players who had acute alterations in the glomerular filtration rate (GFR) after performing the pre-season training protocol. Sixteen male professional soccer players (25 ± 3 years; 179 ± 2 cm; and 77 ± 6 kg) were evaluated for oxygen uptake (VO 2 ), heart rate (HR) and pulse relative oxygen (relative O 2 Pulse) curves with intervals corresponding to 10% of the total duration of CPET. Athletes were grouped according to the GFR and classified as decreased GFR (dGFR; n = 8) and normal GFR (nGFR; n = 8). Athletes from the dGFR group exhibited lower VO 2 values (p values (p values (p < 0.05) when 70% (dGFR 25.6 ± 8.4 vs. nGFR 27.9 ± 9.7 ml·beat -1 ·kg -1 ), 80% (dGFR 26.6 ± 8.8 vs. nGFR 29.1 ± 10.0 ml·beat -1 ·kg -1 ), 90% (dGFR 27.1 ± 9.0 vs. nGFR 30.8 ± 10.6 ml·beat -1 ·kg -1 ) and 100% (dGFR 28 ± 9.2 vs. nGFR 31.8 ± 10.9 ml·beat -1 ·kg -1 ) of the test was complete. A correlation was found (r = -0.66, R 2 = 0.44, p = 0.00) between lower VO 2 peak and elevated levels of urinary protein excretion. In conclusion, soccer players with reduced kidney function after performing the pre-season training protocol also presented alterations in cardiopulmonary variables. We suggest that monitoring of renal function may be used to identify less conditioned soccer players.
Ranchordas, Mayur; Dawson, Joel T.; Russell, Mark
Specific guidelines that aim to facilitate the recovery of soccer players from the demands of training and a congested fixture schedule are lacking; especially in relation to evidence-based nutritional recommendations. The importance of repeated high level performance and injury avoidance while addressing the challenges of fixture scheduling, travel to away venues, and training commitments requires a strategic and practically feasible method of implementing specific nutritional strategies. He...
Taskin, Cengiz; Karakoc, Onder; Taskin, Mine; Dural, Murat
70 soccer players in Gaziantep amateur league voluntarily participated in this study, (average of their ages 19,17±1,34years, average of their heights 181,28±5,06 cm, average of their body weights 76,75±4,43 kg and average of their sports experiences 3,78±0,95 years) to analyze visual and auditory reaction times and aerobic capacities of amateur…
Ingebrigtsen, Jørgen; Bendiksen, Mads; Randers, Morten Bredsgaard
Abstract We examined performance, heart rate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO(2)max, Yo-Yo IR1 and repeated sprint tests (RSA) (n = 51) and match-analyses (n = 39) were also performed. Yo-Yo IR2...
Vargas, Valentine Z; Baptista, Abrahão F; Pereira, Guilherme O C; Pochini, Alberto C; Ejnisman, Benno; Santos, Marcelo B; João, Silvia M A; Hazime, Fuad A
Vargas, VZ, Baptista, AF, Pereira, GOC, Pochini, AC, Ejnisman, B, Santos, MB, João, SMA, and Hazime, FA. Modulation of isometric quadriceps strength in soccer players with transcranial direct current stimulation: a crossover study. J Strength Cond Res 32(5): 1336-1341, 2018-The aim of this study was to evaluate the effect of transcranial direct current stimulation (tDCS) on the maximum isometric muscle contraction (MVIC) of the knee extensors in soccer players at the preprofessional level. Twenty female soccer players aged 15-17 years (mean = 16.1; SD = 0.9) with 5.2 ± 2.6 years of training were randomly divided into 2 groups to receive either active or sham tDCS in a single session (2 mA; 0.057 mA·cm). The MVIC of the knee extensors was evaluated in both lower limbs by manual dynamometry in 5 sets of contractions divided into 4 blocks: (a) prestimulation, (b) during tDCS, (c) 30 minutes after tDCS, and (d) 60 minutes after tDCS. After an interval of 7 days, the groups were evaluated again, and the type of initial stimulation was inverted between participants. The MVIC of the knee extensors increased significantly during active tDCS (dominant limb (DL) = 0.4; IC = 0.1-0.8 N·Kg), 30 minutes after active tDCS (DL = 0.9; IC 0.4-1.4 N·Kg), and 60 minutes after active tDCS (DL = 1.0; IC 0.3-1.6 N·Kg) but not for sham tDCS. Our conclusion was that tDCS temporarily increases isometric quadriceps strength in adolescent female soccer players, which may be useful for both strength training and rehabilitation.
de Queiroz, Roberto Dantas; de Carvalho, Rogério Teixeira; de Queiroz Szeles, Paulo Roberto; Janovsky, César; Cohen, Moisés
to evaluate the return to sport after surgical treatment for pubalgia among 30 professional soccer players and describe the surgical technique used. this case series was evaluated by means of a questionnaire and physical examination on 30 male professional soccer players of mean age 24.4 years (range: 18-30). The mean duration of the symptoms was 18.6 months (range: 13-28). The diagnosis was made through clinical investigation, special maneuvers and complementary examinations, by the same examiner. All the patients underwent surgical treatment after conservative treatment failed; all procedures were performed by the same surgeon using the same technique. Nonparametric comparisons were made to investigate the time taken to recover after the surgery, for the patients to return to their sport. five patients evolved with hematoma, with the need to remove the stitches three weeks after the operation because of a small dehiscence at the site of the operative wound. The wound healed completely in all these cases by five weeks after the surgery. Four patients presented dysuria in the first week, but improved in the second postoperative week. The mean time taken to return to training was around eight weeks (range: seven-nine). All the players returned to competitive soccer practice within 16 weeks. When asked about their degree of satisfaction after the operation (satisfied or dissatisfied), taking into consideration their return to the sport, there was 100% satisfaction, and they returned to professional practice at the same competitive level as before the injury. This degree of satisfaction continued to the last assessment, which was made after 36 months of postoperative follow-up. the surgical technique presented in this case series, with trapezoidal resection of the pubic symphysis in association with bilateral partial tenotomy of the long adductor, was a fast and effective procedure with a low rate of postoperative complications. It was shown to be an excellent
Šimonek, Jaromír; Horička, Pavol; Hianik, Ján
Complex reaction speed, acceleration, maximum speed, speed of whole-body change of direction and agility represent the basic components of sport performance mainly in sport games and combat sports. However, contradictory findings have been reported as to the extent of the relationship between the different speed and agility components. This study comprised 117 players (soccer – 56, basketball – 17, volleyball – 20, and handball – 24) playing youth leagues U15-U17 who were assessed for 10-m sp...
M. Magalhães Sales
Conclusion: The anthropometric profile of soccer players that act in the United Arab Emirates is similar to others around the world. However, regarding the physical fitness, results are still inconclusive, since findings from other studies suggest that the anaerobic power of our sample is alike or lower than other elite players throughout the world. Likewise indirect VO2max, especially given the acknowledged limitations of obtaining indirectly this variable. In addition, making an analysis by playing position, the results of this study are similar to previous research.
Collins, Brian; Rovatsos, Michael
This paper describes an approach to using a hierarchical machine learning model in a two player 3D physics-based soccer video game to improve human player satisfaction. Learning is accomplished at two layers to form a complete game-playing agent such that higher level strategy learning is dependent on lower-level learning of basic behaviors.Supervised learning is used to train neural networks on human data to model the basic behaviors. The reinforcement learning algorithms Sarsa (λ) and Q(λ) ...
Kawasaki, Takayuki; Ota, Chihiro; Yoneda, Takeshi; Maki, Nobukazu; Urayama, Shingo; Nagao, Masashi; Nagayama, Masataka; Kaketa, Takefumi; Takazawa, Yuji; Kaneko, Kazuo
A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated. To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players. Descriptive epidemiology study. A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires. The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury. Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for
Cascone, Piero; Petrucci, Bernardino; Ramieri, Valerio; Marianetti, Titto Matteo; TitoMatteo, Marianetti
Among professional [soccer] players, a relevant incidence of maxillofacial trauma has been reported. The main challenge in these particular patients is to give them the possibility of a very short convalescence period and to make possible their agonistic activity as soon as possible. The authors here present an innovative technique to realize this--the Security Hi-tech Individual Extra-Light Device Mask, a customizable protective shield based on the player's face cast. A completely customized mask was forged over the player's face cast to protect the injured area. This mask shortens convalescence period, and due to its realization, it is comfortable and easy fitting, thus allowing the player to perform at a professional level in his sport activity in the shortest time possible.
Pau, Massimiliano; Ibba, Gianfranco; Leban, Bruno; Scorcu, Marco
In this study, we investigated the static balance of adult and adolescent elite soccer players to understand how expertise and playing position influence postural control. Seventy-one national level players were tested using a force platform to acquire Center-of-Pressure (COP) data in uni- and bipedal stance and calculate sway area (SA), COP path length, velocity and displacements. The results show significant differences in postural sway related to age and playing position only for single-limb stance. In particular, midfielders exhibited significantly lower values of SA with respect to defenders (-48%, p = 0.001) and the under-15 players exhibited SA 42-64% higher than all the others (p = 0.001). In the light of planning training or rehabilitation programs specific for each player's role and age, sway measurements may supply useful, objective and reliable information only for the unipedal test as the bipedal standing appears not challenging enough to let differences in balance abilities emerge.
Whitworth-Turner, Craig; Di Michele, Rocco; Muir, Ian; Gregson, Warren; Drust, Barry
During the competitive season, soccer players are likely exposed to numerous factors that may disrupt the process of sleep. The current investigation looked to evaluate a practical sleep hygiene strategy (10-min showering at ∼40°C before lights out), within a group of 11 youth soccer players in comparison to normal sleeping conditions (control). Each condition consisted of three days within a randomised crossover trial design. Sleep information was collected using a commercial wireless bedside sleep monitor. Measures of skin temperature were evaluated using iButton skin thermistors to establish both distal and proximal skin temperatures and distal to proximal gradient. The shower intervention elevated distal skin temperature by 1.1°C (95% CI: 0.1-2.1°C, p = .04) on average prior to lights out. The elevation in distal temperature was also present during the first 30-min following lights out (1.0°C, 95% CI: 0.4-1.6°C, p sleep latency of the youth soccer players was -7-min lower (95% CI: -13 to -2 min, p sleep efficiency +2% higher (95% CI: 1-3%; p sleep onset latency and improve sleep efficiency in athletes.
Williams, Jeffrey G; Gard, Hannah I; Gregory, Jeana M; Gibson, Amy; Austin, Jennifer
Collegiate soccer players suffer hamstring injuries due to inflexibility and repetitive motions involving intense hamstring lengthening and contraction during sport. Although a popular intervention for muscular injury, there exists limited evidence of the effects of therapeutic cupping on hamstring flexibility. To determine the effect of cupping therapy on hamstring flexibility in collegiate soccer players. Cohort design. Athletic training clinic. Twenty-five, asymptomatic, NCAA Division III soccer players (10 males, 15 females) (age = 19.4 ± 1.30 years, height = 175.1 ± 8.2 cm, mass = 69.5 ± 6.6 kg). A 7-minute therapeutic cupping treatment was delivered to the treatment group. Four 2-inch cups were fixed atop trigger point locations within the hamstring muscle bellies of participants' dominant legs. Control group participants received no intervention between pre- and post-test measurements. Pretest and posttest measurements of hamstring flexibility, using a Passive Straight Leg Raise (PSLR), were performed on both groups. PSLR measurements were conducted by blinded examiners using a digital inclinometer. An independent samples t-test was used to analyze changes in hamstring flexibility from pre- to post-treatment with p-values set a priori at 0.05. An independent samples t-test demonstrated no significant difference in change in hamstring flexibility between participants in the treatment group and those in the control group (t 23 = -.961, p = .35). The findings of this study demonstrated no statistically significant changes in hamstring flexibility following a cupping treatment.
Rusciano, Aiace; Corradini, Giuliano; Stoianov, Ivilin
Performance and injury prevention in elite soccer players are typically investigated from physical-tactical, biomechanical, and metabolic perspectives. However, executive functions, visuospatial abilities, and psychophysiological adaptability or resilience are also fundamental for efficiency and well-being in sports. Based on previous research associating autonomic flexibility with prefrontal cortical control, we designed a novel integrated autonomic biofeedback training method called Neuroplus to improve resilience, visual attention, and injury prevention. Herein, we introduce the method and provide an evaluation of 20 elite soccer players from the Italian Soccer High Division (Serie-A): 10 players trained with Neuroplus and 10 trained with a control treatment. The assessments included psychophysiological stress profiles, a visual search task, and indexes of injury prevention, which were measured pre- and posttreatment. The analysis showed a significant enhancement of physiological adaptability, recovery following stress, visual selective attention, and injury prevention that were specific to the Neuroplus group. Enhancing the interplay between autonomic and cognitive functions through biofeedback may become a key principle for obtaining excellence and well-being in sports. To our knowledge, this is the first evidence that shows improvement in visual selective attention following intense autonomic biofeedback. © 2017 Society for Psychophysiological Research.
Armenis, Elias; Pefanis, Nikolaos; Tsiganos, Georgios; Karagounis, Panagiotis; Baltopoulos, Panagiotis
Sports activities cause increased loads in elite athletes' joints. Current scientific knowledge highlights the importance of applied mechanical loads on the physiology and pathophysiology of the articular cartilage. Thus, it is possible that sporting activity has a role in the development of osteoarthritis (OA), a painful and damaging joint disease. The aim of the present study was to investigate and record osteoarthritic alterations in the ankle and foot complex in former Greek soccer players and also compare them with those in the general population. The study sample consisted of 170 male, former elite soccer players, aged between 42 and 55 years (mean = 49.8 years, standard deviation [SD] = 7.4). A control group of 132 men, aged between 42 and 55 years (mean, 50.7 years, SD = 9.9), with no regular athletic activity were examined. The development of osteoarthritic alterations was recorded through a questionnaire and clinical and radiological examination. Radiographic analysis of the images in former athletes group showed not only more signs of cartilage degeneration in comparison with the control group (P .05). Osteophyte formation is a frequent disease among former soccer players--with variations on radiographic images--but it does not appear in their clinical picture. However, it is likely that both spurs and subchondral sclerosis (main findings) are preclinical manifestations of OA. Prognostic, Level II.
Musculus, Lisa; Lobinger, Babett H.
Psychological characteristics, including personality traits and psychological skills, have been shown to be relevant predictors of soccer performance. In research, general and sport specific standardized self-report questionnaires have been applied in psychological diagnostics of sports talent. However, with regard to the assessment of psychological characteristics of talented soccer players, a gap between research and practice is apparent. While soccer clubs often ask their coaches to assess their players on self-designed, unevaluated scouting sheets, research widely neglects expert coaches’ and clubs’ perspectives on relevant performance characteristics. As we believe that expert coaches’ assessments could be a valid predictor of a player’s current performance and future success, we provide recommendations on how to improve coaches’ assessment of psychological characteristics. As the quality of the assessment of psychological characteristics is crucial, we provide recommendations on how to ensure the central diagnostic standards: objectivity, reliability, and validity in talent assessment. Further, we argue that assessing psychological characteristics should combine self ratings of players and external ratings of coaches in talent development. Sport psychologists should assist clubs and coaches in improving the diagnostics of psychological characteristics as well as in embedding psychological diagnostics and interventions in the talent development process. PMID:29459839
Full Text Available Psychological characteristics, including personality traits and psychological skills, have been shown to be relevant predictors of soccer performance. In research, general and sport specific standardized self-report questionnaires have been applied in psychological diagnostics of sports talent. However, with regard to the assessment of psychological characteristics of talented soccer players, a gap between research and practice is apparent. While soccer clubs often ask their coaches to assess their players on self-designed, unevaluated scouting sheets, research widely neglects expert coaches’ and clubs’ perspectives on relevant performance characteristics. As we believe that expert coaches’ assessments could be a valid predictor of a player’s current performance and future success, we provide recommendations on how to improve coaches’ assessment of psychological characteristics. As the quality of the assessment of psychological characteristics is crucial, we provide recommendations on how to ensure the central diagnostic standards: objectivity, reliability, and validity in talent assessment. Further, we argue that assessing psychological characteristics should combine self ratings of players and external ratings of coaches in talent development. Sport psychologists should assist clubs and coaches in improving the diagnostics of psychological characteristics as well as in embedding psychological diagnostics and interventions in the talent development process.
Thorborg, Kristian; Branci, Sonia; Nielsen, Peter Martin
BACKGROUND: Adductor-related pain is the most common clinical finding in soccer players with groin pain and can be a long-standing problem affecting physical function and performance. Hip adductor weakness has been suggested to be associated with this clinical entity, although it has never been...... investigated. PURPOSE: To investigate whether isometric and eccentric hip strength are decreased in soccer players with adductor-related groin pain compared with asymptomatic soccer controls. The hypothesis was that players with adductor-related groin pain would have lower isometric and eccentric hip adduction...... strength than players without adductor-related groin pain. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Male elite and subelite players from 40 teams were contacted. In total, 28 soccer players with adductor-related groin pain and 16 soccer players without adductor-related groin pain...
Full Text Available Complex training (CXT is the result of a combination of strength and plyometric exercises in the same session. This method has recently been used in the preparation of athletes of different sports. The aim of the present study was to observe the acute effects of a CXT program of 6 weeks: i on agility with the ball, sprinting and the efficiency of crossing and shooting in youth soccer players; ii and the influence of the number of CXT sessions per week (one vs. two. Sixteen youth male soccer players were randomly divided into three groups: a group that performed one weekly CXT session (GCT1, n = 5, age: 13.80 ± 0.45 years; or a group that performed two weekly CXT sessions (GCT2, n = 5, age: 14.20 ± 0.45 years; or a control group that did not perform the CTX (n = 6, age: 14.20 ± 0.84 years. All groups maintained their regular soccer training sessions. No significant interactions were found between GCT1 and GCT2 in all variables. Significant statistical differences were identified (F = 1139, p = 0.02, μp2 = 0531 in the pre-test versus post-test, for both experimental groups, in shot effectiveness. In conclusion, the CXT program proved to be an effective method in boosting abilities and motor skills associated with soccer among young athletes, particularly in increasing shot effectiveness.
Valente-dos-Santos, Joao; Coelho-e-Silva, Manuel J.; Simoes, Filipe; Figueiredo, Antonio J.; Leite, Neiva; Elferink-Gemser, Marije T.; Malina, Robert M.; Sherar, Lauren
This study evaluates the contributions of age. growth, skeletal maturation, playing position and training to longitudinal changes in functional and skill performance in male youth soccer. Players were annually followed over 5 years (n = 83, 4.4 measurements per player). Composite scores for
Delaney, J. Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Troutman, Tracy; Aljufaili, Mahmood; Correa, José A.
Abstract Context: Managing an airway in an unconscious athlete is a lifesaving skill that may be made more difficult by the recent changes in protective equipment. Different airway maneuvers and techniques may be required to help ventilate an unconscious athlete who is wearing full protective equipment. Objective: To assess the effectiveness of different airway maneuvers with football, ice hockey, and soccer players wearing full protective equipment. Design: Crossover study. Setting: University sports medicine clinic. Patients or Other Participants: A total of 146 university varsity athletes, consisting of 62 football, 45 ice hockey, and 39 soccer players. Intervention(s): Athletes were assessed for different airway and physical characteristics. Three investigators then evaluated the effectiveness of different bag-valve-mask (BVM) ventilation techniques in supine athletes who were wearing protective equipment while inline cervical spine immobilization was maintained. Main Outcome Measure(s): The effectiveness of 1-person BVM ventilation (1-BVM), 2-person BVM ventilation (2-BVM), and inline immobilization and ventilation (IIV) was judged by each investigator for each athlete using a 4-point rating scale. Results: All forms of ventilation were least difficult in soccer players and most difficult in football players. When compared with 1-BVM, both 2-BVM and IIV were deemed more effective by all investigators for all athletes. Interference from the helmet and stabilizer were common reasons for difficult ventilation in football and ice hockey players. Conclusions: Sports medicine professionals should practice and be comfortable with different ventilation techniques for athletes wearing full equipment. The use of a new ventilation technique, termed inline immobilization and ventilation, may be beneficial, especially when the number of responders is limited. PMID:21391796
Full Text Available To present time, scientific knowledge about symptoms of common mental disorders and adverse health behaviours among professional soccer players is lacking. Consequently, the aim of the study was to determine the prevalence of symptoms of common mental disorders (distress, anxiety/depression, sleep disturbance and adverse health behaviours (adverse alcohol behaviour, smoking, adverse nutrition behaviour among professional soccer players, and to explore their associations with potential stressors (severe injury, surgery, life events and career dissatisfaction. Cross-sectional analyses were conducted on baseline questionnaires from an ongoing prospective cohort study among male professional players. Using validated questionnaires to assess symptoms of common mental disorders and adverse health behaviours as well as stressors, an electronic questionnaire was set up and distributed by players’ unions in 11 countries from three continents. Prevalence of symptoms of common mental disorders and adverse health behaviours among professional soccer players ranged from 4% for smoking and 9% for adverse alcohol behaviour to 38% for anxiety/depression and 58% for adverse nutrition behaviour. Significant associations were found for a higher number of severe injuries with distress, anxiety/depression, sleeping disturbance and adverse alcohol behaviour, an increased number of life events with distress, sleeping disturbance, adverse alcohol behaviour and smoking, as well as an elevated level of career dissatisfaction with distress, anxiety/depression and adverse nutrition behaviour. Statistically significant correlations (p<0.01 were found for severe injuries and career dissatisfaction with most symptoms of common mental disorders. High prevalence of symptoms of common mental disorders and adverse health behaviours was found among professional players, confirming a previous pilot-study in a similar study population.
Marcos Britto Correa
Full Text Available OBJECTIVES: The aims of this study were to verify the occurrence of dental injuries in professional Brazilian soccer players, the level of knowledge of the teams' medical departments about mouthguards, and the conducts adopted in cases of dental trauma during the match. MATERIAL AND METHODS: Closed questionnaires were sent to the physicians in charge of the medical departments of the 40 teams enrolled in the first and second divisions of the Brazilian professional soccer league in 2007. The data obtained were subjected to descriptive analysis to determine absolute and relative frequencies of answers for each one of the questions. RESULTS: Physicians from 38 (95% of the 40 teams in the first and second divisions answered the questionnaires and 71.1% reported the occurrence of some type of dental injury during soccer practice, dental fractures (74.1% and avulsions (59.3% being the most prevalent ones. Regarding emergency conducts, approximately 50% answered that a successful replantation could be obtained in periods from 6 to 24 h after injury, and 27.8% were not able to answer this question. Regarding mouthguard use, 48.6% of the physicians did not know about mouthguards, and only 21.6% usually recommended their use by the soccer players. Among the physicians who do not recommend the use of mouthguards, 50% justified that it was not necessary. Almost 50% of the medical departments do not have a dentist as part of the health professional staff. CONCLUSIONS: It was possible to conclude that dental injuries are common during professional soccer practice and that there is a lack of information in the medical departments related to the emergency conducts and prevention of dental trauma.
Full Text Available Real Madrid was named as the best club of the 20th century by the International Federation of Football History and Statistics. The aim of this study was to compare if players from Real Madrid covered shorter distances than players from the opposing team. One hundred and forty-nine matches including league, cup and UEFA Champions League matches played by the Real Madrid were monitored during the 2001-2002 to the 2006-2007 seasons. Data from both teams (Real Madrid and the opponent were recorded. Altogether, 2082 physical performance profiles were examined, 1052 from the Real Madrid and 1031 from the opposing team (Central Defenders (CD = 536, External Defenders (ED = 491, Central Midfielders (CM = 544, External Midfielders (EM = 233, and Forwards (F = 278. Match performance data were collected using a computerized multiple-camera tracking system (Amisco Pro®, Nice, France. A repeated measures analysis of variance (ANOVA was performed for distances covered at different intensities (sprinting (>24.0 km/h and high-speed running (21.1-24.0 km/h and the number of sprints (21.1-24.0 km/h and >24.0 km/h during games for each player sectioned under their positional roles. Players from Real Madrid covered shorter distances in high-speed running and sprint than players from the opposing team (p 0.01 from Real Madrid covered shorter distances in high-intensity running and sprint and performed less sprints than their counterparts. Finally, no differences were found in the high-intensity running and sprint distances performed by players from Real Madrid depending on the quality of the opposition.
Full Text Available Patrizia Proia,1 Antonino Bianco,1 Gabriella Schiera,2 Patrizia Saladino,2 Valentina Contrò,1 Giovanni Caramazza,3 Marcello Traina,1 Keith A Grimaldi,4 Antonio Palma,1 Antonio Paoli5 1Sport and Exercise Sciences Research Unit, 2Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Palermo, Italy; 3Regional Sports School of CONI Sicilia, Sicily, Italy; 4Biomedical Engineering Laboratory, Institute of Communication and Computer Systems, National Technical University of Athens, Athens, Greece; 5Department of Biomedical Sciences, University of Padova, Padua, Italy Background: The PPARα gene encodes the peroxisome proliferator-activator receptor alpha, a central regulator of expression of other genes involved in fatty acid metabolism. The purpose of this study was to determine the prevalence of G allele of the PPARα intron 7 G/C polymorphism (rs4253778 in professional Italian soccer players. Methods: Sixty professional soccer players and 30 sedentary volunteers were enrolled in the study. Samples of venous blood were obtained at rest, in the morning, by conventional clinical procedures; blood serum was collected and total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured. An aliquot of anticoagulant-treated blood was used to prepare genomic DNA from whole blood. The G/C polymorphic site in PPARα intron 7 was scanned by using the PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism protocol with TaqI enzyme. Results: We found variations in genotype distribution of PPARα polymorphism between professional soccer players and sedentary volunteers. Particularly, G alleles and the GG genotype were significantly more frequent in soccer players compared with healthy controls (64% versus 48%. No significant correlations were found between lipid profile and genotype background. Conclusion: Previous results
Full Text Available This study investigated athletic performance and homocysteine (Hcy levels in relation to the methylenetetrahydrofolate reductase (MTHFR C677T mutation and explored the relationship between this mutation and other cardiac risk factors in soccer players and sedentary individuals. The study groups consisted of randomly selected soccer players (n=48 from the Turkish Super and Major League and sedentary male students (n=48 aged 18-27. Anthropometric variables, aerobic and anaerobic thresholds were measured, furthermore, biochemical assays were performed. The level of HDL cholesterol, LDL cholesterol, triglyceride, Hcy, folate, vitamin B12, hemogram and MTHFR C677T was investigated. The results showed that there was a statistical difference between the two groups in terms of body mass, body fat, the BMI, the aerobic threshold heart rate (ATHR, aerobic threshold velocity (ATVL and anaerobic threshold velocity (ANTVL. The soccer players were found to have lower levels of triglyceride, total cholesterol and LDL cholesterol, and higher levels of folate than the sedentary participants. The analysis of the alleles of the MTHFR C677T polymorphism showed that the participants that carried TT genotypes had a lower level of vitamin B12 and folate, and a higher level of Hcy than the participants carrying CC and CT genotypes. In conclusion, the baseline homocysteine and cardiovascular fitness levels of healthy young males with the TT genotypes of the MTHFR C677T genotype were found to strongly correlate with their levels of Hcy.
Luciano Meireles de Pontes
Full Text Available The objective of this study was to evaluate the nutritional status and prevalence of metabolic syndrome in amateur soccer players. Thirty-two men (39.0 ± 6.4 years regularly playing soccer were studied. Nutritional status was evaluated according to body mass index (BMI and the World Health Organization classification. Metabolic syndrome was defined according to the criterion of the International Diabetes Federation which, in addition to central obesity (waist circumference > 90 cm, considers two or more of the following conditions in males: triglyceridemia ≥ 150 mg/dl; HDL < 40 mg/dl; systolic pressure ≥ 130 mmHg or diastolic pressure ≥ 85 mm/Hg, and fasting glycemia ≥ 100 mg/dl. Statistical analysis processed descriptive data of percentage, mean, minimum, maximum, and standard deviation. Correlations between pairs of variables were determined by Pearson’s r coefficient. The results showed that 43.8% of the soccer players were eutrophic, 43.8% presented overweight and 12.5% were obese. The prevalence of metabolic syndrome was 37.5% and the most prevalent components were abdominal obesity in 59.4%, hypertension in 40.6%, hypertriglyceridemia in 34.4%, HDL-c in 28.1%, and fasting glycemia in 15.6%. BMI presented a more robust correlation with waist circumference (r = 0.918. In conclusion, the nutritional status of the soccer players studied was characterized by the presence of overweight and obesity. Although the frequency of metabolic syndrome was lower than in other epidemiological studies, these sportsmen should engage in other health-promoting behaviors such as good eating habits and control of stress in addition to physical activity.
Shadle, Ian B; Cacolice, Paul A
Clinical Scenario: Hamstring strains are a common sport-related injury, which may limit athletic performance for an extended period of time. These injuries are common in the soccer setting. As such, it is important to determine an appropriate prevention program to minimize the risk of such an injury for these athletes. Eccentric hamstring training may be an effective and practical hamstring strain prevention strategy. What is the effect of eccentric exercises on hamstring strain prevention in adult male soccer players? Summary of Key Findings: Current literature was searched for studies of level 2 evidence or higher that investigated the effect of eccentric exercises in preventing hamstring strains in adult male soccer players. Three articles returned from the literature search met the inclusion criteria. A fourth article looked at differences in strength gains between eccentric and concentric hamstring strengthening exercises, but did not record hamstring strain incidence. A fifth article, a systematic review, met all the criteria except for the correct population. Of the 3 studies, 2 were randomized control trails and 1 was a cohort study. Clinical Bottom Line: There is robust supportive evidence that eccentric hamstring exercises can prevent a hamstring injury to an elite adult male soccer player. Therefore, it is recommended that athletic trainers and other sports medicine providers evaluate current practices relating to reducing hamstring strains and consider implementing eccentric exercise based prevention programs. Strength of Recommendation: All evidence was attained from articles with a level of evidence 2b or higher, based on the Center for Evidence-Based Medicine (CEBM) criteria, stating that eccentric exercises can decrease hamstring strains.
Práxedes, Alba; Moreno, Alberto; García-González, Luis; Pizarro, David; Del Villar, Fernando
The Relative Age Effect (RAE) in sport has been targeted by many research studies. The objective of this study was to analyze, in amateur clubs, the RAE of soccer players, according to the sport expertise level of the team (e.g., A, B, C and subsequent) that they belong to within the same game category. 1,098 soccer players in formative stages took part in the study, with ages varying between 6 and 18 years old (U8 to U19 categories). All of them were members of 4 Spanish federated clubs. The birth dates were classified into 4 quartiles (Q1 = Jan-Mar; Q2 = Apr-Jun; Q3 = Jul-Sept; Q4 = Oct-Dec)according to the team they belonged to. The results obtained in the chi-squared test and d value (effect size) revealed the existence of RAE in the teams with the highest expertise level, "A" (X2 = 15.342, p = .002, d = 0.4473) and "B" (X2 = 10.905, p = .012, d = 0.3657). However, in the lower level teams, "C and subsequent", this effect was not observed. Present findings show that players born during the first months of the year tend to be selected to play in teams with a higher sport expertise level of each category, due to their physical maturity. Consequently, this causes differences in terms of the experience they accumulate and the motivation that this creates in these players.
Scott, Brendan R; Lockie, Robert G; Knight, Timothy J; Clark, Andrew C; Janse de Jonge, Xanne A K
To compare various measures of training load (TL) derived from physiological (heart rate [HR]), perceptual (rating of perceived exertion [RPE]), and physical (global positioning system [GPS] and accelerometer) data during in-season field-based training for professional soccer. Fifteen professional male soccer players (age 24.9 ± 5.4 y, body mass 77.6 ± 7.5 kg, height 181.1 ± 6.9 cm) were assessed in-season across 97 individual training sessions. Measures of external TL (total distance [TD], the volume of low-speed activity [LSA; 14.4 km/h], very high-speed running [VHSR; >19.8 km/h], and player load), HR and session-RPE (sRPE) scores were recorded. Internal TL scores (HR-based and sRPE-based) were calculated, and their relationships with measures of external TL were quantified using Pearson product-moment correlations. Physical measures of TD, LSA volume, and player load provided large, significant (r = .71-.84; P physical-performance measures of TD, LSA volume, and player load appear to be more acceptable indicators of external TL, due to the greater magnitude of their correlations with measures of internal TL.
Fothergill, Melissa; Wolfson, Sandy; Neave, Nick
The present studies examined the influence of playing venue on psychobiological responses in male soccer players. Many studies have demonstrated the existence of a home advantage, wherein teams perform better at home than away. A recent focus has attempted to explain this advantage from a psychobiological perspective, with studies showing hormonal differences with regard to venue, game outcome, dominance and perceived stress. Two studies investigated testosterone and cortisol responses in relation to home and away venues. In an initial study of 18 male elite Premier League academy soccer players (age, 17.47, SD, 64), salivary cortisol levels were monitored in two competitive matches, both at home and away. Higher post-game cortisol levels were observed at home (p=0.002), with the team winning all its games. In a second study involving a 12 semi-professional group of players (age, 23.17, SD, 3.8), the same post-game cortisol findings at home were replicated (p=0.001), with this team losing all its games. No effects were observed for testosterone in either study. The results extend earlier research findings on the complex relationship which surrounds the psychobiological impact on the home advantage. The findings suggest that higher levels of stress are experienced by home players in their home matches. Copyright © 2017 Elsevier Inc. All rights reserved.
Hardesty, Kelly; Hegedus, Eric J.; Ford, Kevin R.; Nguyen, Anh‐Dung
Background ACL injury prevention programs are less successful in female basketball players than in soccer players. Previous authors have identified anthropometric and biomechanical differences between the athletes and different sport‐specific demands, including a higher frequency of frontal plane activities in basketball. Current injury risk screening and preventive training practices do not place a strong emphasis on frontal plane activities. The medial and lateral triple hop for distance tests may be beneficial for use in the basketball population. Hypothesis/Purpose To 1) establish normative values for the medial and lateral triple hop tests in healthy female collegiate athletes, and 2) analyze differences in test scores between female basketball and soccer players. It was hypothesized that due to the frequent frontal plane demands of their sport, basketball players would exhibit greater performance during these frontal plane performance tests. Study Design Cross‐sectional. Methods Thirty‐two NCAA Division‐1 female athletes (20 soccer, 12 basketball) performed three trials each of a medial and lateral triple hop for distance test. Distances were normalized to height and mass in order to account for anthropometric differences. Repeated measures ANOVAs were performed to identify statistically significant main effects of sport (basketball vs. soccer), and side (right vs. left), and sport x side interactions. Results After accounting for anthropometric differences, soccer players exhibited significantly better performance than basketball players in the medial and lateral triple hop tests (p jumped farther on their left (400.3 ± 41.5 cm) than right (387.9 ± 43.4 cm) limbs, but no side differences were identified in the lateral triple hop. No significant side x sport interactions were identified. Conclusions Women's basketball players exhibit decreased performance of frontal plane hop tests when compared to women's soccer players. Additionally
Beato, Marco; Bianchi, Mattia; Coratella, Giuseppe; Merlini, Michele; Drust, Barry
Beato, M, Bianchi, M, Coratella, G, Merlini, M, and Drust, B. Effects of plyometric and directional training on speed and jump performance in elite youth soccer players. J Strength Cond Res 32(2): 289-296, 2018-Soccer players perform approximately 1,350 activities (every 4-6 seconds), such as accelerations/decelerations and changes of direction (CODs) during matches. It is well established that COD and plyometric training have a positive impact on fitness parameters in football players. This study analyzed the effect of a complex COD and plyometric protocol (CODJ-G) compared with an isolated COD protocol (COD-G) training on elite football players. A randomized pre-post parallel group trial was used in this study. Twenty-one youth players were enrolled in this study (mean ± SD; age 17 ± 0.8 years, mass 70.1 ± 6.4 kg, and height 177.4 ± 6.2 cm). Players were randomized into 2 different groups: CODJ-G (n = 11) and COD-G (n = 10), training frequency of 2 times a week more than 6 weeks. Sprint 10, 30, and 40 m, long jump, triple hop jump, and 505 COD test were considered. Exercise-induced within-group changes in performance for both CODJ-G and COD-G: long jump (effect size [ES] = 0.32 and ES = 0.26, respectively) and sprint 10 m (ES = -0.51 and ES = -0.22, respectively), after 6 weeks of training. Moreover, CODJ-G reported substantially better results (between-group changes) in long jump test (ES = 0.32). In conclusion, this study showed that short-term protocols (CODJ-G and COD-G) are important and able to give meaningful improvements on power and speed parameters in a specific soccer population. CODJ-G showed a larger effect in sprint and jump parameters compared with COD-G after the training protocol. This study offers important implications for designing COD and jumps training in elite soccer.
Pantelis T Nikolaidis
Full Text Available Background: Although maximal heart rate (HR max is widely used to assess exercise intensity in sport training, and particularly in soccer, there are limited data with regards to the use of age-based prediction equations of HR max in soccer players. The aim of this study was to compare the measured-HR max with two prediction equations (Fox-HR max = 220 – age and Tanaka-HR max = 208 – 0.7 × age in soccer players. Methods: Adolescent (n = 162, 15.8 ± 1.5 years and adult players (n = 158, 23.4 ± 4.6 years, all members of competitive clubs, voluntarily performed a graded exercise field test (Conconi protocol to assess HR max . Results: The measured-HR max (197.6 ± 9.4 bpm in total, 200.2 ± 7.9 bpm in adolescent players, and 195.0 ± 10.0 bpm in adult players was explained by the formula HR max = 212.3 – 0.75 × age (r = −0.41, standard error of the estimate = 8.6. In the total sample, Fox-HR max overestimated measured-HR max [mean difference (95% confidence intervals = 2.8 bpm (1.6; 3.9], while Tanaka-HR max underestimated HR max [–3.3 bpm (–4.5; –2.2]. In adolescents, Fox-HR max overestimated measured-HR max [4.0 bpm (2.5; 5.5] and Tanaka-HR max underestimated HR max [– 3.2 bpm (–4.7; –1.8]. In adults, Tanaka-HR max underestimated HR max [–5.0 bpm (–5.3; –4.7], while there was not any difference between Fox-HR max and measured-HR max [1.6 bpm (–3.4; 0.2]. Conclusions: The results of this study failed to validate two widely used prediction equations in a large sample of soccer players, indicating the need for a sport-specific equation. On the other hand, the new equation that we presented should be investigated further by future studies before being adopted by coaches and fitness trainers.
Ramírez-Campillo, Rodrigo; Vergara-Pedreros, Marcelo; Henríquez-Olguín, Carlos; Martínez-Salazar, Cristian; Alvarez, Cristian; Nakamura, Fábio Yuzo; De La Fuente, Carlos I; Caniuqueo, Alexis; Alonso-Martinez, Alicia M; Izquierdo, Mikel
In a randomised controlled trial design, effects of 6 weeks of plyometric training on maximal-intensity exercise and endurance performance were compared in male and female soccer players. Young (age 21.1 ± 2.7 years) players with similar training load and competitive background were assigned to training (women, n = 19; men, n = 21) and control (women, n = 19; men, n = 21) groups. Players were evaluated for lower- and upper-body maximal-intensity exercise, 30 m sprint, change of direction speed and endurance performance before and after 6 weeks of training. After intervention, the control groups did not change, whereas both training groups improved jumps (effect size (ES) = 0.35-1.76), throwing (ES = 0.62-0.78), sprint (ES = 0.86-1.44), change of direction speed (ES = 0.46-0.85) and endurance performance (ES = 0.42-0.62). There were no differences in performance improvements between the plyometric training groups. Both plyometric groups improved more in all performance tests than the controls. The results suggest that adaptations to plyometric training do not differ between men and women.
Belhaj, K; Meftah, S; Mahir, L; Lmidmani, F; Elfatimi, A
This study aims to compare the isokinetic profile of hip abductor and adductor muscle groups between soccer players suffering from chronic adductor-related groin pain (ARGP), soccer players without ARGP and healthy volunteers from general population. Study included 36 male professional soccer players, who were randomly selected and followed-up over two years. Of the 21 soccer players eligible to participate in the study, 9 players went on to develop chronic ARGP and 12 players did not. Ten healthy male volunteers were randomly selected from the general population as a control group. Comparison between the abductor and adductor muscle peak torques for players with and without chronic ARGP found a statistically significant difference on the dominant and non-dominant sides (p muscle significantly stronger than the adductor muscle. In the group of healthy volunteers, the adductor muscle groups were significantly stronger than the abductor muscle groups on both dominant and non-dominant sides (p muscle strength was also significantly decreased on the affected side. This imbalance appears to be a risk factor for adductor-related groin injury. Therefore, restoring the correct relationship between these two agonist and antagonist hip muscles may be an important preventative measure that should be a primary concern of training and rehabilitation programmes.
The purpose of this study was to analyze the leadership power perception of amateur and professional soccer coaches and players according to their belief in good luck or not. Data collected from 165 male soccer coaches and 870 male soccer players including professionals and amateurs. The coaches had a mean age of 40.24 years (SD = 8.40) and had been coaching for an average of 8.56 years (SD = 6.75). The players had a mean age of 18.40 years (SD = 4.00) and had been playing soccer for an average of 6.00 years (SD = 4.15) with license. Adapted Turkish version of Power in Soccer Questionnaire-Other (PSQ-O for soccer players), Power in Soccer Questionnaire-Self (PSQ-S for coaches) and an information form were used for the data collection. Cronbach Reliability Alphas of PSQ-O and PSQ-S range between 0.60 and 0.84. Players' and coaches' data were analyzed by Kruskal-Wallis and Mann Whitney Tests. Analysis of PSQ-O revealed significant differences related to Coersive Power-CP [chi2 (3) = 8.46, p Referent Power-RP [chi2 (3) = 14.84, p 0.05). Results of PSQ-O and PSQ-S indicated complex relationships related to belief in good luck or not. Overall, there are differences between coaches' and players'perception of CP, LP and EP related to belief in good luck or not. The only similarity appears to be in perception of RP. However, there is lack of research to make more certain conclusions. Future researchers should also take into consideration gender, sport experience, age, taking responsibility, self-confidence, attributions, expectations, superstitions, emotions, perception of achievement etc.
Rosas, F; Ramirez-Campillo, R; Diaz, D; Abad-Colil, F; Martinez-Salazar, C; Caniuqueo, A; Cañas-Jamet, R; Loturco, I; Nakamura, F Y; McKenzie, C; Gonzalez-Rivera, J; Sanchez-Sanchez, J; Izquierdo, M
The aim of this study was to compare the effects of a jump training program, with or without haltere type handheld loading, on maximal intensity exercise performance. Youth soccer players (12.1±2.2 y) were assigned to either a jump training group (JG, n=21), a jump training group plus haltere type handheld loading (LJG, n=21), or a control group following only soccer training (CG, n=21). Athletes were evaluated for maximal-intensity performance measures before and after 6 weeks of training, during an in-season training period. The CG achieved a significant change in maximal kicking velocity only (ES=0.11-0.20). Both jump training groups improved in right leg (ES=0.28-0.45) and left leg horizontal countermovement jump with arms (ES=0.32-0.47), horizontal countermovement jump with arms (ES=0.28-0.37), vertical countermovement jump with arms (ES=0.26), 20-cm drop jump reactive strength index (ES=0.20-0.37), and maximal kicking velocity (ES=0.27-0.34). Nevertheless, compared to the CG, only the LJG exhibited greater improvements in all performance tests. Therefore, haltere type handheld loading further enhances performance adaptations during jump training in youth soccer players. © Georg Thieme Verlag KG Stuttgart · New York.
Schuermans, Joke; Van Tiggelen, Damien; Palmans, Tanneke; Danneels, Lieven; Witvrouw, Erik
Although the vast majority of hamstring injuries in male soccer are sustained during high speed running, the association between sprinting kinematics and hamstring injury vulnerability has never been investigated prospectively in a cohort at risk. This study aimed to objectify the importance of lower limb and trunk kinematics during full sprint in hamstring injury susceptibility. Cohort study; level of evidence, 2. At the end of the 2013 soccer season, three-dimensional kinematic data of the lower limb and trunk were collected during sprinting in a cohort consisting of 30 soccer players with a recent history of hamstring injury and 30 matched controls. Subsequently, a 1.5 season follow up was conducted for (re)injury registry. Ultimately, joint and segment motion patterns were submitted to retro- and prospective statistical curve analyses for injury risk prediction. Statistical analysis revealed that index injury occurrence was associated with higher levels of anterior pelvic tilting and thoracic side bending throughout the airborne (swing) phases of sprinting, whereas no kinematic differences during running were found when comparing players with a recent hamstring injury history with their matched controls. Deficient core stability, enabling excessive pelvis and trunk motion during swing, probably increases the primary injury risk. Although sprinting encompasses a relative risk of hamstring muscle failure in every athlete, running coordination demonstrated to be essential in hamstring injury prevention. Copyright © 2017 Elsevier B.V. All rights reserved.
Iglesias-Gutiérrez, Eduardo; García-Rovés, Pablo M; Rodríguez, Carmen; Braga, Socorro; García-Zapico, Pedro; Patterson, Angeles M
The aim of this study was to assess the food habits and nutritional status of high level adolescent soccer players (N = 33; ages 14-16 yrs) living in their home environment. Body composition (height, mass, skinfolds), biochemical and hematological parameters, performance in soccer-specific tests (sprinting, jumping, intermittent endurance), and dietary intake (weighed food intake method) and related behaviors (nutrient supplement use, daily activity profile) were assessed. Daily energy expenditure and energy intake were 12.5 MJ and 12.6 MJ, respectively. Protein (16% of energy intake; 1.9 g/kg of body mass), lipid (38%), and cholesterol (385 mg) intake were above recommendations, while carbohydrates (45%) were below. The food intake of these adolescents was based on cereals and derivates; meat, fish, and eggs; milk and dairy products; biscuits and confectionery; and oil, butter and margarine, which provided 78% of total energy intake, 85% of proteins, 64% of carbohydrates, 90% of lipids, and 47% of fiber. Although diet provided sufficient iron, 48% of individuals showed iron deficiency without anemia. Based on these results, a well designed nutrition intervention would be advisable for optimizing performance, and especially for promoting healthy eating habits in adolescent soccer players.
Full Text Available Kicking and cutting skills in soccer are clearly unilateral, require asymmetrical motor patterns and lead to the development of asymmetrical adaptations in the musculoskeletal function of the lower limbs. Assuming that these adaptations constitute a chronicity-dependent process, this study examined the effects of professional training age (PTA on the composite strength profile of the knee and ankle joint in soccer players. One hundred soccer players (n=100 with short (5-7 years, intermediate (8-10 years and long (>11 years PTA were tested bilaterally for isokinetic concentric and eccentric strength of the knee and ankle muscles. Knee flexion-extension was tested concentrically at 60°, 180° and 300 °/sec and eccentrically at 60° and 180 °/sec. Ankle dorsal and plantar flexions were tested at 60 °/sec for both the concentric and eccentric mode of action. Bilaterally averaged muscle strength [(R+L/2] increased significantly from short training age to intermediate and stabilized afterwards. These strength adaptations were mainly observed at the concentric function of knee extensors at 60°/sec (p = 0. 023, knee flexors at 60°/sec (p = 0.042 and 180°/sec (p = 0.036, and ankle plantar flexors at 60o/sec (p = 0.044. A linear trend of increase in isokinetic strength with PTA level was observed for the eccentric strength of knee flexors at 60°/sec (p = 0.02 and 180°/sec (p = 0.03. Directional (R/L asymmetries decreased with PTA, with this being mainly expressed in the concentric function of knee flexors at 180°/sec (p = 0.04 and at 300 °/sec (p = 0.03. These findings confirm the hypothesis of asymmetry in the strength adaptations that take place at the knee and ankle joint of soccer players mainly along with short and intermediate PTA. Players with a longer PTA seem to adopt a more balanced use of their lower extremities to cope with previously developed musculoskeletal asymmetries and possibly reduce injury risk. This has certain
Full Text Available The aim of this study was to investigate the influence of the number of goal-posts and the positioning of goal-posts used within small-sided games on the frequency of technical actions and offensive scenarios performed by prepubescent players within soccer. The participants were eight male prepubescent soccer players (12.1 ± 0.5 years. The participants were video recorded for 20 min playing four different formats of 4v4 small-sided games: (1 standard two goal game; (2 four goal game, one goal in each corner; (3 two goal game with goal-posts positioned 9.14 m/10 yd infield, scoring only through the back of the goal; (4 four goal-game, one goal positioned 9.14 m/10 yd infield in each corner, scoring through either the front or back of each goal. Chi-squared tests of independence were utilized to statistically explore the impact of the different small-sided game formats. There were significant associations (p < 0.05 observed between the different small-sided game formats and the frequency of turns, dribbles, shots, goals and overlaps performed. For example, players performed more turns in small-sided game format two and more shots during small-sided game format four. It is suggested coaches should consider using a variation of the number and positioning of goal-posts in small-sided games as an effective training tool in the development of prepubescent soccer players. This will enable coaches to vary the focus of sessions, and develop specific technical and tactical actions within a situation similar to that of real match-play.
Full Text Available This cross-sectional study compared somatic, endurance performance determinants and heart rate variability (HRV profiles of professional soccer players divided into different age groups: GI (17–19.9 years; n = 23, GII (20–24.9 years; n = 45, GIII (25–29.9 years; n = 30, and GIV (30–39 years; n = 26. Players underwent somatic and HRV assessment and maximal exercise testing. HRV was analyzed by spectral analysis of HRV, and high (HF and low (LF frequency power was transformed by a natural logarithm (Ln. Players in GIV (83 ± 7 kg were heavier (p 25 years showed negligible differences in Pmax unlike the age group differences demonstrated in VO2max. A shift towards relative sympathetic dominance, particularly due to reduced vagal activity, was apparent after approximately 8 years of competing at the professional level.
Identifying talented young soccer players: conditional, anthropometrical and physiological characteristics as predictors of performance. [Identificación de jóvenes talentos en fútbol: características condicionales, antropométricas y fisiológicas como predictores del rendimiento].
Full Text Available he aim of this study was to provide a complete profile of elite young soccer players. Fifty-five players of the Under-14 category of Athletic Club Bilbao participated in this study. Players were classified into 4 playing positions: forwards (n=30, midfielders (n=15, defenders (n=37 and goalkeepers (n=15. Complete anthropometry, chronological age (CA, age at peak height velocity, 15-m sprint test, agility test, Yo-Yo IT level 1 (Yo-Yo IR1, counter-movement jump and hand dynamometry were measured. Results were transformed into z-scores and summed up to make two performance composites (SCORE and SCOREHG. One-way analysis of variance and a Bonferroni post-hoc test were used to examine the differences between playing positions. Multiple linear regression analysis was performed to estimate the contribution of independent variables to performance indicators. The level of significance was set at P<0.05. Significant differences were observed between playing positions in body mass and height (P<0.05; CA, maturity offset and muscle % (P<0.01; sum of skinfolds, fat %, endomorphy, sprint and agility tests (P<0.001. Stepwise regression analysis revealed that CA and sum of skinfolds were the most important predictors of performance. Collectively, playing positions were characterised by specific anthropometrical characteristics whereas no significant positional differences were observed in performance. This study provides further insight concerning coaches’ practice of selecting young soccer players because of anthropometrical characteristics rather than for performance advantages. Resumen El objetivo de este estudio fue analizar el perfil antropométrico y fisiológico de los futbolistas jóvenes del Athletic Club Bilbao. Cincuenta y cinco jugadores de la categoría Sub-14 participaron en el estudio. Los jugadores se clasificaron en 4 posiciones de juego: delanteros (n=30, centrocampistas (n=15, defensas (n=37 y porteros (n=15. Se realizaron las siguientes
Full Text Available Aim: The purpose of this study was to compare of body mass index (BMI, balance and agility features of soccer players at different positions and to investigate the relation between these features. Material and Methods: Research was carried out on 44 amateur soccer player whom played in different positions in various teams that compete in amateur league of İstanbul. In the research, it was tested vki, balance, agility with ball and agility without ball on soccer players. The average of variables was taken and Kruskal Wallis nonparametric variance analysis was used to determine the difference between groups. Pearson correlation was used to determine correlations between variables. Results: As a result of measuments, when compare between positions, it was found that there was a statistical difference on body mass measurement (p0,01. As a result of correlations, it was found statistically significant relation between body mass and agility with ball between BMI and agility with ball and between body mass and BMI variables (p<0,01. Conclusion: As a result of assesstments it has been revealed that there was a correlation between BMI and dribbling skills on soccer players however there wasn’t found any differences between other parameters as balance and agility because of the trainings that carried out regardless of the positions in soccer. As a conclusion, optimal training programmes that will be held on according to positions of players, additional balance trainings and the identified shortcomings may contribute to the development of soccer players performance and skill with appliying ideal diet programme to maintain the appropriate body weight for players heights.
Scharhag, J; Meyer, T; Görge, G; Kindermann, W
A 32-year-old competitive soccer player presented with palpitations he had felt for 4 weeks during maximal activity (soccer training and match). The physical examination and an exercise electrocardiogram were carried out by his general practitioner up to 19 s at 350 W and a heart rate of 147/min without showing any abnormalities. All blood parameters revealed no signs of illness. During treadmill exercise at a heart rate of 181/min, a non-sustained ventricular tachycardia was induced. Echocardiography showed a dilated left ventricle with an enddiastolic diameter of 70 mm and low fractional shortening (28 %). Cardiac catheterization demonstrated a diminished left ventricular ejection fraction (38 %) and an enlarged enddiastolic volume (199 ml) without signs of coronary artery disease. Electrophysiologic testing induced a non-sustained ventricular tachycardia. The echocardiographic and angiographic results indicated a dilated cardiomyopathy. Competitive sports activities were stopped and treatment with a beta-blocker (metoprolol) and an ACE-antagonist (ramipril) was started. In young male and female athletes, the possibility of severe cardiac abnormalities have to be considered even in the presence of good physical fitness and performance. To reach a high sensitivity for diagnostic ergometry, the work-load must reach the maximal capacity of the cardio-pulmonary system. Differences in the exercise performance of athletes and untrained subjects have to be considered.
Matheus Machado Gomes
Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n4p392 The aim of this study was to compare jump height and kinetic and kinematic com-ponents of countermovement vertical jumps between soccer and basketball players performed in two different arm swing conditions: with arm swing (WAS and without arm swing (NAS. Nine basketball players (21.2 ± 2.9 years; 101.64 ± 14.58 kg; 1.95 ± 0.06 m and nine soccer players (18.2 ± 0.7 years; 77.4 ± 7.58 kg; 1.81 ± 0.07 m performed 12 maximal countermo-vement vertical jumps, including 6 WAS jumps and 6 NAS jumps, on a force platform that recorded the ground reaction force (GRF. The vertical component of the GRF was used to estimate jump height and to calculate the kinematic (duration of eccentric phase, duration of concentric phase, and maximal downward displacement of center of mass and kinetic variables (mean power during the eccentric phase, mean power during the concentric, peak power, and peak force. The results showed no differences in jump height or in kinematic or kinetic variables between basketball and soccer players. In addition, the results showed that the participants of the two groups jumped higher in the WAS condition (0.41 m than in the NAS condition (0.36 m because of a higher peak power (WAS=276.8 W/kg0.67 and NAS=241.3 W/kg0.67 and a longer concentric phase duration (WAS=0.20 s/m0.5 and NAS=0.19 s/m0.5 during WAS jump. These results indicate that the basketball and soccer players studied here showed similar performance and the same kinematic and kinetic pattern in maximal vertical jumps and were comparably affected by the use of arm swing.
Gordon, Reno Eron; Kassier, Susanna Maria; Biggs, Chara
Poor hydration compromises performance and heightens the risk of heat stress which adolescents are particularly susceptible to as they produce comparatively larger amount of metabolic heat during exercise. This study determined the hydration status and fluid intake of socio-economically disadvantaged, male adolescent soccer players during training. A pilot study was conducted among 79 soccer players (mean age 15.9 ± 0.8 years; mean BMI 20.2 ± 2.1 kg/m(2)). Hydration status was determined before and after two training sessions, using both urine specific gravity and percent loss of body weight. The type and amount of fluid consumed was assessed during training. A self-administered questionnaire was used to determine the players' knowledge regarding fluid and carbohydrate requirements for soccer training. Players were at risk of developing heat illness during six of the 14 training sessions (60 - 90 minutes in length). Although on average players were slightly dehydrated (1.023 ± 0.006 g/ml) before and after (1.024 ± 0.007 g/ml) training, some were extremely dehydrated before (24%) and after (27%) training. Conversely some were extremely hyperhydrated before (3%) and after training (6%). The mean percent loss of body weight was 0.7 ± 0.7%. The majority did not consume fluid during the first (57.0%) and second (70.9%) training sessions. An average of 216.0 ± 140.0 ml of fluid was consumed during both training sessions. The majority (41.8%) consumed water, while a few (5.1%) consumed pure fruit juice. More than 90% stated that water was the most appropriate fluid to consume before, during and after training. Very few (5.0%) correctly stated that carbohydrate should be consumed before, during and after training. Approximately a quarter were severely dehydrated. Many did not drink or drank insufficient amounts. The players' beliefs regarding the importance of fluid and carbohydrate consumption did not correspond with their practices. A
Falster, Casper; Stockmann Poulsen, Simon; Joergensen, Uffe
Localised pigmented villonodular synovitis (PVNS) of the knee is a rare diagnosis, with clinical signs and symptoms mimicking meniscal damage or other common knee injuries. We report the case of a 24-year-old female soccer player, seeking treatment after 7 months of persisting knee pain...... analyses confirmed the diagnosis of localised PVNS. The patient was subsequently free of symptoms with no signs of recurrence on MRI and had resumed soccer practice at the 1-year follow-up appointment....
PEDRO GUEDES DE CARVALHO
Full Text Available Problem statement: When a team achieves success, how much of it depends on the coach and/or of the playersprofiles. In this paper we identify the performance psychological profile of elite soccer players from Chelsea andBenfica, assessing their profiles to discover a Mourinho effect, while he is a nowadays special coach and coachedmost of these players.Approach: We applied an international and national validated questionnaire to the players and we complement theanalysis with a qualitative approach with data collected through specific interviews (29 professional players - 21from Chelsea and 8 from Benfica. Statistical procedures consider descriptive, comparative and correlationanalysis.Results: The overall sample values are: Motivation (27.55+2.097, Self-confidence (26.83+2.494, CompetitiveAttitude (26.03+2.758, Positive Thoughts (25.10+2.160, Attention (25.07+3.046, Visualization (23.55+3.429and Negative Thoughts (22.24+2.824. Concerning the comparative analysis between the players that were trainedby Mourinho and other, we could not identify significant statistical differences; however, some of the phenomenaindexes emerge showing that Mourinho players present higher levels in self confidence, attention, motivation andweaker effect of the negative thoughts.Conclusions and recommendations: As the success of the teams where Mourinho coached is an evidence, wesuspect that the main reasons for success should rely upon collective either than individual characteristics of theplayers. This will be the next step in our research on the coaching process.
Navandar, Archit; Veiga, Santiago; Torres, Gonzalo; Chorro, David; Navarro, Enrique
Although the kicking skill is influenced by limb dominance and sex, how a previous hamstring injury affects kicking has not been studied in detail. Thus, the objective of this study was to evaluate the effect of sex and limb dominance on kicking in limbs with and without a previous hamstring injury. 45 professional players (males: n=19, previously injured players=4, age=21.16 ± 2.00 years; females: n=19, previously injured players=10, age=22.15 ± 4.50 years) performed 5 kicks each with their preferred and non-preferred limb at a target 7m away, which were recorded with a three-dimensional motion capture system. Kinematic and kinetic variables were extracted for the backswing, leg cocking, leg acceleration and follow through phases. A shorter backswing (20.20 ± 3.49% vs 25.64 ± 4.57%), and differences in knee flexion angle (58 ± 10o vs 72 ± 14o) and hip flexion velocity (8 ± 0rad/s vs 10 ± 2rad/s) were observed in previously injured, non-preferred limb kicks for females. A lower peak hip linear velocity (3.50 ± 0.84m/s vs 4.10 ± 0.45m/s) was observed in previously injured, preferred limb kicks of females. These differences occurred in the backswing and leg-cocking phases where the hamstring muscles were the most active. A variation in the functioning of the hamstring muscles and that of the gluteus maximus and iliopsoas in the case of a previous injury could account for the differences observed in the kicking pattern. Therefore, the effects of a previous hamstring injury must be considered while designing rehabilitation programs to re-educate kicking movement.
Barker, Leland A; Harry, John R; Dufek, Janet S; Mercer, John A
Barker, LA, Harry, JR, Dufek, JS, and Mercer, JA. Aerial rotation effects on vertical jump performance among highly skilled collegiate soccer players. J Strength Cond Res 31(4): 932-938, 2017-In soccer matches, jumps involving rotations occur when attempting to head the ball for a shot or pass from set pieces, such as corner kicks, goal kicks, and lob passes. However, the 3-dimensional ground reaction forces used to perform rotational jumping tasks are currently unknown. Therefore, the purpose of this study was to compare bilateral, 3-dimensional, and ground reaction forces of a standard countermovement jump (CMJ0) with those of a countermovement jump with a 180° rotation (CMJ180) among Division-1 soccer players. Twenty-four participants from the soccer team of the University of Nevada performed 3 trials of CMJ0 and CMJ180. Dependent variables included jump height, downward and upward phase times, vertical (Fz) peak force and net impulse relative to mass, and medial-lateral and anterior-posterior force couple values. Statistical significance was set a priori at α = 0.05. CMJ180 reduced jump height, increased the anterior-posterior force couple in the downward and upward phases, and increased upward peak Fz (p ≤ 0.05). All other variables were not significantly different between groups (p > 0.05). However, we did recognize that downward peak Fz trended lower in the CMJ0 condition (p = 0.059), and upward net impulse trended higher in the CMJ0 condition (p = 0.071). It was concluded that jump height was reduced during the rotational jumping task, and rotation occurred primarily via AP ground reaction forces through the entire countermovement jump. Coaches and athletes may consider additional rotational jumping in their training programs to mediate performance decrements during rotational jump tasks.
Mohib, Milad; Moser, Nicholas; Kim, Richard; Thillai, Maathavan; Gringmuth, Robert
Introduction: With over 200 million amateur players worldwide, soccer is one of the most popular and internationally recognized sports today. By understanding how and why soccer injuries occur we hope to reduce prevalent injuries amongst elite soccer athletes. Methods: Via a prospective cohort, we examined both male and female soccer players eligible to train with the Ontario Soccer Association provincial program between the ages of 13 to 17 during the period of October 10, 2008 and April 20, 2012. Data collection occurred during all player exposures to potential injury. Exposures occurred at the Soccer Centre, Ontario Training grounds and various other venues on multiple playing surfaces. Results: A total number of 733 injuries were recorded. Muscle strain, pull or tightness was responsible for 45.6% of all injuries and ranked as the most prevalent injury. Discussion: As anticipated, the highest injury reported was muscular strain, which warrants more suitable preventive programs aimed at strengthening and properly warming up the players’ muscles. PMID:25550661
Michael R. McGuigan
Full Text Available The purpose of this study was to monitor the stress-induced alteration in concentrations of salivary immunoglobulin (S-IgA and cortisol and the incidence of upper respiratory tract infections (URTI over the course of a 9-week competitive season in college student-athletes and college students. The subjects consisted of 14 NCAA Division III collegiate female soccer athletes (19.8 ¡À 1.0 years, mean ¡À SD and 14 female college students (22.5 ¡À 2.6 years. Salivary samples were collected for 9 weeks during a competitive soccer season. S-IgA and cortisol concentrations were determined by enzyme linked immunosorbent assay (ELISA. A training and performance questionnaire was given to the subjects every week, to record the subjects' session rating of perceived exertion (RPE for all the training, load, monotony and strain, as well as any injuries or illnesses experienced. The between groups ANOVA procedure for repeated measures showed no changes in salivary concentrations of IgA and cortisol. Chi-square analysis showed that during the 9-week training season injury and illness occurred at a higher rate among the soccer players. There was a significant difference at baseline between soccer and control S-IgA levels (p¡Ü0.05. Decreased levels of S-IgA and increases in the indices of training (load, strain and monotony were associated with an increase in the incidence of illness during the 9-week competitive soccer season.
Ardern, Clare L; Pizzari, Tania; Wollin, Martin R; Webster, Kate E
The aim of this study was to describe the isokinetic thigh muscle strength profile of professional male football players in Australia. Concentric (60° and 240°·s(-1)) and eccentric (30° and 120°·s(-1)) hamstrings and quadriceps isokinetic strength was measured with a HUMAC NORM dynamometer. The primary variables were bilateral concentric and eccentric hamstring and quadriceps peak torque ratios, concentric hamstring-quadriceps peak torque ratios, and mixed ratios (eccentric hamstring 30°·s(-1) ÷ concentric quadriceps 240°·s(-1)). Hamstring strength imbalance was defined as deficits in any 2 of: bilateral concentric hamstring peak torque ratio imbalance. Athletes with strength imbalance had significantly reduced concentric and eccentric bilateral hamstring peak torque ratios at all angular velocities tested; and reduced eccentric quadriceps peak torque (30°·s(-1)) in their stance leg, compared with those without strength imbalance. Approximately, 1 in 4 players had preseason hamstring strength imbalance; and all strength deficits were observed in the stance leg. Concentric and eccentric hamstrings strength imbalance may impact in-season football performance and could have implications for the future risk of injury.
Casamichana, David; Castellano, Julen; Castagna, Carlo
This study compared the physical demands of friendly matches (FMs) and small-sided games (SGs) in semiprofessional soccer players by means of global positioning system technology. Twenty-seven semiprofessional soccer players were monitored during 7 FMs and 9 sessions involving different SGs. Their physical profile was described on the basis of 20 variables related to distances and frequencies at different running speeds, the number of accelerations, and through global indicators of workload such as the work:rest ratio, player workload, and the exertion index. Results showed significant differences (p FM); the distribution of the distance covered in the speed zones 7.0-12.9 km·h(-1) (SG > FM) and >21 km·h(-1) (FM > SG); the distribution of time spent in certain speed zones (FM > SG: 0.0-6.9 and >21 km·h(-1); FM > SG: 7.0-12.9 km·h(-1)). More sprints per hour of play were performed during FMs, with greater mean durations and distances, greater maximum durations and distances, and a greater frequency per hour of play for sprints of 10-40 and >40 m (p < 0.01). The frequency of repeated high-intensity efforts was higher during FM (p < 0.01). The results show that coaches and strength and conditioning professionals should consider FMs during their training routine to foster specific adaptations in the domain of high-intensity effort.
Full Text Available There is no clear evidence that vitamin D effectively improves physical capacity in high-level athletes. The aim of this study was to confirm that vitamin D supplementation of soccer players during eight-week high-intensity training would have a significant effect on their aerobic capacity. The subjects were divided into two groups: the experimental one that was supplemented with vitamin D (SG, n = 20, and the placebo group (PG, n = 16, not supplemented with vitamin D. All the players were subjected to the same soccer training described as High-Intensity Interval Training (HIIT. The data of the vitamin D level, PWC170, lactate threshold (LT were collected just before and after the intervention. A significant increase in vitamin D concentration (119% was observed in the supplemented group, while the non-supplemented group showed a decrease of 8.4%. The studied subjects improved VO2max results by 20% in the SG, and by 13% in the PG. The improvement in velocity at the LT was similar in both groups. Results of this study show that vitamin D can have a positive, though moderate, effect on aerobic performance in players subjected to high-intensity training in the form of small-sided games for 8 weeks.
José F. Guzmán
Full Text Available Omega-3 fatty acids (n-3 has shown to improve neuromotor function. This study examined the effects of docosahexaenoic acid (DHA on complex reaction time, precision and efficiency, in female elite soccer players. 24 players from two Spanish female soccer Super League teams were randomly selected and assigned to two experimental groups, then administered, in a double-blind manner, 3.5 g·day-1 of either DHA-rich fish oil (FO =12 or olive oil (OO = 12 over 4 weeks of training. Two measurements (pre- and post-treatment of complex reaction time and precision were taken. Participants had to press different buttons and pedals with left and right hands and feet, or stop responding, according to visual and auditory stimuli. Multivariate analysis of variance displayed an interaction between supplement administration (pre/post and experimental group (FO/OO on complex reaction time (FO pre = 0.713 ± 0.142 ms, FO post = 0.623 ± 0.109 ms, OO pre = 0.682 ± 1.132 ms, OO post = 0.715 ± 0.159 ms; p = 0.004 and efficiency (FO pre = 40.88 ± 17.41, FO post = 57.12 ± 11.05, OO pre = 49.52 ± 14.63, OO post = 49. 50 ± 11.01; p = 0.003. It was concluded that after 4 weeks of supplementation with FO, there was a significant improvement in the neuromotor function of female elite soccer players
Full Text Available The purpose of this study was to investigate the acute effect of different stretching methods, during a warm-up, on the acceleration and speed of soccer players. The acceleration performance of 20 collegiate soccer players (body height: 177.25 ± 5.31 cm; body mass: 65.10 ± 5.62 kg; age: 16.85 ± 0.87 years; BMI: 20.70 ± 5.54; experience: 8.46 ± 1.49 years was evaluated after different warm-up procedures, using 10 and 20 m tests. Subjects performed five types of a warm-up: static, dynamic, combined static + dynamic, combined dynamic + static, and no-stretching. Subjects were divided into five groups. Each group performed five different warm-up protocols in five non-consecutive days. The warm-up protocol used for each group was randomly assigned. The protocols consisted of 4 min jogging, a 1 min stretching program (except for the no-stretching protocol, and 2 min rest periods, followed by the 10 and 20 m sprint test, on the same day. The current findings showed significant differences in the 10 and 20 m tests after dynamic stretching compared with static, combined, and no-stretching protocols. There were also significant differences between the combined stretching compared with static and no-stretching protocols. We concluded that soccer players performed better with respect to acceleration and speed, after dynamic and combined stretching, as they were able to produce more force for a faster execution.
Full Text Available Background: In order to optimize training in soccer, knowledge about the specific position fitness demands and characteristics is required. Objective: The aim of the study was to determine whether there are position specific differences in somatic, cardiorespiratory and autonomic cardiac profiles of professional senior Czech soccer players. Methods: All players (N = 120 were divided into six groups according to field positions: goalkeeper (GK; n = 11, external defenders (ED; n = 15, central defenders (CD; n = 18, external midfielders (EM; n = 18, central midfielders (CM; n = 24 and forwards (F; n = 34. Players underwent anthropometrical and heart rate variability (HRV assessment, and a maximal incremental running test in order to obtain maximal oxygen uptake (VO2max and heart rate. HRV variables were transformed using the natural logarithm (Ln. Results: GK and CD were significantly (p = .005 heavier than ED, EM, CM, and F; while F were significantly (p = .026 heavier than CM and EM. GK and CD were significantly (p = .008 taller than ED, EM, CM, F; and EM were significantly (p = .041 shorter than CM and F. The only significant (p = .043 difference in percentage of body fat was observed in CD compared with CM. A significantly (p = .021 lower VO2max was observed for GK compared with ED, CD, EM, CM, and F. Supine HRV was significantly (p = .039 lower for Ln LF/HF in GK compared with F. Standing HRV was significantly (p = .03 lower for Ln LF in CD compared with both ED and F, significantly (p = .028 higher for Ln LF/HF in ED compared with CD and EM. Conclusions: In soccer, specific positions are associated with different height, body mass and aerobic capacity. A lower VO2max and vagal activity in GK compared with other playing positions may not be considered as disadvantage for performance in this specific playing position.
Chaabene, Helmi; Negra, Yassine
To assess and compare the effects of 8 wk of in-season (2 sessions/wk) low- and high-volume plyometric training (PT) on measures of physical fitness in prepubertal male soccer players. A total of 25 soccer players were randomly assigned to a low-volume PT group (LPT; n = 13, age 12.68 ± 0.23 y, age at peak height velocity [APHV] 14.25 ± 0.29 y, maturity offset -1.57 ± 0.29 y) or a high-volume PT group (HPT; n = 12, age 12.72 ± 0.27 y, APHV 14.33 ± 0.77 y, maturity offset -1.61 ± 0.76 y). A linear-sprint test (5-m, 10-m, 20-m, and 30-m), change-of-direction (CoD) test, and vertical- (squat-jump [SJ]), countermovement- (CMJ), and horizontal-jump (standing long jump [SLJ]) test were carried out before and after 8 wk of PT. There was a significant main effect of time for sprint outcomes (5-m, P = .005, ES = 0.86; 10-m, P = .006, ES = 0.85; 20-m, P = .03, ES = 0.64, and 30-m, P = .05, ES = 0.57), CoD (P = .002, ES = 0.96), SJ (P = .008, ES = 0.81; CMJ, P = .01, ES = 0.73), and SLJ ability (P = .007, ES = 0.83). There were no significant training group × time interactions in any measured outcomes. After 8 wk of training, results showed similar performance improvement on measures of sprint time, CoD, and jumping ability between LPT and HPT groups. From a time-efficiency perspective, it is recommended to use LPT in prepubertal male soccer players to improve their proxies of athletic performance.
Juan Diego Hernández-Camacho
Full Text Available Introduction: The objective of this study was to analyze the effect of caffeine ingestion in soccer performance, particularly in the countermovement jump test (CMJ. Material and methods: A total of 17 players from a U-19 amateur Spanish team participated in this pilot study. A double-blind placebo-controlled randomized experimental design was used in 2 different sessions (1.5 hour per session separated by 1 week. CMJ was collected at the beginning and at the end of sessions; Rating of Perceived Exertion (RPE was recorded. Players ingested caffeine or placebo at the beginning of session (minute 0 of session, providing a total of 4 mg of caffeine or a placebo per kg of body mass. Side effects from caffeine and placebo ingestions were analyzed. The effect sizes (ES were calculated using values for Cohen’s and Quantitative differences were assessed qualitatively (QA. Results: The jump height with caffeine supplementation at the beginning of training was 37.03 (±3.87 cm and at the end was 39.35 (±4.05 cm, obtaining significant improvements (p<0.05; ES: 0.56; QA: 99/1/0. Significant differences on CMJ at the end of the training session between caffeine and placebo groups were observed (39.35 [±4.05] cm vs. 36.85 [±3.15] cm; p<0.05; ES: 0.65; QA: 0/1/99. Significant differences on RPE between groups were observed. A non-significant tendency to suffer more side effects with caffeine ingestion was obtained. Conclusions: This study shows how the ingestion of 4 mg of caffeine per kg of body mass could be an ergogenic aid to improve soccer performance. However, further studies with bigger soccer players sample would be necessary to refute the present results.
Full Text Available It has been shown that nitrate supplementation can enhance endurance exercise performance. Recent work suggests that nitrate ingestion can also increase intermittent type exercise performance in recreational athletes. We hypothesized that six days of nitrate supplementation can improve high-intensity intermittent type exercise performance in trained soccer players. Thirty-two male soccer players (age: 23 ± 1 years, height: 181 ± 1 m, weight: 77 ± 1 kg, playing experience: 15.2 ± 0.5 years, playing in the first team of a 2nd or 3rd Dutch amateur league club participated in this randomized, double-blind cross-over study. All subjects participated in two test days in which high-intensity intermittent running performance was assessed using the Yo-Yo IR1 test. Subjects ingested nitrate-rich (140 mL; ~800 mg nitrate/day; BR or a nitrate-depleted beetroot juice (PLA for six subsequent days, with at least eight days of wash-out between trials. The distance covered during the Yo-Yo IR1 was the primary outcome measure, while heart rate (HR was measured continuously throughout the test, and a single blood and saliva sample were collected just prior to the test. Six days of BR ingestion increased plasma and salivary nitrate and nitrite concentrations in comparison to PLA (p < 0.001, and enhanced Yo-Yo IR1 test performance by 3.4 ± 1.3% (from 1574 ± 47 to 1623 ± 48 m; p = 0.027. Mean HR was lower in the BR (172 ± 2 vs. PLA trial (175 ± 2; p = 0.014. Six days of BR ingestion effectively improves high-intensity intermittent type exercise performance in trained soccer players.
van Beijsterveldt, A M C; van der Horst, Nick; van de Port, Ingrid G L; Backx, Frank J G
The incidence of soccer (football) injuries is among the highest in sports. Despite this high rate, insufficient evidence is available on the efficacy of preventive training programmes on injury incidence. To systematically study the evidence on preventive exercise-based training programmes to reduce the incidence of injuries in soccer. The databases EMBASE/MEDLINE, PubMed, CINAHL, Cochrane Central Register of controlled trials, PEDro and SPORTDiscus™ were searched for relevant articles, from inception until 20 December 2011. The methodological quality of the included studies was assessed using the PEDro scale. The inclusion criteria for this review were (1) randomized controlled trials or controlled clinical trials; (2) primary outcome of the study is the number of soccer injuries and/or injury incidence; (3) intervention focusing on a preventive training programme, including a set of exercises aimed at improving strength, coordination, flexibility or agility; and (4) study sample of soccer players (no restrictions as to level of play, age or sex). The exclusion criteria were: (1) the article was not available as full text; (2) the article was not published in English, German or Dutch; and (3) the trial and/or training programme relates only to specific injuries and/or specific joints. To compare the effects of the different interventions, we calculated the incidence risk ratio (IRR) for each study. Six studies involving a total of 6,099 participants met the inclusion criteria. The results of the included studies were contradictory. Two of the six studies (one of high and one of moderate quality) reported a statistical significant reduction in terms of their primary outcome, i.e. injuries overall. Four of the six studies described an overall preventive effect (IRRbased programmes to prevent soccer injuries. Some reasons for the contradictory findings could be different study samples (in terms of sex and soccer type) in the included studies, differences between
Tounsi, Mohamed; Jaafar, Hamdi; Aloui, Asma; Souissi, Nizar
This study aimed to examine the combined effects of menstrual cycle phase and moment of day on female soccer players' performances in the five-jump test (5JT), the repeated shuttle-sprint ability test (RSSA), and the Yo-Yo intermittent recovery test level 1 (YYIRT1). Eleven eumenorrheic Tunisian high-level soccer players volunteered to participate. Each subject individually participated in three testing periods: one in the early follicular phase (menses), one in the late follicular phase, and another in the luteal phase. In each period, two test sessions were conducted: one at 07:30 and another at 17:30. The testing routines included the 5JT, the RSSA, and the YYIRT1. None of the measured variables were altered due to menstrual cycle phase (all P>0.05). Mean time during RSSA was significantly lower in the afternoon session compared to the morning session (8.48±0.27 s and 8.77±0.34 s, respectively, P<0.001), while 5JT performance was significantly higher in the afternoon compared to the morning (9.08±0.58 m and 8.60±0.56 m, respectively, P<0.001). Soccer-specific endurance as well as jumping and repeated sprinting ability of Tunisian female high-level soccer players are not affected due to menstrual cycle phase neither in the morning nor in the afternoon.
Lee, Sun-Min; Lee, Jung-Hoon
[Purpose] The purpose of this study was to report the effects of ankle inversion taping using kinesiology tape in a patient with a medial ankle sprain. [Subject] A 28-year-old amateur soccer player suffered a Grade 2 medial ankle sprain during a match. [Methods] Ankle inversion taping was applied to the sprained ankle every day for 2 months. [Results] His symptoms were reduced after ankle inversion taping application for 2 months. The self-reported function score, the reach distances in the S...
Ali Kerim Yilmaz; Menderes Kabadayi; Muhammet Hakan Mayda; Murşit Ceyhun Birinci; Mustafa Özdal
The purpose of this study is to examine the effects of isokinetic knee strength on promptness. 15 soccer players with an average age of 22,80±2,14 years and 15 controls with an average age of 21,60±1,40 years participated in the study. Body composition, isokinetic knee strength measurement at angular speeds of 60o, 180o, 240o and 10 m sprint test were conducted respectively in the study. General warm-up procedure was carried out on the groups before measurements. In statistical analyses, Shap...
Roberto Dantas de Queiroz
Full Text Available OBJECTIVE: to evaluate the return to sport after surgical treatment for pubalgia among 30 professional soccer players and describe the surgical technique used.METHOD: this case series was evaluated by means of a questionnaire and physical examination on 30 male professional soccer players of mean age 24.4 years (range: 18-30. The mean duration of the symptoms was 18.6 months (range: 13-28. The diagnosis was made through clinical investigation, special maneuvers and complementary examinations, by the same examiner. All the patients underwent surgical treatment after conservative treatment failed; all procedures were performed by the same surgeon using the same technique. Nonparametric comparisons were made to investigate the time taken to recover after the surgery, for the patients to return to their sport.RESULTS: five patients evolved with hematoma, with the need to remove the stitches three weeks after the operation because of a small dehiscence at the site of the operative wound. The wound healed completely in all these cases by five weeks after the surgery. Four patients presented dysuria in the first week, but improved in the second postoperative week. The mean time taken to return to training was around eight weeks (range: seven-nine. All the players returned to competitive soccer practice within 16 weeks. When asked about their degree of satisfaction after the operation (satisfied or dissatisfied, taking into consideration their return to the sport, there was 100% satisfaction, and they returned to professional practice at the same competitive level as before the injury. This degree of satisfaction continued to the last assessment, which was made after 36 months of postoperative follow-up.CONCLUSION: the surgical technique presented in this case series, with trapezoidal resection of the pubic symphysis in association with bilateral partial tenotomy of the long adductor, was a fast and effective procedure with a low rate of postoperative
Manore, Melinda M; Patton-Lopez, Megan M; Meng, Yu; Wong, Siew Sun
For adolescent athletes (14-18 years), data on sport nutrition knowledge, behaviors and beliefs are limited, especially based on sex, race/ethnicity and socioeconomic status. High school soccer players ( n = 535; 55% female; 51% White, 41% Latino; 41% National School Lunch Program (NSLP) participants (80% Latino)) completed two questionnaires (demographic/health history and sport nutrition). The sport nutrition knowledge score was 45.6% with higher scores in NSLP-Whites vs. NSLP-Latinos ( p nutritional requirements, but more than twice as likely to report that nutritional supplements were necessary for training ( p nutrition education that enhances food selection skills for health and sport performance.
Murtagh, Conall F; Stubbs, Michael; Vanrenterghem, Jos; O'Boyle, Andrew; Morgans, Ryland; Drust, Barry; Erskine, Robert M
To investigate potential differences in patellar tendon properties between elite and non-elite soccer players, and to establish whether tendon properties were related to power assessed during unilateral jumps performed in different directions. Elite (n = 16; age 18.1 ± 1.0 years) and non-elite (n = 13; age 22.3 ± 2.7 years) soccer players performed vertical, horizontal-forward and medial unilateral countermovement jumps (CMJs) on a force plate. Patellar tendon (PT) cross-sectional area, elongation, strain, stiffness, and Young's modulus (measured at the highest common force interval) were assessed with ultrasonography and isokinetic dynamometry. Elite demonstrated greater PT elongation (6.83 ± 1.87 vs. 4.92 ± 1.88 mm, P = 0.011) and strain (11.73 ± 3.25 vs. 8.38 ± 3.06%, P = 0.009) than non-elite soccer players. Projectile range and peak horizontal power during horizontal-forward CMJ correlated positively with tendon elongation (r = 0.657 and 0.693, P < 0.001) but inversely with Young's modulus (r = - 0.376 and - 0.402; P = 0.044 and 0.031). Peak medial power during medial CMJ correlated positively with tendon elongation (r = 0.658, P < 0.001) but inversely with tendon stiffness (r = - 0.368, P = 0.050). Not only does a more compliant patellar tendon appear to be an indicator of elite soccer playing status but it may also facilitate unilateral horizontal-forward and medial, but not vertical CMJ performance. These findings should be considered when prescribing talent selection and development protocols related to direction-specific power in elite soccer players.
Wong, Del P; Hjelde, Geir H; Cheng, Ching-Feng; Ngo, Jake K
The use of RSA/RCOD index indicates the repeated change-of-direction (RCOD) performance relative to the repeated-sprint ability (RSA) and provides a standardized approach to prioritize training needs for RSA and RCOD. To compare the RSA/RCOD index among different age groups, RSA and RCOD were measured from 20 under-16 players (U16), 20 under-19 players (U19), and 17 first-team professional players (PRO) from a football (soccer) club that has regular participation in the UEFA Champions League. Each player performed the RSA and RCOD tests, during which the fastest time (FT), average time (AT), total time (TT), and percentage decrement score (%Dec) were recorded. No significant differences were found in RSA/RCOD index-FT, AT, TT, and %Dec among the 3 groups (p > 0.05) and between U19 and PRO in all RSA and RCOD measures (p > 0.05). Most values of RSA/RCOD index were 0.51 among the U16, U19, and PRO groups. Moreover, we concluded that the RSA/RCOD index might not be further changed after 16 years of age unless specific training programs for RSA and RCOD are prescribed. Therefore, this study provides an empirical case, and coaches can establish the RSA/RCOD index value relevant to their training system and monitor players' training needs of RSA and RCOD in a longer term.
Marques, Nelson Kautzner, Jr.
Brazilian Soccer began developing its current emphasis on peripheral vision in the late 1950s, by initiative of coach of the Canto do Rio Football Club, in Niteroi, Rio de Janeiro, a pioneer in the development of peripheral vision training in soccer players. Peripheral vision training gained world relevance when a young talent from Canto do Rio,…
Jensen, Jesper; Bandholm, Thomas; Hölmich, Per
Hip adduction strength is important for kicking and acceleration in soccer players. Changes in hip adduction strength may therefore have an effect on soccer players' athletic performance. The purpose of this study was to investigate the acute and sub-acute effects of a kicking drill session on hip...... percentiles), at pre-kicking to 2.65 (2.55-2.81) Nm ∙ kg(-1) (P = 0.024) 24 h post-kicking. This may have implications for the soccer player's ability to maximally activate the hip adductors during kicking and acceleration, and thereby improve performance the day after a kicking drill session....... strength, concerning isometric hip adduction, abduction and flexion torque of the kicking leg and the supporting leg. Ten injury-free male elite soccer players, mean ± s age of 15.8 ± 0.4 years participated. All players underwent a specific 20 min kicking drill session, comprising 45 kicks. The players...
Deminice, R; Rosa, F T; Pfrimer, K; Ferrioli, E; Jordao, A A; Freitas, E
This study aimed to evaluate changes in total body water (TBW) in soccer athletes using a deuterium oxide dilution method and bioelectrical impedance (BIA) formulas after 7 days of creatine supplementation. In a double-blind controlled manner, 13 healthy (under-20) soccer players were divided randomly in 2 supplementation groups: Placebo (Pla, n=6) and creatine supplementation (CR, n=7). Before and after the supplementation period (0.3 g/kg/d during 7 days), TBW was determined by deuterium oxide dilution and BIA methods. 7 days of creatine supplementation lead to a large increase in TBW (2.3±1.0 L) determined by deuterium oxide dilution, and a small but significant increase in total body weight (1.0±0.4 kg) in Cr group compared to Pla. The Pla group did not experience any significant changes in TBW or body weight. Although 5 of 6 BIA equations were sensitive to determine TBW changes induced by creatine supplementation, the Kushner et al. 16 method presented the best concordance levels when compared to deuterium dilution method. In conclusion, 7-days of creatine supplementation increased TBW determined by deuterium oxide dilution or BIA formulas. BIA can be useful to determine TBW changes promoted by creatine supplementation in soccer athletes, with special concern for formula choice. © Georg Thieme Verlag KG Stuttgart · New York.
Enright, Kevin; Morton, James; Iga, John; Drust, Barry
This study compared the adaptive responses to two concurrent training programmes frequently used in professional soccer. Fifteen youth soccer players (17.3 ± 1.6 years, 1.82 ± 0.06 m, 77.0 ± 7.3 kg; VO2 peak, 62.0 ± 4.7 ml(-1) kg(-1) min(-1)) who compete in the English Premier League volunteered for this study. In addition to completing their habitual training practices, the participants were asked to alter the organisation concurrent training by performing strength (S) training either prior to (S + E, n = 8) or after (E + S, n = 7) soccer-specific endurance training (E) 2d wk(-1) for 5 wk(-1). With the exception of 30 m sprint, IMVC PF, quadriceps strength (60°/s(CON), 180°/s(CON), 120°/s(ECC)) pooled data revealed training effects across all other performances measures (P nutrition may be able to modulate small but clinically significant changes in physical performance parameters associated with match-play. This may have practical implications for practitioners who prescribe same day concurrent training protocols.
Full Text Available The Relative Age Effect (RAE in sport has been targeted by many research studies. The objective of this study was to analyze, in amateur clubs, the RAE of soccer players, according to the sport expertise level of the team (e.g., A, B, C and subsequent that they belong to within the same game category. 1,098 soccer players in formative stages took part in the study, with ages varying between 6 and 18 years old (U8 to U19 categories. All of them were members of 4 Spanish federated clubs. The birth dates were classified into 4 quartiles (Q1 = Jan-Mar; Q2 = Apr-Jun; Q3 = Jul-Sept; Q4 = Oct-Decaccording to the team they belonged to. The results obtained in the chi-squared test and d value (effect size revealed the existence of RAE in the teams with the highest expertise level, “A” (X2 = 15.342, p = .002, d = 0.4473 and “B” (X2 = 10.905, p = .012, d = 0.3657. However, in the lower level teams, “C and subsequent”, this effect was not observed. Present findings show that players born during the first months of the year tend to be selected to play in teams with a higher sport expertise level of each category, due to their physical maturity. Consequently, this causes differences in terms of the experience they accumulate and the motivation that this creates in these players.
Full Text Available The aim of the study was to investigate the seasonal variation in isokinetic strength of the knee flexors and extensors, and conventional (H/QCONV and functional (H/QFUNC hamstring to quadriceps strength ratios in highly trained adolescent soccer players. The players (n=11; age 17.8±0.3 were measured at the end of the competitive season (autumn, at the beginning and the end of pre-season (winter and during the sixth week of a new competitive season. Isokinetic peak torque (concentric and eccentric was measured at 60°•s-1 in a sitting position with the hip flexed at 100°. The testing range of motion was set from 10 - 90° of knee flexion. The players performed a set of five maximum repetitions for both the dominant and non-dominant leg. Statistically significant differences (p<0.001 between the four seasonal measurements were noted for peak torque of the dominant leg knee flexors in concentric muscle action only. A post hoc analysis revealed a statistically significant increase in peak torque from the 1st to the 4th measurement (p<0.001; d=0.692 and from the 2nd to the 4th (p<0.01; d=0.564. The differences in the changes of peak torque of the knee flexors and extensors depending on type of muscle action and tendencies found in the H/Q ratios throughout the annual training cycle indicate that strength assessment of the knee flexors and extensors and their balance throughout the annual training cycle could be beneficial for elite male adolescent soccer players both in terms of performance and risk of injury.
Full Text Available The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional speed endurance production (SEP or speed endurance maintenance (SEM training (two additional sessions/wk for 4 weeks during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2 and a repeated sprint test (RST pre- and post-intervention. Yo-Yo IR2 performance increased (p<0.001 by 50 ± 8% and 26 ± 5% in SEP and SEM, respectively, with greater (p=0.03 improvement in SEP. RST performance improved by 2.1 ± 0.3% and 1.3 ± 0.4% in SEP and SEM, respectively, while the RST fatigue index decreased (4.4 ± 0.8 to 3.4 ± 0.5%; p<0.04 in SEP only. Peak and average speed during training were higher (p<0.001 in SEP than in SEM (24.5 ± 0.3 vs 19.2 ± 0.3 and 15.5 ± 0.1 km·h-1 vs 9.4 ± 0.1 km·h-1. Additional in-season anaerobic speed endurance production and maintenance training improves high-intensity exercise performance in competitive soccer players with superior effects of speed endurance production training.
Ramírez-Campillo, Rodrigo; González-Jurado, José Antonio; Martínez, Cristian; Nakamura, Fábio Yuzo; Peñailillo, Luis; Meylan, Cesar M P; Caniuqueo, Alexis; Cañas-Jamet, Rodrigo; Moran, Jason; Alonso-Martínez, Alicia M; Izquierdo, Mikel
To investigate the effects of a six-week plyometric training and creatine supplementation intervention on maximal-intensity and endurance performance in female soccer players during in-season training. Randomized, double-blind, placebo-controlled trial. Young (age 22.9±2.5y) female players with similar training load and competitive background were assigned to a plyometric training group receiving placebo (PLACEBO, n=10), a plyometric training group receiving creatine supplementation (CREATINE, n=10) or a control group receiving placebo without following a plyometric program (CONTROL, n=10). Athletes were evaluated for jumping, maximal and repeated sprinting, endurance and change-of-direction speed performance before and after six weeks of training. After intervention the CONTROL group did not change, whereas both plyometric training groups improved jumps (ES=0.25-0.49), sprint (ES=0.35-0.41), repeated sprinting (ES=0.48-0.55), endurance (ES=0.32-0.34) and change-of-direction speed performance (ES=0.46-0.55). However, the CREATINE group improved more in the jumps and repeated sprinting performance tests than the CONTROL and the PLACEBO groups. Adaptations to plyometric training may be enhanced with creatine supplementation. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Lamas, Leonardo; Drezner, Rene; Otranto, Guilherme; Barrera, Junior
The aim of this study was to define a method for evaluating a player's decisions during a game based on the success probability of his actions and for analyzing the player strategy inferred from game actions. There were developed formal definitions of i) the stochastic process of player decisions in game situations and ii) the inference process of player strategy based on his game decisions. The method was applied to the context of soccer goalkeepers. A model of goalkeeper positioning, with geometric parameters and solutions to optimize his position based on the ball position and trajectory, was developed. The model was tested with a sample of 65 professional goalkeepers (28.8 ± 4.1 years old) playing for their national teams in 2010 and 2014 World Cups. The goalkeeper's decisions were compared to decisions from a large dataset of other goalkeepers, defining the probability of success in each game circumstance. There were assessed i) performance in a defined set of classes of game plays; ii) entropy of goalkeepers' decisions; and iii) the effect of goalkeepers' positioning updates on the outcome (save or goal). Goalkeepers' decisions were similar to the ones with the lowest probability of goal on the dataset. Goalkeepers' entropy varied between 24% and 71% of the maximum possible entropy. Positioning dynamics in the instants that preceded the shot indicated that, in goals and saves, goalkeepers optimized their position before the shot in 21.87% and 83.33% of the situations, respectively. These results validate a method to discriminate successful performance. In conclusion, this method enables a more precise assessment of a player's decision-making ability by consulting a representative dataset of equivalent actions to define the probability of his success. Therefore, it supports the evaluation of the player's decision separately from his technical skill execution, which overcomes the scientific challenge of discriminating the evaluation of a player's decision
Andrews, Michael C; Itsiopoulos, Catherine
Athletes require sufficient nutrition knowledge and skills to enable appropriate selection and consumption of food and fluids to meet their health, body composition, and performance needs. This article reports the nutrition knowledge and dietary habits of male football (soccer) players in Australia. Players age 18 years and older were recruited from 1 A-League club (professional) and 4 National Premier League clubs (semiprofessional). No significant difference in general nutrition knowledge (GNK; 54.1% ± 13.4%; 56.8% ± 11.7%; M ± SD), t(71) = -0.91, p = .37, or sports nutrition knowledge (SNK; 56.9% ± 15.5%; 61.3% ± 15.9%), t(71) = -1.16, p = .25) were noted between professional (n = 29) and semiprofessional (n = 44) players. In general, players lacked knowledge in regard to food sources and types of fat. Although nutrition knowledge varied widely among players (24.6-82.8% correct responses), those who had recently studied nutrition answered significantly more items correctly than those who reported no recent formal nutrition education (62.6% ± 11.9%; 54.0% ± 11.4%), t(67) = 2.88, p = .005). Analysis of 3-day estimated food diaries revealed both professionals (n = 10) and semiprofessionals (n = 31) consumed on average less carbohydrate (3.5 ± 0.8 gC/kg; 3.9 ± 1.8 gC/kg) per day than football-specific recommendations (FIFA Medical and Assessment Research Centre [F-MARC]: 5-10 gC/kg). There was a moderate, positive correlation between SNK and carbohydrate intake (n = 41, ρ = 0.32, p = .04), indicating that players who exhibited greater SNK had higher carbohydrate intakes. On the basis of these findings, male football players in Australia would benefit from nutrition education targeting carbohydrate and fat in an attempt to improve nutrition knowledge and dietary practices.
Russell, Mark; Birch, Jack; Love, Thomas; Cook, Christian; Bracken, Richard M.; Taylor, Tom; Swift, Eamon; Cockburn, Emma; Finn, Charlie; Cunningham, Daniel; Wilson, Laura; Kilduff, Liam P.
In professional youth soccer players, the physiological, performance and perceptual effects of a single whole body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counter-balanced and crossover design, 14 habituated English Premier League academy soccer players performed 15 x 30 m sprints (each followed by a 10 m forced deceleration) on two occasions. Within 20 min of exercise cessation, players entered a WBC chamber (Cryo: 30 s a...
Full Text Available PURPOSE: The aim of this study was to examine the reliability, validity and usefulness of the 30-15IFT in competitive female soccer players. METHODS: Seventeen elite female soccer players participated in the study. A within subject test-retest study design was utilized to assess the reliability of the 30-15 intermittent fitness test (IFT. Seven days prior to 30-15IFT, subjects performed a continuous aerobic running test (CT under laboratory conditions to assess the criterion validity of the 30-15IFT. End running velocity (VCT and VIFT, peak heart rate (HRpeak and maximal oxygen consumption (VO2max were collected and/or estimated for both tests. RESULTS: VIFT (ICC = 0.91; CV = 1.8%, HRpeak (ICC = 0.94; CV = 1.2%, and VO2max (ICC = 0.94; CV = 1.6% obtained from the 30-15IFT were all deemed highly reliable (p>0.05. Pearson product moment correlations between the CT and 30-15IFT for VO2max, HRpeak and end running velocity were large (r = 0.67, p=0.013, very large (r = 0.77, p=0.02 and large (r = 0.57, p=0.042, respectively. CONCLUSION: Current findings suggest that the 30 -15IFT is a valid and reliable intermittent aerobic fitness test of elite female soccer players. The findings have also provided practitioners with evidence to support the accurate detection of meaningful individual changes in VIFT of 0.5 km/h (1 stage and HRpeak of 2 bpm. This information may assist coaches in monitoring ‘real’ aerobic fitness changes to better inform training of female intermittent team sport athletes. Lastly, coaches could use the 30-15IFT as a practical alternative to laboratory based assessments to assess and monitor intermittent aerobic fitness changes in their athletes. Keywords: 30-15 intermittent fitness test, aerobic, cardiorespiratory fitness, intermittent activity, soccer, high intensity interval training.
Rebelo, A; Brito, J; Maia, J
Anthropometric characteristics, physical fitness and technical skills of under-19 (U19) soccer players were compared by competitive level (elite, n=95; non-elite, n=85) and playing position (goalkeeper, central defender, fullback, midfield, forward). Fitness tests included 5- and 30-m sprints......, agility, squat jump (SJ) and countermovement jump (CMJ), strength and Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2). Soccer-specific skills included ball control and dribbling. Independent of position, elite players presented more hours of training per year than non-elite players (d>1.2). Stature...... and body mass discriminated elite from non-elite players among goalkeepers and central defenders (d>0.6). Major differences were noted between elite and non-elite goalkeepers for SJ, CMJ, Yo-Yo IE2, and ball control (d>1.2). Elite central defenders performed better than their non-elite counterparts in SJ...
van den Tillaar, Roland
The aim of this study was to compare kinematics in repeated 30m sprints in female soccer players. Seventeen subjects performed seven 30m sprints every 30s in one session. Kinematics were measured with an infrared contact mat and laser gun, and running times with an electronic timing device. The main findings were that sprint times increased in the repeated sprint ability test. The main changes in kinematics during the repeated sprint ability test were increased contact time and decreased step frequency, while no change in step length was observed. The step velocity increased in almost each step until the 14, which occurred around 22m. After this, the velocity was stable until the last step, when it decreased. This increase in step velocity was mainly caused by the increased step length and decreased contact times. It was concluded that the fatigue induced in repeated 30m sprints in female soccer players resulted in decreased step frequency and increased contact time. Employing this approach in combination with a laser gun and infrared mat for 30m makes it very easy to analyse running kinematics in repeated sprints in training. This extra information gives the athlete, coach and sports scientist the opportunity to give more detailed feedback and help to target these changes in kinematics better to enhance repeated sprint performance.
Luiz Fernando Novack
Full Text Available This study analyzed classical and developed novel mathematical models to predict body fat percentage (%BF in professional soccer players from the South Brazilian region using skinfold thicknesses measurement. Skinfolds of thirty one male professional soccer players (age of 21.48 ± 3.38 years, body mass of 79.05 ± 9.48 kg and height of 181.97 ± 8.11 cm were introduced into eight mathematical models from the literature for the prediction of %BF; these results were then compared to Dual-energy X-ray Absorptiometry (DXA. The classical equations were able to account from 65% to 79% of the variation of %BF in DXA. Statistical differences between most of the classical equations (seven of the eight classic equations and DXA were found, rendering their widespread use in this population useless. We developed three new equations for prediction of %BF with skinfolds from: axils, abdomen, thighs and calves. Theses equations accounted for 86.5% of the variation in %BF obtained with DXA.
Hendry, David T; Crocker, Peter R E; Hodges, Nicola J
Based upon predictions derived from the Developmental Model of Sports Participation, we tested whether hours in domain-specific play (self-led activities) and practice (coach-led activities) during childhood (~5-12 year) in an elite group of youth soccer players from the UK (N = 144) were related to motivation. Independent analysis of three different age groups (Under 13, 15 and 17 year) did not show relations between play and practice activities during childhood and global measures of motivation. However, secondary analysis showed that when controlling for years in soccer, years in the UK Academy system were negatively related to global indices of self-determined motivation (SDI) and positively related to controlled motivation for the oldest players. Despite predictions, there was no evidence that play during childhood was positively related to more SDI. Prospective research is recommended to enable more robust conclusions about the role of early developmental practice activities, especially early specialisation in a high-performance system, on both skill and psychosocial development.
Daniel dos SANTOS
Full Text Available ABSTRACT Objective: To assess the dietary intake and overall diet quality of female soccer players before the competitive games. Methods: This descriptive and cross-sectional study included 21 women aged 20.8±4.5 years from a professional soccer team. Their nutritional status and dietary adequacy during the training period, before competition season, were assessed. Dietary intake was assessed by three 24-hour recalls, one food frequency questionnaire, and the Healthy Eating Index, an overall diet quality index based on food group intake. Results: The athletes have shown proper nutritional status, but a diet deficient in energy due largely to low carbohydrate intake. On the other hand, the intakes of protein, fatty acids, and sodium were above the recommended intakes, even for athletes. Diet quality assessment by the Healthy Eating Index - 2010 resulted in a mean score of 54.6 points of a maximum of 100, indicating a need of improving the overall diet quality. Conclusion: The study found that the dietary patterns of female football players were both quantitatively and qualitatively inappropriate. A nutritional intervention is indicated to improve diet quality, with the inclusion of various foods, such as whole grains, fruits, vegetables, dairy products, and better protein quality, along with a reduction in saturated fats, sodium, and added sugar.
Luiz Carlos Moraes
Full Text Available Este estudo investigou o papel dos pais no desenvolvimento de atletas jovens de futebol. Foram voluntários nesse projeto 20 pais e 12 filhos jogadores, entre as idades de 15 e 18 anos, participantes da temporada 2000 do Campeonato Mineiro. Utilizou-se uma abordagem quantitativa e qualitativa, através de formulários, questionários e entrevistas semi-estruturadas de aprofundamento. Constatou-se que os pais tinham pouco envolvimento nos treinamentos e competições dos atletas, não alteraram a rotina familiar em função dos treinamentos dos mesmos. O relativo apoio dos pais não prejudicou o progresso dos filhos devido os pais permitirem os mesmos praticarem o futebol livremente. Outro aspecto importante foi o progresso dos filhos devido à paixão, à intensidade e freqüência de prática, além do apelo financeiro que o futebol profissional evoca no Brasil. Esses resultados indicam a necessidade de precauções quando se considerar paradigmas de primeiro mundo em outras culturas na qual exista restrição contextual.This study investigated the role of parents in the development of soccer players. Twenty parents and 12 soccer players, between 15 and 18 years old participated in the study. Both quantitative and qualitative approaches were used by administrating questionnaires forms and interviews. It was observed that few changes occurred in the family routines and that parents were minimally involved in their sons' sport activities. This did not appear to be a constraint for their sons' development because of their passion for soccer, the total amount of practice, and a potential lucrative professional career. Researchers should carefully adopt important paradigms from first world countries to another country with contextual differences.
Morgans, Ryland; Owen, Adam; Doran, Dominic; Drust, Barry; Morton, James P
To monitor resting salivary secretory immunoglobulin A (SIgA) levels in international soccer players during the short-term training period that precedes international match play. In a repeated-measure design, saliva samples were obtained from 13 outfield soccer players who participated in the training camps preceding 7 games (5 home and 2 away) of the 2014 FIFA World Cup qualifying campaign. Samples were obtained daily for 4 d preceding each game (and analyzed for SIgA using the IPRO oral-fluid-collection system) at match day minus 1 (MD-1), minus 2 (MD-2), minus 3 (MD-3), and minus 4 (MD-4). SIgA displayed a progressive decline (P = .01) during the 4-d training period (MD-4, 365 ± 127 μg/mL; MD-3, 348 ± 154 μg/mL; MD-2, 290 ± 138 μg/mL; MD-1, 256 ± 90 μg/mL) such that MD-1 values were significantly lower (P = .01) than both MD-4 and MD-3. The 95% confidence intervals for the differences between MD-1 and MD-4 were -191 to -26 and between MD-1 and MD-3 were -155 to -28. Data demonstrate that a short-term soccer-training camp in preparation for international competition induces detectable perturbations to mucosal immunity. Future studies should monitor SIgA (as a practical and noninvasive measure of immunity) alongside internal and external measures of training load in an attempt to strategically individualize training and nutritional strategies that may support optimal preparation for high-level competition.
Leyhr, Daniel; Kelava, Augustin; Raabe, Johannes; Höner, Oliver
Several talent identification and development (TID) programs in soccer have implemented diagnostics to measure players' motor performance. Yet, there is a lack of research investigating the relationship between motor development in adolescence and future, adult performance. This longitudinal study analyzed the three-year development of highly talented young soccer players' speed abilities and technical skills and examined the relevance of this development to their adult success. The current research sample consisted of N = 1,134 players born between 1993 and 1995 who were selected for the German Soccer Association's TID program and participated in nationwide motor diagnostics (sprinting, agility, dribbling, ball control, shooting) four times between the Under 12 (U12) and Under 15 (U15) age class. Relative age (RA) was assessed for all players, and a total motor score was calculated based on performances in the individual tests. In order to investigate players' future success, participants were divided into two groups according to their adult performance level (APL) in the 2014/2015 season: Elite (1st-5th German division; N = 145, 12.8%) and non-elite players (lower divisions; N = 989, 87.2%). Using multilevel regression analyses each motor performance was predicted by Time, Time2 (level-1 predictors), APL, and RA (level-2 covariates) with simultaneous consideration for interaction effects between the respective variables. Time and Time2 were significant predictors for each test performance. A predictive value for RA was confirmed for sprinting and the total motor score. A significant relationship between APL and the motor score as well as between APL and agility, dribbling, ball control, and shooting emerged. Interaction effects distinctly failed to reach significance. The study found a non-linear improvement in players' performance for all considered motor performance factors over a three-year period from early to middle adolescence. While their predictive value
Full Text Available Background and purpose of study : analysis of IRAN premier league soccer players’ technical performance in season 2012-2013, using a computerized match analysis system (Borhan Mobin Development Management Co, IRAN. Material and methods: in this study, data were obtained from 120 players, who performed in competitions 90 minutes. The players were classified into 3 positional roles: defenders, midfielders and forwards. Technical performance variables analysis included: total passes, total successful passes, pass accuracy, total shots; total shots to target, shot accuracy, ball interception and ball losses. The data were statistically analyzed by one-way ANOVA, Kruskal-Wallis, Mann-Whitney U and Tukey post hoc test. Results : The findings of this study showed that players performed about 45 passes per competition. Midfielders and defenders had significantly higher number of passes than forwards. Pass accuracy was about 67% and there were no significant differences between positional roles. Also, the players performed about 0.8 shots per competition, forwards and midfielders had significantly higher number of shots than defenders. Shot accuracy was about 31%; midfielders and forwards had significantly higher shot accuracy than defenders. Forwards showed significantly lower ball interception and higher ball losses than other positions. Conclusion : The result of this study showed that there were significant differences between some technical actions in positional roles. Therefore, coaches can use this information for individualization of training according to playing positions and for optimization of training in the amateur game.
Steenbergen, B.; Kamp, J. van der
We investigated attentional processes that support the performance of high-skilled soccer players with hemiparetic cerebral palsy. Participants (N = 10) dribbled a slalom course as quickly and accurately as possible under two attentional-focus manipulation conditions. In the task-relevant focus
Robert G. Lockie
Full Text Available Freshmen college soccer players will have lower training ages than their experienced teammates (sophomores, juniors, seniors. How this is reflected in field test performance is not known. Freshmen (n = 7 and experienced (n = 10 male field soccer players from the same Division I school completed soccer-specific tests to identify potential differences in incoming freshmen. Testing included: vertical jump (VJ, standing broad jump, and triple hop (TH; 30-m sprint, (0–5, 5–10, 0–10, and 0–30 m intervals; 505 change-of-direction test; Yo-Yo Intermittent Recovery Test Level 2 (YYIRT2; and 6 × 30-m sprints to measure repeated-sprint ability. A MANOVA with Bonferroni post hoc was conducted on the performance test data, and effect sizes and z-scores were calculated from the results for magnitude-based inference. There were no significant between-group differences in the performance tests. There were moderate effects for the differences in VJ height, left-leg TH, 0–5, 0–10 and 0–30 m sprint intervals, and YYIRT2 (d = 0.63–1.18, with experienced players being superior. According to z-score data, freshmen had meaningful differences below the squad mean in the 30-m sprint, YYIRT2, and jump tests. Freshmen soccer players may need to develop linear speed, high-intensity running, and jump performance upon entering a collegiate program.
Bonfanti, Noelia; Lucena, Raquel
Soccer participation worldwide is increasing and every club try to discover new talents. It is well know that there is an important correlation between body composition (BC) and talent detection (TD) and when coaches and selectors choose players, they tend to choose them with optimum BC.
Schuth, G; Carr, G; Barnes, C; Carling, C; Bradley, P S
Positional variation in match performance is well established in elite soccer but no information exists on players switching positions. This study investigated the influence of elite players interchanging from one position to another on physical and technical match performance. Data were collected from multiple English Premier League (EPL) seasons using a computerised tracking system. After adhering to stringent inclusion criteria, players were examined across several interchanges: central-defender to fullback (CD-FB, n = 11, 312 observations), central-midfielder to wide-midfielder (CM-WM, n = 7, 171 observations), wide-midfielder to central-midfielder (WM-CM, n = 7, 197 observations) and attacker to wide-midfielder (AT-WM, n = 4, 81 observations). Players interchanging from CD-FB covered markedly more high-intensity running and sprinting distance (effect size [ES]: -1.56 and -1.26), lost more possessions but made more final third entries (ES: -1.23 and -1.55). Interchanging from CM-WM and WM-CM resulted in trivial to moderate differences in both physical (ES: -0.14-0.59 and -0.21-0.39) and technical performances (ES: -0.48-0.64 and -0.36-0.54). Players interchanging from AT-WM demonstrated a moderate difference in high-intensity running without possession (ES: -0.98) and moderate-to-large differences in the number of clearances, tackles and possessions won (ES: -0.77, -1.16 and -1.41). The data demonstrate that the physical and technical demands vary greatly from one interchange to another but utility players seem able to adapt to these positional switches.
Lockie, Robert G; Jalilvand, Farzad; Moreno, Matthew R; Orjalo, Ashley J; Risso, Fabrice G; Nimphius, Sophia
The ability to complete high-intensity running is essential for soccer. The Yo-Yo Intermittent Recovery Test Level 2 (YYIRT2) can measure this capacity, but there is limited information regarding this assessment in collegiate female soccer players. This study investigated the YYIRT2 as a measure of high-intensity running in this population, and its relationship to other soccer field tests. Twenty-one players from a Division I team were recruited. In addition to the YYIRT2, subjects completed linear (0-5, 0-10, and 0-30 m sprint intervals) and change-of-direction (pro-agility and 60-yard shuttle) speed tests, as well as the YYIRT Level 1 (YYIRT1), to assess relationships with YYIRT2 by correlations (p ≤ 0.05). The correlation of YYIRT1 with the speed tests was also assessed. The YYIRT1 and YYIRT2 were standardized using z-scores for comparison with elite benchmarks to investigate relative performance on each test. The YYIRT2 and YYIRT1 distances did not significantly correlate with those of the speed tests (r = -0.251 to 0.274). There was a large relationship between YYIRT2 and YYIRT1 distances (r = 0.582), although the explained variance was low (33.87%). Mean YYIRT2 z-scores (-4.29 ± 1.66) indicated a performance further from elite benchmarks than those of the YYIRT1 (-1.92 ± 1.61), and 90.5% (19 of 21) subjects performed relatively better in the YYIRT1 than YYIRT2. The YYIRT2 provided a more specific measure of high-intensity running to that of the YYIRT1 in collegiate female soccer players. Coaches may consider using the YYIRT2 to gauge and track progress of high-intensity running capabilities and create training programs to improve this ability in female players.
Mendez-Villanueva, Alberto; Suarez-Arrones, Luis; Rodas, Gil; Fernandez-Gonzalo, Rodrigo; Tesch, Per; Linnehan, Richard; Kreider, Richard; Di Salvo, Valter
The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. T2 values increased substantially after flywheel leg-curl in all regions of the BFl (from 9±8 to 16±8%), BFs (41±6-71±11%), and ST (60±1-69±7%). Nordic hamstring induced a substantial T2 increase in all regions of the BFs (13±8-16±5%) and ST (15±7-17±5%). T2 values after the Russian belt deadlift substantially increased in all regions of the BFl (6±4-7±5%), ST (8±3-11±2%), SM (6±4-10±4%), and proximal and distal regions of BFs (6±6-8±5%). T2 values substantially increased after hip-extension conic-pulley only in proximal and middle regions of BFl (11±5-7±5%) and ST (7±3-12±4%). The relevance of such MRI-based inter- and intra-muscle use in designing more effective resistance training for improving hamstring function and preventing hamstring injuries in elite soccer players should be explored with more mechanistic studies.
Full Text Available To identify individual response patterns in selected aerobic fitness variables of regular starters (ST; N = 7 and non-starters (Non-ST; N = 10, top level professional soccer players were tested for maximal oxygen uptake (VO2max, velocity at 4 mM of lactate (V4, velocity at maximal oxygen uptake (νVO2max and oxygen pulse (O2-pulse in July and December following consecutive periods of fixture congestion. V4 was the only variable that increased significantly in December compared to July (15.1 ± 0.5 vs. 14.6 ± 0.5, p = 0.001. There was an almost certain beneficial large mean team change for V4 (ES = 1.2 (0.67; 1.57, 100/0/0, while beneficial mean team changes were less likely for νVO2max and O2-pulse [ES = 0.31 (-0.08; 0.70, 68/30/2 and ES = 0.24 (0.01; 0.49, 64/36/0, respectively] and unclear for VO2max (ES = 0.02 (-0.31; 0.70, 18/69/13. With the exception of V4 where 10 out of 17 players (7 ST and 3 Non-ST showed positive changes higher than the biological variability, all other variables were characterized by a substantial proportion of changes lower than the biological variability. The present study demonstrated that aerobic fitness variables that require maximal effort may be characterized by greater variability of the individual response pattern compared to that of submaximal aerobic fitness variables irrespective of the accumulated game time. Submaximal aerobic fitness variables appear to be more informative in the physiological evaluation of top level soccer players and this may be an advantage during exposure to periods of consecutive games.
Mendez-Villanueva, Alberto; Suarez-Arrones, Luis; Rodas, Gil; Fernandez-Gonzalo, Rodrigo; Tesch, Per; Linnehan, Richard; Kreider, Richard; Di Salvo, Valter
The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. T2 values increased substantially after flywheel leg-curl in all regions of the BFl (from 9±8 to 16±8%), BFs (41±6–71±11%), and ST (60±1–69±7%). Nordic hamstring induced a substantial T2 increase in all regions of the BFs (13±8–16±5%) and ST (15±7–17±5%). T2 values after the Russian belt deadlift substantially increased in all regions of the BFl (6±4–7±5%), ST (8±3–11±2%), SM (6±4–10±4%), and proximal and distal regions of BFs (6±6–8±5%). T2 values substantially increased after hip-extension conic-pulley only in proximal and middle regions of BFl (11±5–7±5%) and ST (7±3–12±4%). The relevance of such MRI-based inter- and intra-muscle use in designing more effective resistance training for improving hamstring function and preventing hamstring injuries in elite soccer players should be explored with more mechanistic studies. PMID:27583444
Thomassen, Martin; Christensen, Peter Møller; Gunnarsson, Thomas Gunnar Petursson
The present study examined muscle adaptations and alterations in performance of highly trained soccer players with intensified training or training cessation. Eighteen elite soccer players were for a 2-wk period assigned to either a group which performed high intensity training with a reduction....... The present data suggest that short-term intensified training even for trained soccer players can increase muscle Na(+)/K(+) pump alpha2 isoform expression and that cessation of training for two weeks does not affect the expression of Na(+)/K(+) pump isoforms. Resting phosphorylation status of the Na...
DEVELOPMENT OF BODY COMPOSITION, HORMONE PROFILE, PHYSICAL FITNESS, GENERAL PERCEPTUAL MOTOR SKILLS, SOCCER SKILLS AND ON-THE-BALL PERFORMANCE IN SOCCER-SPECIFIC LABORATORY TEST AMONG ADOLESCENT SOCCER PLAYERS
Full Text Available The aim of the present study was to examine the development of on-the-ball skills in soccer-specific laboratory test and to examine how traditional measures of body composition, hormone profile, physical fitness, general perceptual motor skills and soccer skills were related to performance measured in open skill environment among 10, 12, and 14-year-old regional male soccer players (n = 12/group. The measured variables were height, weight, fat, muscle mass, testosterone, 10m sprint, agility, counter movement jump, peripheral awareness, Eye- Hand-Foot coordination, passing skill, dribbling skill and on-the-ball skills (performance time and passing accuracy in soccer-specific laboratory test. A significant main effect by age was found in all measured variables except in fat, in peripheral awareness and in passing accuracy. In discriminant analysis 63.9% (λ = 0.603, F = 4.600, p < 0.01 of the players were classified correctly based on physical fitness and general perceptual motor skills into three ability groups originally classified with performance time in soccer-specific laboratory test. Correlation co- efficient analysis with-in age groups revealed that variables associated with performance time in soccer-specific laboratory test were peripheral awareness (r = 0.72, p < 0.01 in 10-year-olds; testosterone (r = -0.70, p < 0.05, dribbling skill (r = 0.73, p < 0.01 and passing skill (r = 0.73, p < 0.01 in 12-year-olds; agility (r = 0.79, p < 0.01, counter movement jump (r = - 0.62, p < 0.01, dribbling skill (r = 0.80, p < 0.01 and passing skill (r = 0.58, p < 0. 05 in 14-year olds. Corresponding relationships with passing accuracy were weight (r = 0.59, p < 0.05, fat (r = 0.66, p < 0.05, 10m sprint (r = 0.71, p < 0.01 and countermovement jump (r = -0.64, p < 0.05 in 10-year-olds; Eye-Hand-Foot coordination (r = 0.63, p < 0.05 in 14-year- olds. The relationship between soccer-specific anticipation time and performance time in soccer- specific
Full Text Available BACKGROUND: Muscle strength is an important factor in soccer from the performance and health perspective. There is a lack of knowledge about changes in muscle strength of the knee flexors and extensors and their ratios during annual training cycle. OBJECTIVES: The aim of this study was to evaluate the seasonal variability of the observed parameters of isokinetic strength of the knee flexors and extensors in soccer players, U19, from the performance and health perspective. METHODS: The strength of the knee flexors and extensors was measured in players U19 category (n = 9; the average age 18.5 ±0.4 years on the isokinetic dynamometer IsoMed 2000 in angular velocity 60° × s-1. Measurement was performed in concentric/concentric and excentric/excentric mode of muscle action at the beginning of the winter preparatory period, at the end of the preparatory period and at the end of the spring competitive period. Monitored parameters were absolute peak torque (PT, conventional H/Q ratio (H/QCON, functional H/Q ratio (H/QFUN and functional H/Q ratio in range 10-30° of knee flexion (H/QFUN_10-30. RESULTS: Significant change in PT (p < .05 was noted only in cases of the knee extensors of the nondominant leg in the concentric mode. The evaluation of imbalance of the knee flexors and extensors by H/QCON and H/QFUN ratios did not show any significant changes, but there was found a significant decrease of the H/QFUN_10-30 ratio in the dominant leg between measurements at the beginning and at the end of the winter preparatory period. CONCLUSIONS: The results of the current study indicate that throughout the monitored periods of the annual training cycle desirable changes in knee flexors and extensors strength did not occur. The values suggest the disruption of the dynamic stabilization of the knee joint and increase in injury risk. Diﬀerent dynamics of the three observed ratios confirmed that they provide diﬀerent information about the physical fitness of
Delaney, J Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Aljufaili, Mahmood; Correa, José A
To assess the effectiveness of a standard long-handle laryngoscope and a short-handle laryngoscope on ease of possible intubation in football, ice hockey, and soccer players. Prospective crossover study. University Sport Medicine Clinic. Sixty-two university varsity football (62 males), 45 ice hockey (26 males and 19 females), and 39 soccer players (20 males, 19 females). Athletes were assessed for different airway and physical characteristics. Three different physicians then assessed the use of laryngoscopes of different handle sizes in supine athletes who were wearing protective equipment while in-line cervical spine immobilization was maintained. The ease of passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was assessed using both a standard long-handle and a short-handle laryngoscope. Use of a short-handle laryngoscope was easier for all physicians in all sports as compared with a standard-sized laryngoscope. Passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was easiest in soccer players and most difficult in football and ice hockey players for both sizes of laryngoscope. Interference from chest or shoulder pads was a common cause for difficulty in passing the laryngoscope blade into the posterior oropharynx for football and ice hockey players. In the rare instances that an endotracheal intubation is to be attempted on an unconscious athlete, a short-handle laryngoscope may provide the best chance for successful intubation.
Full Text Available The aim of this study was to compare isokinetic strength performance profiles in elite soccer players across different field positions. A total of 111 elite international players of Polish Ekstraklasa (the top division in Poland were examined during the 2010-2015 seasons. The players were classified into six positional roles: central defenders (CD, external defenders (ED, central midfielders (CM, external midfielde