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.
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.
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
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
Clark, Niall A.; Edwards, Andrew M.; Morton, R. Hugh; Butterly, Ronald J.
The purpose of this study was to examine season-to-season variations in physiological fitness parameters among a 1st team squad of professional adult male soccer players for the confirmatory purposes of identifying normative responses (immediately prior to pre-season training (PPS), mid-season (MID), and end-of-season (EOS)). Test-retest data were collected from a student population on the primary dependent variables of anaerobic threshold (AT) and maximal aerobic power (VO2 max) to define meaningful measurement change in excess of test-retest technical error between test-to-test performances. Participants from a pool of 42 professional soccer players were tested over a set sequence of tests during the 3-year period: 1) basic anthropometry, 2) countermovement jump (CMJ) tests 3) a combined AT and VO2 max test. Over the 3-year period there were no test-to-test changes in mean VO2 max performance exceeding pre-defined limits of test agreement (mean of eight measures: 61.6 ± 0.6 ml·kg-1·min-1). In contrast, VO2 at AT was significantly higher at the MID test occasion in seasons 2 (+4.8%; p = 0.04, p elite cohort between test-to-test occasions, VO2 max values did not vary significantly over the study which supports previous short-term observations suggesting a general ‘elite’ threshold of 60 ml·kg-1 min. Interestingly, AT significantly varied where VO2 max was stable and these variations also coincided with on- and off-seasons suggesting that AT is a better indication of acute training state than VO2 max. Key points Maximal aerobic power remains fairly stable across inter- and intra-season measurements. Anaerobic threshold appears more sensitive of training state confirming our earlier observations. The professional players tended to attain optimal performances at the mid-season interval over the 3 seasons, presumably prior to the development of accumulative fatigue. PMID:24150149
Grassi, Alberto; Smiley, Stephen Paul; Roberti di Sarsina, Tommaso; Signorelli, Cecilia; Marcheggiani Muccioli, Giulio Maria; Bondi, Alice; Romagnoli, Matteo; Agostini, Alessandra; Zaffagnini, Stefano
Soccer is considered the most popular sport in the world concerning both audience and athlete participation, and the incidence of ACL injury in this sport is high. The understanding of injury situations and mechanisms could be useful as substratum for preventive actions. To conduct a video analysis evaluating the situations and mechanisms of ACL injury in a homogeneous population of professional male soccer players, through a search entirely performed on the YouTube.com Web site focusing on the most recent years. A video analysis was conducted obtaining videos of ACL injury in professional male soccer players from the Web site YouTube. Details regarding injured players, events and situations were obtained. The mechanism of injury was defined on the basis of the action, duel type, contact or non-contact injury, and on the hip, knee and foot position. Thirty-four videos were analyzed, mostly from the 2014-2015 season. Injuries occurred mostly in the first 9 min of the match (26%), in the penalty area (32%) or near the side-lines (44%), and in non-rainy conditions (97%). Non-contact injuries occurred in 44% of cases, while indirect injuries occurred in 65%, mostly during pressing, dribbling or tackling. The most recurrent mechanism was with an abducted and flexed hip, with knee at first degrees of flexion and under valgus stress. Through a YouTube-based video analysis, it was possible to delineate recurrent temporal, spatial and mechanical characteristics of ACL injury in male professional soccer players. Level IV, case series.
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…
Roescher, C. R.; Elferink-Gemser, M. T.; Huijgen, B. C. H.; Visscher, C.
The development of intermittent endurance capacity, its underlying mechanisms and role in reaching professional level in soccer was investigated. The sample included 130 talented youth soccer players aged 14-18, who became professional (n = 53) or non-professional (n = 77) players in adulthood. In
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.
Bakken, Arnhild; Targett, Stephen; Bere, Tone; Eirale, Cristiano; Farooq, Abdulaziz; Mosler, Andrea B; Tol, Johannes L; Whiteley, Rod; Khan, Karim M; Bahr, Roald
Lower extremity muscle strength tests are commonly used to screen for injury risk in professional soccer. However, there is limited evidence on the ability of such tests in predicting future injuries. To examine the association between hip and thigh muscle strength and the risk of lower extremity injuries in professional male soccer players. Case-control study; Level of evidence, 3. Professional male soccer players from 14 teams in Qatar underwent a comprehensive strength assessment at the beginning of the 2013/2014 and 2014/2015 seasons. Testing consisted of concentric and eccentric quadriceps and hamstring isokinetic peak torques, eccentric hip adduction and abduction forces, and bilateral isometric adductor force (squeeze test at 45°). Time-loss injuries and exposure in training and matches were registered prospectively by club medical staff throughout each season. Univariate and multivariate Cox regression analyses were used to calculate hazard ratios (HRs) with 95% CIs. In total, 369 players completed all strength tests and had registered injury and exposure data. Of these, 206 players (55.8%) suffered 538 lower extremity injuries during the 2 seasons; acute muscle injuries were the most frequent. Of the 20 strength measures examined, greater quadriceps concentric peak torque at 300 deg/s (HR, 1.005 [95% CI, 1.00-1.01]; P = .037) was the only strength measure identified as significantly associated with a risk of lower extremity injuries in multivariate analysis. Greater quadriceps concentric peak torque at 60 deg/s (HR, 1.004 [95% CI, 1.00-1.01]; P = .026) was associated with the risk of overuse injuries, and greater bilateral adductor strength adjusted for body weight (HR, 0.75 [95% CI, 0.57-0.97; P = .032) was associated with a lower risk for any knee injury. Receiver operating characteristic curve analyses indicated poor predictive ability of the significant strength variables (area under the curve, 0.45-0.56). There was a weak association with the risk of
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
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
de Hoyo, Moisés; Sañudo, Borja; Suárez-Arrones, Luis; Carrasco, Luis; Joel, Tom; Domínguez-Cobo, Sergio; Núñez, Francisco J
The aim of the current study was to analyse the acceleration profile in elite professional soccer players according to their initial speed but also considering players' position. Players' accelerations profiles were analysed using a relative acceleration profile according to the initial speed (S1, from 0 to 7 km/h; S2, from 7.1 to 14.3 km/h; and S3, ≥14.4 km/h) and the maximum acceleration. Within-group analyses showed that Center Backs (CB) performed more high intensity accelerations (likely) when they started in S1 than S2 (ES: 0.50). Strikers (S) and Wide Midfielders (W-MD) achieved more accelerations (likely to almost certain) starting in S3 than S1 (ES: 0.80 and 0.59, respectively) and S2 (ES: 0.67 and 1.09, respectively). Full Backs (FB) completed more accelerations (almost certain) starting in S1 and S3 than S2 (ES: 1.39 and 1.36, respectively). Finally, Midfielders (MD) executed a greater number of high intensity accelerations (likely to almost certain) when they started in S1 than S2 (ES: 0.83) and S3 (ES: 0.66), and in S3 than S2 (ES: 4.72). Between-group analyses showed that S, W-MD, and FB performed a greater total number of high intensity accelerations (very likely to almost certain) than CB (ES: 1.94, 1.57, and 1.51, respectively) and MD (ES: 1.23, 0.92; and 0.81, respectively). Furthermore, MD performed substantially greater total number of high intensity accelerations (likely) than CB (ES: 0.56). Results suggest that CB achieved more high-intensity accelerations starting in low and moderate speed, S and W-MD in high speed, and FB combined low and high speed.
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.
Owoeye, Oluwatoyosi Babatunde Alex; Aiyegbusi, Ayoola Ibifubara; Fapojuwo, Oluwaseun Akinleye; Badru, Oluwaseun Abdulganiyu; Babalola, Anike Rasheedat
Research on the epidemiology of football injuries in Africa is very sparse despite its importance for injury prevention planning in a continent with limited sports medicine resources. The vast majority of studies available in literature were conducted in Europe and only a very few studies have prospectively reported the pattern of football injury in Africa. The purpose of this study was to evaluate the incidence and pattern of injuries in a cohort of male and female semi-professional football players in Nigeria. A prospective cohort design was conducted, in which a total of 756 players with an age range of 18-32 years (356 males and 300 females) from 22 different teams (12 male and 10 female teams), were prospectively followed in a National Football Tournament. Physiotherapists recorded team exposure and injuries. Injuries were documented using the consensus protocol for data collection in studies relating to football injury surveillance. An overall incidence of 113.4 injuries/1000 h (95% CI 93.7-136.0) equivalent to 3.7 injuries/match and time-loss incidence of 15.6 injuries/1000 h were recorded for male players and 65.9 injuries/1000 h (95% CI 48.9-86.8) equivalent to 2.2 injuries/match and time-loss incidence of 7.9 injuries/1000 h were recorded for female players. Male players had a significantly higher risk of injuries [IRR = 1.72 (95% CI 1.23-2.45)]. Injuries mostly affected the lower extremity for both genders (n = 81, 70% and n = 31, 62% for males and females respectively). Lower leg contusion (n = 22, 19%) and knee sprain (n = 9, 18%) were the most common specific injury types for male and female players respectively. Most of the injuries were as a result of contact with another player (n = 102, 88%-males; n = 48, 96%-females). Time-loss injuries were mostly estimated as minimal (n = 11, 69%) for male players and severe (n = 4, 66%) for female players. The overall incidence of injuries among Nigerian semi-professional football
An inevitable reality that all athletes have to face is retirement from competition and this experience can lead an acute sense of loss in the athlete. Professional soccer players are no exception. While retirement traditionally occurs for most non-athletes after a long working career that allows them to plan and anticipate the ...
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
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...
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.
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
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.
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...
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.
Thorborg, Kristian; Branci, Sonia; Stensbirk, Frederik
BACKGROUND/AIM: Reference values are needed in order to interpret the Copenhagen Hip and Groin Outcome Score (HAGOS) in male soccer players with hip and groin pain. The aim of this study was to establish reference values for HAGOS in hip and groin injury-free male soccer players. METHODS: We...... included 444 groin injury-free soccer players from 40 clubs (divisions 1-4) in Eastern Denmark, mean age (SD) 23.6 (4.4), training soccer 3.4 (1) times per week. All players were hip and groin injury-free at the time of inclusion (beginning of season, 2011). RESULTS: Of the 444 hip and groin injury...... HAGOS subscales (psoccer players, with no pain in the previous or present season (n=301), are: pain: 80.1-100, symptoms: 64.3-100, activities of daily living: 80...
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.
Full Text Available The purpose of this study was to analyse the leadership power perception of amateur and professional soccer coaches according to their marital status. Data were collected from 165 male soccer coaches (n=71 technical director-manager and A license, n=46 B license, n=48 amateur license. An adapted Turkish version of Power in Soccer Questionnaire-Self (PSQ-S for coaches and an information form were used for the data collection . Cronbach reliability alphas of PSQ-S range between 0.65 and 0.84. Coaches’ data were analysed by Kruskal-Wallis and Mann-Whitney tests. Kruskal-Wallis analysis of PSQ-S revealed significant differences between leadership power perception of amateur and professional soccer coaches according to their marital status related to Referent Power (RP [χ[sup]2[/sup] (3 = 9.61, p0.05. The results indicated that married coaches have higher perception of RP than single coaches, irrespective of being an amateur or a professional. Comparison of professional and amateur coaches suggests that while single professional coaches have higher perception of EP than married professional coaches, the results are the reverse for amateur coaches; in other words, amateur married coaches have higher perception of EP than amateur single coaches. There is a lack of research to draw more certain conclusions. Future researchers should also take into consideration personality, psychological skills, sport experience, age, taking responsibility, attributions, expectations, emotions, perception of achievement, etc.
Full Text Available Strength imbalances between the hamstrings and quadriceps are an essential predictor for hamstring strain in soccer. The study aimed to investigate and compare the muscle strength imbalances of professional soccer players of different performance levels. One hundred and fifty nine senior male professional soccer players from first (n = 75 and second league (n = 84 Portuguese clubs participated in this study. Muscle strength was evaluated with a REV9000 isokinetic dynamometer. Maximal peak torque data were used to calculate quadriceps and hamstrings strength during concentric and eccentric actions, bilateral asymmetry, conventional strength ratios and dynamic control ratios. Second league athletes produced slightly lower conventional strength ratios in the right and left legs (ES = 0.22, p = 0.17 and ES = 0.36, p = 0.023, respectively compared to the first league athletes. No significant differences were found in dynamic control ratios or in bilateral asymmetry among first and second league athletes. These findings do not show a clear link between the competitive level and injury risk in soccer players. However, some of the differences found, particularly in conventional strength ratios, highlight the importance of performing off-season and pre-season strength assessments to prescribe and adjust individual strength training programs among professional soccer players.
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...
Read, Paul J; Oliver, Jon L; De Ste Croix, Mark B A; Myer, Gregory D; Lloyd, Rhodri S
Regulations now state that professional academies in the United Kingdom are required to substantially increase the volume of soccer training. This study assessed the current injury occurrence, providing an update to reports published prior to the introduction of the Elite Player Performance Plan (EPPP). 608 soccer players aged 11-18 years from six professional soccer clubs were prospectively monitored, recording injuries during the 2014-2015 season. An injury rate of 1.32 injuries per player/season was indicated with a mean time loss of 21.9 days per injury. The greatest time loss per injury was in the U14s-U15s, and the highest rate of severe injuries in the U15s. Strains and sprains were the most common injury type, with the knee and ankle the most frequently injured anatomical sites. Seasonal variation indicated two peaks in injury incidence, occurring in September and January. In comparison to a published audit prior to the inception of the EPPP, this study indicates that academy soccer players are three-times more likely to experience an injury. Given that time loss and injury severity also increased during periods that typically follow rapid growth, these players should be considered an important group for training load monitoring and injury prevention strategies.
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
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.
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
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....
Fábio Augusto Sfoggia Verardi
Full Text Available Abstract: This qualitative study, of descriptive and exploratory manner, aims to determine the formation of youth soccer association structure in the professional soccer clubs in the Rio Pardo and Taquari valleys, in order to modernize the sport nowadays. The subjects of this study are five male administrators of different soccer clubs. The results show that in four of these clubs, the work with youth soccer association is recent, covering only the categories for children, junior and youth with various forms of admissions; but all coaches believe in the commitment of such work. It is observed that its main objective is to train athletes in this association to supply the professional team, without, however, a usual line of tactical system to be observed at different levels. The sponsorship is the main income source for the maintenance of these activities, not being exploited for the dissemination and marketing initiatives. All clubs have trained athletes from the youth soccer association playing in their professional teams, but only one club indicated some indices of those players who were sold or borrowed to other clubs. Thus, it shows that the youth soccer association has received some attention from the sports administrators, but there is still the lack of a better professional management on it, developing its various aspects. So, it could provide more satisfactory results, as a profitable alternative to prepare players for professional teams. Keywords: soccer; structure; clubs, training of athletes.
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.
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.
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.
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.
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
Full Text Available At the last World Conference on Sport and Physical Therapy celebrated in Bern (Switzerland, 2015, it was confirmed that the functional skills of an athlete are a very important variable to be considered in the recovery of an injury. On the other hand, its use as a predictive risk tool still lacks solid evidence. The purpose of this study was to determine whether a battery of functional tests (FPT could be used as a preliminary measure for the season in order to identify the injury risk in a professional soccer team in the Spanish Second Division B League. Fifty-two soccer players (ages of 25.3 ± 4.6 years, 10.33% ± 0.9% fat were functionally assessed during two seasons (2012–2013 and 2013–2014 and analyzed from an injury perspective. A total of 125 injuries were recorded. The sample was grouped based on the number of injuries and the required absence days. Except for the bipodal vertical jump (CMJ, none of the functional tests revealed differences among the groups. The correlation study between the functional condition and the suffered injuries did not show any significant results.
Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important...
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.
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
de Queiroz, Roberto Dantas; de Carvalho, Rogério Teixeira; de Queiroz Szeles, Paulo Roberto; Janovsky, César; Cohen, Moisés
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
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.
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.
Soccer in Rwandan high schools can expose players to the risk of injury warranting prevention programmes. The aim of this study was to determine the type, causes, severity and management of injuries among high school soccer players in Rwanda, in order to obtain baseline data for injury prevention programmes.
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 ...
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...
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...
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.
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.
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.
Sapieja, Klaudia M; Dunn J, G H; Holt, Nicholas L
Although perfectionist orientations have been linked to a variety of cognitive, affective, and behavioral correlates in youth sport, little is known about antecedent factors that may influence adolescent athletes' perfectionist orientations. The purpose of this study was to determine whether perceptions of parenting styles differ as a function of adolescent athletes' perfectionist orientations. A total of 194 male youth soccer players (M age = 13.64 years; SD = 1.51; range, 10.67-16.25 years) completed measures of their perfectionist orientations in sport and of their perceptions of maternal and paternal parenting styles. Scores from the parenting style measure were calculated such that higher scores were reflective of higher parental authoritativeness (as perceived by the athletes). Cluster analyses conducted on perfectionism responses produced independent clusters of unhealthy perfectionists, healthy perfectionists, and nonperfectionists. MANOVA results revealed that both healthy- and nonperfectionists had significantly higher perceptions of maternal and paternal authoritativeness than unhealthy perfectionists (ps authoritative parenting may play a role in developing healthy perfectionist orientations (or decrease the likelihood of developing unhealthy perfectionist orientations) in youth sport.
Full Text Available Purpose: To investigate the changes through repeated explosive effort sequences (20+20-m sprint with change of direction, jumping, metabolic response (lactate, as well as the relationship between these variables and fitness qualities (strength and endurance in professional futsal and soccer players. Methods: Male players (n =30, Twelve futsal and twenty soccer players completed three testing sessions. In the first session was measured VO2max on a motorized treadmill. In the second session was measured counter movement jump (CMJ and full squat RM in Smith Machine. Finally, in the third session six repeated-explosive effort sequences (RES was performed. Results: Similar values of lower limbs strength, CMJ height, LAC after RSA test and VO2max (95,12 vs. 94,73; 34,5 vs. 35,9; 13,65 vs. 14,33; 62,78 vs. 62,95 soccer vs. futsal respectively and significant differences when are analysed the loss of performance in velocity (total and between three first and three last and vertical jump height (2,67 vs. 4,4**; 1,28 vs. 2,1*; 2,88 vs. 6,1**; 9,71 vs. 14,3* soccer vs. futsal respectively. Conclusions: Professional futsal and soccer obtain significant differences in speed and vertical jump height (CMJ loss despite having similar values in squat, oxygen consumption, lactate after RSA test and CMJ height. Issue that could be attributed to the characteristics of the sport. This suggests that the volume should be increased oriented ability to perform repeated sprint actions over other type of training aimed at improving aerobic capacity especially at professional level.
Hassabi, Mohammad; Mohammad-Javad Mortazavi, Seyed; Giti, Mohammad-Reza; Hassabi, Majid; Mansournia, Mohammad-Ali; Shapouran, Sara
Despite numerous studies which have been done regarding soccer injuries worldwide, there is lack of available data considering the epidemiology of injuries in the Iranian soccer premier league, although it is the most popular sport in the country. The main goal of this research was to determine the incidence of physical injuries in the studied population, considering other characteristics such as site, type and mechanism as well. Twenty one adult male professional soccer players (age 24±3), members of a team (Tehran-Pas) participating in Iranian premier league, were followed during a 4-month period. The injury characteristics and exposure times were recorded by the team physician during all the matches and training sessions. The total exposure time was 2610 playing hours (2352 h of training versus 258 h of competition). Eighty six percent of the injuries were acute. Incidence of acute injuries was 16.5 (95% CI: 12-22) per 1000 hours of playing (11.5 per 1000 hrs of training and 62 per 1000 hrs of competition). The most common types of injuries were strains followed by contusions, each of which constituted 30% of acute injuries. More than 80% of injuries occurred in lower limbs, especially in thigh and groin regions. Nearly 60% of acute injuries occurred in dominant side of the body, and collision was the reason of about half of the acute injuries. Severity of more than 70% of the injuries was minor. On average each injury had led the player being off the field for about 10 days. The incidence of injury in this research is in range of numbers obtained in important international tournaments but the rate of injuries during training sessions is higher than comparable studies.
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.
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.
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
Rabbani, Alireza; Kargarfard, Mehdi; Twist, Craig
Rabbani, A, Kargarfard, M, and Twist, C. Reliability and validity of a submaximal warm-up test for monitoring training status in professional soccer players. J Strength Cond Res 32(2): 326-333, 2018-Two studies were conducted to assess the reliability and validity of a submaximal warm-up test (SWT) in professional soccer players. For the reliability study, 12 male players performed an SWT over 3 trials, with 1 week between trials. For the validity study, 14 players of the same team performed an SWT and a 30-15 intermittent fitness test (30-15IFT) 7 days apart. Week-to-week reliability in selected heart rate (HR) responses (exercise heart rate [HRex], heart rate recovery [HRR] expressed as the number of beats recovered within 1 minute [HRR60s], and HRR expressed as the mean HR during 1 minute [HRpost1]) was determined using the intraclass correlation coefficient (ICC) and typical error of measurement expressed as coefficient of variation (CV). The relationships between HR measures derived from the SWT and the maximal speed reached at the 30-15IFT (VIFT) were used to assess validity. The range for ICC and CV values was 0.83-0.95 and 1.4-7.0% in all HR measures, respectively, with the HRex as the most reliable HR measure of the SWT. Inverse large (r = -0.50 and 90% confidence limits [CLs] [-0.78 to -0.06]) and very large (r = -0.76 and CL, -0.90 to -0.45) relationships were observed between HRex and HRpost1 with VIFT in relative (expressed as the % of maximal HR) measures, respectively. The SWT is a reliable and valid submaximal test to monitor high-intensity intermittent running fitness in professional soccer players. In addition, the test's short duration (5 minutes) and simplicity mean that it can be used regularly to assess training status in high-level soccer players.
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.
Nickerson, Brett S; Mangine, Gerald T; Williams, Tyler D; Martinez, Ismael A
The purpose of this study was to determine if back squat cluster sets (CS) with varying inter-repetition rest periods would potentiate greater sprint performance compared with a traditional set parallel back squat in collegiate soccer players. Twelve collegiate male soccer players (age, 21.0 ± 2.0 years; height, 180.0 ± 9.0 cm; body mass, 79.0 ± 9.5 kg) performed a 20-m sprint prior to a potentiation complex and at 1, 4, 7, and 10 min postexercise on 3 separate, randomized occasions. On each occasion, the potentiation complex consisted of 1 set of 3 repetitions at 85% 1-repetition maximum (1RM) for the traditional parallel back squat. However, on 1 occasion the 3-repetition set was performed in a traditional manner (i.e., continuously), whereas on the other 2 occasions, 30s (CS 30 ) and 60 s (CS 60 ) of rest were allotted between each repetition. Repeated-measures ANOVA revealed greater (p = 0.022) mean barbell velocity on CS 60 compared with the traditional set. However, faster (p < 0.040) 20-m sprint times were observed for CS 30 (3.15 ± 0.16 s) compared with traditional (3.20 ± 0.17 s) only at 10 min postexercise. No other differences were observed. These data suggest that a single cluster set of 3 repetitions with 30-s inter-repetition rest periods at 85% 1RM acutely improves 20-m sprinting performance. Strength and conditioning professionals and their athletes might consider its inclusion during the specific warm-up to acutely improve athletic performance during the onset (≤10 min) of training or competition.
Hölmich, Per; Thorborg, Kristian; Dehlendorff, Christian
BACKGROUND: Groin injuries cause major problems in the football codes, as they are prevalent and lead to prolonged symptoms and high recurrence. The aim of the present study was to describe the occurrence and clinical presentation of groin injuries in a large cohort of sub-elite soccer players.......0096). Having both adductor and abdominal pain also increased the injury time significantly when compared to injuries with no adductor and no abdominal pain (RIT=4.56, 95% CI 1.91 to 10.91, p=0.001). CONCLUSION: Adductor-related groin injury was the most common clinical presentation of groin injuries in male...... during a season. METHODS: Physiotherapists allocated to each of the participating 44 soccer clubs recorded baseline characteristics and groin injuries sustained by a cohort of 998 sub-elite male soccer players during a full 10-month season. All players with groin injuries were examined using the clinical...
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.
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.
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.
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.
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
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.
Gouttebarge, Vincent; Backx, Frank J. G.; Aoki, Haruhito; Kerkhoffs, Gino M. M. J.
Evidence on the prevalence of symptoms related to distress, anxiety/depression or substance abuse/dependence, - typically referred to as symptoms of common mental disorders (CMD) - is lacking in European professional football (soccer). The aims of the present study were to investigate the prevalence
Jaspers, Arne; Brink, Michel S.; Probst, Steven G M; Frencken, Wouter G. P.; Helsen, Werner F.
Background In professional senior soccer, training load monitoring is used to ensure an optimal workload to maximize physical fitness and prevent injury or illness. However, to date, different training load indicators are used without a clear link to training outcomes. Objective The aim of this
Marc A. Briggs
Full Text Available This study investigated the energy intake and expenditure of professional adolescent academy-level soccer players during a competitive week. Over a seven day period that included four training days, two rest days and a match day, energy intake (self-reported weighed food diary and 24-h recall and expenditure (tri-axial accelerometry were recorded in 10 male players from a professional English Premier League club. The mean macronutrient composition of the dietary intake was 318 ± 24 g·day−1 (5.6 ± 0.4 g·kg−1 BM carbohydrate, 86 ± 10 g·day−1 (1.5 ± 0.2 g·kg−1 BM protein and 70 ± 7 g·day−1 (1.2 ± 0.1 g·kg−1 BM fats, representing 55% ± 3%, 16% ± 1%, and 29% ± 2% of mean daily energy intake respectively. A mean daily energy deficit of −1302 ± 1662 kJ (p = 0.035 was observed between energy intake (9395 ± 1344 kJ and energy expenditure (10679 ± 1026 kJ. Match days (−2278 ± 2307 kJ, p = 0.012 and heavy training days (−2114 ± 2257 kJ, p = 0.016 elicited the greatest deficits between intake and expenditure. In conclusion, the mean daily energy intake of professional adolescent academy-level soccer players was lower than the energy expended during a competitive week. The magnitudes of these deficits were greatest on match and heavy training days. These findings may have both short and long term implications on the performance and physical development of adolescent soccer players.
Briggs, Marc A.; Cockburn, Emma; Rumbold, Penny L. S.; Rae, Glen; Stevenson, Emma J.; Russell, Mark
This study investigated the energy intake and expenditure of professional adolescent academy-level soccer players during a competitive week. Over a seven day period that included four training days, two rest days and a match day, energy intake (self-reported weighed food diary and 24-h recall) and expenditure (tri-axial accelerometry) were recorded in 10 male players from a professional English Premier League club. The mean macronutrient composition of the dietary intake was 318 ± 24 g·day−1 (5.6 ± 0.4 g·kg−1 BM) carbohydrate, 86 ± 10 g·day−1 (1.5 ± 0.2 g·kg−1 BM) protein and 70 ± 7 g·day−1 (1.2 ± 0.1 g·kg−1 BM) fats, representing 55% ± 3%, 16% ± 1%, and 29% ± 2% of mean daily energy intake respectively. A mean daily energy deficit of −1302 ± 1662 kJ (p = 0.035) was observed between energy intake (9395 ± 1344 kJ) and energy expenditure (10679 ± 1026 kJ). Match days (−2278 ± 2307 kJ, p = 0.012) and heavy training days (−2114 ± 2257 kJ, p = 0.016) elicited the greatest deficits between intake and expenditure. In conclusion, the mean daily energy intake of professional adolescent academy-level soccer players was lower than the energy expended during a competitive week. The magnitudes of these deficits were greatest on match and heavy training days. These findings may have both short and long term implications on the performance and physical development of adolescent soccer players. PMID:26445059
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.
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.
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
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 The aim of this study was to investigate maximum aerobic power (VO2 max and anaerobic threshold (AT as determinants of training status among professional soccer players. Twelve professional 1st team British male soccer players (age: 26.2 ± 3.3 years, height: 1.77 ± 0.05 m, body mass: 79.3 ± 9.4 kg agreed to participate in the study and provided informed consent. All subjects completed a combined test of anaerobic threshold (AT and maximum aerobic power on two occasions: Test 1 following 5 weeks of low level activity at the end of the off-season and Test 2 immediately following conclusion of the competitive season. AT was assessed as both lactate threshold (LT and ventilatory threshold (VT. There was no change in VO2 max between Test 1 and Test 2 (63.3 ± 5.8 ml·kg-1·min-1 vs. 62.1 ± 4.9 ml·kg-1·min-1 respectively, however, the duration of exercise tolerance (ET at VO2 max was significantly extended from Test 1 to Test 2 (204 ± 54 vs. 228 ± 68 s respectively (P<0.01. LT oxygen consumption was significantly improved in Test 2 versus Test 1 (P<0.01 VT was also improved (P<0.05. There was no significant difference in VO2 (ml·kg-1·min-1 corresponding to LT and VT. The results of this study show that VO2 max is a less sensitive indicator to changes in training status in professional soccer players than either LT or VT.
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.
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
Devlin, Brooke L; Leveritt, Michael D; Kingsley, Michael; Belski, Regina
Sports nutrition professionals aim to influence nutrition knowledge, dietary intake and body composition to improve athletic performance. Understanding the interrelationships between these factors and how they vary across sports has the potential to facilitate better-informed and targeted sports nutrition practice. This observational study assessed body composition (DXA), dietary intake (multiple-pass 24-hr recall) and nutrition knowledge (two previously validated tools) of elite and subelite male players involved in two team-based sports; Australian football (AF) and soccer. Differences in, and relationships between, nutrition knowledge, dietary intake and body composition between elite AF, subelite AF and elite soccer players were assessed. A total of 66 (23 ± 4 years, 82.0 ± 9.2 kg, 184.7 ± 7.7 cm) players participated. Areas of weaknesses in nutrition knowledge are evident (57% mean score obtained) yet nutrition knowledge was not different between elite and subelite AF and soccer players (58%, 57% and 56%, respectively, p > .05). Dietary intake was not consistent with recommendations in some areas; carbohydrate intake was lower (4.6 ± 1.5 g/kg/day, 4.5 ± 1.2 g/kg/day and 2.9 ± 1.1 g/kg/day for elite and subelite AF and elite soccer players, respectively) and protein intake was higher (3.4 ± 1.1 g/kg/day, 2.1 ± 0.7 g/kg/day and 1.9 ± 0.5 g/kg/day for elite and subelite AF and elite soccer players, respectively) than recommendations. Nutrition knowledge was positively correlated with fat-free soft tissue mass (n = 66; r 2 = .051, p = .039). This insight into known modifiable factors may assist sports nutrition professionals to be more specific and targeted in their approach to supporting players to achieve enhanced performance.
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.
Malone, Shane; Owen, Adam; Newton, Matt; Mendes, Bruno; Collins, Kieran D; Gabbett, Tim J
To examine the association between combined sRPE measures and injury risk in elite professional soccer. Observational cohort study. Forty-eight professional soccer players (mean±SD age of 25.3±3.1 yr) from two elite European teams were involved within a one season study. Players completed a test of intermittent-aerobic capacity (Yo-YoIR1) to assess player's injury risk in relation to intermittent aerobic capacity. Weekly workload measures and time loss injuries were recorded during the entire period. Rolling weekly sums and week-to-week changes in workload were measured, allowing for the calculation of the acute:chronic workload ratio, which was calculated by dividing the acute (1-weekly) and chronic (4-weekly) workloads. All derived workload measures were modelled against injury data using logistic regression. Odds ratios (OR) were reported against a reference group. Players who exerted pre-season 1-weekly loads of ≥1500 to ≤2120AU were at significantly higher risk of injury compared to the reference group of ≤1500AU (OR=1.95, p=0.006). Players with increased intermittent-aerobic capacity were better able to tolerate increased 1-weekly absolute changes in training load than players with lower fitness levels (OR=4.52, p=0.011). Players who exerted in-season acute:chronic workload ratios of >1.00 to soccer players. A higher intermittent-aerobic capacity appears to offer greater injury protection when players are exposed to rapid changes in workload in elite soccer players. Moderate workloads, coupled with moderate-low to moderate-high acute:chronic workload ratios, appear to be protective for professional soccer players. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
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....
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.
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.
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.
Bougault, Valérie; Drouard, François; Legall, Franck; Dupont, Grégory; Wallaert, Benoit
A high prevalence of respiratory allergies and exercise-induced bronchoconstriction (EIB) has been reported among endurance athletes. This study was designed to analyze the frequency of sensitization to respiratory allergens and EIB in young soccer players. Prospective cohort design. Youth academy and reserve professional soccer team during the seasons 2012 to 2013 and 2013 to 2014. Eighty-five soccer players (mean age: 20 ± 4 years) participated. Players underwent skin prick tests (SPTs) during the seasons 2012 to 2013 and 2013 to 2014. Spirometry and a eucapnic voluntary hyperpnea test were performed on soccer players during the first season 2012 to 2013 (n = 51) to detect EIB. Two self-administered questionnaires on respiratory history and allergic symptoms (European Community Respiratory Health Survey and Allergy Questionnaire for Athletes) were also distributed during both seasons (n = 59). The number of positive SPTs, exercise-induced respiratory symptoms, presence of asthma, airway obstruction, and EIB. Forty-nine percent of players were sensitized to at least one respiratory allergen, 33% reported an allergic disease, 1 player presented airway obstruction at rest, and 16% presented EIB. Factors predictive of EIB were self-reported exercise-induced symptoms and sensitization to at least 5 allergens. Questioning players about exercise-induced respiratory symptoms and allergies as well as spirometry at the time of the inclusion medical checkup would improve management of respiratory health of soccer players and would constitute inexpensive preliminary screening to select players requiring indirect bronchial provocation test or SPTs. This study showed that despite low frequencies, EIB and allergies are underdiagnosed and undertreated in young soccer players.
Palmer, Ty B; Hawkey, Matt J; Smith, Doug B; Thompson, Brennan J
The purpose of this study was to examine the effectiveness of maximal and rapid isometric torque characteristics of the posterior muscles of the hip and thigh and lower-body power to discriminate between professional status in full-time and part-time professional soccer referees. Seven full-time (mean ± SE: age = 36 ± 2 years; mass = 82 ± 4 kg; and height = 179 ± 3 cm) and 9 part-time (age = 34 ± 2 years; mass = 84 ± 2 kg; and height = 181 ± 2 cm) professional soccer referees performed 2 isometric maximal voluntary contractions (MVCs) of the posterior muscles of the hip and thigh. Peak torque (PT) and absolute and relative rate of torque development (RTD) were calculated from a torque-time curve that was recorded during each MVC. Lower-body power output was assessed through a vertical jump test. Results indicated that the rapid torque characteristics were greater in the full-time compared with the part-time referees for absolute RTD (p = 0.011) and relative RTD at 1/2 (p = 0.022) and 2/3 (p = 0.033) of the normalized torque-time curve. However, no differences were observed for PT (p = 0.660) or peak power (Pmax, p = 0.149) between groups. These findings suggest that rapid torque characteristics of the posterior muscles of the hip and thigh may be sensitive and effective measures for discriminating between full-time and part-time professional soccer referees. Strength and conditioning coaches may use these findings to help identify professional soccer referees with high explosive strength-related capacities and possibly overall refereeing ability.
Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important role that physical performance plays in match outcomes. Time-motion analyses have also influenced practice as player conditioning programmes can be tailored according to the different physical demands identified across individual playing positions. Yet despite a more systematic approach to physical conditioning, data indicate that even at the very highest standards of competition, the contemporary player is still susceptible to transient and end-game fatigue. Over the course of this article, the author suggests that a more pragmatic approach to interpreting the current body of time-motion analysis data and its application in the practical setting is nevertheless required. Examples of this are addressed using findings in the literature to examine (a) the association between competitive physical performance and 'success' in professional soccer, (b) current approaches to interpreting differences in time-motion analysis data across playing positions, and (c) whether data can realistically be used to demonstrate the occurrence of fatigue in match-play. Gaps in the current literature and directions for future research are also identified.
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.
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.
Hart, David; Funk, Lennard
An evidence base for the management and prevention of shoulder injuries in soccer is lacking. The aim of this study was to demonstrate the type, mechanism and recovery time after surgery associated with serious shoulder injuries sustained in professional soccer to build an evidence base foundation. Fifty-two professional soccer players underwent shoulder surgery for injuries sustained during match play. Of these, 25 fulfilled the inclusion criteria. Data were collected for injury mechanism and type; clinical, radiological and surgical findings and procedures; and return to full participation. Subjects were all managed by the same surgeon. Labral injuries represented the most common injury type affecting 21 (84 %) subjects; two rotator cuff (8 %) and two combined labral/rotator cuff (8 %) injuries were less common. Fourteen (56 %) subjects sustained a high-energy trauma injury in a combined abduction and external rotation position. Six (24 %) subjects sustained a low-energy trauma mechanism in variable positions, while five (20 %) had a gradual onset of symptoms. Twenty-two (88 %) subjects reported a dislocation as a feature of their presentation. All of the subjects with high- and low-energy trauma mechanisms reported a dislocation occurring at the time of injury. Eight (32 %) subjects had sustained a previous significant shoulder injury to the ipsilateral side. Goalkeepers did not sustain low-energy trauma injuries. Outfield players returned to full participation in a mean time of 11.6 weeks, while goalkeepers did so in 11.1 weeks post-surgery. Return to participation time ranged from 7 to 24 weeks with a median of 11 weeks. Professional soccer players can expect a return to participation within 12 weeks post-surgery. The majority of serious shoulder injuries in soccer occur at a positional extreme of external rotation and abduction in high-energy situations, while a significant number occur in low-energy situations away from this position. Most serious shoulder
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.
Wood, Susan; Harrison, Lesley K; Kucharska, Jo
Male professional footballers (soccer) represent an at-risk population of developing mental health difficulties and not accessing professional support. One in four current footballers report mental health difficulties. Higher prevalence is reported after retirement. This qualitative study aimed to provide in-depth insight into male professional footballers' lived experiences of mental health difficulties and help-seeking. Seven participants were interviewed. Data were analysed using interpretative phenomenological analysis. One superordinate theme emerged; 'Survival'. This related to survival in the professional football world, of mental health difficulties and after transition into the 'real world'. Six subordinate themes are explored alongside literature pertaining to male mental health, identity, injury, transition, and emotional development. Shame, stigma, fear and level of mental health literacy (knowledge of mental health and support) were barriers to help-seeking. Support for professional footballers' mental wellbeing requires improvement. Recommendations are made for future research, mental health education and support.
João Paulo Lara de Siqueira
Full Text Available Whereas an initial step in the management of stakeholders is the identification and classification of these actors, this study sought to answer the research question: how managers of Brazilian professional soccer clubs identify and classify their stakeholders? The theoretical framework used was the Stakeholder Theory, developed by Freeman (1984 and other researchers. The method used was proposed by Almeida et al. (2000, which assesses the saliency through the concepts power, legitimacy and urgency, that were proposed in the study of Mitchell et al. (1997. There were two propositions concerning the context of Brazilian soccer clubs: first, that the urgency perceived by managers in the demands of a stakeholder is high when his legitimacy is high and other one is that the most salient stakeholders for the managers are those with high degrees of legitimacy. Stakeholders were surveyed as perceived by the managers of Sociedade Esportiva Palmeiras. Three types of stakeholders were classified as demanding (sponsors, partners and the partner for the construction of the new stadium and three as dependents (members, athletes of professional soccer team and the media. Other stakeholders identified were classified as irrelevant, including the fans and and the organized groups of fans. It can be said that in the specific case of these managers of this particular football club, the trend was the acceptance of both propositions.
Helsen, Werner F; Baker, Joseph; Michiels, Stijn; Schorer, Joerg; Van Winckel, Jan; Williams, A Mark
The relative age effect (RAE) refers to an asymmetry in the birth-date distribution favouring players born early in the selection year and discriminating against participants born later in the year. While the RAE effect was initially reported in sport more than two decades ago, there have been few attempts to examine whether player selection strategies have changed over time in light of our improved understanding of the phenomenon. We compared the birth-date distributions of professional soccer players in ten European countries over a 10-year period involving the 2000-2001 and 2010-2011 competitive seasons, respectively. Chi-square goodness-of-fit tests were used to compare differences between the observed and expected birth-date distributions across selection years. Generally, results indicated no change in the RAE over the past 10 years in professional soccer, emphasizing the robust nature of this phenomenon. We propose a change in the structure of youth involvement in soccer to reduce the impact of the RAE on talent identification and selection.
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 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
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.
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.
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
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
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.
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.
Full Text Available Angiotensin-1 converting enzyme (ACE gene and α-actinin-3 (ACTN3 gene polymorphisms are considered to be the most important candidate genes for genetic predisposition to human athletic performance. In the present study, we aimed to analyze the distribution of ACE and ACTN3 polymorphisms for the first time in male Turkish soccer players. In this prospective study, our cohort consisted of 25 professional players, all with Turkish ancestry. Polymerase chain reaction (PCR-restriction length polymorphism was used for the characterization of the genotype of ACTN3 and single PCR for ACE . For ACE genotype, 16%, 44%, and 40% of the players had insertion/insertion (II, insertion/deletion (ID, and deletion/deletion (DD genotypes, respectively, whereas 20% had XX, 36% had RX, and 44% had RR genotypes for ACTN3 . When we examined the allelic percentages, for ACE , D allele was recorded as 62 and I as 38, and for ACTN3 , R allele was 62 and X was 38. Our results were in agreement with the previous reports, indicating the presence of ACTN3 D and ACE X allele in soccer players. We suggest that ACE and ACTN3 genotypes are important biomarkers for genetic counseling for the individuals who are prone to be successful soccer players.
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.
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
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.
Ranchordas, Mayur K; Tiller, Nicholas B; Ramchandani, Girish; Jutley, Raj; Blow, Andrew; Tye, Jonny; Drury, Ben
The purpose of this paper was to report normative data on regional sweat sweat-sodium concentrations of various professional male team-sport athletes, and to compare sweat-sodium concentrations among sports. Data to this effect would inform our understanding of athlete sodium requirements, thus allowing for the individualisation of sodium replacement strategies. Accordingly, data from 696 athletes (Soccer, n = 270; Rugby, n = 181; Baseball, n = 133; American Football, n = 60; Basketball, n = 52) were compiled for a retrospective analysis. Regional sweat-sodium concentrations were collected using the pilocarpine iontophoresis method, and compared to self-reported measures collected via questionnaire. Sweat-sodium concentrations were significantly higher ( p soccer (43.2 ± 12.0 mmol·L -1 ) or rugby (44.0 ± 12.1 mmol·L -1 ), but with no differences among the N.American or British sports. There were strong positive correlations between sweat-sodium concentrations and self-reported sodium losses in American football ( r s = 0.962, p soccer ( r s = 0.748, p strategies to meet the sodium demands of professional team-sport athletes. Moreover, these novel data suggest that self-reported measures of sodium loss might serve as an effective surrogate in the absence of direct measures; i.e., those which are more expensive or non-readily available.
Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István
The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 - 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer.
Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István
The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 – 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer. PMID:23717351
Tenga, Albin; Holme, Ingar; Ronglan, Lars Tore; Bahr, Roald
Methods that include an assessment of opponent interactions are thought to provide a more valid analysis of team match performance. The purpose of this study was to examine the effect of playing tactics on goal scoring by assessing opponent interactions in Norwegian elite soccer. The sample included 203 team possessions leading to goals (cases) and 1688 random team possessions (control group) from 163 of 182 (90%) matches played in the men's professional league during the 2004 season. Multidimensional qualitative data using ten ordered categorical variables were obtained to characterize each team possession. The proportion of goals scored during counterattacks (52%) was higher than during elaborate attacks (48%), while for the control group the proportion using elaborate attacks (59%) was higher than when using counterattacks (41%) (P = 0.002). Multiple logistic regression analyses showed that, for the main variable "team possession type", counterattacks were more effective than elaborate attacks when playing against an imbalanced defence (OR = 1.64; 95% confidence interval: 1.03 to 2.61; P = 0.038). Assessment of opponent interactions is critical to evaluate the effectiveness of offensive playing tactics on the probability of scoring goals, and improves the validity of team match-performance analysis in soccer.
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
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
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
Vincent Gouttebarge, Frank J.G. Backx, Haruhito Aoki, Gino M.M.J. Kerkhoffs
Full Text Available Evidence on the prevalence of symptoms related to distress, anxiety/depression or substance abuse/dependence, – typically referred to as symptoms of common mental disorders (CMD – is lacking in European professional football (soccer. The aims of the present study were to investigate the prevalence of symptoms related to CMD (distress, anxiety/depression, sleeping disturbance, adverse alcohol behaviour, and adverse nutrition behaviour in professional footballers from five European countries, and to explore associations of the outcome measures under study with life events and career dissatisfaction. A cross-sectional design was used. Questionnaires were distributed among professional footballers by the national players’ unions in Finland, France, Norway, Spain and Sweden. The highest prevalence of symptoms related to common mental disorders were 18% for distress (Sweden, 43% for anxiety/depression (Norway, 33% for sleeping disturbance (Spain, 17% for adverse alcohol behaviour (Finland, and 74% for adverse nutrition behaviour (Norway. In Finland, France and Sweden, both life events and career dissatisfaction were associated with distress, anxiety/depression, adverse alcohol behaviour, and adverse nutrition behaviour. Results suggest the need for self-awareness in professional football about common mental disorders and a multidisciplinary approach by the medical team.
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
van der Horst, N
The aim of the studies reported in this thesis was to investigate strategies for the prevention of hamstring injuries. Hamstring injuries are the most prevalent muscle injury in soccer. In spite of efforts to reduce the occurrence of hamstring injuries in soccer, injury rates have not decreased over the last three decades. Therefore, research on hamstring injury prevention is necessary to reduce hamstring injury rates. Exercise programs to reduce soccer injuries are easy to implement during r...
Fowler, Peter; Duffield, Rob; Waterson, Adam; Vaile, Joanna
The current study examined the acute and longitudinal effects of regular away travel on training load (TL), player wellness, and injury surrounding competitive football (soccer) matches. Eighteen male professional football players, representing a team competing in the highest national competition in Australia, volunteered to participate in the study. Training loads, player wellness and injury incidence, rate, severity, and type, together with the activity at the time of injury, were recorded on the day before, the day of, and for 4 d after each of the 27 matches of the 2012-13 season. This included 14 home and 13 away matches, further subdivided based on the midpoint of the season into early (1-13) and late competition (14-27) phases. While TLs were significantly greater on day 3 at home compared with away during the early competition phase (P=.03), no other significant effects of match location were identified (P>.05). Total TL and mean wellness over the 6 d surrounding matches and TL on day 3 were significantly reduced during the late compared with the early competition phase at home and away (P.05), training missed due to injury was 60% and 50% greater during the late than during the early competition phase at home and away, respectively. In conclusion, no significant interactions between match location and competition phase were evident during the late competition phase, which suggests that away travel had negligible cumulative effects on the reduction in player wellness in the latter half of the season.
Keiner, Michael; Sander, Andre; Wirth, Klaus; Hartmann, Hagen
The purpose of this study was to establish whether physical attributes can differentiate between professional, amateur and elite youth soccer players; such a distinction could aid in the selection process for youth soccer. Therefore, this investigation evaluated a suspected difference in the performance tests of the slow and fast stretch and the shortening cycle (squat jump [SJ], countermovement jump [CMJ], and drop jump from varying heights [DJ]) among professional, amateur and elite youth s...
van der Horst, N
The aim of the studies reported in this thesis was to investigate strategies for the prevention of hamstring injuries. Hamstring injuries are the most prevalent muscle injury in soccer. In spite of efforts to reduce the occurrence of hamstring injuries in soccer, injury rates have not decreased over
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.
Full Text Available The aim of this study was to compare physical fitness parameters of male adolescent soccer players and sedentary counterparts. A total of 26 male adolescents participated in this study voluntarily: Active soccer players (n: 3, age x : 13,00 ± 0,00 and sedentary counterparts (n: 13, age x :12,92 ± 0,75. The EUROFIT test battery was used to determine physical fitness. The test battery includes body height and weight measurements, touching the discs, flamingo balan ce, throwing health ball, vertical jumping, sit and reach, sit - up for 30 s, 20 meter sprint run, and 20 meter shuttle run tests. Data were analyzed by Mann Whitney U test. Significance was defined as p.05. In conclusion, children who do sports are more successful on most of the fitness parameters than sedentary children.
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 The purpose of this study was to investigate the influence that different frequencies of deceleration and acceleration actions had on the physiological demands in professional soccer players. Thirteen players were monitored via microelectromechanical devices during shuttle running protocols which involved one, three, or seven 180 degree directional changes. Heart rate exertion (HRE (1.1 ± 0.7 and rating of perceived exertion (RPE (5 ± 1 were significantly higher for the protocol which included seven directional changes when compared to the protocols which included one (HRE 0.5 ± 0.3, ES = 1.1, RPE 3 ± 0, ES = 2.7 or three (HRE 0.5 ± 0.2, ES = 1.1, RPE 3 ± 1, ES = 1.9 directional changes (p < 0.05. The gravitational force (g-force as measured through accelerometry (ACC also showed a similar trend when comparing the seven (8628.2 ± 1630.4 g to the one (5888.6 ± 1159.1 g, ES = 1.9 or three (6526.9 ± 1257.6 g, ES = 1.4 directional change protocols (p < 0.05. The results of this study suggest that increasing the frequency of decelerations and accelerations at a high intensity running (HIR speed alters the movement demands and elevates the physiological responses in professional players. This data has implications for the monitoring of physical performance and implementation of training drills.
Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G; Krustrup, Peter; Mohr, Magni
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 soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement ( p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip abductors (6 ± 1%) demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery.
Full Text Available 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 soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement (p ≤ 0.05 at 0 h post-match with knee flexors (14 ± 3% and hip abductors (6 ± 1% demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05 for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin and 24 h into recovery (creatine kinase, respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02. In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery.
Silvers-Granelli, Holly J; Bizzini, Mario; Arundale, Amelia; Mandelbaum, Bert R; Snyder-Mackler, Lynn
The FIFA 11+ injury prevention program has been shown to decrease the risk of soccer injuries in men and women. The program has also been shown to decrease time loss resulting from injury. However, previous studies have not specifically investigated how the program might impact the rate of anterior cruciate ligament (ACL) injury in male soccer players. The purpose of this study was to examine if the FIFA 11+ injury prevention program can (1) reduce the overall number of ACL injuries in men who play competitive college soccer and whether any potential reduction in rate of ACL injuries differed based on (2) game versus practice setting; (3) player position; (4) level of play (Division I or II); or (5) field type. This study was a prospective cluster randomized controlled trial, which was conducted in 61 Division I and Division II National Collegiate Athletic Association men's soccer teams over the course of one competitive soccer season. The FIFA 11+ is a 15- to 20-minute on-the-field dynamic warm-up program used before training and games and was utilized as the intervention throughout the entire competitive season. Sixty-five teams were randomized: 34 to the control group (850 players) and 31 to the intervention group (675 players). Four intervention teams did not complete the study and did not submit their data, noting insufficient time to complete the program, reducing the number for per-protocol analysis to 61. Compliance to the FIFA 11+ program, athletic exposures, specific injuries, ACL injuries, and time loss resulting from injury were collected and recorded using a secure Internet-based system. At the end of the season, the data in the injury surveillance system were crosshatched with each individual institution's internal database. At that time, the certified athletic trainer signed off on the injury collection data to confirm their accuracy and completeness. A lower proportion of athletes in the intervention group experienced knee injuries (25% [34 of
Bruguera, M; Arrizabalaga, P; Londoño, M C; Padrós, J
The awards for the excellence of the Official College of Physicians of Barcelona (COMB) were instituted in 2004 to recognize the excellence of the professional exercise. The winners are yearly chosen by juries appointed by the board of government, whose members propose for the award doctors who, in their opinion, have an exemplary professional and human behaviour. The number of male and female doctors who have obtained this recognition has been analysed in relation with the sex distribution in the juries. Likewise it has been compared the ratios men-to-women of those who have been rewarded and this ratio among physicians of more than 45 years. Between the awarded physicians the ratio men-to-women was of 2.7/1 (range, from 1.2/1 for awardees in primary care to 6/1 in research). The men-to-women ratio among those who were awarded was in parallel to the man-to-women ratios of the juries. The ratio between men and women among members of the COMB of more than 45 years was 1.4/1, whereas in those who were awarded it was of 2.7/1. The increase in the proportion of women in the juries in the last four years has been followed by an increase in the number of female physicians awarded. This data demonstrates that the predominance of male doctors among those who were awarded does not depend so much on the age factor, but basically on the proportion of male and female doctors in the juries. Copyright © 2013 Elsevier España, S.L. All rights reserved.
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....
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.
Van Doormaal, Mitchell C M; Van Der Horst, Nick; Backx, Frank J G; Smits, Dirk Wouter; Huisstede, Bionka M A
BACKGROUND: 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. PURPOSE: To investigate the relationship between hamstring flexibility and hamstring injuries
Full Text Available Home advantage in team sports has an important role in determining the outcome of a game. The aim of the present study was to identify the soccer game- related statistics that best discriminate home and visiting teams according to the team quality. The sample included all 380 games of the Spanish professional men's league. The independent variables were game location (home or away and the team quality. Teams were classified into four groups according to their final ranking at the end of the league. The game-related statistics registered were divided into three groups: (i variables related to goals scored; (ii variables related to offense and (iii variables related to defense. A univariate (t-test and Mann-Whitney U and multivariate (discriminant analysis analysis of data was done. Results showed that home teams have significantly higher means for goal scored, total shots, shots on goal, attacking moves, box moves, crosses, offsides committed, assists, passes made, successful passes, dribbles made, successful dribbles, ball possession, and gains of possession, while visiting teams presented higher means for losses of possession and yellow cards. In addition, the findings of the current study confirm that game location and team quality are important in determining technical and tactical performances in matches. Teams described as superior and those described as inferior did not experience the same home advantage. Future research should consider the influence of other confounding variables such as weather conditions, game status and team form
João Bourbon de Albuquerque II
Full Text Available Abstract AIMS To verify the incidence of injuries in professional soccer athletes in Aracaju-SE and to identify associated factors. METHODS This was an observational, prospective cohort study involving 39 healthy athletes, followed for seven months and evaluated on four occasions (start on preseason and two evaluations with three months of interval between each through data collection sheet and orthopedic physical examination. RESULTS Participants were 20 athletes from Club Sportivo Sergipe and 19 from Associação Desportiva Confiança, with mean age of 26 years (CI 95%: 25.2-28 years, and mean career time of 9.6 years (CI 95%: 7.9-11.3 years. The 13 (2.4 / 1000 hours diagnosed injuries occurred almost exclusively in the lower limbs and thigh muscle stretch was the most common injury. Injuries were mostly mild to moderate (69%. There was no significant association with any of the variables analyzed. CONCLUSION Low incidence of injuries was observed in this study. Predominantly, lesions occurred on non-rainy days and were due to trauma. Lower limbs were the most affected location and thigh stretch was the most common injury.
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.
Anderson, Liam; Naughton, Robert J; Close, Graeme L; Di Michele, Rocco; Morgans, Ryland; Drust, Barry; Morton, James P
The daily distribution of macronutrient intake can modulate aspects of training adaptations, performance and recovery. We therefore assessed the daily distribution of macronutrient intake (as assessed using food diaries supported by the remote food photographic method and 24-hr recalls) of professional soccer players (n = 6) of the English Premier League during a 7-day period consisting of two match days and five training days. On match days, average carbohydrate (CHO) content of the prematch (recovery from an evening kick-off) were similar (p > .05) though such intakes were lower than contemporary guidelines considered optimal for prematch CHO intake and postmatch recovery. On training days, we observed a skewed and hierarchical approach (p lunch (0.6 g·kg -1 )>breakfast (0.3 g·kg -1 )>evening snacks (0.1 g·kg -1 ). We conclude players may benefit from consuming greater amounts of CHO in both the prematch and postmatch meals so as to increase CHO availability and maximize rates of muscle glycogen resynthesis, respectively. Furthermore, attention should also be given to ensuring even daily distribution of protein intake so as to potentially promote components of training adaptation.
Koundourakis, Nikolaos E; Androulakis, Nikolaos E; Malliaraki, Niki; Tsatsanis, Christos; Venihaki, Maria; Margioris, Andrew N
The aim of this study was to examine the effects of a six-week off-season detraining period on exercise performance, body composition, and on circulating sex steroid levels in soccer players. Fifty-five professional male soccer players, members of two Greek Superleague Teams (Team A, n = 23; Team B, n = 22), participated in the study. The first two weeks of the detraining period the players abstained from any physical activity. The following four weeks, players performed low-intensity (50%-60% of VO2max) aerobic running of 20 to 30 minutes duration three times per week. Exercise performance testing, anthropometry, and blood sampling were performed before and after the six-week experimental period. Our data showed that in both teams A and B the six-week detraining period resulted in significant reductions in maximal oxygen consumption (60,31±2,52 vs 57,67±2,54; pperiod resulted in a rapid loss of exercise performance adaptations and optimal body composition status, but did not affect sex steroid resting levels. The insignificant changes in sex steroid concentration indicate that these hormones were a non-contributing parameter for the observed negative effects of detraining on exercise performance and body composition.
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...
Lago-Ballesteros, Joaquin; Lago-Peñas, Carlos; Rey, Ezequiel
The aim of this study was to analyse the influence of playing tactics, opponent interaction and situational variables on achieving score-box possessions in professional soccer. The sample was constituted by 908 possessions obtained by a team from the Spanish soccer league in 12 matches played during the 2009-2010 season. Multidimensional qualitative data obtained from 12 ordered categorical variables were used. Sampled matches were registered by the AMISCO PRO system. Data were analysed using chi-square analysis and multiple logistic regression analysis. Of 908 possessions, 303 (33.4%) produced score-box possessions, 477 (52.5%) achieved progression and 128 (14.1%) failed to reach any sort of progression. Multiple logistic regression showed that, for the main variable "team possession type", direct attacks and counterattacks were three times more effective than elaborate attacks for producing a score-box possession (P tactics on producing score-box possessions.
Full Text Available AbstractSports foundations aiming at promoting sports activities partly outline the nonprofit area with specific concern. This study attempts to know the functions, general interests of professional soccer foundations in Spain, to describe their main characteristics and to ascertain if there are significant differences among them, according to their descriptive features. A document survey and analysis was carried out, with an assistance of own establishment of documental database. The findings not only indicate a significant difference between the classification of Spanish soccer foundations and their antiquities, but also manifest the tendency of the existence of physical person in members of founders with regard to its antiquity. The results of the present work implied that there were great dissimilarities of the elaboration of regulations depending on different regions in Spain.ResumenDentro del sector asociativo, las fundaciones deportivas tienen el propósito específico de desarrollar actividades de promoción deportiva. Este estudio intentó conocer las funciones, e intereses generales, de las fundaciones del fútbol profesional en España, describiendo sus principales características y comprobando si existían diferencias significativas entre ellos. Se utilizó el análisis documental y se realizó una base de datos documental. Los resultados indicaron que existía una diferencia significativa entre los diferentes tipos de clasificación de una fundación del fútbol profesional en España en función de la antigüedad de dicha fundación. También se manifestó una tendencia de la existencia de personas físicas o no, dentro del tipo de fundadores, en función de la antigüedad de la organización. La presente investigación pone de manifiesto la gran variedad en las legislaciones dependiendo de la comunidad autónoma de origen.http://dx.doi.org/10.5232/ricyde2013.03106
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.
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.
Hammami, Amri; Randers, Morten B.; Kasmi, Sofien
, and enjoyment responses. Over 8 weeks, the between-group analysis revealed that soccer training had a large beneficial effect on postural balance (45%) when compared with control group with unclear effects on other fitness parameters. Conclusion: Adolescent soccer players had markedly higher physical fitness......, postural balance, flexibility, and aerobic capacity. After baseline testing, Purposes 2 and 3 were addressed by randomly assigning the untrained boys to either a soccer-training group (small-sided games, 2 sessions per week for 8 weeks) or to a control group, followed by identical retesting. Results......: At baseline, physical fitness was higher (p postural balance. Small-sided games using 6 v 6 or 4 v 4 elicited similar heart rate (HR) (mean: ~ 85% peak heart rate, HRpeak), rate of perceived exertion...
Harry, John R; Barker, Leland A; Mercer, John A; Dufek, Janet S
Harry, JR, Barker, LA, Mercer, JA, and Dufek, JS. Vertical and horizontal impact force comparison during jump landings with and without rotation in NCAA Division I male soccer players. J Strength Cond Res 31(7): 1780-1786, 2017-There is a wealth of research on impact force characteristics when landing from a jump. However, there are no data on impact forces during landing from a jump with an airborne rotation about the vertical axis. We examined impact force parameters in the vertical and horizontal axes during vertical jump (VJ) landings and VJ landings with a 180° rotation (VJR). Twenty-four Division I male soccer players performed 3 VJ and VJR landings on a dual-force platform system. Paired-samples t-tests (α = 0.05) compared differences in the first (F1) and second (F2) peak vertical ground reaction forces, times to F1 (tF1), F2 (tF2), and the end of the impact phase, vertical impulse, and anterior-posterior and medial-lateral force couples. Effect sizes (ES; large >0.8) were computed to determine the magnitude of the differences. Lower jump height (41.60 ± 4.03 cm, VJ landings; 39.40 ± 4.05 cm, VJR landings; p = 0.002; ES = 0.39), greater F2 (55.71 ± 11.95 N·kg, VJ; 68.16 ± 14.82 N·kg; p jump with 180° airborne rotation is different than landing from a jump without an airborne rotation. Male Division I soccer players could benefit from increasing the volume of VJR landings during training to address the differences in jump height and force parameters compared with VJ landings.
Alentorn-Geli, Eduard; Alvarez-Diaz, Pedro; Ramon, Silvia; Marin, Miguel; Steinbacher, Gilbert; Rius, Marta; Seijas, Roberto; Ares, Oscar; Cugat, Ramon
There is a large number of publications evaluating neuromuscular risk factors for anterior cruciate ligament (ACL) injury in athletes. However, most of them have involved the female athlete and, in addition, the gastrocnemius muscles have been less investigated by far compared with the quadriceps and hamstring. The purpose of this study was to investigate the role of the gastrocnemius muscles as neuromuscular risk factors for ACL injury in male soccer players, through tensiomyography (TMG). All competitive male soccer players with confirmed ACL tear included in this study underwent resting TMG assessment of gastrocnemius medialis (GM) and gastrocnemius lateralis muscles of the uninjured side. The same values were obtained from a sex-, and sports level-matched control group in both sides. The maximal displacement (D m), delay time (T d), contraction time (T c), sustained time (T s), and half-relaxation time (T r) were obtained for both muscles. TMG values of the uninjured side in ACL-injured group were compared with the mean values between both sides in the control subjects. There were no significant between-group differences in demographic characteristics. Most TMG parameters of the gastrocnemius muscles were not significantly different between the two groups. Only the GM-T r (p = 0.02) and GM-D m (p = 0.006) were significantly higher in the ACL-injured group compared with control group. Neuromuscular characteristics in terms of mechanical and contractile properties of the gastrocnemius muscles may not be significant risk factors for ACL injury in male soccer players.
Francimara Budal Arins
Full Text Available > This study aimed to characterize physiological responses of indoor soccer (futsal professional players to training sessions, according to playing position. The sample was composed by five players ( X =23.9±3.0 yrs of an adult professional futsal team from Florianópolis, SC, Brazil. The athletes performed a maximal exercise test for measuring oxygen consumption, heart rate (HR and respiratory quotient (RQ, variables used to create regression equations for energy expenditure (EE, kcal prediction and to estimate relative work intensity (% max HR. During the sessions, HR was measured with a S610i Polar® monitor. The results showed that the goalkeeper played at 60% to 70% max HR. The mid-fi elders and the attacker worked at more intense levels (81% to 100%, while the defender varied the intensity at intermediate exercise range (71% to 90%. Total EE was similar among mid-fi elders and attacker ( X =339.5 kcal, while the defender presented lower values ( X =255.0 kcal. The goalkeeper had the lowest EE ( X =106.9 kcal. The results agreed with those reported in soccer studies and facilitate planning and control of an individualized training program according to playing position. ABSTRACT Este estudo objetivou caracterizar as respostas fi siológicas de atletas profissionais de futsal durante o treinamento coletivo, de acordo com a posição tática desempenhada. A amostra foi composta pelos cinco jogadores titulares ( X =23,9±3,0 anos de uma equipe de futsal masculino profi ssional adulto da cidade de Florianópolis, SC. Os atletas foram avaliados por um teste ergoespirométrico máximo, que forneceu o consumo de oxigênio, a freqüência cardíaca (FC e o quociente respiratório (RQ, valores utilizados para gerar equações de regressão para estimativa do gasto calórico (GCal e da intensidade do trabalho (expressa em % FC máxima predita pela idade (% FC máx. Durante os coletivos, a FC foi mensurada com um monitor Polar modelo S610i®. Os
Ravé, Guillaume; Fortrat, Jacques-Olivier
To show that heart rate variability (HRV) in the standing position better reflects the way in which athletes adapt to training in so-called intermittent sports than the indicator of resting parasympathetic tone usually employed in endurance sports. Twenty professional soccer players (intermittent sport) took part in a 5-week training session divided into three successive periods: "Warm-up", "Intensive training" and "Tapering". At the beginning and end of each of the three periods, a stand test was carried out and the heart rate was recorded, beat by beat (Polar Team 2). We analysed HRV to determine the indicator mostly used to demonstrate training adaptation in endurance sports (lnRMSSD supine, natural logarithm of root mean square of the successive differences) as well as indicators obtained by means of spectral analysis in both supine and standing position. A decrease in heart rate was observed in the supine position at rest during training (-5.2 ± 1.3 bpm) while lnRMSSD and spectral analysis indicators remained unchanged. The "Warm-up" caused an increase in spectral analysis total power in standing position which was further highlighted by "Tapering" (3.39 ± 0.09, 3.61 ± 0.08 and 3.65 ± 0.09 log ms(2), respectively). However, the autonomic changes are probably more complex than a change in autonomic activity or balance since spectral analysis autonomic indicators remained unchanged. HRV in the standing position could monitor training adaptation in intermittent sports contrary to the indicator usually employed in endurance sports. However, the significance of the HRV change in the standing position during training remains unclear.
Vescovi, Jason D
The aim of this study was to determine sprint profiles of professional female soccer players and evaluate how various speed thresholds impact those outcomes. Seventy-one professional players competing in full matches were assessed repeatedly during 12 regular season matches using a Global Positioning System (GPS). Locomotion ≥18 km · h⁻¹ was defined as sprinting and each event was classified into: Zone 1: 18.0-20.9 km· h⁻¹; Zone 2: 21.0-22.9 km · h⁻¹; Zone 3: 23.0-24.9 km · h⁻¹ and Zone 4: >25 km · h⁻¹. Outcomes included: duration (s), distance (m), maximum speed (km · h⁻¹), duration since previous sprint (min) and proportion of total sprint distance. In total 5,019 events were analysed from 139 player-matches. Mean sprint duration, distance, maximum speed and time between sprints were 2.3 ± 1.5 s, 15.1 ± 9.4 m, 21.8 ± 2.3 km· h⁻¹, and 2.5 ± 2.5 min, respectively. Mean sprint distances were 657 ± 157, 447 ± 185, and 545 ± 217 m for forwards, midfielders and defenders, respectively (P ≤ 0.046). Midfielders had shorter sprint duration (P = 0.023), distance (P ≤ 0.003) and maximum speed (P professional female soccer players covered 5.3 ± 2.0% of total distance ≥18 km · h⁻¹ with positional differences and percent decrements distinct from other previously identified elite players. These data should guide the development of high intensity and sprint thresholds for elite-standard female soccer players.
Jadczak, Łukasz; Grygorowicz, Monika; Dzudziński, Witold; Śliwowski, Robert
Jadczak, Ł, Grygorowicz, M, Dzudziński, W, and Śliwowski, R. Comparison of static and dynamic balance at different levels of sport competition in professional and junior elite soccer players. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to compare body balance control and balance recovery strategies of professional football players, representing various sports levels in static (eyes open, eyes closed) and dynamic conditions, both on the dominant and nondominant leg. Three groups of professional and junior elite soccer players were investigated: a PRO group (n = 52), a U-21 group (n = 55), and a U-19 group (n = 47). The study of body balance control was performed using a Delos Postural Proprioceptive System measurement tool. The analysis of the results showed an effect of group (p balance on both legs, which allows for a comprehensive comparison of body balance control and the balance recovery strategy depending on the represented sport level. Our study indicates that the higher the sport level of football players (the PRO group), the better their balance, which may indirectly contribute to the prevention of injuries and more effective performance of any actions directly related to the game.
Marc A. Briggs
Full Text Available Collecting accurate and reliable nutritional data from adolescent populations is challenging, with current methods providing significant under-reporting. Therefore, the aim of the study was to determine the accuracy of a combined dietary data collection method (self-reported weighed food diary, supplemented with a 24-h recall when compared to researcher observed energy intake in male adolescent soccer players. Twelve Academy players from an English Football League club participated in the study. Players attended a 12 h period in the laboratory (08:00 h–20:00 h, during which food and drink items were available and were consumed ad libitum. Food was also provided to consume at home between 20:00 h and 08:00 h the following morning under free-living conditions. To calculate the participant reported energy intake, food and drink items were weighed and recorded in a food diary by each participant, which was supplemented with information provided through a 24-h recall interview the following morning. Linear regression, limits of agreement (LOA and typical error (coefficient of variation; CV were used to quantify agreement between observer and participant reported 24-h energy intake. Difference between methods was assessed using a paired samples t-test. Participants systematically under-reported energy intake in comparison to that observed (p < 0.01 but the magnitude of this bias was small and consistent (mean bias = −88 kcal·day−1, 95% CI for bias = −146 to −29 kcal·day−1. For random error, the 95% LOA between methods ranged between −1.11 to 0.37 MJ·day−1 (−256 to 88 kcal·day−1. The standard error of the estimate was low, with a typical error between measurements of 3.1%. These data suggest that the combined dietary data collection method could be used interchangeably with the gold standard observed food intake technique in the population studied providing that appropriate adjustment is made for the systematic under
Briggs, Marc A.; Rumbold, Penny L. S.; Cockburn, Emma; Russell, Mark; Stevenson, Emma J.
Collecting accurate and reliable nutritional data from adolescent populations is challenging, with current methods providing significant under-reporting. Therefore, the aim of the study was to determine the accuracy of a combined dietary data collection method (self-reported weighed food diary, supplemented with a 24-h recall) when compared to researcher observed energy intake in male adolescent soccer players. Twelve Academy players from an English Football League club participated in the study. Players attended a 12 h period in the laboratory (08:00 h–20:00 h), during which food and drink items were available and were consumed ad libitum. Food was also provided to consume at home between 20:00 h and 08:00 h the following morning under free-living conditions. To calculate the participant reported energy intake, food and drink items were weighed and recorded in a food diary by each participant, which was supplemented with information provided through a 24-h recall interview the following morning. Linear regression, limits of agreement (LOA) and typical error (coefficient of variation; CV) were used to quantify agreement between observer and participant reported 24-h energy intake. Difference between methods was assessed using a paired samples t-test. Participants systematically under-reported energy intake in comparison to that observed (p < 0.01) but the magnitude of this bias was small and consistent (mean bias = −88 kcal·day−1, 95% CI for bias = −146 to −29 kcal·day−1). For random error, the 95% LOA between methods ranged between −1.11 to 0.37 MJ·day−1 (−256 to 88 kcal·day−1). The standard error of the estimate was low, with a typical error between measurements of 3.1%. These data suggest that the combined dietary data collection method could be used interchangeably with the gold standard observed food intake technique in the population studied providing that appropriate adjustment is made for the systematic under-reporting common to such
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...
Suarez-Arrones, L; Torreño, N; Requena, B; Sáez De Villarreal, E; Casamichana, D; Barbero-Alvarez, J C; Munguía-Izquierdo, D
The aim was to quantify for the first time the physical and physiological profile of professional soccer players in official games using GPS and heart rate (HR) response. Thirty professional soccer players were investigated during a half in competitive club level matches (N.=348) using GPS devices. The relative total distance was 118.9±10.7 m∙min(-1) and player's Work-To-Rest Ratio was 2.1:1. Defenders covered the lowest total distance, while Second-Strikers (2(nd)S) and Wide-Midfielders (W-MD) traveled the greatest total distance. Defenders presented the lowest Work-To-Rest Ratio values. Playing position also impacted on all sprinting performance results, except in average sprint distance and time of sprint. The number of sprints and repeated-sprint sequences recorded by the W-MD and Strikers (S) were significantly greater than any other group. The average HR recorded was 87.1%HRmax and the relationship between the external and internal load value (Effindex) was 1.4 with significant differences in both between playing positions. W-MD recorded a significantly smaller average HR than any other group and Centre-Backs showed a significantly smaller Effindex value than any other group. Conversely, W-MD showed a significantly greater Effindex value than any other group, except the 2(nd)S. This study has verified a number of statistically significant differences between the different playing positions. Coaches should be focused on the specific physical and physiological requirements of the playing positions to optimize the training prescription in soccer. The relationships between external and internal load measures among position-specific indicates that players with less overall running performance during match-play were the worst in Effindex.
The coaching carousel or turnover is an extreme but frequently occurring phenomenon in soccer. Among the reasons for firing a coach, the most common is the existence of a shock-effect: a new coach would be able to motivate the players better and therefore to improve results. Using data from the Spanish Soccer League during the seasons from 1997?1998 to 2006?2007, this paper investigates the relationship between team performance and coach change over time. The empirical analysis shows that the...
Jaspers, Arne; Beéck, Tim Op De; Brink, Michel S; Frencken, Wouter G P; Staes, Filip; Davis, Jesse J; Helsen, Werner F
Machine learning may contribute to understanding the relationship between the external load and internal load in professional soccer. Therefore, the relationship between external load indicators and the rating of perceived exertion (RPE) was examined using machine learning techniques on a group and individual level. Training data were collected from 38 professional soccer players over two seasons. The external load was measured using global positioning system technology and accelerometry. The internal load was obtained using the RPE. Predictive models were constructed using two machine learning techniques, artificial neural networks (ANNs) and least absolute shrinkage and selection operator (LASSO), and one naive baseline method. The predictions were based on a large set of external load indicators. Using each technique, one group model involving all players and one individual model for each player was constructed. These models' performance on predicting the reported RPE values for future training sessions was compared to the naive baseline's performance. Both the ANN and LASSO models outperformed the baseline. Additionally, the LASSO model made more accurate predictions for the RPE than the ANN model. Furthermore, decelerations were identified as important external load indicators. Regardless of the applied machine learning technique, the group models resulted in equivalent or better predictions for the reported RPE values than the individual models. Machine learning techniques may have added value in predicting the RPE for future sessions to optimize training design and evaluation. Additionally, these techniques may be used in conjunction with expert knowledge to select key external load indicators for load monitoring.
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.
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.
Saulière, Guillaume; Dedecker, Jérôme; Marquet, Laurie-Anne; Rochcongar, Pierre; Toussaint, Jean-Francois; Berthelot, Geoffroy
The clinical and biological follow-up of individuals, such as the biological passport for athletes, is typically based on the individual and longitudinal monitoring of hematological or urine markers. These follow-ups aim to identify abnormal behavior by comparing the individual's biological samples to an established baseline. These comparisons may be done via different ways, but each of them requires an appropriate extra population to compute the significance levels, which is a non-trivial issue. Moreover, it is not necessarily relevant to compare the measures of a biomarker of a professional athlete to that of a reference population (even restricted to other athletes), and a reasonable alternative is to detect the abnormal values by considering only the other measurements of the same athlete. Here we propose a simple adaptive statistic based on maxima of Z-scores that does not rely on the use of an extra population. We show that, in the Gaussian framework, it is a practical and relevant method for detecting abnormal values in a series of observations from the same individual. The distribution of this statistic does not depend on the individual parameters under the null hypothesis, and its quantiles can be computed using Monte Carlo simulations. The proposed method is tested on the 3-year follow-up of ferritin, serum iron, erythrocytes, hemoglobin, and hematocrit markers in 2577 elite male soccer players. For instance, if we consider the abnormal values for the hematocrit at a 5% level, we found that 5.57% of the selected cohort had at least one abnormal value (which is not significantly different from the expected false-discovery rate). The approach is a starting point for more elaborate models that would produce a refined individual baseline. The method can be extended to the Gaussian linear model, in order to include additional variables such as the age or exposure to altitude. The method could also be applied to other domains, such as the clinical patient
Lynall, Robert C; Clark, Michael D; Grand, Erin E; Stucker, Jaclyn C; Littleton, Ashley C; Aguilar, Alain J; Petschauer, Meredith A; Teel, Elizabeth F; Mihalik, Jason P
There are limited nonlaboratory soccer head impact biomechanics data. This is surprising given soccer's global popularity. Epidemiological data suggest that female college soccer players are at a greater concussion injury risk than their male counterparts. Therefore, the purposes of our study were to quantify head impact frequency and magnitude during women's soccer practices and games in the National Collegiate Athletic Association and to characterize these data across event type, playing position, year on the team, and segment of game (first and second halves). Head impact biomechanics were collected from female college soccer players (n = 22; mean ± SD age = 19.1 ± 0.1 yr, height = 168.0 ± 3.5 cm, mass = 63.7 ± 6.0 kg). We employed a helmetless head impact measurement device (X2 Biosystems xPatch) before each competition and practice across a single season. Peak linear and rotational accelerations were categorized based on impact magnitude and subsequently analyzed using appropriate nonparametric analyses. Overall, women's college soccer players experience approximately seven impacts per 90 min of game play. The overwhelming majority (~90%) of all head impacts were categorized into our mildest linear acceleration impact classification (10g-20g). Interestingly, a higher percentage of practice impacts in the 20g-40g range compared with games (11% vs 7%) was observed. Head impact biomechanics studies have provided valuable insights into understanding collision sports and for informing evidence-based rule and policy changes. These have included changing the football kickoff, ice hockey body checking ages, and head-to-head hits in both sports. Given soccer's global popularity, and the growing public concern for the potential long-term neurological implications of collision and contact sports, studying soccer has the potential to impact many athletes and the sports medicine professionals caring for them.
Barbosa, Carlos V da Silva; Silva, Alexandre S; de Oliveira, Caio V C; Massa, Nayara M L; de Sousa, Yasmim R F; da Costa, Whyara K A; Silva, Ayice C; Delatorre, Plínio; Carvalho, Rhayane; Braga, Valdir de Andrade; Magnani, Marciane
Nutritional intervention with antioxidants rich foods has been considered a strategy to minimize the effects of overtraining in athletes. This experimental, randomized, and placebo-controlled study evaluated the effects of consumption of sesame ( Sesamum indicum L.) on muscle damage markers, oxidative stress, systemic inflammation, and aerobic performance in male semi-professional soccer players. Twenty athletes were randomly assigned to groups that received 40 g (two tablespoons) per day of sesame or a placebo during 28 days of regular training (exposed to routine training that includes loads of heavy training in the final half of the season). Before and after intervention, creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), C-reactive protein (hs-CRP), and aerobic capacity were evaluated. Before intervention, a physiologic imbalance was noted in both groups related to CK and LDH levels. Sesame intake caused a reduction of CK (19%, p < 0.05), LDH (37%, p < 0.05), MDA (55%, p < 0.05) and hs-CRP (53%, p < 0.05) and increased SOD (14%, p < 0.05), vitamin A (25%, p < 0.05), and vitamin E (65%, p < 0.05) in the experimental group. These phenomena were accompanied by increased aerobic capacity (17%, p < 0.05). The placebo group showed an increase in CK (5%, p < 0.05) and no significant change in LDH, SOD or vitamin A. MDA levels decreased (21%, p < 0.05) and vitamin E increased (14%, p < 0.05) in the placebo group, but to a much lesser extent than in the experimental group. These results show that sesame consumption may reduce muscle damage and oxidative stress while improving the aerobic capacity in soccer players.
Schmikli, Sandor L.; de Vries, Wouter R.; Brink, Michel S.; Backx, Frank J. G.
Objective 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). Design A prospective case-control study using a monthly performance monitor with a standardised field
Diment, Gregory Michael
a systematic observation checklist of mental toughness behavior in professional soccer. Consistent with existing studies, the results created a systematic observation instrument containing 15 mental toughness behaviors. Practical implications include goal-setting, game analysis and self-modeling interventions...
The coaching carousel or turnover is an extreme but frequently occurring phenomenon in soccer. Among the reasons for firing a coach, the most common is the existence of a shock-effect: a new coach would be able to motivate the players better and therefore to improve results. Using data from the Spanish Soccer League during the seasons from 1997-1998 to 2006-2007, this paper investigates the relationship between team performance and coach change over time. The empirical analysis shows that the shock effect of a turnover has a positive impact on team performance in the short term. Results reveal no impact of coach turnover in the long term. The favourable short-term impact on team performance of a coach turnover is followed by continued gradual worsening of results. The turnover effect is nonexistent when the comparison between the new coach and the old coach is done over 10, 15 or 20 matches before and after termination.
Bar-Eli, Michael; Tenenbaum, Gershon; Geister, Sabine
This study documents the effect of players' dismissals on team performance in professional soccer. Our aim was to determine whether the punishment meted out for unacceptable player behaviour results in reduced team performance. The official web site of the German Soccer Association was used for coding data from games played in the first Bundesliga between the 1963 - 64 and 2003 - 04 (n = 41) seasons. A sample of 743 games where at least one red card was issued was used to test hypotheses derived from crisis theory (Bar-Eli & Tenenbaum, 1989a). Players' dismissals weaken a sanctioned team in terms of the goals and final score following the punishment. The chances of a sanctioned team scoring or winning were substantially reduced following the sanction. Most cards were issued in the later stages of matches. The statistics pertaining to outcome results as a function of game standing, game location, and time phases - all strongly support the view that teams can be considered conceptually similar to individuals regarding the link between stress and performance. To further develop the concept of team and individual psychological performance crisis in competition, it is recommended that reversal theory (Apter, 1982) and self-monitoring and distraction theories (Baumeister, 1984) be included in the design of future investigations pertaining to choking under pressure.
Thorborg, Kristian; Branci, Sonia; Nielsen, Martin Peter; Tang, Lars; Nielsen, Michael Bachmann; Hölmich, Per
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. 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. Cross-sectional study; Level of evidence, 3. 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. 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). Large eccentric hip adduction strength deficits were found in soccer players with adductor-related groin pain compared with asymptomatic soccer players, while no isometric
Renan Felipe Hartmann Nunes
Full Text Available Muitos profissionais do esporte periodizam o treinamento do futebol e do futsal de forma semelhante. Todavia, pouco se conhece das respostas físicas e fisiológicas dos atletas de futsal. Esse estudo comparou perfil antropométrico, capacidade aeróbia e produção de potência entre atletas profissionais de futsal e futebol. Onze jogadores de futsal (idade 24,1±2,4anos e 21 jogadores de futebol (idade 22,6±3,6anos do sexo masculino submeteram-se a duas sessões experimentais: (I avaliação antropométrica, teste de esforço máximo em esteira e (II teste de velocidade de 30 metros (capacidade de sprint repetido, CSR. Empregou-se teste t para amostras independentes, permitindo verificar possíveis diferenças entre as modalidades (pMany professional sports training periodize soccer and futsal similarly. However, little is known about physical and physiological responses of futsal players. This study compared anthropometric, aerobic capacity and power production among professional indoor and outdoor soccer players. Eleven futsal players (age 24.1±2.4 years and 21 soccer players (age 22.6±3.6 years males underwent two experimental sessions: (i anthropometric measurements, maximal effort test treadmill and (II test speed of 30 meters (repeated sprint ability, CSA. It was applied t-test for independent samples to verify possible differences between the modalities (p>0,05. The futsal players showed higher values of HR VT (177,2±10 e 67,1±10,8 bpm VO2max ;VO2VT; %VO2max (62,5±4,3 e 52,1±4,6; 58,7±5,6 e 43,1±4,6; 76±8,4 e 93,9±5,3 ml·kg-1·min-1 compared with soccer players, respectively. These results demonstrate the need for specific methods of training for outdoor and indoor soccer.
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.
Idoate, Fernando; Calbet, Jose A. L.; Izquierdo, Mikel; Sanchis-Moysi, Joaquin
Purpose To determine the volume and degree of asymmetry of the rectus abdominis muscle (RA) in professional soccer players. Methods The volume of the RA was determined using magnetic resonance imaging (MRI) in 15 professional male soccer players and 6 non-active male control subjects. Results Soccer players had 26% greater RA volume than controls (Psoccer players (P = 0.42) and in controls (P = 0.75) (Dominant/non-dominant = 0.99, in both groups). Segmental analysis showed a progressive increase in the degree of side-to-side asymmetry from the first lumbar disc to the pubic symphysis in soccer players (r = 0.80, Psoccer players, although this trend was not statistically significant (P = 0.14). Conclusions Professional soccer is associated with marked hypertrophy of the rectus abdominis muscle, which achieves a volume that is 26% greater than in non-active controls. Soccer induces the hypertrophy of the non-dominant side in proximal regions and the dominant side in regions closer to pubic symphysis, which attenuates the pattern of asymmetry of rectus abdominis observed in non-active population. It remains to be determined whether the hypertrophy of rectus abdominis in soccer players modifies the risk of injury. PMID:21541351
Gatterer, H; Ruedl, G; Faulhaber, M; Regele, M; Burtscher, M
Soccer is characterized by high injury rates that necessitate interventions for its reduction. The "11" is a multi-modal preventive program that was developed to reduce injury rate. However, outcomes on the effectiveness of the program are not unambiguous and data for the largest group at risk (i.e., male adult amateur players) are missing. The study aims to assess the injury rate in male adult amateur soccer players of different levels and to evaluate the effectiveness of the prevention program the "11". Three amateur soccer teams participated in the study during the first round of a competition season. Two teams played at a regional level (6th Italian league) and one team at a provincial level (7th Italian league). The regional league is of a higher skill level compared to the provincial league. Duration and frequency of training and match sessions and the occurrence of time-loss injuries were recorded. One team of the 6th league performed an injury prevention program. The total injury rate for the intervention and the control team in the 6th league was 3.3 (CI 0.7-5.9) and 4.3 (CI 1.3-7.3) injuries/1000 h, respectively (P=0.841). The 6th league control team tended to have a lesser injury rate compared to the 7th league team (P=0.081). The relative risk was 2 fold higher in the 7th compared to the 6th league team (P=0.0285 one tailed). Present results show that injury rate in amateur soccer depended rather on the skill level than the prevention program. In this study the prevention program the "11" was not shown to be highly effective in soccer player of intermediate level (i.e., 6th Italian league).
Helsen, Werner F.; Starkes, Janet L.; Van Winckel, Jan
Since 1997 and following the guidelines of the International Football Association, the Belgian Soccer Federation has used January 1st as the start of the selection year. Previously, August 1 was the start. This shift prompted an investigation of changes in birth-date distributions throughout youth categories for 1996-1997 compared to the 1997-1998 competitive years. Birth dates were considered for national youth league players, ages 10-12, 12-14, 14-16, and 16-18 years. 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 both before and after the August to January shift. Results indicated that from 1996 to 1997, youth players born from January to March (the early part of the new selection year) were more likely to be identified as "talented" and to be exposed to higher levels of coaching. In comparison, players born late in the new selection year (August to October) were assessed as "talented" in significantly lower proportions. Specific suggestions are presented to reduce the relative age effect. Am. J. Hum. Biol. 12:729-735, 2000. Copyright 2000 Wiley-Liss, Inc.
Daniel Barbosa Coelho
Full Text Available Serum creatine kinase (CK concentration has been widely used as an indicator of skeletal muscle damage in sports. However, there are no longitunal studies on post-game CK kinetics in Soccer during a competitive season. The aim of this study was to evaluate serum CK kinetics in professional Soccer players at different post-game times during a competitive season without training interruption. Seventeen professional soccer players (age: 22.2±3.1 years, height: 179±6.0 cm, body fat percentage: 9.5±1.1, and 67.0±3.5 mL O2/kg/min were evaluated over a period of 3 months of the national championship. Serum CK concentration was measured before the beginning of the season (baseline and at four different times after a soccer game (post-1: 12-20 h, post-2: 36-48 h, post-3: 60-65 h, and post-4: 90-110 h. Plasma CK concentrations were higher at all times when compared to baseline (p<0.05. Post-2 CK concentration was lower than post-1 and higher than post-3 and -4 (p<0.05, with no significant differences between post-3 and post-4. In conclusion, serum CK kinetics was influenced by the training routine of the soccer players, with a peak between 12 and 20 h after the game, returning to normal within 60-65 h. This procedure can be used to monitor the recovery state of athletes and game and training intensities.
Carling, Christopher; Bradley, Paul; McCall, Alan; Dupont, Gregory
This study investigated variability in competitive high-speed running performance in an elite soccer team. A semi-automated tracking system quantified running performance in 12 players over a season (median 17 matches per player, 207 observations). Variability [coefficient of variation (CV)] was compared for total sprint distance (TSD, >25.2 km/h), high-speed running (HSR, 19.8-25.2 km/h), total high-speed running (THSR, ≥19.8 km/h); THSR when the team was in and out of ball possession, in individual ball possession, in the peak 5 min activity period; and distance run according to individual maximal aerobic speed (MAS). Variability for % declines in THSR and distance covered at ≥80% MAS across halves, at the end of play (final 15 min vs. mean for all 15 min periods) and transiently (5 min period following peak 5 min activity period), was analysed. Collectively, variability was higher for TSD versus HSR and THSR and lowest for distance run at ≥80% MAS (CVs: 37.1%, 18.1%, 19.8% and 11.8%). THSR CVs when the team was in/out of ball possession, in individual ball possession and during the peak 5 min period were 31.5%, 26.1%, 60.1% and 23.9%. Variability in THSR declines across halves, at the end of play and transiently, ranged from 37.1% to 142.6%, while lower CVs were observed in these metrics for running at ≥80% MAS (20.9-53.3%).These results cast doubt on the appropriateness of general measures of high-speed activity for determining variability in an elite soccer team, although individualisation of HSR thresholds according to fitness characteristics might provide more stable indicators of running performance and fatigue occurrence.
Rago, Vincenzo; Silva, João R; Mohr, Magni; Barreira, Daniel; Krustrup, Peter; Rebelo, António N
In Southern European countries it is very frequent to perform medium-sized games (MSG) as last training drill. We analyzed the individual variability and changes in activity patterns during MSG throughout the preseason. Activity profile during MSGs (10v10+goalkeepers, duration: 10-min, field length: 50 m, width: 90 m, area per player: 204.5 m2) was quantified using a GPS in 14 professional male players (6 defenders, 5 midfielders 5 and attackers). Inter-individual variability was higher for high-intensity (HIR), very-high speed (VHS), maximum acceleration (Accmax) and maximum deceleration (Decmax) distance (CV=25.2 to 43.3%), compared to total distance (TD), total acceleration (Acctot) and total deceleration (Dectot) distance (CV= 8.3 to 18.3 %). Defenders showed higher variability in TD, HIR, VHS, Acctot and Dectot (ES= 1.30 to 11.28) compared to the other field positions, whereas attackers showed higher variability in HIR, VHS Accmax and Decmax (ES=-4.92 to 2.07) than other the field positions. Variability in TD regularly increased (ES= -2.13 to -0.91) towards the end of the preseason, while HIR and VHS variability tended to increase over the 3rd and the 4th preseason week (ES=-0.94 to -3.05). However, the behavior of variability across the preseason period was more unpredictable for Acctot and Dectot, both decreasing in the 3rd week (ES= 0.70 to 1.20), while Decmax increased in the 4th week (ES=-0.91±0.59). During MSGs, individual variability of activity differs among field positions, and tends to increase with either speed or acceleration intensity, underlining the need of an individualized approach for training load monitoring.
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.
Full Text Available PURPOSE: To determine the volume and degree of asymmetry of the rectus abdominis muscle (RA in professional soccer players. METHODS: The volume of the RA was determined using magnetic resonance imaging (MRI in 15 professional male soccer players and 6 non-active male control subjects. RESULTS: Soccer players had 26% greater RA volume than controls (P<0.05, due to hypertrophy of both the dominant (28% greater volume, P<0.05 and non-dominant (25% greater volume, P<0.01 sides, after adjusting for age, length of the RA muscle and body mass index (BMI as covariates. Total volume of the dominant side was similar to the contralateral in soccer players (P = 0.42 and in controls (P = 0.75 (Dominant/non-dominant = 0.99, in both groups. Segmental analysis showed a progressive increase in the degree of side-to-side asymmetry from the first lumbar disc to the pubic symphysis in soccer players (r = 0.80, P<0.05 and in controls (r = 0.75, P<0.05. The slope of the relationship was lower in soccer players, although this trend was not statistically significant (P = 0.14. CONCLUSIONS: Professional soccer is associated with marked hypertrophy of the rectus abdominis muscle, which achieves a volume that is 26% greater than in non-active controls. Soccer induces the hypertrophy of the non-dominant side in proximal regions and the dominant side in regions closer to pubic symphysis, which attenuates the pattern of asymmetry of rectus abdominis observed in non-active population. It remains to be determined whether the hypertrophy of rectus abdominis in soccer players modifies the risk of injury.
Eleftherios Kellis, Nikiforos Galanis, Chrysanthos Chrysanthou, Nikolaos Kofotolis
Full Text Available This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF were monitored at 6 occasions (up until 1 year after injury. The size of the scar / hematoma was reduced by 63.56% (length and 67.9% (width after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention.
Crema, Michel D; Godoy, Ivan R B; Abdalla, Rene J; de Aquino, Jose Sanchez; Ingham, Sheila J McNeill; Skaf, Abdalla Y
Discrepancies exist in the literature regarding the association of the extent of injuries assessed on magnetic resonance imaging (MRI) with recovery times. MRI-detected edema in grade 1 hamstring injuries does not affect the return to play (RTP). Retrospective cohort study. Level 4. Grade 1 hamstring injuries from 22 professional soccer players were retrospectively reviewed. The extent of edema-like changes on fluid-sensitive sequences from 1.5-T MRI were evaluated using craniocaudal length, percentage of cross-sectional area, and volume. The time needed to RTP was the outcome. Negative binomial regression analysis tested the measurements of MRI-detected edema-like changes as prognostic factors. The mean craniocaudal length was 7.6 cm (SD, 4.9 cm; range, 0.9-19.1 cm), the mean percentage of cross-sectional area was 23.6% (SD, 20%; range, 4.4%-89.6%), and the mean volume was 33.1 cm 3 (SD, 42.6 cm 3 ; range, 1.1-161.3 cm 3 ). The mean time needed to RTP was 13.6 days (SD, 8.9 days; range, 3-32 days). None of the parameters of extent was associated with RTP. The extent of MRI edema in hamstring injuries does not have prognostic value. Measuring the extent of edema in hamstring injuries using MRI does not add prognostic value in clinical practice.
García-García, Oscar; Serrano-Gómez, Virginia; Hernández-Mendo, Antonio; Morales-Sánchez, Verónica
The aim of the study was to determine the mechanical and neuromuscular profile of knee extensor and flexor muscles in professional soccer players at the start of the pre-season, and to calculate percentages for symmetry, as well as examine differences according to the player's positional role. The vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF) and biceps femoris (BF) of 16 professional soccer players were evaluated by means of tensiomyography (TMG) on the first day of the pre-season. A paired-samples t test (p < .05) was used to compare the dominant and non-dominant lower limb. One-way ANOVA was applied, with the positional role as an independent factor. No differences were observed between the dominant and non-dominant leg. The highest degree of symmetry corresponded to the VM (92.5 ± 2.7%), and the lowest to the BF (80.7 ± 10.9%). The positional role was associated with significant differences in some of the variables for the BF, RF and VM, although only the half-relaxation time in the BF and the time to sustain force in the VM differed across all the playing positions considered. TMG was shown to be a useful way of evaluating the neuromuscular characteristics of soccer players at the start of the pre-season, and of establishing baseline values for individual players.
Full Text Available The aim of the study was to determine the mechanical and neuromuscular profile of knee extensor and flexor muscles in professional soccer players at the start of the pre-season, and to calculate percentages for symmetry, as well as examine differences according to the player’s positional role. The vastus medialis (VM, vastus lateralis (VL, rectus femoris (RF and biceps femoris (BF of 16 professional soccer players were evaluated by means of tensiomyography (TMG on the first day of the pre-season. A paired-samples t test (p < .05 was used to compare the dominant and non-dominant lower limb. One-way ANOVA was applied, with the positional role as an independent factor. No differences were observed between the dominant and non-dominant leg. The highest degree of symmetry corresponded to the VM (92.5 ± 2.7%, and the lowest to the BF (80.7 ± 10.9%. The positional role was associated with significant differences in some of the variables for the BF, RF and VM, although only the half-relaxation time in the BF and the time to sustain force in the VM differed across all the playing positions considered. TMG was shown to be a useful way of evaluating the neuromuscular characteristics of soccer players at the start of the pre-season, and of establishing baseline values for individual players.
What do Italy and Germany have in common? The world's largest PV markets and world class soccer. But while PV systems are frequently found on the rooftops of Germany's soccer stadiums, Italy has left this potential largely untapped.
Tenga, Albin; Holme, Ingar; Ronglan, Lars Tore; Bahr, Roald
Methods of analysis that include an assessment of opponent interactions are thought to provide a more valid means of team match performance. The purpose of this study was to examine the effect of playing tactics on achieving score-box possession by assessing opponent interactions in Norwegian elite soccer matches. We analysed a random series of 1703 team possessions from 163 of 182 (90%) matches played in the professional men's league during the 2004 season. Multidimensional qualitative data obtained from ten ordered categorical variables were used. Offensive tactics were more effective in producing score-box possessions when playing against an imbalanced defence (28.5%) than against a balanced defence (6.5%) (P tactics on producing score-box possessions, and improves the validity of team match-performance analysis in soccer.
The influence of modern studded and bladed soccer boots and sidestep cutting on noncontact knee loading during match play conditions is not fully understood. Modern soccer boot type and sidestep cutting compared with straight-ahead running do not significantly influence knee internal tibia axial and valgus moments, anterior joint forces, and flexion angles. Controlled laboratory study. Fifteen professional male outfield soccer players undertook trials of straight-ahead running and sidestep cutting at 30 degrees and 60 degrees with a controlled approach velocity on a Fédération Internationale de Football Association (FIFA) approved soccer surface. Two bladed and 2 studded soccer boots from 2 manufacturers were investigated. Three-dimensional inverse dynamics analysis determined externally applied internal/external tibia axial and valgus/varus moments, anterior forces, and flexion angles throughout stance. The soccer boot type imparted no significant difference on knee loading for each maneuver. Internal tibia and valgus moments were significantly greater for sidestep cutting at 30 degrees and 60 degrees compared with straight-ahead running. Sidestep cutting at 60 degrees compared with straight-ahead running significantly increased anterior joint forces. Varying soccer boot type had no effect on knee loading for each maneuver, but sidestep cutting significantly increased internal tibia and valgus moments and anterior joint forces. Sidestep cutting, irrespective of the modern soccer boot type worn, may be implicated in the high incidence of noncontact soccer anterior cruciate ligament injuries by significantly altering knee loading.
Irgens, Ågot; Troland, Kari; Grønning, Marit
The aim of the present study was to explore the potential differences between female and male professional divers with regards to demographics, diving certificates, areas of diving, diving activity and health effects. The Norwegian Labour Inspection Authority's Diving certificate register contains data on all professional inshore divers who have held a certificate at any time since 1980. Forty nine per cent of these divers responded to the "Norwegian diver 2011" questionnaire. Of these divers 64 female and 1327 male divers completed the questionnaire about their professional diving career, certificate, year of onset and the year they stopped diving professionally if they were not still active in the diving industry. The level of general education was higher among female divers. More males than females were fully certified in diving. The mean age was lower among female than male fully certified divers. Fully certified female divers reported a lower total number of dives, shallower dives and diving for a shorter period of time than the male divers. They also had a lower percentage of work within the quay/construction sector and more often worked as teachers/instructors. A lower percentage of fully certified females than males had experienced decompression sickness (16.7% vs. 26.9%). Life-threatening events and psychologically challenging events were less common among females, as were adverse health effects. No such gender differences were seen for divers with a restricted certificate. The fully certified, female professional divers in our study had a very short diving career, reported fewer and shallower dives, and chose less physically demanding jobs than their male counterparts. They also had a higher level of education, reported less health problems and a better quality of life. The health effects seem to be related to the type of work rather than to gender.
Karsten, Bettina; Larumbe-Zabala, Eneko; Kandemir, Gokhan; Hazir, Tahir; Klose, Andreas; Naclerio, Fernando
The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (psoccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer.
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.
Mohammad Fayiz Abumoh'd
Full Text Available This study investigated the effect of caffeine contained in sports drink on hormones producing energy and sprint test performance in male soccer players. Twelve participants (25.97 ± 2.70 y performed the test under thre e conditions (one week apart: caffeine with sports drink (SD-CAF, sports drink (SD, and placebo (PLA. Using a double-blind, placebo-controlled, randomized, crossover protocol, participants performed SD-CAF trial (5 mg/kg of caffeine contained in 300 ml of sports drink 30 minutes prior to sprinting test (7 × 30 m, SD trial (solely 300 ml of sports drink 30 minutes prior to sprinting test, or placebo. Blood analysis indicated significantly higher level of free thyroxine in SD-CAF (21.450 ± 3.048 compared to SD (18.742 ± 1.151 and PLA (16.983 ± 1.783. Similar findings existed regarding insulin (P 0.05. No significant differences were observed between trials in first–fourth repetitions (P > 0.05. Time of fifth-seventh repetitions were significantly lower in SD-CAF compared to SD and PLA (P < 0.05, and were significantly lower in SD than that in PLA (P < 0.05. The time of 7th repetition was (4.331 ± 0.210, 4.610 ± 0.197, 4.81 6 ± 0.171 s for SD-CAF, SD, and PLA, respectively; P < 0.05. In conclusion, caffeine interferes hormones that are responsible for producing energy which in turn have a positive effect on repeated sprint bouts.
Horsley Ian G
Full Text Available Abstract Objective To identify posture types that exist in professional rugby players, and compare them with a population of non-overhead athletes in order to identify possible relationships towards the potential for shoulder injuries. Design Observational design Setting: Sports Medicine Clinic Participants: Convenience sample Methodology: Static assessment of posture was carried out in standing, active and passive range of glenohumeral motion, and isometric strength was carried out in accordance with previously recorded protocols. Interventions Nil Outcome Measures: Observational classification of posture, active and passive range of glenohumeral joint range of motion, isometric strength of selected muscle groups, selected muscle flexibility and Hawkins and Neer impingement tests. Results There was a significant difference on range of motion between the two groups (0.025–0.000, isometric middle (0.024–0.005, and lower trapezius (0.01–0.001. Conclusion: There were significant differences between strength and flexibility of muscles around the shoulder girdle between professional rugby players and a control group of professional non-overhead athletes.
Carling, Christopher; Le Gall, Franck; McCall, Alan; Nédélec, Mathieu; Dupont, Gregory
Squad management, injury and physical, tactical and technical match performance were investigated in a professional soccer team across five consecutive league seasons (2008-2013, 190 league games) with specific focus on a championship-winning season (2010/11). For each player, match participation and time-loss injuries were recorded, the latter prospectively diagnosed by the team's physician. Defending and attacking tactical and technical performance indicators investigated included ball possession and possession in opponents' half, passes, forward passes, completed passes and forward passes, crosses and completed crosses, goal attempts and goal attempts on target, successful final third entries, free-kicks and 50/50 duels won/lost. Physical performance measures included total distance and distance covered at high-speeds (≥19.1 km/h). Results showed that during the 2010/11 season, squad utilisation was lowest potentially owing to the observed lower match injury occurrence and working days lost to injury thereby increasing player availability. In 2010/11, the team won both its highest number of points and conceded its lowest number of goals especially over the second half of this season. The team also won its highest number of games directly via a goal from a substitute and scored and conceded a goal first on the highest and lowest number of occasions, respectively. While multivariate analysis of variance (MANOVA) detected a significant difference in some attacking and defensive performance indicators across the five seasons, these were generally not distinguishing factors in 2010/11. Similarly, univariate ANOVAs showed a significant difference in running distances covered across seasons, but the trend was for less activity in 2010/11.
Traser, Louisa; Knab, Jana; Echternach, Matthias; Fuhrer, Hannah; Richter, Bernhard; Buerkle, Hartmut; Schumann, Stefan
The respiratory system is a central part of voice production, but details in breath control during phonation are not yet fully understood. This study therefore aims to investigate regional ventilation of the lungs during phonation. It was analyzed in 11 professional singers using electrical impedance tomography during breathing and phonation with maximum phonation time. Our results show differences in impedance changes between phonation and exhalation in the courses of time and amplitude normalized curves. Furthermore, differences related to gender and professionalism were found in the temporal and spatial profiles of regional ventilation. For female singers (sopranos and mezzo-sopranos) the anterior region participated less at the start of ventilation, and was more stable at the midpoint compared to male singers (tenors). This might be an expression of a smaller relative movement in rib cage and anterior diaphragm, primarily in early phonation. Copyright © 2017 Elsevier B.V. All rights reserved.
Full Text Available Professional soccer players have a lengthy playing season, throughout which high levels of physical stress are maintained. The following recuperation period, before starting the next pre-season training phase, is generally considered short but sufficient to allow a decrease in these stress levels and therefore a reduction in the propensity for injury or musculoskeletal tissue damage. We hypothesised that these physical extremes influence the body composition, blood flow, and endothelial/immune function, but that the recuperation may be insufficient to allow a reduction of tissue stress damage. Ten professional football players were examined at the end of the playing season, at the end of the season intermission, and after the next pre-season endurance training. Peripheral blood flow and body composition were assessed using venous occlusion plethysmography and DEXA scanning respectively. In addition, selected inflammatory and immune parameters were analysed from blood samples. Following the recuperation period a significant decrease of lean body mass from 74.4+/-4.2 kg to 72.2+/-3.9 kg was observed, but an increase of fat mass from 10.3+/-5.6 kg to 11.1+/-5.4 kg, almost completely reversed the changes seen in the pre-season training phase. Remarkably, both resting and post-ischemic blood flow (7.3+/-3.4 and 26.0+/-6.3 ml/100 ml/min respectively, were strongly reduced during the playing and training stress phases, but both parameters increased to normal levels (9.0+/-2.7 and 33.9+/-7.6 ml/100 ml/min during the season intermission. Recovery was also characterized by rising levels of serum creatinine, granulocytes count, total IL-8, serum nitrate, ferritin, and bilirubin. These data suggest a compensated hypo-perfusion of muscle during the playing season, followed by an intramuscular ischemia/reperfusion syndrome during the recovery phase that is associated with muscle protein turnover and inflammatory endothelial reaction, as demonstrated by i
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...
Schuermans, Joke; Danneels, Lieven; Van Tiggelen, Damien; Palmans, Tanneke; Witvrouw, Erik
With their unremittingly high incidence rate and detrimental functional repercussions, hamstring injuries remain a substantial problem in male soccer. Proximal neuromuscular control ("core stability") is considered to be of key importance in primary and secondary hamstring injury prevention, although scientific evidence and insights on the exact nature of the core-hamstring association are nonexistent at present. The muscle activation pattern throughout the running cycle would not differ between participants based on injury occurrence during follow-up. Case-control study; Level of evidence, 3. Sixty amateur soccer players participated in a multimuscle surface electromyography (sEMG) assessment during maximal acceleration to full-speed sprinting. Subsequently, hamstring injury occurrence was registered during a 1.5-season follow-up period. Hamstring, gluteal, and trunk muscle activity time series during the airborne and stance phases of acceleration were evaluated and statistically explored for a possible causal association with injury occurrence and absence from sport during follow-up. Players who did not experience a hamstring injury during follow-up had significantly higher amounts of gluteal muscle activity during the front swing phase ( P = .027) and higher amounts of trunk muscle activity during the backswing phase of sprinting ( P = .042). In particular, the risk of sustaining a hamstring injury during follow-up lowered by 20% and 6%, with a 10% increment in normalized muscle activity of the gluteus maximus during the front swing and the trunk muscles during the backswing, respectively ( P hamstring injury occurrence in male soccer players. Higher amounts of gluteal and trunk muscle activity during the airborne phases of sprinting were associated with a lower risk of hamstring injuries during follow-up. Hence, the present results provide a basis for improved, evidence-based rehabilitation and prevention, particularly focusing on increasing neuromuscular
Full Text Available There is an ongoing concern about the risk of injury to the spine in professional rugby players. The objective of this study was to investigate the prevalence of vertebral fracture using vertebral fracture assessment (VFA dual energy X-ray absorptiometry (DXA imaging in professional male rugby players. Ninety five professional rugby league (n = 52 and union (n = 43 players (n = 95; age 25.9 (SD 4.3 years; BMI: 29.5 (SD 2.9 kg.m2 participated in the research. Each participant received one VFA, and one total body and lumbar spine DXA scan (GE Lunar iDXA. One hundred and twenty vertebral fractures were identified in over half of the sample by VFA. Seventy four were graded mild (grade 1, 40 moderate (grade 2 and 6 severe (grade 3. Multiple vertebral fractures (≥2 were found in 37 players (39%. There were no differences in prevalence between codes, or between forwards and backs (both 1.2 v 1.4; p>0.05. The most common sites of fracture were T8 (n = 23, T9 (n = 18 and T10 (n = 21. The mean (SD lumbar spine bone mineral density Z-score was 2.7 (1.3 indicating high player bone mass in comparison with age- and sex-matched norms. We observed a high number of vertebral fractures using DXA VFA in professional rugby players of both codes. The incidence, aetiology and consequences of vertebral fractures in professional rugby players are unclear, and warrant timely, prospective investigation.
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....
Russell, Mark; Birch, Jack; Love, Thomas; Cook, Christian J; Bracken, Richard M; Taylor, Tom; Swift, Eamon; Cockburn, Emma; Finn, Charlie; Cunningham, Daniel; Wilson, Laura; Kilduff, Liam P
Russell, M, Birch, J, Love, T, Cook, CJ, Bracken, RM, Taylor, T, Swift, E, Cockburn, E, Finn, C, Cunningham, D, Wilson, L, and Kilduff, LP. The effects of a single whole-body cryotherapy exposure on physiological, performance, and perceptual responses of professional academy soccer players after repeated sprint exercise. J Strength Cond Res 31(2): 415-421, 2017-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, counterbalanced, and crossover design, 14 habituated English Premier League academy soccer players performed 15 × 30 m sprints (each followed by a 10 m forced deceleration) on 2 occasions. Within 20 minutes of exercise cessation, players entered a WBC chamber (Cryo: 30 seconds at -60° C, 120 seconds at -135° C) or remained seated (Con) indoors in temperate conditions (∼25° C). Blood and saliva samples, peak power output (countermovement jump), and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2-hour and 24-hour postexercise. When compared with Con, a greater testosterone response was observed at 2-hour (+32.5 ± 32.3 pg·ml, +21%) and 24-hour (+50.4 ± 48.9 pg·ml, +28%) postexercise (both P = 0.002) in Cryo (trial × treatment interaction: P = 0.001). No between-trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and creatine kinase), performance (peak power output), or perceptual (recovery or soreness) markers (all trial × treatment interactions: P > 0.05); all of which were influenced by exercise (time effects: all P ≤ 0.05). A single session of WBC performed within 20 minutes of repeated sprint exercise elevated testosterone concentrations for 24 hours but did not affect any other performance, physiological, or perceptual measurements taken. Although unclear, WBC may be
Campos-Vazquez, Miguel Angel; Mendez-Villanueva, Alberto; Gonzalez-Jurado, Jose Antonio; León-Prados, Juan Antonio; Santalla, Alfredo; Suarez-Arrones, Luis
To describe the internal training load (ITL) of common training sessions performed during a typical week and to determine the relationships between different indicators of ITL commonly employed in professional football (soccer). Session-rating-of-perceived-exertion TL (sRPE-TL) and heart-rate- (HR) derived measurements of ITL as Edwards TL and Stagno training impulses (TRIMPMOD) were used in 9 players during 3 periods of the season. The relationships between them were analyzed in different training sessions during a typical week: skill drills/circuit training + small-sided games (SCT+SSGs), ball-possession games+technical-tactical exercises (BPG+TTE), tactical training (TT), and prematch activation (PMa). HR values obtained during SCT+SSGs and BPG+TTE were substantially greater than those in the other 2 sessions, all the ITL markers and session duration were substantially greater in SCT+SSGs than in any other session, and all ITL measures in BPG+TTE were substantially greater than in TT and PMa sessions. Large relationships were found between HR>80% HRmax and HR>90% HRmax vs sRPE-TL during BPG+TTE and TT sessions (r=.61-.68). Very large relationships were found between Edwards TL and sRPE-TL and between TRIMPMOD and sRPE-TL in sessions with BPG+TTE and TT (r=.73-.87). Correlations between the different HR-based methods were always extremely large (r=.92-.98), and unclear correlations were observed for other relationships between variables. sRPE-TL provided variable-magnitude within-individual correlations with HR-derived measures of training intensity and load during different types of training sessions typically performed during a week in professional soccer. Caution should be applied when using RPE- or HR-derived measures of exercise intensity/load in soccer training interchangeably.
Bettonviel A, E O; Brinkmans N, Y J; Russcher, Kris; Wardenaar, Floris C; Witard, Oliver C
The nutritional status of elite soccer players across match, postmatch, training and rest days has not been defined. Recent evidence suggests the pattern of dietary protein intake impacts the daytime turnover of muscle proteins and, as such, influences muscle recovery. We assessed the nutritional status and daytime pattern of protein intake in senior professional and elite youth soccer players and compared findings against published recommendations. Fourteen senior professional (SP) and 15 youth elite (YP) soccer players from the Dutch premier division completed nutritional assessments using a 24-hr web-based recall method. Recall days consisted of a match, postmatch, rest, and training day. Daily energy intake over the 4-day period was similar between SP (2988 ± 583 kcal/day) and YP (2938 ± 465 kcal/day; p = .800). Carbohydrate intake over the combined 4-day period was lower in SP (4.7 ± 0.7 g·kg-1 BM·day-1) vs. YP (6.0 ± 1.5 g·kg-1 BM·day-1, p = .006) and SP failed to meet recommended carbohydrate intakes on match and training days. Conversely, recommended protein intakes were met for SP (1.9 ± 0.3 g·kg-1 BM·day-1) and YP (1.7 ± 0.4 g·kg-1 BM·day-1), with no differences between groups (p = .286). Accordingly, both groups met or exceeded recommended daily protein intakes on individual match, postmatch, rest and training days. A similar "balanced" daytime pattern of protein intake was observed in SP and YP. To conclude, SP increased protein intake on match and training days to a greater extent than YP, however at the expense of carbohydrate intake. The daytime distribution of protein intake for YP and SP aligned with current recommendations of a balanced protein meal pattern.
Gouttebarge, Vincent; Aoki, Haruhito; Lambert, Michael; Stewart, William; Kerkhoffs, Gino
Recent reports suggest that exposure to repetitive concussions in sports is associated with an increased risk of symptoms of distress, anxiety and depression, sleep disturbance or substance abuse/dependence (typically referred as symptoms of common mental disorders[CMD]) and of later development of neurodegenerative disease, in particular chronic traumatic encephalopathy (CTE). The primary aim of this study was to explore the relationship between sports career-related concussions and the subsequent occurrence of symptoms of CMD among former male professional athletes retired from football (soccer), ice hockey and rugby (union). Cross-sectional analyses were performed on baseline electronic questionnaires from three prospective cohort studies among former male professional athletes retired from football (soccer), ice hockey and rugby (union). The number of confirmed concussions was examined through a single question, while symptoms of distress, anxiety and depression, sleep disturbance and adverse alcohol use were assessed using validated questionnaires. From 1,957 former professional athletes contacted, a total of 576 (29%) completed the questionnaire. Of these, 23% had not incurred a concussion during their career, 34% had two or three, 18% four or five, and 11% six or more concussions. The number of sports career-related concussions was a predictor for all outcome measures (β = 0.072-0.109; P ≤ 0.040). Specifically, former professional athletes who reported a history of four or five concussions were approximately 1.5 times more likely to report symptoms of CMD, rising to a two- to five-fold increase in those reporting a history of six or more sports career-related concussions. These data demonstrate an association between exposure to sports concussion and subsequent risk of symptoms of CMD in former professional athletes across a range of contact sports. Further work to explore the association between sports concussion and symptoms of CMD is required; in
Nikolaos E Koundourakis
Full Text Available PURPOSE: The aim of this study was to examine the effects of a six-week off-season detraining period on exercise performance, body composition, and on circulating sex steroid levels in soccer players. METHODS: Fifty-five professional male soccer players, members of two Greek Superleague Teams (Team A, n = 23; Team B, n = 22, participated in the study. The first two weeks of the detraining period the players abstained from any physical activity. The following four weeks, players performed low-intensity (50%-60% of VO2max aerobic running of 20 to 30 minutes duration three times per week. Exercise performance testing, anthropometry, and blood sampling were performed before and after the six-week experimental period. RESULTS: Our data showed that in both teams A and B the six-week detraining period resulted in significant reductions in maximal oxygen consumption (60,31±2,52 vs 57,67±2,54; p<0.001, and 60,47±4,13 vs 58,30±3,88; p<0.001 respectively, squat-jump (39,70±3,32 vs 37,30±3,08; p<0.001, and 41,05±3,34 vs 38,18±3,03; p<0.001 respectively, and countermovement-jump (41,04±3,99 vs 39,13±3,26; p<0.001 and 42,82±3,60 vs 40,09±2,79; p<0.001 respectively, and significant increases in 10-meters sprint (1,74±0,063 vs 1,79±0,064; p<0.001, and 1,73±0,065 vs 1,78±0,072; p<0.001 respectively, 20-meters sprint (3,02±0,05 vs 3,06±0,06; p<0.001, and 3,01±0,066 vs 3,06±0,063; p<0.001 respectively, body fat percentage (Team A; p<0.001, Team B; p<0.001, and body weight (Team A; p<0.001, Team B; p<0.001. Neither team displayed any significant changes in the resting concentrations of total-testosterone, free-testosterone, dehydroepiandrosterone-sulfate, Δ4-androstenedione, estradiol, luteinizing hormone, follicle-stimulating hormone, and prolactin. Furthermore, sex steroids levels did not correlate with exercise performance parameters. CONCLUSION: Our results suggest that the six-week detraining period resulted in a rapid loss of
Landry, Scott C; McKean, Kelly A; Hubley-Kozey, Cheryl L; Stanish, William D; Deluzio, Kevin J
Female athletes are 2 to 8 times more likely than male athletes to injure the anterior cruciate ligament during a non-contact athletic maneuver. Identifying anterior cruciate ligament injury risk factors in female athletes may help with the development of preventive training programs aimed at reducing injury rates. Differences between genders in lower limb kinematics, kinetics, and neuromuscular patterns will be identified in an adolescent soccer population during an unanticipated side-cut maneuver. Controlled laboratory study. Forty-two elite adolescent soccer players (21 male and 21 female) performed an unanticipated side-cut maneuver, with the 3-dimensional kinematic, kinetic, and electromyographic lower limb data being analyzed using principal component analysis. The female athletes had higher gastrocnemius activity, normalized to maximal voluntary isometric contractions, and a mediolateral gastrocnemius activation imbalance that was not present in the male athletes during early stance to midstance of the side-cut. Female athletes demonstrated greater rectus femoris muscle activity throughout stance, and the only hamstring difference identified was a mediolateral activation imbalance in male athletes only. Female athletes performed the side-cut with less hip flexion and more hip external rotation and also generated a smaller hip flexion moment compared with the male athletes. This is the first study to identify gender-related differences in gastrocnemius muscle activity during an unanticipated cutting maneuver. The increased and imbalanced gastrocnemius muscle activity, combined with increased rectus femoris muscle activity and reduced hip flexion angles and moments in female subjects, may all have important contributing roles in the higher noncontact ACL injury rates observed in female athletes.
Benedito Sergio Denadai
Full Text Available The purposes of this study were to determine whether low intensity resistance training combined with blood flow restriction (LI-BFR could affect the concentric hamstrings/quadriceps muscle strength ratio (Hcon:Qcon of professional soccer players with Hcon:Qcon imbalance (Study 1, and whether hamstrings strength response observed after LI-BFR is associated with muscle hypertrophy (Study 2. In the Study 1, athletes were randomly divided into a training group (n = 6 and a control group (n = 5. In the Study 2, all athletes (n = 11 have performed the training programme. The athletes participated in a 6-week (twice a week supervised training programme (unilateral knee flexion at 30% 1RM consisting of 12 training sessions. Peak concentric torque of knee flexors (+8%; P < 0.001 and Hcon:Qcon (+9%; P < 0.01 were significantly increased after LI-BFR. Moreover, the cross sectional area (CSA of the hamstrings was significantly increased (+10%; P < 0.001 after LI-BFR. Thus, the addition of hamstrings strength training programme using LI-BFR during preseason is able to enhance both Hcon:Qcon and hamstrings CSA of professional soccer players with Hcon:Qcon imbalance.
Kopelman, D; Kaplan, U; Hatoum, O A; Abaya, N; Karni, D; Berber, A; Sharon, P; Peskin, B
Chronic groin pain appears in athletes with a diverse etiology. In a select few, it can be defined as a sportsman's hernia, that may be related, among other pathologies, to weakness of the posterior inguinal wall and may successfully respond to surgery. Surgical repair of the sportsman's hernia is associated with good functional outcomes, if the diagnosis is based on meticulous examination and follows a simple selection flowchart. Prospective case cohort study. The study assessed patients recruited from 2006 until the present assessed by a dedicated team with clinical and radiographic features of a sportsman's hernia who had failed a specified period of conservative therapies. Surgery was performed using a tension-free mesh open inguinal hernia repair. Of 246 male patients with chronic groin pain, 51 underwent surgery (mean age 20.7 years, range 14-36 years) with 58 inguinal procedures performed. Of the operated group, seven underwent bilateral surgery with a direct hernia found in 9/58 operated sides (15.5%), an indirect hernial sac in 8/58 (14%) and a direct and indirect hernia being found in 3/58 (5%) of operated sides. There was no post-operative morbidity (median follow-up 36.1 months; range 1-74 months), with two failures (3.45 % of operated sides). All other patients were asymptomatic, returned to full sports activity within 4.3 weeks (range 3-8 weeks) after surgery, and required no analgesics or further treatment. Selective surgical hernia repair, based on meticulous anamnesis and physical examination is effective in the management of chronic groin pain in athletes.
Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G
soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement (p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip...... decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery...... (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing...
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.
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.
Wesam Saleh A Al Attar
Trial registration: ACTRN12615001206516. [Al Attar WSA, Soomro N, Pappas E, Sinclair PJ, Sanders RH (2017 Adding a post-training FIFA 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduces injury rates among male amateur soccer players: a cluster-randomised trial. Journal of Physiotherapy 63: 235–242
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.
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.
Diment, Gregory Michael
Psychological Skills Training (PST) has been a tool used by sport psychology consultants. However, within soccer many of these programs have been delivered as workshops, homework tasks, or individual consultations with athletes. The aim of the project was to develop an ecological intervention...... by creating a series of drillbased sessions to train psychological skills, and educate coaches about how to implement and integrate PST as a natural part of daily training. The program was delivered to the youth academies in nine Danish professional soccer clubs and consisted of three phases: (a) planning...... of the program, (b) education and designing soccer drills, and (c) delivery of the drills on the soccer pitch. The program was well received by clubs, coaches, and players. With regards to project aims, the intervention was generally considered a success. Coaches reported that the drill-based nature...
Smith, Mitchell R.; Zeuwts, Linus; Lenoir, Matthieu; Hens, Nathalie; De Jong, Laura M. S.; Coutts, Aaron J.
This study aimed to investigate the impact of mental fatigue on soccer-specific decision-making. Twelve well-trained male soccer players performed a soccer-specific decision-making task on two occasions, separated by at least 72 h. The decision-making task was preceded in a randomised order by 30
Harøy, Joar; Thorborg, Kristian; Serner, Andreas; Bjørkheim, André; Rolstad, Linn E; Hölmich, Per; Bahr, Roald; Andersen, Thor Einar
The FIFA 11+ was developed as a complete warm-up program to prevent injuries in soccer players. Although reduced hip adduction strength is associated with groin injuries, none of the exercises included in the FIFA 11+ seem to specifically target hip adduction strength. To investigate the effect on eccentric hip adduction strength of the FIFA 11+ warm-up program with or without the Copenhagen adduction exercise. Randomized controlled trial; Level of evidence, 1. We recruited 45 eligible players from 2 U19 elite male soccer teams. Players were randomized into 2 groups; 1 group carried out the standard FIFA 11+ program, while the other carried out the FIFA 11+ but replaced the Nordic hamstring exercise with the Copenhagen adduction exercise. Both groups performed the intervention 3 times weekly for 8 weeks. Players completed eccentric strength and sprint testing before and after the intervention. Per-protocol analyses were performed, and 12 players were excluded due to low compliance (<67% of sessions completed). The main outcome was eccentric hip adduction strength (N·m/kg). Between-group analyses revealed a significantly greater increase in eccentric hip adduction strength of 0.29 Nm/kg (8.9%; P = .01) in favor of the group performing the Copenhagen adduction exercise, whereas no within-group change was noted in the group that used the standard FIFA 11+ program (-0.02 N·m/kg [-0.7%]; P = .69). Including the Copenhagen adduction exercise in the FIFA 11+ program increases eccentric hip adduction strength, while the standard FIFA 11+ program does not. Registration: Registration: ISRCTN13731446 (International Standard Randomised Controlled Trial Number registry).
Datson, Naomi; Hulton, Andrew; Andersson, Helena; Lewis, Tracy; Weston, Matthew; Drust, Barry; Gregson, Warren
The popularity and professionalism of female soccer has increased markedly in recent years, with elite players now employed on either a professional or semi-professional basis. The previous review of the physiological demands of female soccer was undertaken two decades ago when the sport was in its relative infancy. Increased research coupled with greater training and competition demands warrants an updated review to consider the effect on physical performance and injury patterns. The physical demands of match-play along with the influence of factors such as the standard of competition, playing position and fatigue have been explored. Total distance covered for elite female players is approximately 10 km, with 1.7 km completed at high speed (>15 kmh(-1)) [corrected].Elite players complete 28% more high-speed running and 24 % more sprinting than moderate-level players. Decrements in high-speed running distance have been reported between and within halves, which may indicate an inability to maintain high-intensity activity. Although the physical capacity of female players is the most thoroughly researched area, comparisons are difficult due to differing protocols. Elite players exhibit maximal oxygen uptake (VO2max) values of 49.4-57.6 mL·kg(-1)·min(-1), Yo Yo Intermittent Endurance test level 2 (YYIE2) scores of 1,774 ± 532 m [mean ± standard deviation (SD)] and 20 m sprint times of 3.17 ± 0.03 s (mean ± SD). Reasons for the increased prevalence of anterior cruciate ligament injuries in females (2-6 times greater than males) are discussed, with anatomical, biomechanical loading and neuromuscular activation differences being cited in the literature. This review presents an in-depth contemporary examination of the applied physiology of the female soccer player.
Harper, Liam D.; Fothergill, Melissa; West, Daniel J.; Stevenson, Emma; Russell, Mark
Qualitative research investigating soccer practitioners’ perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time reg...
Anderson, Liam; Orme, Patrick; Naughton, Robert J; Close, Graeme L; Milsom, Jordan; Rydings, David; O'Boyle, Andy; Di Michele, Rocco; Louis, Julien; Hambly, Catherine; Speakman, John Roger; Morgans, Ryland; Drust, Barry; Morton, James P
In an attempt to better identify and inform the energy requirements of elite soccer players, we quantified the energy expenditure (EE) of players from the English Premier League (n = 6) via the doubly labeled water method (DLW) over a 7-day in-season period. Energy intake (EI) was also assessed using food diaries, supported by the remote food photographic method and 24 hr recalls. The 7-day period consisted of 5 training days (TD) and 2 match days (MD). Although mean daily EI (3186 ± 367 kcals) was not different from (p > .05) daily EE (3566 ± 585 kcals), EI was greater (p recovery from match play was not in accordance with guidelines to promote muscle glycogen storage.
Male breast cancer treatment may include surgery with or without radiation therapy, chemotherapy, endocrine therapy, and/or HER2-directed therapy. Get detailed information about the diagnosis and treatment of newly diagnosed and recurrent male breast cancer in this summary for clinicians.
Tak, Igor; Glasgow, Philip; Langhout, Rob; Weir, Adam; Kerkhoffs, Gino; Agricola, Rintje
Soccer (football) players often have hip and groin symptoms (HGS), and a previous groin injury is a risk factor for a relapse. Decreased hip range of motion (HROM) has been related to both hip and groin pain and the presence of a cam deformity. How these factors interact is unknown. The first aim was to study whether HGS are associated with HROM. The second aim was to study the association of the presence of a cam deformity with HROM. Additionally, the influence of a cam deformity on the relationship between HGS and HROM was examined. Cross-sectional study; Level of evidence, 3. Seasonal screening data of 2 professional soccer clubs were used. Variables for HGS were current hip or groin pain, the Copenhagen Hip and Groin Outcome Score (HAGOS), and previous hip- and groin-related time-loss injuries (HGTIs). HROM was determined for hip internal rotation (IR), external rotation, and total rotation (TR) in the supine position and for the bent knee fall out (BKFO) test. A cam deformity was defined by an alpha angle >60° on standardized anteroposterior pelvic and frog-leg lateral radiographs. Sixty players (mean [±SD] age, 23.1 ± 4.2 years) were included. All were noninjured at the time of screening. Current hip or groin pain was not associated with HROM. Hips of players in the lowest HAGOS interquartile range (thus most affected by complaints; n = 12) showed less IR (23.9° ± 8.7° vs 28.9° ± 7.8°, respectively; P = .036) and TR (58.2° ± 13.5° vs 65.6° ± 11.8°, respectively; P = .047) than those in the highest interquartile range (n = 29). No such differences were found for BKFO (P = .417). Hips of players with a previous HGTI showed less IR (21.1° ± 6.8° vs 28.3° ± 8.9°, respectively; P < .001) and TR (56.0° ± 8.2° vs 64.5° ± 13.6°, respectively; P < .001) than those without a previous HGTI. This was independent of the presence of a cam deformity. BKFO did not differ between groups (P = .983). Hips with a cam deformity showed less but
Vitale, Jacopo Antonino; Lombardi, Giovanni; Cavaleri, Luca; Graziani, Rosa; Schoenhuber, Herbert; Torre, Antonio La; Banfi, Giuseppe
Vitamin D is essential for the maintenance and promotion of musculoskeletal health, for the functioning of the immune, cardiovascular and reproductive systems, and its main action is to keep calcium and phosphate plasmatic physiological concentrations at intestinal, renal and bony level. Vitamin D affects several parameters related to physical performance too and a particularly high percentage of vitamin D insufficiency and deficiency in professional athletes has been observed. Several variables are able to impair the synthesis of 25(OH)D in athletes, specifically both genetic and environmental factors, but the most probable explanation for the deficient/insufficient vitamin D levels is the insufficient ultraviolet B light (UVB) exposure during winter. To confirm this, the existence of a circannual rhythm of vitamin D in professional soccer players, highlighting a peak in summer and lowest values in winter regardless the period of the season, has been documented. Nonetheless, from what we are aware of, no other study adopted a chronobiologic approach to better understand and describe the circannual variations of serum 25(OH)D in other sport disciplines. Therefore, we studied serum vitamin D in a cohort of top-level professional skiers, during a period of three consecutive competitive seasons (2015, 2016 and 2017), in order to evaluate, with a rhythmometric approach, the vitamin D behavior along the year. The study population was composed by 152 professional Italian alpine skiers of FISI (Winter Sport Italian Federation), 63 females and 89 males (mean age: 24.1 ± 3.2 years) and a total of 298 blood drawings were carried out to determine plasma 25(OH)D. Vitamin D data were compared between genders and then processed with the population mean cosinor tests to evaluate the presence of a circannual rhythm, both for female and male athletes. In total, 77 skiers (50.7%) showed, at least once during the three competitive seasons, an insufficient level of 25(OH)D and
muscle injury detection. The use of 0.47 of Hcon/Qcon as a discriminate value resulted in significantly lower sensitivity when compared to 0.658 threshold (sensitivity of 16.7% vs. 91.7%, respectively; t = 6.125,p = 0.0133. Calculated values of specificity (when three different cut-off were applied were also significantly different. Threshold of 0.6 of Hcon/Qcon resulted with significantly lower specificity compared to 0.47 value (specificity of 46.9% vs. 94.5%, respectively; t = 153.0,p<0.0001, and significantly higher specificity when compared to 0.658 (specificity of 46.9% vs. 24.1%, respectively; t = 229.0, p<0.0001.The use of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic testing. The interpretation of usefulness of isokinetic test as a screening tool in a group of male professional football players to predict hamstring injury occurrence within the next 12 months might be therefore significantly biased due to the different threshold values of Hcon/Qcon. Using one "normative" value as a cut-off (e.g. 0.47 or 0.60, or 0.658 to quantify soccer players (or not to the group with a higher risk of knee injury might result in biased outcomes due to the natural strength asymmetry that is observed within the group of soccer players.
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…
Matsuda, Sho; Fukubayashi, Toru; Hirose, Norikazu
There is a large amount of information regarding risk factors for fifth metatarsal stress fractures; however, there are few studies involving large numbers of subjects. This study aimed to compare the static foot alignment and distribution of foot pressure of athletes with and without a history of fifth metatarsal stress fractures. The study participants comprised 335 collegiate male soccer players. Twenty-nine with a history of fifth metatarsal stress fractures were in the fracture group and 306 were in the control group (with subgroups as follows: 30 in the fracture foot group and 28 in the non-fracture group). We measured the foot length, arch height, weight-bearing leg-heel alignment, non-weight-bearing leg-heel alignment, forefoot angle relative to the rearfoot, forefoot angle relative to the horizontal axis, and foot pressure. The non-weight-bearing leg-heel alignment was significantly smaller and the forefoot angle relative to the rearfoot was significantly greater in the fracture foot group than in the control foot group (P = 0.049 and P = 0.038, respectively). With regard to plantar pressure, there were no significant differences among the groups. Midfield players had significantly higher rates of fifth metatarsal stress fracture in their histories, whereas defenders had significantly lower rates (chi-square = 13.2, P stress fractures according to the type of foot (kicking foot vs. pivoting foot) or the severity of ankle sprain. Playing the midfield position and having an everted rearfoot and inverted forefoot alignment were associated with fifth metatarsal stress fractures. This information may be helpful for preventing fifth metatarsal stress fracture recurrence. More detailed load evaluations and a prospective study are needed in the future.
Mojtaba Salemi khozani
Full Text Available Aggression is one of the general phenomenon that athletes often directly or indirectly deal with. There are rare issues that are significant as much aggression and violence in sport. The explanation for violent behavior in humans is often the subject of research in the science of sociology. Social changes around the world in recent centuries had a significant impact on cultural structure. In this study, the researchers focused on the aggression of professional and semi-professional athletes in Taekwondo in Isfahan, Iran. The cross-sectional method was applied in this study. To analyze, we examined the relationships between predictor variables and the dependent variable or the variance criterion to explain the changes. The results shown that there was no significant difference between terms of anger and physical aggression among professional and semi-professional. On the other hand, there was meaningful differences between verbal aggression and hostility amongst participants. In addition, the amounts of aggression amongst professional players were more than semi-professional players.
Conceição de Maria Pinheiro Barros
Full Text Available The Professional Executive Secretary has been occupying space increasingly evident in the labor market and organizational structure, both because of market demand, the needs of dynamism in the modern administration that demonstrates the growth of the reference to it. It has sought in his field vision and attitude of performance excellence with fulfilling its role with its own characteristics. This study aims to investigate the general challenges for the Executive Secretariat professional male in contemporary organizations. We defined the following objectives: to analyze the insertion of the male in the profession of Executive Secretary and identify the challenges faced by the Executive Secretary of the males to their development and professional growth. To this end, we performed a literature search, followed by a field survey. It is a qualitative research because data collected, and then make a qualitative analysis of results from selected literature. The survey was conducted in organizations from the public and private, state of Ceará. The sample was represented by professional male graduates in the executive secretariat at the Federal University of Ceará and working in the area. After analyzing the data it was concluded that despite the obstacles to be overcome, the tendency is that these opportunities work for the professional male grow, requiring that all actors in the field to seek gender equity in the profession.
McAleer, Stephen S; Lippie, Ed; Norman, Darcy; Riepenhof, Helge
Study Design Case series. Background Pubic bone stress (PBS) is a common acute or chronic response of the pelvis in sports where sprinting, kicking, twisting, and cutting are the dominant movements. There are few nonoperative rehabilitation strategies for the condition reported in the literature, and the outcome of conservative treatment has not been documented. Case Description Five professional and academy soccer players complaining of pubic symphysis pain, confirmed as PBS on magnetic resonance imaging and objective assessment, were treated with a nonoperative rehabilitation program that featured functional and clinical objective markers as progression criteria. Interventions in the acute phase included pharmacological and physical therapeutic modalities to reduce pain initially. Rehabilitation management focused on improving range of motion at the hips and thorax, adductor strengthening, trunk and lumbopelvic stability, gym-based strength training, and field-based rehabilitation and conditioning. Clinical follow-up was performed at least 8 months following return to play. Outcomes All players demonstrated reduced or resolved pain, increased adductor squeeze strength, and return to pain-free training and match play. Return-to-training time averaged 40.6 days (range, 30-60 days) and return to play averaged 49.4 days (range, 38-72 days) within the 5 players. At final follow-up (mean, 29.6 months; range, 16-33 months), there had been no recurrences. Discussion This report of 5 cases suggests that a nonoperative protocol, using clinical and functional progression criteria, may be successful in rehabilitating athletes with PBS for return to sport within 11 weeks. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2017;47(9):683-690. Epub 3 Aug 2017. doi:10.2519/jospt.2017.7314.
Rostgaard Andersen, Thomas; Schmidt, Jakob Friis; Pedersen, Mogens Theisen
The effects of 52 weeks of soccer or resistance training were investigated in untrained elderly men. The subjects aged 68.1±2.1 yrs were randomised into a soccer (SG; n = 9), a resistance (RG; n = 9) and a control group (CG; n = 8). The subjects in SG and RG, respectively, trained 1.7±0.3 and 1...... expression decreased by 38% (psoccer training reduces BMI and improves anti-oxidative capacity, while long-term resistance training impacts muscle protein enzyme expression and increases lean body mass in elderly men....
Coelho, Daniel Barbosa; Pimenta, Eduardo Mendonça; Veneroso, Christiano Eduardo; Morandi, Rodrigo Figueiredo; Pacheco, Diogo Antônio Soares; Pereira, Emerson Rodrigues; Coelho, Leonardo Gomes Martins; Silami-Garcia, Emerson
Soccer is a sport practiced worldwide, on all continents. It is considered an intermittent activity of high intensity and long duration, in which movements that require great strength and speed, such as jumps and sprints, result in high levels of muscle microtrauma, hampering athletes' training and recovery. The present study aimed to evaluate the magnitude of changes in different markers of physiological demand resulting from a soccer match in healthy individuals. Ten healthy male physical e...
Koc, Baris B; Somorjai, Nicolaas; P M Kiesouw, Egid; Vanderdood, Kurt; Meesters-Caberg, Marleen; Draijer, Frits W; Jansen, Edwin J P
A Morel-Lavallée lesion is a post-traumatic closed degloving injury of soft tissue. The lesion is due to a shearing trauma with separation of subcutaneous tissue from underlying fascia. When conservative treatment fails, surgical treatment is imperative. Commonly, open drainage and debridement is performed. This case report describes a Morel-Lavallée lesion of the knee in a professional soccer player who was successfully treated with endoscopic debridement and fibrin glue injection after failure of conservative management. This method achieves the goal of an open surgical debridement without exposing patients to an increased morbidity. Copyright © 2016. Published by Elsevier B.V.
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...
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 ...
Van de Hoef, S; Huisstede, B M A; Brink, M S; de Vries, N; Goedhart, E A; Backx, F J G
Hamstring injuries are the most common muscle injury in amateur and professional soccer. Most hamstring injuries occur in the late swing phase, when the hamstring undergoes a stretch-shortening cycle and the hamstring does a significant amount of eccentric work. The incidence of these injuries has not decreased despite there being effective injury prevention programmes focusing on improving eccentric hamstring strength. As this might be because of poor compliance, a more functional injury prevention exercise programme that focuses on the stretch-shortening cycle might facilitate compliance. In this study, a bounding exercise programme consisting of functional plyometric exercises is being evaluated. A cluster-randomized controlled trial (RCT). Male amateur soccer teams (players aged 18-45 years) have been randomly allocated to intervention and control groups. Both groups are continuing regular soccer training and the intervention group is additionally performing a 12-week bounding exercise programme (BEP), consisting of a gradual build up and maintenance programme for the entire soccer season. The primary outcome is hamstring injury incidence. Secondary outcome is compliance with the BEP during the soccer season and 3 months thereafter. Despite effective hamstring injury prevention programmes, the incidence of these injuries remains high in soccer. As poor compliance with these programmes may be an issue, a new plyometric exercise programme may encourage long-term compliance and is expected to enhance sprinting and jumping performance besides preventing hamstring injuries. NTR6129 . Retrospectively registered on 1 November 2016.
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.
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
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
Krustrup, Peter; Christensen, Jesper F.; Randers, Morten Bredsgaard
We examined the physical demands of small-sided soccer games in untrained middle-age males and muscle adaptations and performance effects over 12 weeks of recreational soccer training in comparison with continuous running. Thirty-eight healthy subjects (20-43 years) were randomized into a soccer....... Blood lactate during running at 11 km/h was lowered (p soccer organized as small-sided games stimulates both aerobic and anaerobic...
Sæther, Stig Arve; Aspvik, Nils Petter
Background Talented football players are expected to overcome large training and match loads, indicating a high weekly level of physical activity (PA). Aims With the use of accelerometers, the aim of this study was to objectively describe the players’ total time spent in moderate-to-vigorous PA (MVPA), vigorous PA (VPA) and very vigorous PA (VVPA) per day in 1 week. Since high-intensity PA has been highlighted as important in terms of overall PA load, we also included 2 and 4 min bouts of VPA. Methods Data were collected in three junior teams in professional football clubs in March (club 1: 2014, club 2: 2012 and club 3: 2011). A one-way analysis of variance was applied to analyse differences between the three respective clubs. Results The players averaged 77.2–86.2 min in MVPA, 14.9–18.5 min in VPA and 1.0–3.1 in VVPA per day. While there were no differences in total time spent in MVPA and VPA per day, VVPA was significantly higher in club 1 (p<0.01) compared with clubs 2 and 3. Moreover, when using the VPA bouts, club 3 (p<0.01) achieved significantly more time in this intensity compared with clubs 1 and 2. Conclusion This study acknowledges the importance of including both club-related and non-club-related PA when analysing talented football players’ PA level. We suggest that future studies examining players’ PA with accelerometers should emphasise time spent in high-intensity PA and how this is associated with physical overload, psychological burnout and risk of injury. PMID:28879031
Lameiras, João; Almeida, Pedro L; Garcia-Mas, Alexandre
In team sports, athletes' goals may focus on the task (enhancing performance, developing better skills, etc.) or on ego (being better than the others, achieving superiority, etc.). This study investigated the relationships between athletes' goal orientation and their tendency to cooperate with teammates and coaches. 158 professional men (M age = 24.1 yr., SD = 4.6) who played on various sport teams participated in this study. Goal orientation was measured with the Portuguese version of the Task and Ego Orientation in Sport Questionnaire, and cooperation was measured with the Questionário de Cooperação Desportiva. Cooperation was positively correlated with task orientation, and negatively correlated with ego orientation. Overall, the findings support that in sports, directing the players' focus on task may promote prosocial behavior.
Female soccer players often have only limited time available to prepare and consume meals, due to the constraints faced by having to combine training and playing with full-time occupations. The energy expenditure of females playing soccer has been estimated at approximately 70% VO2 max, corresponding to an energy production of around 4600 kJ (1100 kcal). As with male soccer players, carbohydrate consumption is essential to support the demands of playing, training and to facilitate recovery. There are some reports to suggest that females in team sports may consume diets with a low energy intake, due to the desire to lose or maintain body weight. In extreme cases, this can result in eating disorders. However, there is no clear evidence to suggest that this problem is common among female soccer players. To maintain a consistent balance between energy intake and expenditure, players should receive nutritional advice to cover all phases of the year, not just the competitive season. Dietary calcium and iron supplements may be a useful precautionary measure, in players who are known to be at risk of deficiencies in these areas. Correct and sensitive nutritional counselling is essential for players and coaches.
Carling, C; Le Gall, F; Dupont, G
In this study, the effects of a prolonged period of fixture congestion (8 successive official matches in 26 days) on physical performance and injury risk and severity in a professional soccer team were investigated. Computerised motion-analysis was used to analyse the overall distance covered and that run at light- (0.0-11.0 km·h - 1); low- (11.1-14.0 km·h - 1); moderate- (14.1-19.7 km·h - 1) and high-intensities (≥19.8 km·h - 1) for the team as a whole. Distances were measured in metres per minute. Information on match injuries was recorded prospectively. The overall distance covered varied across successive matches (pvs. 116.0 ± 8.0 m·min - 1 and 115.5 ± 11.0 m·min - 1). Distance run in light-intensity exercise also varied (pvs. 1, 2, 3, 5 and 6 (75.5 ± 3.8 m·min - 1 vs. 70.6 ± 2.4 m·min - 1, 71.8 ± 3.4 m·min - 1, 69.3 ± 2.6 m·min - 1, 71.5 ± 3.1 m·min - 1, and 70.3 ± 2.8 m·min - 1) and in game 8 vs. game 3 (73.1 ± 3.8 vs. 69.3 ± 2.6 m·min - 1), respectively. When comparing match halves, there were no differences across games in overall or high-intensity distance covered and performance in these measures was similar for matches played before, during and after this period. Globally, no difference over the 8 games combined was observed between the reference team and opponents in any of the performance measures whereas the overall distance covered and that in low- (both pindividual games. The incidence of match injury during the congested fixture period was similar to rates reported outside this period but the mean lay-off duration of injuries was substantially shorter during the former (p<0.05). In summary, while the overall distance run and that covered at lower intensities varied across games, high-intensity running performance and injury risk were generally unaffected during a prolonged period of fixture congestion. These results might be linked to squad rotation and post-match recovery
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 ...
Andersen, Thomas Rostgaard; Schmidt, Jakob Friis; Pedersen, Mogens Theisen; Krustrup, Peter; Bangsbo, Jens
The effects of 52 weeks of soccer or resistance training were investigated in untrained elderly men. The subjects aged 68.1±2.1 yrs were randomised into a soccer (SG; n = 9), a resistance (RG; n = 9) and a control group (CG; n = 8). The subjects in SG and RG, respectively, trained 1.7±0.3 and 1.8±0.3 times weekly on average during the intervention period. Muscle function and body composition were determined before and after 16 and 52 weeks of the intervention period. In SG, BMI was reduced by 1.5% and 3.0% (psoccer training reduces BMI and improves anti-oxidative capacity, while long-term resistance training impacts muscle protein enzyme expression and increases lean body mass in elderly men. Trial Registration ClinicalTrials.gov: NCT01530035 PMID:26886262
Randers, Morten Bredsgaard; Andersen, Jesper Løvind; Petersen, Jesper
Abstract The aim was to investigate performance variables and indicators of cardiovascular health profile in elderly soccer players (SP, n = 11) compared to endurance-trained (ET, n = 8), strength-trained (ST, n = 7) and untrained (UT, n = 7) age-matched men. The 33 men aged 65-85 years underwent...
Radman, Ivan; Wessner, Barbara; Bachl, Norbert; Ruzic, Lana; Hackl, Markus; Baca, Arnold; Markovic, Goran
The study aimed to evaluate the test–retest reliability of a newly developed 356 Soccer Shooting Test (356-SST), and the discriminative ability of this test with respect to the soccer players' proficiency level and leg dominance. Sixty-six male soccer players, divided into three groups based on their proficiency level (amateur, n = 24; novice semi-professional, n = 18; and experienced semi-professional players, n = 24), performed 10 kicks following a two-step run up. Forty-eight of them repeated the test on a separate day. The following shooting variables were derived: ball velocity (BV; measured via radar gun), shooting accuracy (SA; average distance from the ball-entry point to the goal centre), and shooting quality (SQ; shooting accuracy divided by the time elapsed from hitting the ball to the point of entry). No systematic bias was evident in the selected shooting variables (SA: 1.98±0.65 vs. 2.00±0.63 m; BV: 24.6±2.3 vs. 24.5±1.9 m s-1; SQ: 2.92±1.0 vs. 2.93±1.0 m s-1; all p>0.05). The intra-class correlation coefficients were high (ICC = 0.70–0.88), and the coefficients of variation were low (CV = 5.3–5.4%). Finally, all three 356-SST variables identify, with adequate sensitivity, differences in soccer shooting ability with respect to the players' proficiency and leg dominance. The results suggest that the 356-SST is a reliable and sensitive test of specific shooting ability in men’s soccer. Future studies should test the validity of these findings in a fatigued state, as well as in other populations. PMID:26812247
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
Rijken, Noortje H.; Soer, Remko; de Maar, Ewold; Prins, Hilco; Teeuw, Wouter B.; Peuscher, Jan; Oosterveld, Frits G. J.
The aim of this pilot study was to investigate the effects of an intervention consisting of mental coaching combined with either electro encephalogram (EEG) alpha power feedback or heart rate variability (HRV) feedback on HRV, EEG outcomes and self-reported factors related to stress, performance, recovery and sleep quality in elite athletes. A prospective pilot study was performed with two distinct cohorts. Soccer players were provided with four sessions of mental coaching combined with daily...
Gray, C.M.; Hunt, K.; Mutrie, N.; Anderson, A.S.; Treweek, S.; Wyke, S.
BACKGROUND: The prevalence of male obesity is increasing, but men are less likely than women to attend existing weight management programmes. We have taken a novel approach to reducing perceived barriers to weight loss for men by using professional football (soccer) clubs to encourage participation
Full Text Available This study aims to investigate professional readiness of a selected group of male and female experts in Iranian sports organizations. It is a descriptive study with an applied objective. The statistical population of the study includes the entire selected male and female experts (406 experts of Iranian sports organizations among which 352 cases cooperated with the researchers and therefore were selected as research sample. Measurement tool is the professional readiness assessment standard questionnaire (Aliabadi, 2014; the validity and reliability of this questionnaire have been approved by sport experts. The descriptive and inferential statistics including KS- and T-test was used to analyze the data. The results indicate that there is no significant difference between male and female experts in sports organizations regarding mental readiness and its components (motivation, commitment, confidence; but there is a significant difference at 0.01 level between them with regard to work readiness and its components (skill, knowledge, experience. Moreover, based on the average of work/technical readiness components, male experts are better than female experts.
Koning, Ruud H.
In this paper, we estimate an ordered probit model for soccer results in The Netherlands. The result of a game is assumed to be determined by home advantage and quality differences of the opposing teams. The parameters of the model are used to assess whether competitive balance in Dutch professional
Bredtmann, Julia; Crede, Carsten J.; Otten, Sebastian
In this paper, we propose a new estimation strategy that uses the variation in success between the male and the female national soccer team within a country to identify the causal impact of gender equality on women’s soccer performance. In particular, we analyze whether within-country variations...... in labor force participation rates and life expectancies between the genders, which serve as measures for the country’s gender equality, are able to explain diff erences in the international success of male and female national soccer teams. Our results reveal that diff erences in male and female labor...... force participation rates and life expectancies are able to explain the international soccer performance of female teams, but not that of male teams, suggesting that gender equality is an important driver of female sport success....
Full Text Available Background: Weight loss and decreasing the Body fat percentage (BF% is motivated to optimize performance. In order to achieve these, many supplements are used by athletes, however the possible negative or synergic effects have not been fully described in the literature, specifically in humans. The present study was conducted to investigate the co-administration effects of two common used supplements in body weight and BF% management to recommend athletes for safe weight and BF% reduction. Materials and Methods: In the present double-blind, randomized, parallel, placebo-controlled study, the effect of six-week co-administration of caffeine and carnitine was determined on changes in body weight (BW, BF%, serum leptin concentration and lipid profile (triglyceride, HDL Cholesterol, LDL Cholesterol and Total Cholesterol, fasting blood glucose (FBG, and free fatty acid (FFA changes. Twenty eight male teen soccer players from Ahvaz-Iran, were divided in three groups (group CafPlc, caffeine (6 mg/kg/day + dextrose; group CafCar, caffeine (6 mg/kg/day + carnitine (2g; and group Plc, dextrose. Results: Caffeine-carnitine had a lowering effect on BW (P=0.02 and BF% (P=0.03, compared to caffeine alone and placebo in male teen soccer players (mean age of 16.92 ± 0.76 years. TG was significantly decreased in CafCar (P=0.04. FFA levels were increased in CafCar (P=0.04 and there was significant differences between CafCar and Plc groups (P=0.01. FBG was increased in both CafPlc and CafCar (P=0.01 and P=0.02, respectively, with no significant differences between groups. Conclusion: The synergistic effect of caffeine-carnitine might be suggested to decrease the BF% and BW, besides it may prevent the increment of FFA levels; however it should be prescribed cautiously since it increased FBG levels.
Goff, John Eric; Carre, Matt J
We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.
Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: email@example.com [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)
We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.
Dupont, Gregory; Nedelec, Mathieu; McCall, Alan; McCormack, Derek; Berthoin, Serge; Wisløff, Ulrik
Recovery duration may be too short during the congested fixtures of professional soccer players with regard to maintaining physical performance and a low injury rate. To analyze the effects of 2 matches per week on physical performance and injury rate in male elite soccer players. Cohort study; Level of evidence, 3. Match results, match-related physical performance, and injuries were monitored during 2 seasons (2007-2008 and 2008-2009) for 32 professional soccer players in a top-level team participating in the UEFA (Union of European Football Associations) Champions League. Total distance, high-intensity distance, sprint distance, and number of sprints were collected for 52 home matches. Injuries and player participation in matches and training were recorded throughout the full season. Physical performance, as characterized by total distance covered, high-intensity distance, sprint distance, and number of sprints, was not significantly affected by the number of matches per week (1 versus 2), whereas the injury rate was significantly higher when players played 2 matches per week versus 1 match per week (25.6 versus 4.1 injuries per 1000 hours of exposure; P physical performance tested but is not long enough to maintain a low injury rate. The present data highlight the need for player rotation and for improved recovery strategies to maintain a low injury rate among athletes during periods with congested match fixtures.
Prognostic factors for specific lower extremity and spinal musculoskeletal injuries identified through medical screening and training load monitoring in professional football (soccer): a systematic review
Sergeant, Jamie C; Parkes, Matthew J; Callaghan, Michael J
Background Medical screening and load monitoring procedures are commonly used in professional football to assess factors perceived to be associated with injury. Objectives To identify prognostic factors (PFs) and models for lower extremity and spinal musculoskeletal injuries in professional/elite football players from medical screening and training load monitoring processes. Methods The MEDLINE, AMED, EMBASE, CINAHL Plus, SPORTDiscus and PubMed electronic bibliographic databases were searched (from inception to January 2017). Prospective and retrospective cohort studies of lower extremity and spinal musculoskeletal injury incidence in professional/elite football players aged between 16 and 40 years were included. The Quality in Prognostic Studies appraisal tool and the modified Grading of Recommendations Assessment, Development and Evaluation synthesis approach was used to assess the quality of the evidence. Results Fourteen studies were included. 16 specific lower extremity injury outcomes were identified. No spinal injury outcomes were identified. Meta-analysis was not possible due to heterogeneity and study quality. All evidence related to PFs and specific lower extremity injury outcomes was of very low to low quality. On the few occasions where multiple studies could be used to compare PFs and outcomes, only two factors demonstrated consensus. A history of previous hamstring injuries (HSI) and increasing age may be prognostic for future HSI in male players. Conclusions The assumed ability of medical screening tests to predict specific musculoskeletal injuries is not supported by the current evidence. Screening procedures should currently be considered as benchmarks of function or performance only. The prognostic value of load monitoring modalities is unknown. PMID:29177074
Manzi, Vincenzo; D'Ottavio, Stefano; Impellizzeri, Franco M; Chaouachi, Anis; Chamari, Karim; Castagna, Carlo
The aim of this study was to examine the training load (TL) profile of professional elite level basketball players during the crucial parts of the competitive season (pre-play-off finals). Subjects were 8 full-time professional basketball players (age 28 +/- 3.6 years, height 199 +/-7.2 cm, body mass 102 +/- 11.5 kg, and body fat 10.4 +/- 1.5%) whose heart rate (HR) was recorded during each training session and their individual response to TL monitored using the session-rate of perceived exertion (RPE) method (200 training sessions). The association between the session-RPE method and training HR was used to assess the population validity of the session-RPE method. Significant relationships were observed between individual session-RPE and all individual HR-based TL (r values from 0.69 to 0.85; p 0.05). Elite male professional basketball imposes great physiological and psychological stress on players through training sessions and official competitions (1-2 per week). Consequently, the importance of a practical and valid method to assess individual TL is warranted. In this research, we demonstrated that session-RPE may be considered as a viable method to asses TL without the use of more sophisticated tools (i.e., HR monitors). The session-RPE method enabled the detection of periodization patterns in weekly planning in elite professional basketball during the crucial part of the competitive season (1 vs. 2 weekly fixtures model).
Full Text Available Purpose. The present study aimed to examine the current methods employed to assess anticipation in soccer players as well as to elicit the main findings of recent studies. Methods. The study was carried out in systematic review form and its sample comprised nine scientific papers published in academic journals. Only the studies involving soccer players (professionals and amateurs, except goalkeepers were included in this review. Results and conclusions. We observed that most of the studies employed video footage obtained from soccer matches, which are occluded at a given point for study participants to quickly and precisely elicit the positions of opponents, teammates and the ball as well as anticipate actions (dribbling, shooting, passing from surrounding players (teammates and opponents. In addition, the studies compared the performance of players from both high and low competitive levels in anticipation tasks.
Webster, R L; Ellis, T S
Measures of reported self-confidence in performing financial analysis by 59 professional male analysts, 31 born between 1946 and 1964 and 28 born between 1965 and 1976, were investigated and reported. Self-confidence in one's ability is important in the securities industry because it affects recommendations and decisions to buy, sell, and hold securities. The respondents analyzed a set of multiyear corporate financial statements and reported their self-confidence in six separate financial areas. Data from the 59 male financial analysts were tallied and analyzed using both univariate and multivariate statistical tests. Rated self-confidence was not significantly different for the younger and the older men. These results are not consistent with a similar prior study of female analysts in which younger women showed significantly higher self-confidence than older women.
Nasi, Milena; Cristani, Alessandro; Pinti, Marcello; Lamberti, Igor; Gibellini, Lara; De Biasi, Sara; Guazzaloca, Alessandro; Trenti, Tommaso; Cossarizza, Andrea
Exercise exerts various effects on the immune system, and evidence is emerging on its anti-inflammatory effects; the mechanisms on the basis of these modifications are poorly understood. Mitochondrial DNA (mtDNA) released from damaged cells acts as a molecule containing the so-called damage-associated molecular patterns and can trigger sterile inflammation. Indeed, high plasma levels of mtDNA are associated to several inflammatory conditions and physiological aging and longevity. The authors evaluated plasma mtDNA in professional male volleyball players during seasonal training and the possible correlation between mtDNA levels and clinical parameters, body composition, and physical performance. Plasma mtDNA was quantified by real-time PCR every 2 mo in 12 professional volleyball players (PVPs) during 2 consecutive seasons. As comparison, 20 healthy nonathlete male volunteers (NAs) were analyzed. The authors found lower levels of mtDNA in plasma of PVPs than in NAs. However, PVPs showed a decrease of circulating mtDNA only in the first season, while no appreciable variations were observed during the second season. No correlation was observed among mtDNA, hematochemical, and anthropometric parameters. Regular physical activity appeared associated with lower levels of circulating mtDNA, further confirming the protective, anti-inflammatory effect of exercise.
Nedelec, Mathieu; McCall, Alan; Carling, Chris; Legall, Franck; Berthoin, Serge; Dupont, Grégory
International audience; In the formerly published part I of this two-part review, we examined fatigue after soccer matchplay and recovery kinetics of physical performance, and cognitive, subjective and biological markers. To reduce the magnitude of fatigue and to accelerate the time to fully recover after completion, several recovery strategies are now used in professional soccer teams. During congested fixture schedules, recovery strategies are highly required to alleviate post-match fatigue...
Full Text Available Background: Determining somatic models and profiles in young athletes has recently become a fundamental element in selecting basketball playing positions. The aim of this study was to assess the relationship between the body build of young and adult elite male basketball players at different playing positions. Methods: Participants consisted of 35 young (age: 14.09 ± 0.30 years, n = 35 and 35 adult professional basketball players (age: 24.45 ± 5.40 years, n = 35 competing in elite leagues. The anthropometric characteristics assessed included body mass, body height, skinfolds, somatotypes, girths, and breadths. Results: The centers in both age groups were significantly taller and heavier (p < 0.001 compared to forwards and guards. The greatest difference between categories were in the guards’ personal height (from 169.36 to 186.68 = 17.32 cm. The guards from the professional team were closest in height to the forwards (difference = 7.17 cm compared to young players where the difference between guards and forwards was 13.23 cm. Young competitors were more ectomorphic (2.12-3.75-4.17, while professional players were more mesomorphic (2.26-4.57-3.04. Significant criteria for center selection at professional level seems to be personal height and arm span ratio. Conclusions: The results indicate that the selection for basketball playing positions should include the analysis of body height and mass, shoulder breadth, humerus breadth, femur breadth and specifically for centers the difference between personal the height and arm span.
Setuain, Igor; Lecumberri, Pablo; Izquierdo, Mikel
The present research aimed to describe an inertial unit (IU)-based sprint mechanics evaluation model for assessing players' readiness to return to competition after suffering a grade I hamstring injury. A professional male football player (age 19years; height 177cm; weight 70kg, midfielder, Spanish, 3° Division) with a grade 1 biceps femoris injury was evaluated at pre-season, at return to play after injury and at the end of the competitive season. Sprint mechanics were analyzed via the use of an inertial orientation tracker (Xsens Technologies B.V. Enschede, Netherlands) attached over the L3-L4 region of the subject's lumbar spine. Sprint mechanics such as horizontal components of ground reaction force were assessed in both legs during sprinting actions. Findings and interpretation: Both the coefficient of the horizontal force application (SFV) and the ratio of forces (DRF) applied at increasing velocity were decreased in the injured limb compared with the contralateral healthy limb at the return to play evaluation (73% and 76% reductions, respectively) and returned to symmetrical levels at the end-season evaluation. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available Abstract Background During a soccer game, the cardiovascular system is severely taxed The referees must be alert and their level of fitness must be such that fatigue will not impair their decision-making. Referee's peak overall performance is usually after 40 when the performance starts to decline. We evaluated the morphological and functional cardiac profile of professional soccer referees. Materials and methods We submitted to a clinical and echocardiographic exam a group of 120 professional soccer referees aged 25 – 45 years, including the first division of the Italian Championship, matched with 120 soccer players, including élite soccer players. Data were compared using an unpaired Student's t test. Statistical significance was with p Results Right ventricle dimensions (22.2 ± 3.8 vs 25.9 ± 2.4 mm and Left Ventricular Mass Index (LVMi (100.5 ± 45.2 vs 105.4 ± 17.3 were significantly greater in referees than in active soccer players. Left atrium dimensions (33.7 ± 8.9 vs 36.2 ± 3.1 mm, aortic root (29.7 ± 7.9 vs 32.1 ± 3 mm and LVMi (115.1 ± 16.7 vs 134.1 ± 19.9 g/m2 were significantly greater in élite soccer players than in first-division referees. Conclusion Our investigation shows that right ventricle is greater in referees than in soccer players. The differences (left atrium, aortic root and LVMi between first division referees and élite soccer players may derive from the different training workloads.
The mechanisms underlying the relative age effect in sport events have been investigated for more than two decades. The present study focused on the relationship between the relative age effect and lengths of professional careers among professional male Japanese baseball players. The birth dates of players and lengths of professional careers were collected from an official publication, and data were divided into four quarters (Q1: April-June; Q2: July-September; Q3: October-December; Q4: January-March of the following year) grouped by 3 years. Based on the data for Q4, the expected numbers for the lengths of professional careers were calculated for Q1, Q2, and Q3. The number of players with professional careers of more than 19 years was significantly smaller in Q4 than in Q1, Q2, and Q3. The relative age effect among professional male Japanese baseball players was associated with the lengths of professional careers. Relative age appears to be a very important factor for the development of expertise among male Japanese baseball players and involves long-term disadvantages after becoming professional players.
Daniel Kroeff de Araujo Corrêa
Full Text Available O presente artigo analisa os aspectos que influenciam a performance do jogador de futebol e os fatores contextuais relacionados. Com esse objetivo, fez-se um estudo entrevistando 2 ex-atletas, 2 jogadores que ainda atuam, 2 treinadores e 2 preparadores físicos - todos experientes e consagrados em suas profissões - para verificar quais são os fatores considerados importantes para a performance dos jogadores de futebol. Realizou-se análise de conteúdo sobre os dados das entrevistas. Constatou-se que muitos fatores envolvem o contexto que influencia o desempenho. Esses podem ser divididos em fatores psicológicos, físicos, técnicos e táticos e de suporte social oferecido ao jogador. A partir das categorias levantadas, estabeleceram-se as bases para construção de um questionário contendo os principais temas abordados pelos entrevistados, o qual será utilizado num estudo posterior.The present article analyzes the factors that influence the performance of soccer players and the contextual factors related to their performance. In this study the following people were interviewed: 2 former-athletes, 2 players that are still active, 2 coaches and 2 physical trainers, all experienced and renowned. The article aims at verifying which are the factors considered important for the performance of soccer players. Content analysis was performed on the data of the interviews. Results show that many factors are related to the context that influences the performance. These can be divided in categories involving psychological, physical, technical and tactical factors; there were also factors that involve the social background offered to the player. From the categories raised, the basis for the development of a questionnaire involving the main subjects of the interviews was elaborated and will be used in a following study.
Schenk, K; Bizzini, M; Gatterer, H
Referees are an integral part of soccer, and their performance is fundamental for regular match flow, irrespective of the competition level or age classes. So far, scientific interest was mainly limited to aspects of exercise physiology and match performance of soccer referees, whereas recommendations for nutrition were adopted from active professional soccer. In contrast to elite soccer players, most referees are non-professional and engaged in different occupations. Furthermore, elite referees and soccer players differ in regard to age, body composition, aerobic capacity, and training load. Thus, referees' caloric needs and recommended daily carbohydrate intake may generally be lower compared to active soccer players, with higher intakes limited to periods of increased training load and match days or for referees engaged in physical demanding occupations. With respect to fluid intake, pre-match and in-match hydration strategies generally valid in sports are recommended also for referees to avoid cognitive and physical performance loss, especially when officiating in extreme climates and altitude. In contrast to elite soccer, professional assistance concerning nutrition and training is rarely available for national elite referees of most countries. Therefore, special attention on education about adequate nutrition and fluid intake, about the dietary prevention of deficiencies (iron in female referees, vitamin D irrespective of sex and age), and basic precautions for travels abroad is warranted. In conclusion, the simple adoption of nutritional considerations from active soccer for referees may not be appropriate. Recommendations should respect gender differences, population-specific physical characteristics, and demands just as well as individual characteristics and special needs. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Baran, Funda; Aktop, Abdurrahman; Ozer, Dilara; Nalbant, Sibel; Aglamis, Ece; Barak, Sharon; Hutzler, Yeshayahu
The study investigated the effects of a Special Olympics (SO) Unified Sport (UNS) soccer program on anthropometry, physical fitness and soccer skills of male youth athletes with and without intellectual disabilities (ID) who participated in a training group (TRG) and in a comparison group (CG) without specific training. Youth with ID (WID) were…
Toni Caparrós, Martí Casals, Álvaro Solana, Javier Peña
Full Text Available The primary purpose of this study was to identify potential risk factors for sports injuries in professional basketball. An observational retrospective cohort study involving a male professional basketball team, using game tracking data was conducted during three consecutive seasons. Thirty-three professional basketball players took part in this study. A total of 29 time-loss injuries were recorded during regular season games, accounting for 244 total missed games with a mean of 16.26 ± 15.21 per player and season. The tracking data included the following variables: minutes played, physiological load, physiological intensity, mechanical load, mechanical intensity, distance covered, walking maximal speed, maximal speed, sprinting maximal speed, maximal speed, average offensive speed, average defensive speed, level one acceleration, level two acceleration, level three acceleration, level four acceleration, level one deceleration, level two deceleration, level three deceleration, level four deceleration, player efficiency rating and usage percentage. The influence of demographic characteristics, tracking data and performance factors on the risk of injury was investigated using multivariate analysis with their incidence rate ratios (IRRs. Athletes with less or equal than 3 decelerations per game (IRR, 4.36; 95% CI, 1.78-10.6 and those running less or equal than 1.3 miles per game (lower workload (IRR, 6.42 ; 95% CI, 2.52-16.3 had a higher risk of injury during games (p < 0.01 in both cases. Therefore, unloaded players have a higher risk of injury. Adequate management of training loads might be a relevant factor to reduce the likelihood of injury according to individual profiles.
Consumo máximo de oxigênio e limiar anaeróbio de jogadores de futebol: comparação entre as diferentes posições Maximal oxygen uptake and anaerobic threshold in professional soccer players: comparison between different positions
Full Text Available O grau de desenvolvimento das capacidades físicas no futebol é fator determinante do nível desportivo do jogador. O objetivo do presente estudo foi comparar valores de limiar anaeróbio e consumo máximo de oxigênio entre jogadores profissionais de futebol de diferentes posições. Para tanto, 25 atletas (idade = 22,08 ± 8,28 anos, peso = 76,12 ± 9,8kg, altura = 179,8 ± 7,1cm e relação corporal = 12,21 ± 3,67% de gordura corporal foram divididos em cinco grupos, como se segue: goleiros (GO, zagueiros (ZA, laterais (LA, meio-campistas (MC e atacantes (AT. O VO2max foi determinado em esteira ergométrica através de análise direta e a velocidade de corrida correspondente ao limiar anaeróbio fixo de 4mM (V4mM, em teste de campo (2 x 1.000m a 90 e 95% da velocidade máxima para a distância através de interpolação linear. A V4mM foi menor (p The development of physical capacities in soccer determines the player's level of performance. The aim of this study was to compare anaerobic threshold and maximal oxygen uptake values between professional soccer players playing in different positions. Twenty-five male athletes (age = 22.08 ± 8.82 years, weight = 76.12 ± 9.8 kg, height = 179.8 ± 7.1 cm and body composition = 12.21 ± 3.67% body fat were divided into five groups as follows: goalkeepers (GO, full backs (FB, sideways (SW, midfield (MF and forwards (FO and evaluated twice in two to three days period. For direct maximal oxygen uptake (VO2max determination, subjects were submitted to an incremental continuous treadmill exercise until fatigue occurred. Two-speeds track test (2 x 1,000 m at 90 and 95% of maximal speed and linear interpolation were employed for 4mM blood lactate running speed (V4mM or anaerobic threshold assessment. Main results are present below. V4mM for GO group was significantly lower (p 0.05 from one another. Since these athletes were under the same training program, the differences above may be explained by
Mohr, Magni; Krustrup, Peter; Bangsbo, Jens
This review describes when fatigue may develop during soccer games and the potential physiological mechanisms that cause fatigue in soccer. According to time?-?motion analyses and performance measures during match-play, fatigue or reduced performance seems to occur at three different stages......, acidity or the breakdown of creatine phosphate. Instead, it may be related to disturbances in muscle ion homeostasis and an impaired excitation of the sarcolemma. Soccer players' ability to perform maximally is inhibited in the initial phase of the second half, which may be due to lower muscle...... concentrations in a considerable number of individual muscle fibres. In a hot and humid environment, dehydration and a reduced cerebral function may also contribute to the deterioration in performance. In conclusion, fatigue or impaired performance in soccer occurs during various phases in a game, and different...
Soccer is the most popular sport in the world, with FIFA recognising more than 265 million amateur players. Despite the fact that soccer is a contact sport, it is perceived to be relatively safe to play, a factor that has contributed to its status as the fastest growing team sport in the USA. Acute and minor injuries predominate in the statistics, with contusions and abrasions being the most commonly recorded. As would be expected, the majority of soccer injuries are to the lower limbs, with serious truncal and spinal trauma being rare. This article examines the type and anatomic location of injuries sustained by children and adolescents who play soccer, and the main mechanisms whereby such injuries occur. The risk factors underpinning injury occurrence are considered, along with injury avoidance tactics. (orig.)
Paterson, Anne [Royal Belfast Hospital for Sick Children, Radiology Department, Belfast (United Kingdom)
Soccer is the most popular sport in the world, with FIFA recognising more than 265 million amateur players. Despite the fact that soccer is a contact sport, it is perceived to be relatively safe to play, a factor that has contributed to its status as the fastest growing team sport in the USA. Acute and minor injuries predominate in the statistics, with contusions and abrasions being the most commonly recorded. As would be expected, the majority of soccer injuries are to the lower limbs, with serious truncal and spinal trauma being rare. This article examines the type and anatomic location of injuries sustained by children and adolescents who play soccer, and the main mechanisms whereby such injuries occur. The risk factors underpinning injury occurrence are considered, along with injury avoidance tactics. (orig.)
Soccer is the most popular sport in the world, with FIFA recognising more than 265 million amateur players. Despite the fact that soccer is a contact sport, it is perceived to be relatively safe to play, a factor that has contributed to its status as the fastest growing team sport in the USA. Acute and minor injuries predominate in the statistics, with contusions and abrasions being the most commonly recorded. As would be expected, the majority of soccer injuries are to the lower limbs, with serious truncal and spinal trauma being rare. This article examines the type and anatomic location of injuries sustained by children and adolescents who play soccer, and the main mechanisms whereby such injuries occur. The risk factors underpinning injury occurrence are considered, along with injury avoidance tactics.
Lee, Seungbum; Han, Keunsu
Whereas there have been many academic studies on European soccer team supporters, relatively few studies have looked at supporters in Asia, especially regarding their supporting behavior and culture. Broadly, the purpose of this paper is to describe the behavior and culture of supporters of the Korean professional soccer league (K-League).…
Hou, D.; Driessen, Theo
Inspired by the first lustrum of the Club Positioning Matrix (CPM) for professional Dutch soccer teams, we model the interaction between soccer teams and their potential fans as a cooperative cost game based on the annual voluntary sponsorships of fans in order to validate their fan registration in
Full Text Available Study aim: due to a series of failures and the drastic reduction in the quality of Hungarian soccer, greater emphasis should be put on coaches’ professional development and talent development programs. The aim of this study was to present the newly established Hungarian Soccer Development Program that focuses on the development of youth talent.
Rijken, Noortje H; Soer, Remko; de Maar, Ewold; Prins, Hilco; Teeuw, Wouter B; Peuscher, Jan; Oosterveld, Frits G J
The aim of this pilot study was to investigate the effects of an intervention consisting of mental coaching combined with either electro encephalogram (EEG) alpha power feedback or heart rate variability (HRV) feedback on HRV, EEG outcomes and self-reported factors related to stress, performance, recovery and sleep quality in elite athletes. A prospective pilot study was performed with two distinct cohorts. Soccer players were provided with four sessions of mental coaching combined with daily HRV biofeedback (Group A); track and field athletes were provided with four sessions of mental coaching in combination with daily neurofeedback (Group B). Measurements were performed at baseline, post intervention and at 5 weeks follow-up. Objective measures: EEG and ECG. Subjective measures: Numeric Rating Scale for performance, Pittsburgh Sleep Quality Index, Rest and Stress Questionnaire and Sports Improvement-60. Group characteristics were too distinct to compare the interventions. Linear mixed models were used to analyze differences within groups over time. In Group A, significant changes over time were present in alpha power at 5 of 7 EEG locations (p HRV low frequency power and recovery scale of the REST-Q significantly increased (p = 0.02 and HRV or EEG alpha power feedback may increase HRV and alpha power and may lead to better performance-related outcomes and stress reduction. Further research is needed to elucidate the effects of either type of feedback and to compare effects with a control group.
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.
Full Text Available The purpose of this study was to determine the reliability and usefulness of the 30-15 Intermittent Fitness Test (30-15IFT in professional male and female futsal players. Thirteen male (24.4 ± 5.6 years; 174.5 ± 10.3 cm; 70.3 ± 9.9 kg and fourteen female (23.3 ± 4.5 years; 165.8 ± 6.2 cm; 61.7 ± 5.5 kg professional futsal players performed the 30-15IFT on two occasions, separated by 5 days. Maximal intermittent running velocity (VIFT and heart rate at exhaustion (HRpeak data were collected for both tests. Reliability was assessed by the intraclass correlation coefficient (ICC, typical error (TE expressed as a coefficient of variation (CV, and smallest worthwhile change (SWC. VIFT demonstrated very good reliability between sessions, both for male (ICC = 0.92 and female (ICC = 0.96 players. As the TE for VIFT and HRpeak was similar to the calculated SWC for both male and female players, the usefulness of the test was rated as “medium”. A change in performance of at least 2 stages in male players, or a change of more than 1 stage in female players could be interpreted as a meaningful change in aerobic futsal fitness. The results of this study demonstrate that the 30-15IFT is both a reliable and useful test for male and female professional futsal players.
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....
Jakobsen, Markus Due; Sundstrup, Emil; Krustrup, Peter
The aim of this study was to examine the effect of intense intermittent exercise performed as soccer training or interval running in comparison with continuous endurance running exercise on postural balance in young healthy untrained males. Young sedentary men were randomized to soccer training...... strength and countermovement jump velocity. Postural control was improved in response to 12 weeks of soccer training and high-intensity interval running, respectively, while less-marked changes were observed following continuous running. Notably, the reduced variability in CoP acceleration after soccer...
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.
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.
The purpose of the present study was to examine the relationship between coaching efficacy and conflict management style of the soccer coaches. The sample included 224 male soccer coaches ranging in coaching experience from 2 to 15 years. The Coaching Efficacy Scale and The Rahim Organizational Conflict Inventory were used to measure coaching…
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
Estudo comparativo do consumo de oxigênio e limiar anaeróbio em um teste de esforço progressivo entre atletas profissionais de futebol e futsal Estudio comparativo del consumo de oxígeno y límite anaeróbico en un test de esfuerzo progresivo entre atletas profesionales de fútbol y fútbol de salón Comparative study of the oxygen consumption and anaerobic threshold in a progressive exertion test in professional soccer and indoor soccer athletes
Ernesto Cesar Pinto Leal Junior
progresivo. Participaron voluntariamente 31 individuos del sexo masculino, entre ellos: 19 atletas profesionales de fútbol, y 12 atletas profesionales de fútbol de salón. Los deportistas fueron sometidos a un protocolo de evaluación cardiorrespiratoria progresiva por el método ergoespirométrico, y os resultados fueron analizados en relación a su diferencia estadística a través del test t-Student (p 0,05; a pesar de eso hubo diferencia estadística entre los dos grupos en relación al límite anaeróbico (LA (p Oxygen consumption (VO2 has been very useful for the functional evaluation of athletes. Ergospirometry is a non-invasive procedure used to evaluate the physical performance or the functional ability of an individual, connecting the analysis of the inspired gases with the respiratory variables. This evaluation method is extremely important to sports, since it brings significant contribution in the verification of indices of cardiorespiratory aptitude, which is the case f the maximal oxygen consumption (VO2 max and the anaerobic threshold (AT. The present study had as objective to compare oxygen consumption and anaerobic threshold in professional soccer and indoor soccer athletes in a progressive test. 31 male individuals voluntarily participated in the test, being: 19 professional soccer athletes and 12 professional indoor soccer athletes. The athletes were submitted to a progressive cardiorespiratory evaluation protocol through the ergospirometric method, and the results were analyzed concerning their statistical difference through the t-Student test (p 0,05; however, there was statistically difference between the two groups concerning the anaerobic threshold (AT (p < 0,05. Based on the results obtained in our study we concluded that even practicing sports with different characteristics, the athletes from both groups have similar indices of oxygen consumption. Nevertheless, the anaerobic threshold between the two groups did not present the same similarity
Full Text Available Soccer referees enforce the laws of the game and the decisions they make can directly affect match results. Fixtures within European competitions take place in climatic conditions that are often challenging (e.g. Moscow ~ -5oC, Madrid ~30oC. Effects of these temperatures on player performance are well documented; however, little is known how this environmental stress may impair cognitive performance of soccer referees and if so, whether exercise exasperates this. The present study aims to investigate the effect of cold (COLD; 5oC, 40% relative humidity (RH, hot (HOT; 30oC, 40% RH and temperate (CONT; 18oC, 40% RH conditions on decision making during soccer specific exercise. On separate occasions within each condition, thirteen physically active males; either semi-professional referees or semi-professional soccer players completed three 90 min intermittent treadmill protocols that simulated match play, interspersed with 4 computer delivered cognitive tests to measure vigilance and dual task capacity. Core and skin temperature, heart rate, rating of perceived exertion and thermal sensation were recorded throughout the protocol. There was no significant difference between conditions for decision making (p > 0.05 despite significant differences in measured physiological variables (skin temperature = HOT 34.5 ± 5.1°C; CONT 31.2 ± 0.1°C and COLD 26.7 ± 0.5°C; p < 0.05. It is hypothesised that the lack of difference observed in decision making ability between conditions was due to the exercise protocol used, as it may not have elicited an appropriate and valid soccer specific internal load to alter cognitive functioning.
Taylor, Lee; Fitch, Natalie; Castle, Paul; Watkins, Samuel; Aldous, Jeffrey; Sculthorpe, Nicholas; Midgely, Adrian; Brewer, John; Mauger, Alexis
Soccer referees enforce the laws of the game and the decisions they make can directly affect match results. Fixtures within European competitions take place in climatic conditions that are often challenging (e.g., Moscow ~ -5°C, Madrid ~30°C). Effects of these temperatures on player performance are well-documented; however, little is known how this environmental stress may impair cognitive performance of soccer referees and if so, whether exercise exasperates this. The present study aims to investigate the effect of cold [COLD; -5°C, 40% relative humidity (RH)], hot (HOT; 30°C, 40% RH) and temperate (CONT; 18°C, 40% RH) conditions on decision making during soccer specific exercise. On separate occasions within each condition, 13 physically active males; either semi-professional referees or semi-professional soccer players completed three 90 min intermittent treadmill protocols that simulated match play, interspersed with 4 computer delivered cognitive tests to measure vigilance and dual task capacity. Core and skin temperature, heart rate, rating of perceived exertion (RPE) and thermal sensation (TS) were recorded throughout the protocol. There was no significant difference between conditions for decision making in either the dual task (interaction effects: FALSE p = 0.46; MISSED p = 0.72; TRACKING p = 0.22) or vigilance assessments (interaction effects: FALSE p = 0.31; HIT p = 0.15; MISSED p = 0.17) despite significant differences in measured physiological variables (skin temperature: HOT vs. CONT 95% CI = 2.6 to 3.9, p decision making ability between conditions was due to the exercise protocol used, as it may not have elicited an appropriate and valid soccer specific internal load to alter cognitive functioning.
Johan Torp Rasmussen, Ludvig; Østergaard, Lars Domino
Creativity is essential in soccer due to the unpredictable and complex situations occurring in the game, where stereotypical play gradually loses its efficiency. Further, creativity is an important psychological factor for the development of soccer expertise, and valuing creativity increases...... sessions where TSCP was implemented at a youth team indicate that the application of TCSP exercises establishes a playful, judgment-free and autonomy-supportive training environment, where soccer players are able to unfold their creative potential. The creative environment helped the youth players...... in the intervention engage in unfamiliar activities that they did not dare to do in normal training sessions (i.e., performed difficult, new and playful technical skills), which developed creative abilities important for game performance (i.e., idea generation abilities and not fearing mistakes)....
Aldous, Jeffrey W F; Akubat, Ibrahim; Chrismas, Bryna C R; Watkins, Samuel L; Mauger, Alexis R; Midgley, Adrian W; Abt, Grant; Taylor, Lee
This study investigated the reliability and validity of a novel nonmotorised treadmill (NMT)-based soccer simulation using a novel activity category called a "variable run" to quantify fatigue during high-speed running. Twelve male University soccer players completed 3 familiarization sessions and 1 peak speed assessment before completing the intermittent soccer performance test (iSPT) twice. The 2 iSPTs were separated by 6-10 days. The total distance, sprint distance, and high-speed running distance (HSD) were 8,968 ± 430 m, 980 ± 75 m and 2,122 ± 140 m, respectively. No significant difference (p > 0.05) was found between repeated trials of the iSPT for all physiological and performance variables. Reliability measures between iSPT1 and iSPT2 showed good agreement (coefficient of variation: 0.80). Furthermore, the variable run phase showed HSD significantly decreased (p ≤ 0.05) in the last 15 minutes (89 ± 6 m) compared with the first 15 minutes (85 ± 7 m), quantifying decrements in high-speed exercise compared with the previous literature. This study validates the iSPT as a NMT-based soccer simulation compared with the previous match-play data and is a reliable tool for assessing and monitoring physiological and performance variables in soccer players. The iSPT could be used in a number of ways including player rehabilitation, understanding the efficacy of nutritional interventions, and also the quantification of environmentally mediated decrements on soccer-specific performance.
Delaney, J Scott; Al-Kashmiri, Ammar; Correa, José A
To examine the mechanisms of injury for concussions in university football, ice hockey, and soccer. Prospective cohort design. McGill University Sport Medicine Clinic. Male and female athletes participating in varsity football, ice hockey, and soccer. Athletes were followed prospectively over a 10-year period to determine the mechanisms of injury for concussions and whether contact with certain areas of the body or individual variables predisposed to longer recovery from concussions. For soccer, data were collected on whether concussions occurred while attempting to head the ball. There were 226 concussions in 170 athletes over the study period. The side/temporal area of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. Contact from another player's head or helmet was the most probable mechanism in football and soccer. In hockey, concussion impacts were more likely to occur from contact with another body part or object rather than another head/helmet. Differences in mechanisms of injuries were found between males and females in soccer and ice hockey. Athletes with multiple concussions took longer to return to play with each subsequent concussion. Half of the concussions in soccer were related to attempting to head the soccer ball. The side of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. In ice hockey and soccer, there are differences in the mechanisms of injury for males and females within the same sport.
Kiliç, Ö; Aoki, H.; Goedhart, E.; Hägglund, M.; Kerkhoffs, G. M. M. J.; Kuijer, P. P. F. M.; Waldén, M.; Gouttebarge, V.
Psychological factors have shown to be predictors of injury in professional football. However, it seems that this is a two-way relationship, as severe musculoskeletal time-loss injuries have shown to be associated with the onset of symptoms of common mental disorders (CMD). There is no longitudinal
Souglis, Athanasios; Bogdanis, Gregory C; Chryssanthopoulos, Costas; Apostolidis, Nikolaos; Geladas, Nikos D
This study examined the influence of sex and playing position on the time-course of selected oxidative stress, inflammation and muscle damage markers following an official soccer match. Sixty professional soccer players (30 male and 30 female) were divided into three groups, according to their playing position: defenders, midfielders and attackers. Each group consisted of 10 male and 10 female players. Sixty healthy volunteers (30 males and 30 females) served as control. Blood samples were taken before and after the match and daily for five days after the match. Analysis of variance revealed different responses over time between sex and playing positions, as shown by the 3-way interaction, for creatine kinase (CK), protein carbonyls (PC), catalase, fibrinogen (FIB), uric acid (UA), lactate dehydrogenase (LDH), reduced glutathione, C-reactive protein and interleukin-6 (IL-6) (p position, for all oxidative, inflammatory and muscle damage indices (psexes, midfielders had higher peaks in all indices compared with defenders (p sex and playing position influence the time-course of selected oxidative stress, inflammation and muscle damage markers following an official soccer game. This information should be taken into account by practitioners for the design of training programs following match play.
Reynolds, Bryson B.; Patrie, James; Henry, Erich J.; Goodkin, Howard P.; Broshek, Donna K.; Wintermark, Max; Druzgal, T. Jason
Background: The effects of head impact in sports are of growing interest for clinicians, scientists, and athletes. Soccer is the most popular sport worldwide, but the burden of head impact in collegiate soccer is still unknown. Purpose: To quantify head impact associated with practicing and playing collegiate soccer using wearable accelerometers. Study Design: Descriptive epidemiological study. Methods: Mastoid patch accelerometers were used to quantify head impact in soccer, examining differences in head impact as a function of sex and event type (practice vs game). Seven female and 14 male collegiate soccer players wore mastoid patch accelerometers that measured head impacts during team events. Data were summarized for each athletic exposure, and statistical analyses evaluated the mean number of impacts, mean peak linear acceleration, mean peak rotational acceleration, and cumulative linear and rotational acceleration, each grouped by sex and event type. Results: There were no differences in the frequency or severity of head impacts between men’s and women’s soccer practices. For men’s soccer, games resulted in 285% more head impacts than practices, but there were no event-type differences in mean impact severity. Men’s soccer games resulted in more head impacts than practices across nearly all measured impact severities, which also resulted in men’s soccer games producing a greater cumulative impact burden. Conclusion: Similar to other sports, men’s soccer games have a greater impact burden when compared with practices, and this effect is driven by the quantity rather than severity of head impacts. In contrast, there were no differences in the quantity or severity of head impacts in men’s and women’s soccer practices. These data could prompt discussions of practical concern to collegiate soccer, such as understanding sex differences in head impact and whether games disproportionately contribute to an athlete’s head impact burden. PMID:28491885
Hansen, Bodil Olai; Tvede, Mich
-dimensional, then equilibria in pure strategies exist, and; if the quality of players is multi-dimensional, then there need not exist equilibria in pure strategies, but equilibria in mixed strategies exist. Equilibria in mixed strategies resemblance signings on deadline day in european soccer...
Andersen, Thomas Bull; Dörge, Henrik C.; Thomsen, Franz Ib
An equation to describe the velocity of the soccer ball after the collision with a foot was derived. On the basis of experimental results it was possible to exclude certain factors and only describe the angular momentum of the system, consisting of the shank, the foot and the ball, leading...
Soccer, or football as it is called in the rest of the world, is the most popular and fastest-growing global sport, with an estimated 240 million people regularly playing what Brazilian star Pele called "the beautiful game." Millions, worldwide, watch it on television. In 2006, the average viewership for each match of the month-long World Cup was…
Full Text Available The aim of the study was to evaluate and organize systematically the available literature on skill-related performance in young and adult male soccer players in an attempt to identify the most common topics, ascertain the weaknesses, and elucidate the main contributions of the scientific papers on this issue. A systematic review of the Institute for Scientific Information (ISI Web of Knowledge database was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA guidelines. The keywords ‘football’ and ‘soccer’ were used, each associated with the following terms: ‘technical analysis,’ ‘technical performance,’ ‘technical activity,’ ‘technical skill,’ ‘technical demands,’ ‘technical profiles,’ ‘technical characteristics,’ ‘technical actions,’ ‘technical scores,’ ‘technical ability,’ ‘motor skills,’ and ‘skill acquisition’. From the 2830 papers, only 60 were reviewed, of which 75% had been published in years 2011-2015 and 53.3% concerned professional or seniors players (above the U-20 category. Out of the 41 papers that analysed the skill-related performance in the match, 48.8% evaluated the performance in small-sided and conditioned games. Among the 27 papers that used validated instruments, 88.9% assessed technical actions outside the match context (e.g. dribbling, shooting tests. Future research should pay attention to the definition and classification of the skill-related variables under investigation in match context and propose tests for measured skill-related performance in soccer, considering that the representativeness task design allies the players’ possibilities of action to the situation of the match.
Bekkers, J.E.J.; de Windt, Th.S.; Brittberg, M.
The prevalence of focal articular cartilage lesions among athletes is higher than in the general population. Treatment goals differ considerably between the professional and recreational athlete. High financial stakes and the short duration of a professional career influence the treatment selection for the professional athlete, while such parameters weigh differently in recreational sports. This article describes our investigation of the relation between sports and a high prevalence of focal cartilage lesions. In addition, we provide a critical review of the best available evidence for cartilage surgery and treatment selection, evaluate specific patient profiles for professional and recreational athletes, and propose a treatment algorithm for the treatment of focal cartilage lesions in football (soccer) players. PMID:26069606
Callum G. Brownstein
Full Text Available Aim: Previous research into the etiology of neuromuscular fatigue following competitive soccer match-play has primarily focused on peripheral perturbations, with limited research assessing central nervous system function in the days post-match. The aim of the present study was to examine the contribution and time-course of recovery of central and peripheral factors toward neuromuscular fatigue following competitive soccer match-play.Methods: Sixteen male semi-professional soccer players completed a 90-min soccer match. Pre-, post- and at 24, 48, and 72 h participants completed a battery of neuromuscular, physical, and perceptual tests. Maximal voluntary contraction force (MVC and twitch responses to electrical (femoral nerve and transcranial magnetic stimulation (TMS of the motor cortex during isometric knee-extension and at rest were measured to assess central nervous system (voluntary activation, VA and muscle contractile (potentiated twitch force, Qtw, pot function. Electromyography responses of the rectus femoris to single- and paired-pulse TMS were used to assess corticospinal excitability and short-interval intracortical inhibition (SICI, respectively. Fatigue and perceptions of muscle soreness were assessed via visual analog scales, and physical function was assessed through measures of jump (countermovement jump height and reactive strength index and sprint performance.Results: Competitive match-play elicited significant post-match declines in MVC force (−14%, P < 0.001 that persisted for 48 h (−4%, P = 0.01, before recovering by 72 h post-exercise. VA (motor point stimulation was reduced immediately post-match (−8%, P < 0.001, and remained depressed at 24 h (−5%, P = 0.01 before recovering by 48 h post-exercise. Qtw,pot was reduced post-match (−14%, P < 0.001, remained depressed at 24 h (−6%, P = 0.01, before recovering by 48 h post-exercise. No changes were evident in corticospinal excitability or SICI. Jump performance
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
Jordet, Geir; Elferink-Gemser, Marije T.
This study was designed to capture the first-hand experiences of stressors, coping, and emotions that elite professional soccer players have during a major soccer penalty shootout. Eight players who each took part in an important European Championships penalty shootout were interviewed. The results
Daniela Acquadro Maran
Full Text Available The aim of this work was to investigate stalking experiences in a sample of Health Care Professionals, or HCPs, who experienced domestic violence in their previous relationships with an intimate romantic or non-romantic who had become their stalkers. A comparison between males and females was made to highlight the differences among the genders. The findings showed that, for the most part, the victims experienced stalking by a stalker that was not of the same gender. Moreover, the nature of the relationship was romantic, for the most part, for both female and male subjects, suggesting that the principal motivation of stalking is the disruption of an intimate relationship. Regarding domestic violence, females described the phenomenon from a different perspective, indicating verbal, physical, and sexual abuse, while males indicated only verbal abuse. Females tended to amplify, more than the males, depression, and state and trait anxiety. Even if all symptoms were expressed in both females and males, the males exhibited a lack of confidence in their bodies, and the emotional literacy made the expression of distress more difficult. At the same time, the expression of anxiety presented in the women permitted them to become progressively less victimized over time; depression and anxiety allow the recognition of these symptoms as signs of distress and to intervene to reduce them.
Acquadro Maran, Daniela; Varetto, Antonella
The aim of this work was to investigate stalking experiences in a sample of Health Care Professionals, or HCPs, who experienced domestic violence in their previous relationships with an intimate romantic or non-romantic who had become their stalkers. A comparison between males and females was made to highlight the differences among the genders. The findings showed that, for the most part, the victims experienced stalking by a stalker that was not of the same gender. Moreover, the nature of the relationship was romantic, for the most part, for both female and male subjects, suggesting that the principal motivation of stalking is the disruption of an intimate relationship. Regarding domestic violence, females described the phenomenon from a different perspective, indicating verbal, physical, and sexual abuse, while males indicated only verbal abuse. Females tended to amplify, more than the males, depression, and state and trait anxiety. Even if all symptoms were expressed in both females and males, the males exhibited a lack of confidence in their bodies, and the emotional literacy made the expression of distress more difficult. At the same time, the expression of anxiety presented in the women permitted them to become progressively less victimized over time; depression and anxiety allow the recognition of these symptoms as signs of distress and to intervene to reduce them.
Nichols, Andrew W
To investigate the effectiveness of a 10-week hamstring exercise training program in reducing the incidence and severity of new and recurrent hamstring injuries among male soccer players. Cluster-randomized (by team)controlled trial, stratified by level of play and geographic location. Sample size was calculated with 80% power to show a relative risk reduction for injury of 50% at P ≤ 0.05. Soccer community study in Denmark during the period January to December 2008. Teams in the top 5 soccer divisions (2 professional and 3 amateur)were invited to participate. The exclusion criterion for teams was that they already used eccentric hamstring exercises, and for participants was that they joined the teams after the beginning of the season. Of 116 teams, 54 were eligible and willing to be randomized and 50 were included in the analysis (942 players). Teams in both the intervention and control groups followed their normal training programs. At the beginning of the study period, the intervention teams added 27 sessions of the Nordicham string exercise (after warm-up) during the 10-week period of the mid-season break. The exercise begins with the player kneeling with the torso upright and rigid, and the feet held down to the ground by a partner. The player lowers his torso forwards toward the ground braking with his hamstring muscles until the chest reaches the ground (eccentric phase). He returns to the upright position, pushing with his hands to minimize the concentric phase load. Sessions per week and sets and repetitions per session increased to 3, 3, and 12, respectively. Team coaches supervised the sessions. A hamstring injury was defined as an acute occurrence of a “physical complaint in the region of the posterior thigh sustained during a soccer match or training, irrespective of the need for medical attention or time loss from soccer activities.” Injuries were recorded by the teams’ medical staff on standardized forms. Only first injuries during the season
Daniel Barbosa Coelho
Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2013v15n6p667 Soccer is a sport practiced worldwide, on all continents. It is considered an intermittent activity of high intensity and long duration, in which movements that require great strength and speed, such as jumps and sprints, result in high levels of muscle microtrauma, hampering athletes’ training and recovery. The present study aimed to evaluate the magnitude of changes in different markers of physiological demand resulting from a soccer match in healthy individuals. Ten healthy male physical education students participated in the study and were evaluated in two matches: the semi-final and final games of the college tournament at the federal university where they studied. Blood samples were collected from each volunteer pre- and post-match. Cortisol, IL-6 and CK concentrations were increased after the match (p < 0.05. Testosterone and alpha-actin concentrations did not change. Our results indicate that changes in some of the acute response markers evaluated in players before and after competitive soccer matches provide important information for planning training or recovery, as well as nutritional strategies for improving performance.
Daniel Barbosa Coelho
Full Text Available Soccer is a sport practiced worldwide, on all continents. It is considered an intermittent activity of high intensity and long duration, in which movements that require great strength and speed, such as jumps and sprints, result in high levels of muscle microtrauma, hampering athletes’ training and recovery. The present study aimed to evaluate the magnitude of changes in different markers of physiological demand resulting from a soccer match in healthy individuals. Ten healthy male physical education students participated in the study and were evaluated in two matches: the semi-final and final games of the college tournament at the federal university where they studied. Blood samples were collected from each volunteer pre- and post-match. Cortisol, IL-6 and CK concentrations were increased after the match (p < 0.05. Testosterone and alpha-actin concentrations did not change. Our results indicate that changes in some of the acute response markers evaluated in players before and after competitive soccer matches provide important information for planning training or recovery, as well as nutritional strategies for improving performance.
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...
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.
Objective. To investigate the effectiveness of accelerated rehabilitation and accelerated hydrotherapy after anterior cruciate ligament (ACL) reconstruction in male athletes participating in soccer. Design. A non-concurrent single subject, multiple baseline design (ABA design) was conducted over 10 weeks. A series of three ...
The purpose of this study was to determine the contribution of selected stressors to the level of stress experienced by South African soccer officials. Forty-two South African Football Association (SAFA) accredited officials, attending a training camp in Potchefstroom, participated in this study. The group comprised of 40 male ...
The occurrence of injuries in sports and the negligence of the injured players are key factors in the early exit of talented players from competitive sport in developing countries. It is for this reason that this study prospectively observed and documented injuries to male soccer players who participated in the 2001 Moi Golden ...
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…
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...
Rascle, Olivier; Traclet, Alan; Souchon, Nicolas; Coulomb-Cabagno, Genevieve; Petrucci, Carrie
The purpose of this study was to investigate the aggressor-victim difference in perceived legitimacy of aggression in soccer as a function of score information (tied, favorable, unfavorable), sporting penalization (no risk, yellow card, red card), and type of aggression (instrumental, hostile). French male soccer players (N = 133) read written…
Haan, M.; Koning, Ruud H.; Witteloostuijn, A. van
Recent decades have witnessed major changes in the market for European soccer. The most profound were the Bosman ruling, which lifted restrictions in the European labor market for soccer talent, and the introduction of the Champions' League, a high-profile international competition that generates
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.
Maria Luzete Costa Cavalcante
Full Text Available ABSTRACT OBJECTIVE: The present study aimed to evaluate the muscle fatigue of the quadriceps muscle in high-performance soccer players undergoing (anterior cruciate ligament ACL reconstruction. METHODS: We evaluated 17 high-performance soccer players from three professional soccer teams of a state in Brazil from August 2011 to July 2012. All subjects were evaluated between 5.5 and 7 months after ACL reconstruction with a Biodex(r isokinetic dynamometer (System 4 Pro with test protocol CON/CON at 60°/s and 300°/s with 5 and 15 repetitions, respectively. In the calculation of local muscle fatigue, the fatigue index was used, which is calculated by dividing the labor done in the first one-third of the repetitions by that done at the final one-third of the repetitions, and multiplying by 100 to express a unit in percentage (i.e., as a discrete quantitative variable. RESULTS: All subjects were male, with a mean age of 21.3 ± 4.4 years and mean BMI 23.4 ± 1.53 cm; left dominance was observed in 47% (n = 8 of athletes, and right dominance, in 53% (n = 9 of athletes; and the limb involved in the lesion was the dominant in 29% (n = 5 and the non-dominant in 71% (n = 12. Fatigue rates were 19.6% in the involved limb and 29.0% in the non-involved limb. CONCLUSION: The results allow us to conclude that there was no significant difference between the limbs involved and not in ACL injuries regarding local muscle fatigue. No association was observed between the dominant side and the limb involved in the ACL injury.
Smith, Mitchell R; Zeuwts, Linus; Lenoir, Matthieu; Hens, Nathalie; De Jong, Laura M S; Coutts, Aaron J
This study aimed to investigate the impact of mental fatigue on soccer-specific decision-making. Twelve well-trained male soccer players performed a soccer-specific decision-making task on two occasions, separated by at least 72 h. The decision-making task was preceded in a randomised order by 30 min of the Stroop task (mental fatigue) or 30 min of reading from magazines (control). Subjective ratings of mental fatigue were measured before and after treatment, and mental effort (referring to treatment) and motivation (referring to the decision-making task) were measured after treatment. Performance on the soccer-specific decision-making task was assessed using response accuracy and time. Visual search behaviour was also assessed throughout the decision-making task. Subjective ratings of mental fatigue and effort were almost certainly higher following the Stroop task compared to the magazines. Motivation for the upcoming decision-making task was possibly higher following the Stroop task. Decision-making accuracy was very likely lower and response time likely higher in the mental fatigue condition. Mental fatigue had unclear effects on most visual search behaviour variables. The results suggest that mental fatigue impairs accuracy and speed of soccer-specific decision-making. These impairments are not likely related to changes in visual search behaviour.
Heydar Sadeghi; Siavash Shirvanipour; Raghad Mimar
Objective: The purpose of this study was to compare vertical ground reaction force during forward and backward walking among the male professional Karatekas with genu varum and normal knee. Methods: 20 professional male Karates (in genu varum and normal groups) participated in this semi-experimental study. The vertical ground reaction force was measured using force plate system during forward and backward walking utilizing 250 Hz frequency. Mixed ANOVA test was run to analyze the obtained ...
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.
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
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.
Hunt, Devyani; Rho, Monica; Yemm, Ted; Fong, Kathryn; Brophy, Robert H.
Purpose Examination of the hip provides information regarding risk for pre-arthritic hip disorders, knee injuries, and low back pain. The purpose of this study was to report a hip screening examination of asymptomatic female soccer athletes and to test the hypothesis that these findings vary by competition experience. Methods Asymptomatic females from a youth soccer club, a college, and a professional team were evaluated. Passive hip range of motion, hip abduction strength, and hip provocative tests were assessed. Data were compared for the grade/middle school, high school, college, and professional athletes. Results One hundred and seventy-two athletes with a mean age of 16.7 ± 5 years (range 10–30) participated. Professional athletes had less flexion (HF) for both hips (p hips as compared to all other groups (p hip abduction strength as compared to other groups (p hip tests were found in 22 % of all players and 36 % of the professionals. In professionals, a positive provocative test was associated with ipsilateral decreased HF (p = 0.04). Conclusion Asymptomatic elite female soccer athletes with the most competition experience had less bilateral hip flexion and preferred kicking leg IR than less-experienced athletes. Positive provocative hip tests were found in 22 % of athletes. Future studies are needed to show whether these findings link to risk for intra-articular hip or lumbar spine and knee disorders. Level of evidence III. PMID:24150125
Ekstrand, Jan; van Dijk, C. Niek
There is little information about Metatarsal Five (MT-5) fractures for specific sports. To study the occurrence, the imaging characteristics, the lay-off times and healing problems of MT-5 fractures among male footballers. Sixty-four European elite teams were monitored from 2001 to 2012. x-Rays were
Applies Erving Goffman's stigma theory to impressions of 25 women in educational administration careers. Analyzes data from an earlier study to show how women administrators, confronted with male leadership norms, deviate, acquire stigma, and become marginal. Concludes with suggestions for change, citing 32 references. (MLH)
Livingston, Wade G.; Scott, David A.; Havice, Pamela A.; Cawthon, Tony W.
The term "camouflage" implies obscurity and concealment. Male student veterans who return from the military often employ a social camouflage; though some may reveal and discuss their military experience, their overriding objective is to blend in, have a "normal" college experience, and graduate. This creates challenges for housing professionals…
Krustrup, Peter; Randers, Morten Bredsgaard; Andersen, Lars Juel
INTRODUCTION: The present study investigated the fitness and health effects of medium-term soccer training for untrained hypertensive middle-aged men. METHODS: Thirty-three untrained males (31-54 y) with mild-to-moderate hypertension were randomised 2:1 to a soccer training group (STG, two 1-h...... sessions per week, n=22, 68% on medication) and a doctor advice group receiving traditional physician-guided recommendations on cardiovascular risk factor modification (DAG, n=11, 73% on medication). Two-way repeated-measurement ANOVA time-group statistics was applied. RESULTS: During soccer training...
Krustrup, Peter; Nielsen, Jens Jung; Krustrup, Birgitte
To examine the effects of regular participation in recreational soccer on health profile, 38 healthy untrained Danish males aged 20-43 years were randomised into a soccer group (SO; n=14), a running group (RU; n=13) and a control group (CO; n=11). Training was performed for one hour two-three times.......05) in SO and RU, respectively, after 12 weeks. No changes in any of the measured variables were observed for CO. In conclusion, participation in regular recreational soccer training, organised as small-sided drills, has significant beneficial effects on health profile and physical capacity for untrained...
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.
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.
Okholm Kryger, Katrine; Dor, Frédéric; Guillaume, Marion; Haida, Amal; Noirez, Philippe; Montalvan, Bernard; Toussaint, Jean-François
The number of retirements, withdrawals, and "lucky losers" (the replacement of a player who withdraws before the start of the tournament by a losing player from the qualifying round) from professional tennis tournaments has increased, but the reasons behind such departures have not yet been analyzed. An official consensus statement has been conducted to allow a general categorization of injuries in tennis. To determine the reasons for departure and injury rates in professional tennis. Descriptive epidemiology study. All reasons for departures were collected from official Association of Tennis Professionals (ATP) and Women's Tennis Association (WTA) web pages. All tournaments apart from the 4 major competitions (the Australian Open, French Open, Wimbledon, and US Open) were included for the period 2001-2012 for men and women. Personal data, tournament information, surface, match setting, date, and reason were obtained for each departure scenario. Variations in departure and injury rates were seen throughout the season. Women left and were injured significantly more than men. Women mainly left because of thigh injuries, whereas men left mainly because of back injuries. Playing surface only had an influence on the risk of lower back injuries. Only women's departures were affected by the tournament round. A high number of departures from tournaments have occurred during the past 10 years on the ATP and WTA circuits. Injuries were the main reasons of these departures, regardless of the type of departure and player sex. The back and thigh were the main locations of injuries for men and women, respectively. © 2014 The Author(s).
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
Rodrigues, Ana Carolina; Lasmar, Rodrigo Pace; Caramelli, Paulo
Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered as an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of 6–12 incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years, some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the establishment of safety
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.
Ana Carolina Oliveira Rodrigues
Full Text Available Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of six to twelve incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the
Coelho, Daniel Barbosa; Pimenta, Eduardo Mendonça; Veneroso, Christiano Eduardo; Pacheco, Diogo Antônio Soares; Pereira, Emerson Rodrigues; Coelho, Leonardo Gomes Martins; Silami-Garcia, Emerson
Soccer is a sport practiced worldwide, on all continents. It is considered an intermittent activity of high intensity and long duration, in which movements that require great strength and speed, such as jumps and sprints, result in high levels of muscle microtrauma, hampering athletes’ training and recovery. The present study aimed to evaluate the magnitude of changes in different markers of physiological demand resulting from a soccer match in healthy individuals. Ten healthy male physical e...
Junge, A; Cheung, K; Edwards, T; Dvorak, J
Objectives: In reviewing the literature on sports injuries, few studies could be found in which exposure related incidences of injury in different types of sport were compared. These studies indicated that ice hockey, handball, basketball, soccer, and rugby are popular team sports with a relatively high risk of injury. The aim of the study was to compare the characteristics and incidence of injuries in male youth amateur soccer and rugby players.
Distribuição de subgrupos com base nas respostas fisiológicas em jogadores profissionais de futebol pela técnica K Means Cluster Subgroup distribution based on physiological responses in professional soccer players by K-means cluster technique
Luiz Fernando Novack
improved in all athletes collectively. CONCLUSION: The results make us conclude that group distribution by K Means Clustering technique can be performed using physiological responses of athletes in an attempt to optimize training for professional soccer players with focus on the common main training needs regardless of their tactical function played on the field.
Thygesen, Lau Caspar; Grønbaek, Morten; Johansen, Christoffer
Epidemiological studies are remarkably consistent, especially among men, in showing that overweight and obesity [body mass index (BMI) >25] are associated with increased risk of colon cancer. However, no prospective studies address the influence of weight change in adulthood on subsequent colon...... cancer risk. In this study, we investigated whether weight change influences colon cancer risk utilizing prospectively collected weight data. We included 46,349 men aged 40-75 participating in the Health Professionals Follow-Up Study. Questionnaires including items on weight were completed every second......-year period, we documented 765 cases of colon cancer. Cumulative mean BMI >22.5 was associated with significantly increased risk of colon cancer. The short-term weight change in the prior 2 to 4 years was positively and significantly associated with risk [HR = 1.14 (95% confidence interval, 1...
To prevent the social worker being jammed between the economic and rationalized logic of managers and politicians on the one hand, and the life world of the people on the other, he needs to develop a healthy identity. The social constructive view can help to overcome the identity crisis the social
Lubiatowski, Przemyslaw; Kaczmarek, Piotr; Cisowski, Pawel; Breborowicz, Ewa; Grygorowicz, Monika; Dzianach, Marcin; Krupecki, Tomasz; Laver, Lior; Romanowski, Leszek
Glenohumeral range of motion adaptations may affect throwing athletes and contribute to shoulder injury. The purpose of this study was to evaluate shoulder rotation deficits among elite professional handball players and its correlation to the presence of shoulder pain and morphological changes. Eighty-seven elite professional handball players and 41 healthy non-athlete volunteers participated in the study. Evaluations included measurement of range of internal and external rotation, total arch of motion, identification of shoulder pain and ultrasound scan for diagnosis of rotator cuff tears and internal impingement. Glenohumeral rotational deficits (>20-25°) were found among 11 players group (13%). The throwing shoulders in the players group showed a decrease in internal rotation and an increase in external rotation with significantly larger ranges among players compared to the non-athlete group. Internal rotation deficit >20° was associated with higher incidence of shoulder pain among players. Both internal rotation deficits (>25°) and total arch of motion deficit (>20°) co-existed with higher incidence of internal impingement. Shoulder pain was common (36/97-41%) and was associated with decreased external rotation and total arch of motion. Internal impingement (found in 13/87-15%) correlated with decreased rotation ranges and a greater deficit in total arch of motion, whereas higher gain in external rotation correlated with a partial rotator cuff tear (found in 12/87-14%). Shoulder pathologies and problems commonly affected the group of handball players. Greater glenohumeral rotational deficits in throwing shoulders of handball players correlate with shoulder pain and internal impingement, while increased external rotation with partial rotator cuff tears. Such deficits affect 13% of the athlete population. Major clinical relevance of the study is to monitor handball players' shoulders both clinically and by proper imaging. Evaluation of range of rotation seems
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
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.
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
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.
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 ...
La influencia de la densidad competitiva en el resultado de los equipos en el fútbol de alto nivel. (The influence of a congested football calendar on the results obtained by teams in professional soccer.
Joaquín Lago Ballesteros
Full Text Available Resumen Existe una considerable variación en el número de partidos disputados por los equipos de fútbol durante una temporada. Los mejores equipos juegan varios partidos a la semana tanto en las competiciones domesticas como en la Liga de Campeones. Se ha especulado que un período cargado de partidos puede limitar el rendimiento de los conjuntos. En este trabajo se estudia el efecto que tiene para un equipo disputar un partido de la Liga de Campeones sobre el resultado alcanzado en el encuentro de la Liga Española en el fin de semana anterior. La muestra consiste en 374 partidos de la Liga Española jugados por los equipos que se encontraban simultáneamente disputando la Liga de Campeones entre las temporadas 2003-2004 y 2006- 2007. Los resultados alcanzados mediante un modelo logit multinomial permiten demostrar que disputar un partido de la Liga de Campeones no reduce la probabilidad de ganar en el partido de la Liga Española. Además se ha verificado que la probabilidad de ganar en el partido del fin de semana de la Liga Española es mayor cuando el partido de la Liga de Campeones a disputar pertenece a la fase de liguilla respecto a si se corresponde con el formato de eliminación directa.Palabras clave: fútbol; liga española; liga de campeones; logit multinomial; densidad competitive. Abstract There is a considerable variation in the number of matches played per season by clubs in the Spanish Soccer. The successful top clubs play several matches a week in domestic leagues as well as in the UEFA Champions League. It has been speculated that a period full of matches can lead to player fatigue which may result in underperformance. Using data from 374 matches of the Spanish Soccer League played from the 2003-04 to the 2006-07 seasons and according to the estimation based on logit multinomial this study shows that Spanish Champions League teams did not perform below their normal standard at the weekend when they played a Champions
Romann, Michael; Fuchslocher, Jörg
Relative age effects (RAEs) refer to age differences between children in the same selection year. The present study investigated the prevalence of RAEs and their link to playing positions in Swiss junior soccer. Swiss male junior soccer players (n=50,581) representing 11% of the age-matched population - members of extra-curricular soccer teams - were evaluated to determine the influence of RAEs on Swiss junior soccer. Subgroups were the national talent development programme (n=2880), and U-15 to U-21 national teams (n=630). While no RAEs were found for the self-selected extra-curricular soccer teams or for the U-20 teams (P>0.05), significant RAEs were found for talent development and the national U-15 to U-19 and U-21 teams (Pborn early in the year were significantly overrepresented compared with goalkeepers, midfielders and strikers (Ptalent identification process for U-15 to U-18 teams, significantly influencing the selection of players in talent development teams already at an early age, but do not influence self-selected participation in extra-curricular soccer. Additionally, the RAE bias may be a predictor of playing positions in national teams. To minimise RAEs in Swiss soccer, systematic education for all coaches regarding RAEs should be established, in addition to a slotting system with rotating calendar cut-off dates.
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.
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
Bruno Manfredini Baroni
Full Text Available Although soccer and futsal are sports with similar motor actions, the differences in size and match dynamics result in distinct physiological requirements. The objective of this study was to evaluate and compare parameters of aerobic capacity between professional soccer and futsal athletes. A total of 553 ergospirometric evaluations were performed: 367 soccer players (32 goalkeepers, 335 on-court players and 186 futsal athletes (22 goalkeepers, 164 on-court players. The results were analyzed separately for each modality (comparison between goalkeepers and on-court players and compared between soccer and futsal athletes. Soccer and futsal goalkeepers presented lower maximal oxygen uptake (VO2max, second ventilatory threshold (VT2, and speed to reach these thresholds than on-court players of the respective modalities. Soccer goalkeepers were superior in terms of these parameters when compared to futsal goalkeepers. No differences in VO2max or VT2 were observed between soccer and futsal on-court players, although soccer athletes reached the thresholds at higher speeds. In conclusion, soccer and futsal goalkeepers present lower aerobic capacity than on-court players. Soccer players show better performance in aerobic tests than futsal athletes
Unnithan, Viswanath; White, Jordan; Georgiou, Andreas; Iga, John; Drust, Barry
The purpose of this review article was firstly to evaluate the traditional approach to talent identification in youth soccer and secondly present pilot data on a more holistic method for talent identification. Research evidence exists to suggest that talent identification mechanisms that are predicated upon the physical (anthropometric) attributes of the early maturing individual only serve to identify current performance levels. Greater body mass and stature have both been related to faster ball shooting speed and vertical jump capacity respectively in elite youth soccer players. This approach, however, may prematurely exclude those late maturing individuals. Multiple physiological measures have also been used in an effort to determine key predictors of performance; with agility and sprint times, being identified as variables that could discriminate between elite and sub-elite groups of adolescent soccer players. Successful soccer performance is the product of multiple systems interacting with one another. Consequently, a more holistic approach to talent identification should be considered. Recent work, with elite youth soccer players, has considered whether multiple small-sided games could act as a talent identification tool in this population. The results demonstrated that there was a moderate agreement between the more technically gifted soccer player and success during multiple small-sided games.
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.
Cahill, Leah E; Chiuve, Stephanie E; Mekary, Rania A; Jensen, Majken K; Flint, Alan J; Hu, Frank B; Rimm, Eric B
Among adults, skipping meals is associated with excess body weight, hypertension, insulin resistance, and elevated fasting lipid concentrations. However, it remains unknown whether specific eating habits regardless of dietary composition influence coronary heart disease (CHD) risk. The objective of this study was to prospectively examine eating habits and risk of CHD. Eating habits, including breakfast eating, were assessed in 1992 in 26 902 American men 45 to 82 years of age from the Health Professionals Follow-up Study who were free of cardiovascular disease and cancer. During 16 years of follow-up, 1527 incident CHD cases were diagnosed. Cox proportional hazards models were used to estimate relative risks and 95% confidence intervals for CHD, adjusted for demographic, diet, lifestyle, and other CHD risk factors. Men who skipped breakfast had a 27% higher risk of CHD compared with men who did not (relative risk, 1.27; 95% confidence interval, 1.06-1.53). Compared with men who did not eat late at night, those who ate late at night had a 55% higher CHD risk (relative risk, 1.55; 95% confidence interval, 1.05-2.29). These associations were mediated by body mass index, hypertension, hypercholesterolemia, and diabetes mellitus. No association was observed between eating frequency (times per day) and risk of CHD. Eating breakfast was associated with significantly lower CHD risk in this cohort of male health professionals.
Karoline Pegoraro Silveira
Full Text Available Soccer is one of the world’s most popular team sports and corresponds to one ofthe leading causes of sports injuries (SI. This study aimed to analyze the nosographic profile of the sports injuries common to soccer, according to theage group: childhood, youth and adulthood. We selected 209 soccer players, from amateurs to professional players of a sports club from Campo Grande/MS.Participants were divided into four age groups: G1 (childhood, G2 (juvenile,G3 (teenagers and G4 (adults. To obtain information about the injuries, we used a morbidity survey. Generally, 74 athletes reported sports injuries, with register of 92 SI. Concerning injury types, muscle injuries totalized 43.47%, followed by joint damage (34.78% and tendon injury (14.13%, respectively (p 0.05. A higher proportion of registers involved medical-therapeutic approach and asymptomatic return. The evidence shows a higher rate of muscle and joint injuries by contact in the lower limbs in soccer practitioners, regardless of age group. The practice of training seemsto be the main cause of injuries in adolescents and adults.
Karoline Pegoraro Silveira
Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2013v15n4p476 Soccer is one of the world’s most popular team sports and corresponds to one ofthe leading causes of sports injuries (SI. This study aimed to analyze the nosographic profile of the sports injuries common to soccer, according to the age group: childhood, youth and adulthood. We selected 209 soccer players, from amateurs to professional players of a sports club from Campo Grande/MS. Participants were divided into four age groups: G1 (childhood, G2 (juvenile,G3 (teenagers and G4 (adults. To obtain information about the injuries, we used a morbidity survey. Generally, 74 athletes reported sports injuries, with register of 92 SI. Concerning injury types, muscle injuries totalized 43.47%, followed by joint damage (34.78% and tendon injury (14.13%, respectively (p 0.05. A higher proportion of registers involved medical-therapeutic approach and asymptomatic return. The evidence shows ahigher rate of muscle and joint injuries by contact in the lower limbs in soccer practitioners, regardless of age group. The practice of training seems to be the main cause of injuries in adolescents and adults.
Rodríguez-Ruiz, D.; Diez-Vega, I.; Rodríguez-Matoso, D.; Fernandez-del-Valle, M.; Sagastume, R.; Molina, J. J.
The aim of this study was to evaluate the normalized response speed (Vrn) of the knee musculature (flexor and extensor) in high competitive level volleyball players using tensiomyography (TMG) and to analyze the muscular response of the vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), and biceps femoris (BF) in accordance with the specific position they play in their teams. One hundred and sixty-six players (83 women and 83 men) were evaluated. They belonged to eight teams in the Spanish women's superleague and eight in the Spanish men's superleague. The use of Vrn allows avoiding possible sample imbalances due to anatomical and functional differences and demands. We found differences between Vrn in each of the muscles responsible for extension (VM, RF, and VL) and flexion (BF) regardless of the sex. Normalized response speed differences seem to be larger in setters, liberos and outside players compared to middle blockers and larger in males when compared to females. These results of Vrn might respond to the differences in the physical and technical demands of each specific position, showing an improved balance response of the knee extensor and flexor musculature in male professional volleyball players. PMID:25003109
Full Text Available The aim of this study was to evaluate the normalized response speed (Vrn of the knee musculature (flexor and extensor in high competitive level volleyball players using tensiomyography (TMG and to analyze the muscular response of the vastus medialis (VM, rectus femoris (RF, vastus lateralis (VL, and biceps femoris (BF in accordance with the specific position they play in their teams. One hundred and sixty-six players (83 women and 83 men were evaluated. They belonged to eight teams in the Spanish women’s superleague and eight in the Spanish men’s superleague. The use of Vrn allows avoiding possible sample imbalances due to anatomical and functional differences and demands. We found differences between Vrn in each of the muscles responsible for extension (VM, RF, and VL and flexion (BF regardless of the sex. Normalized response speed differences seem to be larger in setters, liberos and outside players compared to middle blockers and larger in males when compared to females. These results of Vrn might respond to the differences in the physical and technical demands of each specific position, showing an improved balance response of the knee extensor and flexor musculature in male professional volleyball players.
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
Grygorowicz, Monika; Michałowska, Martyna; Walczak, Tomasz; Owen, Adam; Grabski, Jakub Krzysztof; Pyda, Andrzej; Piontek, Tomasz; Kotwicki, Tomasz
To measure the sensitivity and specificity of differences cut-off values for isokinetic Hcon/Qcon ratio in order to improve the capacity to evaluate (retrospectively) the injury of hamstring muscles in professional soccer screened with knee isokinetic tests. Retrospective study. Medical and biomechanical data of professional football players playing for the same team for at least one season between 2010 and 2016 were analysed. Hamstring strain injury cases and the reports generated via isokinetic testing were investigated. Isokinetic concentric(con) hamstring(H) and quadriceps(Q) absolute strength in addition with Hcon/Qcon ratio were examined for the injured versus uninjured limbs among injured players, and for the injured and non-injured players. 2 x 2 contingency table was used for comparing variables: predicted injured or predicted uninjured with actual injured or actual uninjured. Sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratio were calculated for three different cut-off values (0.47 vs. 0.6 vs. 0.658) to compare the discriminative power of an isokinetic test, whilst examining the key value of Hcon/Qcon ratio which may indicate the highest level of ability to predispose a player to injury. McNemar's chi2 test with Yates's correction was used to determine agreement between the tests. PQStat software was used for all statistical analysis, and an alpha level of p hamstring injuries during the analysed period. None of these players sustained recurrence of hamstring injury. One player sustained hamstring strain injury on both legs, thus the total number of injuries was 12. Application of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic test used as a tool for muscle injury detection. The use of 0.47 of Hcon/Qcon as a discriminate value resulted in significantly lower sensitivity when compared to 0.658 threshold (sensitivity of 16.7% vs
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....
Forsman, Hannele; Gråstén, Arto; Blomqvist, Minna; Davids, Keith; Liukkonen, Jarmo; Konttinen, Niilo
The objective of this study was to create a valid, self-reported, game-specific soccer competence scale. A structural model of perceived competence, performance measures and motivation was tested as the basis for the scale. A total of 1321 soccer players (261 females, 1060 males) ranging from 12 to 15 years (13.4 ± 1.0 years) participated in the study. They completed the Perceived Game-Specific Soccer Competence Scale (PGSSCS), self-assessments of tactical skills and motivation, as well as technical and speed and agility tests. Results of factor analyses, tests of internal consistency and correlations between PGSSCS subscales, performance measures and motivation supported the reliability and validity of the PGSSCS. The scale can be considered a suitable instrument to assess perceived game-specific competence among young soccer players.
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.
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.
Brophy, Robert H.; Schmitz, Leah; Wright, Rick W.; Dunn, Warren R.; Parker, Richard D.; Andrish, Jack T.; McCarty, Eric C.; Spindler, Kurt P.
Background There is limited information on outcomes and return to play (RTP) after ACL reconstruction (ACLR) in soccer athletes. Hypothesis The purpose of this study was to (i) test the hypotheses that player sex, side of injury and graft choice do not influence RTP, and (ii) define the risk for future ACL injury in soccer players after ACLR. Study design Retrospective cohort study, Level II. Methods Soccer players in a prospective cohort were contacted to determine RTP following ACLR. Information regarding if and when they returned to play, their current playing status, the primary reason they stopped playing soccer (if relevant) and incidence of subsequent ACL surgery was recorded. Results Initially, 72% of 100 soccer athletes (55 male, 45 female) with a mean age of 24.2 years at the time of ACL reconstruction returned to soccer. At average follow up of 7.0 years, 36% were still playing, a significant decrease compared to initial RTP (psoccer athletes had undergone further ACL surgery, including 9 on the contralateral knee and 3 on the ipsilateral knee. In a univariate analysis, females were more likely to have future ACL surgery (20% v. 5.5%, p=0.03). Soccer athletes who underwent ACLR on their non-dominant limb had a higher future rate of contra-lateral ACLR (16%) than soccer athletes who underwent ACLR on their dominant limb (3.5%) (p=0.03). Conclusion Younger and male soccer players are more likely to return to play after ACL reconstruction. Return to soccer following ACLR declines over time. PMID:23002201
Nortje, L.; Dicks, M.S.; Coopoo, Y.; Savelsbergh, G.J.P.
The main goal of the study was to examine whether a relationship existed between self-reported and in situ tactical decision-making in the form of actions for small-sided soccer games, namely 4-vs.-4 and 8-vs.-8 games. Sixteen skilled male soccer players participated and completed the Tactical
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.
Russell, Mark; Kingsley, Michael
investigated the influence of caffeine ingestion (n = 2) and fluid provision (n = 3). Findings were reported for a total of 171 participants and all but one of the included articles used cross-over study designs. Most participants (94 %) were male, highly trained (reported maximal aerobic capacity range 50-59 ml·kg(-1)·min(-1)) and exercised in temperate environments (reported temperature range 13-25 °C). Six of the eight studies reported that carbohydrates, consumed in the form of a 6-8 % solution of glucose, sucrose or maltodextrin at rates of 30-60 g·h(-1), enhanced at least one aspect of skilled performance over the duration of exercise (75-90 min). Although some evidence exists to support the consumption of caffeine (6 mg·kg(-1) body mass [BM]) and prescribed fluid to preserve skills performed during soccer-specific exercise, findings from the small number of included studies were inconsistent. The outcome measures and methods used to quantify skilled performance were not consistent across studies; consequently, it was not possible to perform meta-analyses to produce pooled effect sizes in this review. The findings from this systematic review suggest that nutritional interventions, which provide carbohydrate, caffeine and fluid, have potential to preserve skills performed under conditions that induce soccer-specific fatigue. The weight of current evidence supports the consumption of carbohydrate, but is less conclusive with respect to caffeine and fluid provision. It is likely that the efficacy of a nutritional intervention will be modulated by factors including the dose consumed, the mode of administration, individual responsiveness to the intervention and interactions with other physiological changes occurring during soccer-specific exercise. Consequently, these factors should be considered when using carbohydrates, caffeine and fluid provision to maintain skilled performances in soccer. Future research should seek to optimise the nutritional strategies employed to
Pavel Frýbort, Jakub Kokštejn, Martin Musálek, Vladimír Süss
Full Text Available A soccer player’s capability to control and manage his behaviour in a game situation is a prerequisite, reflecting not only swift and accurate tactical decision-making, but also prompt implementation of a motor task during intermittent exercise conditions. The purpose of this study was to analyse the relationship between varying exercise intensity and the visual-motor response time and the accuracy of motor response in an offensive game situation in soccer. The participants (n = 42 were male, semi-professional, soccer players (M age 18.0 ± 0.9 years and trained five times a week. Each player performed four different modes of exercise intensity on the treadmill (motor inactivity, aerobic, intermittent and anaerobic activity. After the end of each exercise, visual-motor response time and accuracy of motor response were assessed. Players’ motion was captured by digital video camera. ANOVA indicated no significant difference (p = 0.090 in the accuracy of motor response between the four exercise intensity modes. Practical significance (Z-test = 0.31 was found in visual-motor response time between exercise with dominant involvement of aerobic metabolism, and intense intermittent exercise. A medium size effect (Z-test = 0.34 was also found in visual-motor response time between exercise with dominant involvement of aerobic metabolism and exercise with dominant involvement of anaerobic metabolism, which was confirmed by ANOVA (897.02 ± 57.46 vs. 940.95 ± 71.14; p = 0.002. The results showed that different modes of exercise intensity do not adversely affect the accuracy of motor responses; however, high-intensity exercise has a negative effect on visual-motor response time in comparison to moderate intensity exercise.
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
Toni Caparrós, Eduard Alentorn-Geli, Gregory D. Myer, Lluís Capdevila, Kristian Samuelsson, Bruce Hamilton, Gil Rodas
Full Text Available The objectives of this study were to determine the relationship among game performance, injury rate, and practice exposure in a professional male basketball team. A retroospective analysis of prospective collected data was conducted over seven consecutive seasons (2007/2008 to 2013/2014. Data collection included sports performance during competition (statistical evaluation, injury rate, and total exposure (games and practices. Over the surveillance period, 162 injuries (91 practice; 71 matches occurred over 32,668 hours of exposure (556 games and 2005 practices. There was a strong positive correlation between: 1 exposure (total number of practices and hours of exposure and the total number of injuries (r = 0.77; p = 0.04; 2 exposure (total hours of exposure and total hours of practice exposure and performance (total team ranking (r = 0.77 and p = 0.04, and r = 0.8 and p = 0.03, respectively; and 3 total number of injuries and performance (total team ranking (r = 0.84; p = 0.02. While increasing practice and competition time is related to greater team performance, it also increases the number of injuries. However, higher injury rates were not associated with worse overall team performance. Efforts to reduce high-risk activity during practice, optimally replaced with injury prevention training, might help to reduce injury risk.
Full Text Available DESCRIPTION This book addresses and appropriately explains the soccer match analysis, looks at the very latest in match analysis research, and at the innovative technologies used by professional clubs. This handbook is also bridging the gap between research, theory and practice. The methods in it can be used by coaches, sport scientists and fitness coaches to improve: styles of play, technical ability and physical fitness; objective feedback to players; the development of specific training routines; use of available notation software, video analysis and manual systems; and understanding of current academic research in soccer notational analysis. PURPOSE The aim is to provide a prepared manual on soccer match analysis in general for coaches and sport scientists. Thus, the professionals in this field would gather objective data on the players and the team, which in turn could be used by coaches and players to learn more about performance as a whole and gain a competitive advantage as a result. The book efficiently meets these objectives. AUDIENCE The book is targeted the athlete, the coach, the sports scientist professional or any sport conscious person who wishes to analyze relevant soccer performance. The editors and the contributors are authorities in their respective fields and this handbook depend on their extensive experience and knowledge accumulated over the years. FEATURES The book demonstrates how a notation system can be established to produce data to analyze and improve performance in soccer. It is composed of 9 chapters which present the information in an order that is considered logical and progressive as in most texts. Chapter headings are: 1. Introduction to Soccer Match Analysis, 2. Developing a Manual Notation System, 3. Video and Computerized Match Analysis Technology, 4. General Advice on Analyzing Match Performance, 5. Analysis and Presentation of the Results, 6. Motion Analysis and Consequences for Training, 7. What Match
Ré, Alessandro H Nicolai; Cattuzzo, Maria Teresa; Henrique, Rafael Dos Santos; Stodden, David F
This study examined the relative contribution of age, stage of puberty, anthropometric characteristics, health-related fitness, soccer-specific tests and match-related technical performance to variance in involvements with the ball during recreational 5-a-side small-sided (32 × 15 m) soccer matches. Using a cross-sectional design, 80 healthy male students (14.6 ± 0.5 years of age; range 13.6-15.4) who played soccer recreationally were randomly divided into 10 teams and played against each other. Measurements included height, body mass, pubertal status, health-related fitness (12-min walk/run test, standing long jump, 15-m sprint and sit-ups in 30 s), soccer-specific tests (kicking for speed, passing for accuracy and agility run with and without a ball), match-related technical performance (kicks, passes and dribbles) and involvements with the ball during matches. Forward multiple regression analysis revealed that cardiorespiratory fitness (12-min walk/run test) accounted for 36% of the variance in involvements with the ball. When agility with the ball (zigzag running) and power (standing long jump) were included among the predictors, the total explained variance increased to 62%. In conclusion, recreational adolescent players, regardless of their soccer-specific skills, may increase participation in soccer matches most through physical activities that promote improvement in cardiorespiratory fitness, muscle power and agility.
Bretzin, Abigail C; Mansell, Jamie L; Tierney, Ryan T; McDevitt, Jane K
Soccer players head the ball repetitively throughout their careers; this is also a potential mechanism for a concussion. Although not all soccer headers result in a concussion, these subconcussive impacts may impart acceleration, deceleration, and rotational forces on the brain, leaving structural and functional deficits. Stronger neck musculature may reduce head-neck segment kinematics. The relationship between anthropometrics and soccer heading kinematics will not differ between sexes. The relationship between anthropometrics and soccer heading kinematics will not differ between ball speeds. Pilot, cross-sectional design. Level 3. Division I soccer athletes (5 male, 8 female) were assessed for head-neck anthropometric and neck strength measurements in 6 directions (ie, flexion, extension, right and left lateral flexions and rotations). Participants headed the ball 10 times (25 or 40 mph) while wearing an accelerometer secured to their head. Kinematic measurements (ie, linear acceleration and rotational velocity) were recorded at 2 ball speeds. Sex differences were observed in neck girth ( t = 5.09, P soccer heading kinematics for sex and ball speeds. Neck girth and neck strength are factors that may limit head impact kinematics.
Goedecke, Julia H; White, Nicholas J; Chicktay, Waheed; Mahomed, Hafsa; Durandt, Justin; Lambert, Michael I
This study investigated how performance was affected after soccer players, in a postprandial state, ingested a 7% carbohydrate (CHO) solution compared to a placebo (0% CHO) during a simulated soccer match. Using a double-blind placebo-controlled design, 22 trained male league soccer players (age: 24 ± 7 years, wt: 73.4 ± 12.0 kg, VO2max: 51.8 ± 4.3 mL O2/kg/min) completed two trials, separated by 7 days, during which they ingested, in random order, 700 mL of either a 7% CHO or placebo drink during a simulated soccer match. Ratings of perceived exertion (RPE), agility, timed and run to fatigue were measured during the trials. Change in agility times was not altered by CHO vs. placebo ingestion (0.57 ± 1.48 vs. 0.66 ± 1.00, p = 0.81). Timed runs to fatigue were 381 ± 267 s vs. 294 ± 159 s for the CHO and placebo drinks, respectively (p = 0.11). Body mass modified the relationship between time to fatigue and drink ingestion (p = 0.02 for drink × body mass), such that lower body mass was associated with increased time to fatigue when the players ingested CHO, but not placebo. RPE values for the final stage of the simulated soccer match were 8.5 ± 1.7 and 8.6 ± 1.5 for the CHO and placebo drinks respectively (p = 0.87). The group data showed that the 7% CHO solution (49 g CHO) did not significantly improve performance during a simulated soccer match in league soccer players who had normal pre-match nutrition. However, when adjusting for body mass, increasing CHO intake was associated with improved time to fatigue during the simulated soccer match.
Julia H. Goedecke
Full Text Available Aim: This study investigated how performance was affected after soccer players, in a postprandial state, ingested a 7% carbohydrate (CHO solution compared to a placebo (0% CHO during a simulated soccer match. Methods: Using a double-blind placebo-controlled design, 22 trained male league soccer players (age: 24 ± 7 years, wt: 73.4 ± 12.0 kg, VO2max: 51.8 ± 4.3 mL O2/kg/min completed two trials, separated by 7 days, during which they ingested, in random order, 700 mL of either a 7% CHO or placebo drink during a simulated soccer match. Ratings of perceived exertion (RPE, agility, timed and run to fatigue were measured during the trials. Results: Change in agility times was not altered by CHO vs. placebo ingestion (0.57 ± 1.48 vs. 0.66 ± 1.00, p = 0.81. Timed runs to fatigue were 381 ± 267 s vs. 294 ± 159 s for the CHO and placebo drinks, respectively (p = 0.11. Body mass modified the relationship between time to fatigue and drink ingestion (p = 0.02 for drink × body mass, such that lower body mass was associated with increased time to fatigue when the players ingested CHO, but not placebo. RPE values for the final stage of the simulated soccer match were 8.5 ± 1.7 and 8.6 ± 1.5 for the CHO and placebo drinks respectively (p = 0.87. Conclusions: The group data showed that the 7% CHO solution (49 g CHO did not significantly improve performance during a simulated soccer match in league soccer players who had normal pre-match nutrition. However, when adjusting for body mass, increasing CHO intake was associated with improved time to fatigue during the simulated soccer match.
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.
Zhang, Ran; Sutcliffe, Siobhan; Giovannucci, Edward; Willett, Walter C; Platz, Elizabeth A; Rosner, Bernard A; Dimitrakoff, Jordan D; Wu, Kana
Although chronic prostatitis/chronic pelvic pain syndrome is a prevalent urological disorder among men of all ages, its etiology remains unknown. Only a few previous studies have examined associations between lifestyle factors and chronic prostatitis/chronic pelvic pain syndrome, of which most were limited by the cross-sectional study design and lack of control for possible confounders. To address these limitations we performed a cohort study of major lifestyle factors (obesity, smoking and hypertension) and chronic prostatitis/chronic pelvic pain syndrome risk in the HPFS (Health Professionals Follow-up Study), a large ongoing cohort of United States based male health professionals. The HPFS includes 51,529 men who were 40 to 75 years old at baseline in 1986. At enrollment and every 2 years thereafter participants have completed questionnaires on lifestyle and health conditions. In 2008 participants completed an additional set of questions on recent chronic prostatitis/chronic pelvic pain syndrome pain symptoms modified from the NIH (National Institutes of Health)-CPSI (Chronic Prostatitis Symptom Index) as well as questions on approximate date of symptom onset. The 653 participants with NIH-CPSI pain scores 8 or greater who first experienced symptoms after 1986 were considered incident chronic prostatitis/chronic pelvic pain syndrome cases and the 19,138 who completed chronic prostatitis/chronic pelvic pain syndrome questions but did not report chronic prostatitis/chronic pelvic pain syndrome related pain were considered noncases. No associations were observed for baseline body mass index, waist circumference, waist-to-hip ratio, cigarette smoking and hypertension with chronic prostatitis/chronic pelvic pain syndrome risk (each OR ≤1.34). In this large cohort study none of the lifestyle factors examined was associated with chronic prostatitis/chronic pelvic pain syndrome risk. As the etiology of chronic prostatitis/chronic pelvic pain syndrome remains unknown
Oliveira, César Chaves; Ferreira, Diogo; Caetano, Carlos; Granja, Diana; Pinto, Ricardo; Mendes, Bruno; Sousa, Mónica
Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition). PMID:29910389
Oliveira, César Chaves; Ferreira, Diogo; Caetano, Carlos; Granja, Diana; Pinto, Ricardo; Mendes, Bruno; Sousa, Mónica
Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition).
Crawshaw, Marilyn; Glaser, Adam; Hale, Juliet; Sloper, Patricia
Interviews were undertaken with 22 health and social work professionals. Their analysis was completed using "selective transcription", noting understanding of process, issues and themes, and building a picture against which to consider the analysis of subsequent interviews with teenagers and parents. Professionals were also asked to identify areas for feedback from these participants. This work was part of a larger study of (i) the perceptions of adolescent males and their parents of fertility preservation services following a cancer diagnosis, and (ii) national postal surveys of common practices, areas of variance and issues experienced by professionals in UK regional paediatric oncology centres and licensed assisted conception centres. A large number of concerns were identified, which reflected professionals' difficulties in building and maintaining a relevant, adequate knowledge and skills base given the limited numbers of teenagers offered this service. The lack of appropriate training about the legal and consent frameworks, and the processes involved was also highlighted across all professional groups as was the confusion around professional and legal responsibilities for follow up. Thus, there was considerable professional uncertainty in a number of aspects of this sensitive area of service provision. Consideration needs to be given to the needs for national guidance, for training, support and updating, for liaison between the different health and social care sectors that may be involved, and for appropriate information systems. These need to be in place for each stage of the process, from diagnosis through to eventual discharge from the health system.
Upshur Ross EG
Full Text Available Abstract A 42 year-old male former semi-professional soccer player sustained a right lower extremity popliteal contusion during a soccer game. He was clinically diagnosed with a possible traumatic deep vein thrombosis (DVT, and sent for confirmatory tests. A duplex doppler ultrasound was positive for DVT, and the patient was admitted to hospital for anticoagulation (unfractionated heparin, warfarin. Upon discharge from hospital the patient continued oral warfarin anticoagulation (six months, and the use of compression stockings (nine months. He followed up with his family doctor at regular intervals for serial coagulation measurements, and ultrasound examinations. The patient's only identified major thrombotic risk factor was the traumatic injury. One year after the initial deep vein thrombosis (DVT the patient returned to contact sport, however he continued to have intermittent symptoms of right lower leg pain and right knee effusion. Athletes can develop vascular injuries in a variety of contact and non-contact sports. Trauma is one of the most common causes of lower extremity deep vein thrombosis (DVT, however athletic injuries involving lower extremity traumatic DVT are seldom reported. This diagnosis and the associated risk factors must be considered during the initial physical examination. The primary method of radiological diagnosis of lower extremity DVT is a complete bilateral duplex sonography, which can be augmented by other methods such as evidence-based risk factor analysis. Antithrombotic medication is the current standard of treatment for DVT. Acute thrombolytic treatment has demonstrated an improved therapeutic efficacy, and a decrease in post-DVT symptoms. There is a lack of scientific literature concerning the return to sport protocol following a DVT event. Athletic individuals who desire to return to sport after a DVT need to be fully informed about their treatment and risk of reoccurrence, so that appropriate decisions can be
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
Influência do nível competitivo e da posição tática sobre parâmetros de desempenho aeróbio de atletas profissionais de futebol do Brasil Influence of competitive level and tactical position on parameters of aerobic performance in professional soccer athletes from Brazil
Bruno Manfredini Baroni
Full Text Available Este estudo objetivou verificar a influência do nível competitivo e da posição tática sobre parâmetros relacionados ao desempenho aeróbio de atletas profissionais de futebol. Foram analisadas 453 avaliações ergoespirométricas de atletas profissionais de futebol (42 goleiros, 92 zagueiros, 61 laterais, 174 meio-campistas e 84 atacantes que atuavam em quatro níveis competitivos: Campeonato Nacional Série A; Série B; Série C; e Campeonato Estadual. Não foram encontradas diferenças nos valores médios de consumo máximo de oxigênio (VO2max e segundo limiar ventilatório (LV2 entre os níveis competitivos (p > 0,05. Os goleiros apresentaram VO2max e LV2 (56 e 50 mL/kg/min, respectivamente significativamente inferiores aos zagueiros (59 e 52 mL/kg.min; p = 0,002 e p = 0,028, laterais (60 e 53 mL/kg.min; p This study aimed to verify the influence of the competitive level and the tactical position on parameters related to aerobic performance of professional soccer players. 453 ergospirometric evaluations were analyzed from soccer professional athletes (42 goalkeepers, 92 full backs, 61 sideways, 174 midfielders and 84 forwards that acted in four competitive levels: National Championship Series A; Series B; Series C; and State Championship. It was found no differences in mean values of maximal oxygen uptake (VO2max and second ventilatory threshold (LV2 between the competitive levels (p > 0.05. The goalkeepers showed VO2max and LV2 (56 and 50 mL/kg.min, respectively significant lower than full backs (59 and 52 mL/kg.min; p = 0.002 e p = 0.028, sideways (60 and 53 mL/kg.min; p = 0.000 e p = 0.004, midfields (59 and 52 mL/kg.min; p = 0.002 e p = 0.031 and forwards (59 and 52 mL/kg.min; p = 0.047 e p = 0.036. Therefore, the findings suggest that: 1 the aerobic performance does not differ according the competitive level; and 2 the goalkeepers have aerobic performance inferior to out-field players, which do not show differences between them.
Baran, Funda; Aktop, Abdurrahman; Özer, Dilara; Nalbant, Sibel; Ağlamış, Ece; Barak, Sharon; Hutzler, Yeshayahu
The study investigated the effects of a Special Olympics (SO) Unified Sport (UNS) soccer program on anthropometry, physical fitness and soccer skills of male youth athletes with and without intellectual disabilities (ID) who participated in a training group (TRG) and in a comparison group (CG) without specific training. Youth with ID (WID) were randomly selected out of all the students between the ages 12 and 15, with a diagnosis of educable mental retardation and no secondary disabilities, who were attending a special education school. Participants without ID (WoID) were randomly selected from a regular secondary school out of the same age groups of male students. All participants were given permission by their parents or guardians to participate in the study. Participants in the TRG included 23 youth WID and 23 youth WoID. Mean ages were = 14.1 (SD = 1.1) and 13.2 (SD = 0.79) respectively. Fifteen WID, and 15 WoID comprised the CG. Mean ages were 14.51 (SD = 0.81) and 13.78 (SD = 0.49) respectively. Prior to and following the program measurements were conducted, and data were collected on students' anthropometric and fitness components of the Brockport physical fitness test as well as a soccer skill performance based on the SO soccer skill test. Participants in the TRG trained 8 weeks, 1.5h per session, three times per week, in an after-school soccer program. CG did not participate in any sports program outside of the school physical education class. Dependent t tests and effect size calculations revealed that SO athletes and non-disabled partners scored significantly higher with regard to physical fitness and football skills in most variables compared with their CG. This Unified Program was successful in increasing fitness and soccer skill performance of youth WID as well as of those WoID. Copyright © 2012 Elsevier Ltd. All rights reserved.
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 ...
Prather, Heidi; Hunt, Devyani; McKeon, Kathryn; Simpson, Scott; Meyer, E Blair; Yemm, Ted; Brophy, Robert
To determine the prevalence of stress fractures, menstrual dysfunction and disordered eating attitudes in elite female soccer athletes. Cross-sectional descriptive study. Female soccer athletes were recruited from a national level youth soccer club, an NCAA Division I university team, and a women's professional team. Two hundred twenty female soccer athletes with a mean age of 16.4 ± 4 years and BMI of 20.8 ± 2 kg/m(2) completed the study, representing all athletes from the included teams. One-time surveys completed by the athletes. Height and weight were recorded, and body mass index (BMI) was calculated for each athlete. Athletes reported age of menarche, history of missing 3 or more menses within a 12-month period and stress fracture. The Eating Attitudes Test (EAT-26) was used to assess the athlete's body perception and attitudes toward eating. Of the 220 soccer athletes, 3 athletes (1.6%) had a low BMI for their age, and 19 (8.6%) reported stress fractures of the lower extremity. Among athletes who had reached menarche, the average onset was 13 + 1 year; menstrual dysfunction were present in 21 (19.3%). On the EAT-26, 1 player scored in the high risk range (>20) and 17 (7.7%) scored in the intermediate risk range (10-19) for eating disorders. Athletes with an EAT-26 score ≥ 10 points had a significantly higher prevalence of menstrual dysfunction in the past year compared to athletes with an EAT-26 score of less than 10 (P = .02). Elite female soccer athletes are susceptible to stress fractures and menstrual dysfunction and have delayed onset of menarche despite normal BMI and appropriate body perception and attitudes towards eating. Further studies are needed to better understand stress fracture risk in female soccer athletes and in other team sports to determine how these findings relate to long-term bone health in this population. Copyright © 2016. Published by Elsevier Inc.
Vaismoradi, Mojtaba; Salsali, Mahvash; Ahmadi, Fazlollah
The purpose of the present study was to explore the perspectives of Iranian male nursing students regarding the role of nursing education in developing a professional identity. A qualitative design, based on the content analysis approach, was used to collect the data and analyze the perspectives of 14 Iranian male nursing students who were chosen by using a purposive sampling strategy. After the selection of the participants, semistructured interviews were held in order to collect the data. During the data analysis, three main themes emerged: "reality-expectation incompatibility", "being supported by the educational system", and "nursing image rectification". The second theme consisted of two categories: "feeling trusted" and "being defended". This study will be useful to nurse educators and administrators in relation to what constitutes nursing students' professional identity within the Iranian culture and context and how nursing education can play an effective role in developing their professional identity in order to devise strategies to attract male students to the nursing profession and promote their retention after graduation. © 2010 The Authors. Japan Journal of Nursing Science © 2010 Japan Academy of Nursing Science.
Full Text Available The aim of the study was to investigate seasonal variations in fitness and performance indices of professional male soccer players. Eighteen professional male soccer players (age range 22–32 years completed three similar sets of tests at three stages of the season: before preseason; after preseason and the middle of the competitive in-season. A significant decrease in body mass and percent fat was found during the preseason. A significant improvement (p < 0.05 was found in the vertical jump (preseason: 37.0 ± 5.3, post-preseason: 39.0 ± 4.8, mid-season: 40.3 ± 5.5 cm, the 4 × 10-m agility test (preseason: 8.1 ± 0.2, post-preseason: 7.9 ± 0.2, mid-season: 8.1 ± 0.3 s, flexibility (preseason: 45.2 ± 8.8, post-preseason: 48.2 ± 7.0, mid-season: 49.9 ± 6.9 cm and aerobic capacity (preseason: 52.7 ± 6.6, post-preseason: 56.4 ± 6.0, mid-season: 57.4 ± 5.4 mL/kg/min during preseason, with no further change during mid-season. Repeated sprint test (RST (6 × 30-m performance indices showed significant deterioration (p < 0.05 in ideal sprint time (IS; preseason: 21.8 ± 1.0, post-preseason: 23.0 ± 0.8, mid-season: 23.2 ± 0.8 s and total sprint time (TS; preseason: 22.5 ± 0.7, post-preseason: 23.5 ± 0.6, mid-season: 23.8 ± 0.6 s during preseason, with no further changes during mid-season. However, performance decrement (PD significantly decreased during the preseason with no change during mid-season. The findings suggest that while power training was probably responsible for the anaerobic fitness improvement, the high-volume training led to improvement in aerobic fitness during the preseason. However, the low-intensity aerobic-type training, coupled with the high total training load, may have led to fatigue and decreases in IS and TS during the preseason.
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.
Ruscello, Bruno; Esposito, Mario; Partipilo, Filippo; DI Cicco, Dalila; Filetti, Cristoforo; Pantanella, Laura; D'Ottavio, Stefano
To investigate the applicability of three different exercise to rest ratios in RSA training in women's soccer players, applying those ones already adopted in male adult and young players, when performing three different sprinting modes (straight, shuttle and sprinting with changing of direction). 15 trained female soccer players (height: 1.65 ± 0.06 m; weight: 59.3 ± 9.0 kg; BMI 21.6 ± 2.7 kg·m-2; age: 23.3±5.9 years) participated to the study. In order to compare the different values of the time recorded, an Index of Fatigue was used. Recovery times among trials in the sets were administered according to the 1:5, 1:3; 1:2 exercise to rest ratio, respectively. Blood lactate concentrations at the end of each set (3') were analyzed. Significant differences among trials within each set (Repeated Measures Anova; p0.05). Significant differences were found in blood lactate concentrations (pRSA in women's soccer players, keeping the performances in the speed domain (IF% < ⊕7-8%) but inducing the fatigue processes sought with this kind of training method.
Arnason, Arni; Sigurdsson, Stefan B; Gudmundsson, Arni; Holme, Ingar; Engebretsen, Lars; Bahr, Roald
To investigate the relationship between physical fitness and team success in soccer, and to test for differences in physical fitness between different player positions. Participants were 306 male soccer players from 17 teams in the two highest divisions in Iceland. Just before the start of the 1999 soccer season, the following variables were tested: height and weight, body composition, flexibility, leg extension power, jump height, and peak O2 uptake. Injuries and player participation in matches and training were recorded through the 4-month competitive season. Team average physical fitness was compared with team success (final league standing) using a linear regression model. Physical fitness was also compared between players in different playing positions. A significant relationship was found between team average jump height (countermovement jump and standing jump) and team success (P = 0.009 and P = 0.012, respectively). The same trend was also found for leg extension power (P = 0.097), body composition (% body fat, P = 0.07), and the total number of injury days per team (P = 0.09). Goalkeepers demonstrated different fitness characteristics from outfield players. They were taller and heavier, more flexible in hip extension and knee flexion, and had higher leg extension power and a lower peak O2 uptake. However, only minor differences were observed between defenders, midfield players, and attackers. Coaches and medical support teams should pay more attention to jump and power training, as well as preventive measures and adequate rehabilitation of previous injuries to increase team success.
de Sousa, M Vieira; Fukui, R; Krustrup, Peter
Background: Moderate calorie-restricted diets and exercise training prevent loss of lean mass and cardiovascular risk. Because adherence to routine exercise recommendation is generally poor, we utilized recreational soccer training as a novel therapeutic exercise intervention in type 2 diabetes (T2......D) patients. Objective: We compared the effects of acute and chronic soccer training plus calorie-restricted diet on protein catabolism and cardiovascular risk markers in T2D. Design, setting and subjects: Fifty-one T2D patients (61.1±6.4 years, 29 females: 22 males) were randomly allocated...... to the soccer+diet-group (SDG) or to the dietgroup (DG). The 40-min soccer sessions were held 3 times per week for 12 weeks. Results: Nineteen participants attended 100% of scheduled soccer sessions, and none suffered any injuries. The SDG group showed higher levels of growth hormone (GH), free fatty acids...
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
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.
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.
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.
Incidência de lesões nos jogadores de futebol masculino sub-21 durante os Jogos Regionais de Sertãozinho-SP de 2006 Injury incidence in sub-21 male soccer players during Regional Games of Sertãozinho-SP 2006
Luiz Fernando Approbato Selistre
emphasizing technique, currently the physical components are more favored, increasing hence the injury risk. OBJECTIVE: The aim of this study was to perform an epidemiological survey of sub-21 male soccer player's injuries in the Regional Games 2006. METHODS: This study was of epidemiological descriptive and analytical type, with a transversal design. All games of the modality were followed, and the injuries found were registered by their prevalence and classification. Injuries were classified according to their profile and anatomical segment and according to athletes' position as well. RESULTS: The highest prevalence of injuries was found in the lower extremities 127 (74.7%, and muscular injuries were the most frequent 64 (37.6%. Midfielders were the most affected players 72 (42.4%. The most frequent injury type in goalkeepers and defenders were contusions with 7 (63.6% and 11 (50%, respectively. Strikers, outside midfielders and midfielders showed mostly muscular injuries, with 11 (36.7%, 12 (34.3% and 33 (45.8%, respectively. CONCLUSIONS: In conclusion, this study demonstrated higher incidence of injuries in lower extremities in sub-21 soccer players, being muscular injuries the most common ones. The results also suggest that injuries are directly related with the characteristics of each athlete's position.
Goff, John Eric; Carre, Matt J.
We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…
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,…
Marshall, Paul W. M.; Lovell, Ric; Jeppesen, Gitte K.; Andersen, Kristoffer; Siegler, Jason C.
Purpose To examine changes in hamstring muscle fatigue and central motor output during a 90-minute simulated soccer match, and the concomitant changes in hamstring maximal torque and rate of torque development. Method Eight amateur male soccer players performed a 90-minute simulated soccer match, with measures performed at the start of and every 15-minutes during each half. Maximal torque (Nm) and rate of torque development (RTD; Nm.s–1) were calculated from maximal isometric knee flexor contractions performed at 10° of flexion. Hamstring peripheral fatigue was assessed from changes in the size and shape of the resting twitch (RT). Hamstring central motor output was quantified from voluntary activation (%) and normalized biceps femoris (BF) and medial hamstrings (MH) electromyographic amplitudes (EMG/M). Results Maximal torque was reduced at 45-minutes by 7.6±9.4% (phamstring peripheral fatigue. Conclusion Centrally mediated reductions in maximal torque and rate of torque development provide insight into factors that may explain hamstring injury risk during soccer. Of particular interest were early reductions during the first-half of hamstring rate of torque development, and the decline in maximal EMG/M of biceps femoris in the latter stages of the half. These are important findings that may help explain why the hamstrings are particularly vulnerable to strain injury during soccer. PMID:25047547
Wong, Pui-lam; Chamari, Karim; Mao, De Wei; Wisløff, Ulrik; Hong, Youlian
To measure the plantar pressure in four soccer-related movements in 15 male soccer players (mean (SD) age 20.9 (1.3) years, height 173 (4) cm, weight 61.7 (3.6) kg). To record plantar pressure distribution, the players wore soccer boots with 12 circular studs and with an insole pressure recorder device equipped with 99 sensors. Plantar pressure was recorded in five successful trials in each of the four soccer-related movements: running, sideward cutting, 45 degrees cutting and landing from a vertical jump. Each footprint was divided into 10 recorded areas for analysis. Compared with running at 3.3 m/s, maximal speed sideward cutting and 45 degrees cutting induced higher peak pressure (pplantar surface as compared with the lateral side. These data suggest that the medial side of the plantar surface may be more prone to injuries, and that foot orthosis adoption, improved soccer boot design and specific muscle training could be considered to reduce pressure and the subsequent risk of injury.
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.
Abbott, Will; Brownlee, Thomas E; Harper, Liam D; Naughton, Robert J; Clifford, Tom
This study examined if subjective wellbeing in soccer players was affected by match location, match result and opposition quality before a match (PRE), 1 day after (POST-1), and 3 days after a match (POST-3). Eleven professional male soccer players from the under 23 squad playing in the Premier League 2 division completed a wellbeing questionnaire before and after 17 matches. Match training load (session-rating perceived exertion) was not different, regardless of the location, result, or quality of opposition faced (P > 0.05). Subjective wellbeing was not different at PRE (P > 0.05); however, at POST-1 and POST-3, stress and mood were ≥20% lower after playing away from home or losing (P sleep were ≥12% worse after playing against a higher-level opposition at POST-1. Coaches need to be aware that match location, match result and the quality of the opposition can influence post-match wellbeing, irrespective of match load.
Silva, João Renato; Rebelo, António; Marques, Franklim; Pereira, Laura; Seabra, André; Ascensão, António; Magalhães, José
This study aimed to analyze changes in performance, muscle function, and stress-related biochemical markers in professional soccer players (n = 14) at 4 timepoints (3 for performance and 4 for stress-related biochemical markers) during the soccer season [Formula: see text] preseason (E1), midseason (E2), end of the season (E3) [Formula: see text] and after the end of the recovery period (E4). Performance in 5- and 30-m sprints, countermovement jump, and agility, and maximal isokinetic knee extension and knee flexion strength were measured (E1 to E3). We observed increased in-season levels of myoglobin (E2 > E1 and E4; p E1 and E4; p player during the competition period), performance, and hormonal and redox parameters (r = 0.456-0.615; p soccer players face significant changes in biomarkers of physiologic strain (muscle damage and oxidative stress-related markers) during the season, but values return to normal during the off-season. Additionally, MAT influences physical, hormonal, and oxidative stress-related parameters in professional soccer players.
Smith, Nicholas A; Chounthirath, Thiphalak; Xiang, Huiyun
To investigate the epidemiology of youth soccer-related injuries treated in emergency departments in the United States. A retrospective analysis was conducted of soccer-related injuries among children 7 through 17 years of age from 1990 through 2014 with data from the National Electronic Injury Surveillance System. Injury rates were calculated from soccer participation data. An estimated 2 995 765 (95% confidence interval [CI], 2 309 112-3 682 418) children 7 through 17 years old were treated in US emergency departments for soccer-related injuries during the 25-year study period, averaging 119 831 (95% CI, 92 364-147 297) annually. The annual injury rate per 10 000 soccer participants increased significantly, by 111.4%, from 1990 to 2014. Patients 12 to 17 years old accounted for 72.7% of injuries, 55.5% of patients were male, and most injuries occurred in a place of sport or recreation (68.5%) or school (25.7%). Struck by (38.5%) and fell (28.7%) were the leading mechanisms of injury. Injuries most commonly were diagnosed as sprain or strain (34.6%), fracture (23.2%), and soft tissue injury (21.9%), and occurred to the upper extremity (20.7%), ankle (17.8%), and head or neck (17.7%). Concussions or other closed head injuries accounted for 7.3% of the injuries, but the annual rate of concussions/closed head injuries per 10 000 participants increased significantly, by 1595.6%, from 1990 to 2014. This study is the first to comprehensively investigate soccer-related injuries and calculate injury rates based on soccer participation data among children at the national level. The increasing number and rate of pediatric soccer-related injuries, especially soccer-related concussions/closed head injuries, underscore the need for increased efforts to prevent these injuries. Copyright © 2016 by the American Academy of Pediatrics.
Nielsen, Joachim; Krustrup, Peter; Nybo, Lars
Whole muscle glycogen levels remain low for a prolonged period following a soccer match. The present study was conducted to investigate how this relates to glycogen content and particle size in distinct subcellular localizations. Seven high-level male soccer players had a vastus lateralis muscle...... biopsy collected immediately after and 24, 48, 72 and 120 h after a competitive soccer match. Transmission electron microscopy was used to estimate the subcellular distribution of glycogen and individual particle size. During the first day of recovery, glycogen content increased by ~60% in all...
Krustrup, Peter; Ørtenblad, Niels; Nielsen, Joachim
The aim of this study was to examine maximal voluntary knee-extensor contraction force (MVC force), sarcoplasmic reticulum (SR) function and muscle glycogen levels in the days after a high-level soccer game when players ingested an optimised diet. Seven high-level male soccer players had a vastus...... lateralis muscle biopsy and a blood sample collected in a control situation and at 0, 24, 48 and 72 h after a competitive soccer game. MVC force, SR function, muscle glycogen, muscle soreness and plasma myoglobin were measured. MVC force sustained over 1 s was 11 and 10% lower (P ...
The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.
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
O'Kane, John W
Soccer is among the most popular youth sports with over 3 million youth players registered in the U.S. Soccer is unique in that players intentionally use their head to strike the ball, leading to concerns that heading could cause acute or chronic brain injury, especially in the immature brains of children. Pub Med search without date restriction was conducted in November 2014 and August 2015 using the terms soccer and concussion, heading and concussion, and youth soccer and concussion. 310 articles were identified and reviewed for applicable content specifically relating to youth athletes, heading, and/or acute or chronic brain injury from soccer. Soccer is a low-risk sport for catastrophic head injury, but concussions are relatively common and heading often plays a role. At all levels of play, concussions are more likely to occur in the act of heading than with other facets of the game. While concussion from heading the ball without other contact to the head appears rare in adult players, some data suggests children are more susceptible to concussion from heading primarily in game situations. Contributing factors include biomechanical forces, less developed technique, and the immature brain's susceptibility to injury. There is no evidence that heading in youth soccer causes any permanent brain injury and there is limited evidence that heading in youth soccer can cause concussion. A reasonable approach based on U.S. Youth Soccer recommendations is to teach heading after age 10 in controlled settings, and heading in games should be delayed until skill acquisition and physical maturity allow the youth player to head correctly with confidence.
Perin, Charles; Vuillemot, Romain; Fekete, Jean-Daniel
This article presents SoccerStories, a visualization interface to support analysts in exploring soccer data and communicating interesting insights. Currently, most analyses on such data relate to statistics on individual players or teams. However, soccer analysts we collaborated with consider that quantitative analysis alone does not convey the right picture of the game, as context, player positions and phases of player actions are the most relevant aspects. We designed SoccerStories to support the current practice of soccer analysts and to enrich it, both in the analysis and communication stages. Our system provides an overview+detail interface of game phases, and their aggregation into a series of connected visualizations, each visualization being tailored for actions such as a series of passes or a goal attempt. To evaluate our tool, we ran two qualitative user studies on recent games using SoccerStories with data from one of the world's leading live sports data providers. The first study resulted in a series of four articles on soccer tactics, by a tactics analyst, who said he would not have been able to write these otherwise. The second study consisted in an exploratory follow-up to investigate design alternatives for embedding soccer phases into word-sized graphics. For both experiments, we received a very enthusiastic feedback and participants consider further use of SoccerStories to enhance their current workflow.
Boylan, Matthew R; Khalili, Hamed; Huang, Edward S; Michaud, Dominique S; Izard, Jacques; Joshipura, Kaumudi J; Chan, Andrew T
OBJECTIVES: Periodontal disease has been associated with higher circulating levels of inflammatory markers and conditions associated with chronic inflammation, including vascular disease, diabetes mellitus, and cancer. Limited data exist on the relationship between periodontal disease and gastric and duodenal ulcer. METHODS: We conducted a prospective cohort study of 49,120 men in the Health Professionals Follow-up Study, aged 40–75 years at enrollment in 1986. Biennially, we assessed periodo...
Kalyn, Brenda; Campbell, Eric; McAvoy, Alekcei; Weimer, Michelle
Teacher candidates entering the world of curricula face the realities of teaching a variety of subjects, some more conceptually foreign than others. One challenging area for teacher candidates, particularly males, is in dance education (Gard, 2008; Kiley, 2010). A teacher's former dance experience, beliefs about who dances and why, personal…
Full Text Available The term of professional sport is considered. The models of entrepreneurial activity are described in this sphere. The structure of income of soccer clubs of France, USA and Ukraine is analysed. The tendencies of receipt of profits are rotined on the example of professional soccer clubs of Ukraine. It is marked that in Ukraine actual two models of orientation of conduct of sporting business on condition of high-efficiency management and marketing. For the increase of profits necessary changes are in a current legislation.
Full Text Available The present systematic review and meta-analysis aimed to assess the perturbations in hormonal and psychological homeostasis in response to soccer match-play. These perturbations were explored according to match outcome (i.e., win versus loss, gender, type of contest (i.e., competitive versus non-competitive fixtures and competitive level (i.e., novice versus high-level. The review was conducted according to the Population/Intervention or Exposure/Comparison/Outcome(s (PICO criteria and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA guidelines. Match outcome, type of contest and competitive levels were moderator variables in the examined steroid hormones responses to a soccer match-play. Different testosterone responses were seen between match winners (increase and losers (decrease when compared to pre-game or baseline values (p <0.05, whilst no changes could be detected for cortisol relative to match outcome in female soccer players. Males (Δ% = 6.26; ES = 0.28 demonstrated a marginally lower increase in testosterone levels when compared to females (Δ% = 49.16; ES = 1.00, though not statistically significant. Females (Δ% = 162.7; ES = 0.98 did not demonstrate elevated cortisol match response compared to males (Δ% = 34.60; ES = 1.20. Male novice soccer match-play increased cortisol levels compared to high-level soccer match-play (Q = 18.08, p<0.001. Competitive soccer matches increased cortisol levels compared to non-competitive fixtures (i.e., collegiate tournament. Additionally, competitive levels moderate the relationship between a soccer match and testosterone levels (p <0.001, regardless of gender differences. From the presented systematic review and meta-analysis it appears (1 cortisol changes are associated with cognitive anxiety in starter female soccer players, while (2 testosterone changes are associated with changes in mood state in females and social connectedness in male soccer players. This
Sattler, Tine; Hadžić, Vedran; Dervišević, Edvin; Markovic, Goran
Vertical jump (VJ) performance is an important element for successful volleyball practice. The aims of the study were (a) to explore the overall VJ performance of elite volleyball players of both sexes, (b) to explore the differences in VJ performance among different competition levels and different playing positions, and (c) to evaluate the sex-related differences in the role of the arm swing and 3-step approach with arm swing on the jump height. We assessed the VJ capacity in 253 volleyball players (113 males and 140 females) from Slovenian first and second Volleyball Division. The height of squat jump (SJ), countermovement jump, block jump, and attack jump was tested using an Optojump system. We observed significant differences (p ≤ 0.05) in VJ height between different levels of play that were most pronounced in the SJ. Position-related differences in VJ performance were observed in male players between receivers and setters (p ≤ 0.05), whereas in females, VJ performance across different playing positions seems equal. Finally, we found that male players significantly better use the arm swing during VJ than females (p ≤ 0.05), whereas the use of eccentric part of the jump and approach before the spike to improve VJ performance seem to be equally mastered activity in both sexes. These results could assist coaches in the development of jumping performance in volleyball players. Furthermore, presented normative data for jump heights of elite male and female volleyball players could be useful in selection and profiling of young volleyball players.
Jamilia J. Blake
Full Text Available African American males are at increased risk for experiencing disciplinary practices that exclude them from the school environment. It is believed that African American males’ overrepresentation in the receipt of these practices contributes to their involvement in the criminal justice system as they approach adolescence and enter adulthood. The connection of exclusionary discipline with incarceration rates is termed the School to Prison Pipeline. Although some scholars have identified school-wide initiatives as having potential in curtailing African American males’ overrepresentation in these punitive discipline practices, less discussion has focused on the role of school-based mental health professionals to address this issue. School-based mental health professionals possess a unique set of skills that may assist schools in decreasing African American males’ exposure to exclusionary discipline practices and consequently reducing their risk for adverse outcomes. The purpose of this review is to provide school-based mental health professionals with specific recommendations for reducing this negative educational experience.
In order to definitively determine many complex exploration curiosities, we must bring samples to terrestrial laboratories for detailed analyses by collaborating laboratories and analysts. We report this endeavor in SOCCER, NEARER, Stardust and LIFE.
Suggests that a positive relationship exists between encounter group experience and the soccer team performance--a conclusion worthy of consideration in further research in the fields of psychology and sociology of sports. (Author)
Clausen, Mikkel Bek; Zebis, Mette Kreutzfeldt; Møller, Merete
BACKGROUND: Previous studies report varying rates of time-loss injuries in adolescent female soccer, ranging from 2.4 to 5.3 per 1000 athlete-exposures or 2.5 to 3.7 per 1000 hours of exposure. However, these studies collected data using traditional injury reports from coaches or medical staff......, with methods that significantly underestimate injury rates compared with players' self-reports. PURPOSE: The primary aim was to investigate the injury incidence in adolescent female soccer using self-reports via mobile telephone text messaging. The secondary aim was to explore the association between soccer...... exposure, playing level, and injury risk. STUDY DESIGN: Descriptive epidemiology study and cohort study; Level of evidence, 2 and 3. METHODS: During a full adolescent female soccer season in Denmark (February-June 2012), a population-based sample of 498 girls aged 15 to 18 years was included...
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.
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
Kim, Hyoung-Gook; Roeber, Steffen; Samour, Amjad; Sikora, Thomas
In this paper, we present an automatic extraction of goal events in soccer videos by using audio track features alone without relying on expensive-to-compute video track features. The extracted goal events can be used for high-level indexing and selective browsing of soccer videos. The detection of soccer video highlights using audio contents comprises three steps: 1) extraction of audio features from a video sequence, 2) event candidate detection of highlight events based on the information provided by the feature extraction Methods and the Hidden Markov Model (HMM), 3) goal event selection to finally determine the video intervals to be included in the summary. For this purpose we compared the performance of the well known Mel-scale Frequency Cepstral Coefficients (MFCC) feature extraction method vs. MPEG-7 Audio Spectrum Projection feature (ASP) extraction method based on three different decomposition methods namely Principal Component Analysis( PCA), Independent Component Analysis (ICA) and Non-Negative Matrix Factorization (NMF). To evaluate our system we collected five soccer game videos from various sources. In total we have seven hours of soccer games consisting of eight gigabytes of data. One of five soccer games is used as the training data (e.g., announcers' excited speech, audience ambient speech noise, audience clapping, environmental sounds). Our goal event detection results are encouraging.
Rasmussen, Ludvig Johan Torp; Østergaard, Lars Domino
Creativity is essential in soccer due to the unpredictable and complex situations occurring in the game, where stereotypical play gradually loses its efficiency. Further, creativity is an important psychological factor for the development of soccer expertise, and valuing creativity increases satisfaction and well-being. Although creative players…
This thesis deals with the determination of the player labour market for the American professional sports league Major League Soccer (MLS). In the theoretical part I focus on the description of the league's development along with the salary politics rules. Using the two stages least square method in the empirical part I then provide the model for the estimation of player's marginal productivity (MRP). In the first step I explain the correlation between the percentages of obtained points by te...
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.
Wing, Christopher E; Turner, Anthony N; Bishop, Chris J
The purpose of this investigation was to examine the importance of strength and power in relation to key performance indicators (KPI's) within competitive soccer match play. This was achieved through using an experimental approach where fifteen subjects were recruited from a professional soccer club's scholarship squad during the 2013/14 season. Following anthropometric measures, power and strength were assessed across a range of tests which included the squat jump (SJ), countermovement jump (CMJ), 20 metre (m) sprint and arrowhead change of direction test. A predicted 1-repetition maximum (RM) was also obtained for strength by performing a 3RM test for both the back squat and bench press and a total score of athleticism (TSA) was provided by summing z-scores for all fitness tests together, providing one complete score for athleticism. Performance analysis data was collected during 16 matches for the following KPIs: passing, shooting, dribbling, tackling and heading. Alongside this, data concerning player ball involvements (touches) was recorded. Results showed that there was a significant correlation (p soccer performance, particularly when players are required to win duels of a physical nature. There were no other relationships found between the fitness data and the KPI's recorded during match play which may indicate that other aspects of player's development such as technical skill, cognitive function and sensory awareness are more important for soccer-specific performance.
Russell, Mark; Benton, David; Kingsley, Michael
This study investigated the influence of carbohydrate supplementation on skill performance throughout exercise that replicates soccer match-play. Experimentation was conducted in a randomised, double-blind and cross-over study design. After familiarization, 15 professional academy soccer players completed a soccer match simulation incorporating passing, dribbling and shooting on two separate occasions. Participants received a 6% carbohydrate-electrolyte solution (CHO) or electrolyte solution (PL). Precision, success rate, ball speed and an overall index (speed-precision-success; SPS) were determined for all skills. Blood samples were taken at rest, immediately before exercise, every 15 min during exercise (first half: 15, 30 and 45 min; second half: 60, 75 and 90 min), and 10 min into the half time (half-time). Carbohydrate supplementation influenced shooting (time×treatment interaction: pinteraction: pCarbohydrate supplementation attenuated decrements in shooting performance during simulated soccer match-play; however, further research is warranted to optimise carbohydrate supplementation regimes for high-intensity intermittent sports. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
... 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, ...
Annibal Parracho Sant'Anna
Full Text Available The final ranking of a championship is determined by quality attributes combined with other factors which should be filtered out of any decision on relegation or draft for upper level tournaments. Factors like referees' mistakes and difficulty of certain matches due to its accidental importance to the opponents should have their influence reduced. This work tests approaches to combine classification rules considering the imprecision of the number of points as a measure of quality and of the variables that provide reliable explanation for it. Two home-advantage variables are tested and shown to be apt to enter as explanatory variables. Independence between the criteria is checked against the hypothesis of maximal correlation. The importance of factors and of composition rules is evaluated on the basis of correlation between rank vectors, number of classes and number of clubs in tail classes. Data from five years of the Brazilian Soccer Championship are analyzed.
Monteiro Cristiano Ralo
Full Text Available Hydration should be considered before, during and after the exercise. This review intends to approach the main points of hydration process in soccer. The replacement of fluids during exercise is proportional to some factors, such as: exercise intensity; climatic conditions; the athlete's acclimatization; the athlete's physical conditioning; physiologic individual characteristics and the player's biomechanics. Performance is improved when players ingest not only water but also carbohydrate. The rates that carbohydrate and water are absorbed by the organism are limited by the rates of gastric emptying and intestinal absorption. The composition of drinks offered to the players should be influenced by the relative importance of the need of supplying carbohydrates or water; it should be remembered that the depletion of carbohydrate can result in fatigue and decrease of performance, but it is not usually a life-threatening condition. The addition of carbohydrate in these drinks increases the concentrations of blood glucose, increases the use of external fuel through the increase of the glucose oxidation in the muscles and it spares muscle glycogen. So, the ingestion of carbohydrate before and during the exercise can delay the emergence of fatigue and increase the players' performance. Several tactics can be used to avoid dehydration, like hyperhydration before exercise and player's acclimatization. The ideal situation to restore the player's fluid losses is between the sessions of exercises. Since soccer is a sport with quite peculiar characteristics related to hydration, the players should be concerned and educated about the importance of fluid ingestion before, during and after the exercise.
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.
Luciano Antonacci Condessa
Full Text Available This study compared the exercise intensity of four specific soccer training sessions (friendly and training match, tactical and technical workouts. Ten professional soccer players (24.2 ± 3.7 years, 177.9 ± 7.3 cm, 63.2 ± 4.6 mLO2•kg-1•min-l were recruited. A treadmill progressive interval test was performed to determine the players' VO2max, maximal heart rate (HRmax, HR-VO2 curve, and the heart rate corresponding to blood lactate concentrations of 2 and 4 mmol/L. The heart rate during the training sessions was used to estimate the exercise intensity and to classify them into intensity zones (low-intensity: 4 mmol/L. Exercise intensities were different among training sessions (friendly match: 86.0 ± 5.1% HRmax; training match: 81.2 ± 4.1% HRmax; tactical workout: 70.4 ± 5.3% HRmax; technical workout: 62.1 ± 3.6% HRmax. The friendly match presented the highest percentage of time performed in the high-intensity zone.
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
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.
Interest and participation in soccer continue to grow in every part of the world. The increase in the number of people participating in soccer in Rwanda is also prominent. However, with the increase in the number of people participating in soccer there is an increase in the risk of injuries, thus making prevention of injury more ...
Eggels, H.; van Elk, R.; Pechenizkiy, M.
In elite soccer, decisions are often based on recent results and emotions. In this paper, we propose a method to determine the expected winner of a match in elite soccer. The expected result of a soccer match is determined by estimating the probability of scoring for the individual goal scoring
Rutten, E.A.; Biesta, G.J.J.; Dekovic, M.; Stams, G.J.J.M.; Schuengel, C.; Verweel, P.
The aim of this pilot study was to examine the possible effects of a forum theatre intervention on moral team atmosphere, moral reasoning, fair play attitude and on- and off-field antisocial and prosocial behaviour in male adolescent soccer players from 10 to 18 years of age (n = 99). From pre-test
Rutten, Esther A.; Biesta, Gert J. J.; Dekovic, Maja; Stams, Geert Jan J. M.; Schuengel, Carlo; Verweel, Paul
The aim of this pilot study was to examine the possible effects of a forum theatre intervention on moral team atmosphere, moral reasoning, fair play attitude and on- and off-field antisocial and prosocial behaviour in male adolescent soccer players from 10 to 18 years of age (n = 99). From pre-test to post-test, small but positive changes were…
Rutten, E.A.; Biesta, G.J.J.; Dekovic, M.; Stams, G.J.J.M.; Schuengel, C.; Verweel, P.
The aim of this pilot study was to examine the possible effects of a forum theatre intervention on moral team atmosphere, moral reasoning, fair play attitude and on- and off-field antisocial and prosocial behaviour in male adolescent soccer players from 10 to 18 years of age (n = 99). From pre-test
Rutten, E.A.; Biesta, G.J.J.; Deković, M.; Stams, G.J.J.M.; Schuengel, C.; Verweel, P.
The aim of this pilot study was to examine the possible effects of a forum theatre intervention on moral team atmosphere, moral reasoning, fair play attitude and on‐ and off‐field antisocial and prosocial behaviour in male adolescent soccer players from 10 to 18 years of age (n = 99). From pre‐test
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...
Fieseler, Georg; Hermassi, Souhail; Hoffmeyer, Birgit; Schulze, Stephan; Irlenbusch, Lars; Bartels, Thomas; Delank, Karl-Stefan; Laudner, Kevin G; Schwesig, René
The primary aim of the study was to examine the anthropometric characteristics as well as throwing and sprinting performance of professional handball players classified by playing position and competition level. 21 male players (age: 25.2±5.1 years) from the first German handball league (FGL) and 34 male players (age: 26.1±4.1 years) from the third German handball league (TGL) were categorized as backs, pivots, wings and goalkeepers. Measurements included anthropometric data (height, mass and body mass index (BMI)), throwing and sprinting performance selected out of a complex handball test (HBCT), which was conducted twice (2 rounds). During the HBCT, the subjects performed two sprints (10, 20 m), two standing throws with run-up (ST) and four vertical jump throws (VJT) over a hurdle (20 cm) with and without precision for goal shot. The anthropometric data revealed a significantly (P=0.038 and η2=0.079) shorter body height for TGL than for FGL players. In the cohort of first league athletes the pivots were the tallest (1.98±0.04 m), backs in the third league showed the maximum body height (1.90±0.05 m). Regarding body mass, pivots were the heaviest players independent from the league membership. The FGL players showed a significantly (P0.10) higher throwing velocity in all type of throws. Body height was significantly related to ST (r=0.53) and VJT (r=0.52) in the first round of HBCT but only for the FGL athletes. Throwing velocity was also correlated with BMI (r=-0.50) among the TGL players. Substantial differences of body characteristics, throwing and sprinting performance between playing positions and competitive levels underline the importance of a careful scouting and position-specific training for professional handball players.
Radman, Ivan; Wessner, Barbara; Bachl, Norbert; Ruzic, Lana; Hackl, Markus; Prpic, Tomislav; Markovic, Goran
The aim of the present study was to examine the acute effects of graded physiological strain on soccer kicking performance. Twenty-eight semi-professional soccer players completed both experimental and control procedure. The experimental protocol incorporated repeated shooting trials combined with a progressive discontinuous maximal shuttle-run intervention. The initial running velocity was 8 km/h and increasing for 1 km/h every 3 min until exhaustion. The control protocol comprised only eight subsequent shooting trials. The soccer-specific kicking accuracy (KA; average distance from the ball-entry point to the goal center), kicking velocity (KV), and kicking quality (KQ; kicking accuracy divided by the time elapsed from hitting the ball to the point of entry) were evaluated via reproducible and valid test over five individually determined exercise intensity zones. Compared with baseline or exercise at intensities below the second lactate threshold (LT2), physiological exertion above the LT2 (blood lactate > 4 mmol/L) resulted in meaningful decrease in KA (11-13%; p soccer kicking performance. The results suggest that high-intensity physiological exertion above the player's LT2 impairs soccer kicking performance. In contrast, light to moderate physiological stress appears to be neither harmful nor beneficial for kicking performance.
Read, Paul J; Oliver, Jon L; De Ste Croix, Mark B A; Myer, Gregory D; Lloyd, Rhodri S
Early specialisation is characterised by formal participation in a single sport at the exclusion of others. Limited data are available to support this approach in the development of soccer players who attain elite status later in life. Of growing concern is the associated increased risk of injury and suggestions that single sport specialisation is a risk factor independent of age, growth, biological maturation and training volumes. In the United Kingdom, elite soccer organisations have recently adopted an early sport specialisation approach following the introduction of the Elite Player Performance Plan. A key tenet of this programme is increased opportunities for training through a marked rise in the specified on-pitch hours per week. The accumulation of high training hours may be less of a relevant marker for success, and the impact of such a significant increase in training volume for young athletes who are experiencing a range of growth and maturational processes is currently unknown. This critical commentary includes an evidence-based discussion of the effectiveness of early sport specialisation and the potential injury risks associated with such programmes placing a specific focus on elite male youth soccer players. Available data indicate that modifications to the existing Elite Player Performance Plan framework could enhance players' development and reduce injury risk. Proposed alterations include reduced volume of soccer-specific training at key stages of growth and maturation and guidelines for the provision of a greater variety of physical activities that are integrated within other programme components.
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.
Boylan, Matthew R; Khalili, Hamed; Huang, Edward S; Michaud, Dominique S; Izard, Jacques; Joshipura, Kaumudi J; Chan, Andrew T
Periodontal disease has been associated with higher circulating levels of inflammatory markers and conditions associated with chronic inflammation, including vascular disease, diabetes mellitus, and cancer. Limited data exist on the relationship between periodontal disease and gastric and duodenal ulcer. We conducted a prospective cohort study of 49,120 men in the Health Professionals Follow-up Study, aged 40-75 years at enrollment in 1986. Biennially, we assessed periodontal disease, tooth loss, and other risk factors for gastric and duodenal ulcer. We validated diagnoses of gastric and duodenal ulcer through medical record review. We used Cox proportional hazards modeling, adjusting for potential confounders, to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). We documented 138 cases of gastric ulcer and 124 cases of duodenal ulcer with available information on Helicobacter pylori status over 24 years of follow-up. After adjustment for risk factors, including smoking and regular use of aspirin and non-steroidal anti-inflammatory drugs, men with periodontal disease with bone loss had a multivariate HR of ulcer of 1.62 (95% CI, 1.24-2.12). Periodontal disease appeared to be associated with a similar risk of developing ulcers that were H. pylori negative (HR 1.75; 95% CI, 1.26-2.43) than H. pylori positive (HR 1.40; 95% CI, 0.87-2.24), as well as ulcers in the stomach (HR 1.75; 95% CI, 1.21-2.53) than ulcers in the duodenum (HR 1.47; 95% CI, 0.98-2.19). Periodontal disease is associated with an increased risk of incident gastric and duodenal ulcer. This relationship may be mediated by alterations in the oral and gastrointestinal microbiome and/or systemic inflammatory factors.
Pinosa, C; Gagnayre, R
To assess the working conditions of Cambodian male nurses specialised in anaesthesia and intensive care (NSAIs), degree of satisfaction, whether training was suited to the Cambodian needs and practical application of training. Prospective survey. Two training years including 30 NSAIs. External assessors evaluated working conditions, practice of anaesthesia, analysed logbooks and theatre reports, organised semi-directive interviews and examinations using clinical cases. Out of the 30 NSAIs, 28 had an appointment, mainly in anaesthesia (80% of their activity) and three-quarters of them felt that their skills were appreciated by their superiors. Seventeen had some form of responsibility in the management of a department. For the administration of an anaesthetic, 13 NSAIs of the second year had achieved an acceptable level of performance and resolved effectively 85% of the submitted cases. Twenty-two NSAIs reported difficulty in applying techniques learned during their training to real working conditions. The causes were poor equipment, poor organisation and poor relations with the hierarchy. The latter cause decreased the capacity to take appropriate decisions, which was the most common error made by the second year NSAIs. Finally, as their wages remained unchanged, 19 out of the 28 NSAIs were obliged to look for an additional source of income. This survey shows the medium-term effectiveness of an NSAI training programme basing on teaching and public health principles and organised in the humanitarian aid sector.
Pallesen, Ståle; Gundersen, Hilde Stokvold; Kristoffersen, Morten; Bjorvatn, Bjørn; Thun, Eirunn; Harris, Anette
Many athletes sleep poorly due to stress, travel, and competition anxiety. In the present study, we investigated the effects of sleep deprivation on soccer skills (juggling, dribbling, ball control, continuous kicking, 20 and 40 m sprint, and 30 m sprint with changes of direction). In all, 19 male junior soccer players (14-19 years old) were recruited and participated in a cross-balanced experimental study comprising two conditions; habitual sleep and 24 hours sleep deprivation. In both conditions, testing took place between 8 a.m. and 10 a.m. Order of tests was counterbalanced. Each test was conducted once or twice in a sequence repeated three times. The results revealed a negative effect of sleep deprivation on the continuous kicking test. On one test, 30 meter sprint with directional changes, a significant condition × test repetition interaction was found, indicating a steeper learning curve in the sleep deprived condition from Test 1 to Test 2 and a steeper learning curve in the rested condition from Test 2 to Test 3. The results are discussed in terms of limitations and strengths, and recommendations for future studies are outlined.
Meyers, M C; Stewart, C C; Laurent, C M; Leunes, A D; Bourgeois, A E
Athletes at Olympic Developmental Program (ODP) camps experience unusually high levels of expectations and inherent mental and physical challenges within such a short span of time. With the increasing emphasis on talent development, there has been consensus by the ODP staff to more clearly define present levels of coping skills, in order to enhance athletic prediction, maximize training efforts, identify the predisposition to injury, and focus on areas pertinent to successful performance. This study examined athletic and pain coping skills of U. S. ODP soccer athletes not previously investigated. Following written informed consent, 70 males completed the Athletic Coping Skills Inventory and the Sports Inventory for Pain. Data were analyzed by competitive level (U-14, U-15), and skill position (goalkeeper/defense, midfield/foward). MANOVA indicated a significant main effect across competitive level (Wilks' Lambda F(12,57) = 2.27; p = 0.02; n-beta = 0.915) but no significant effect by skill position (Wilks' Lambda F(12,57) = 0.931; p = 0.523; n-beta = 0.457). Post hoc analyses indicated that U-15 athletes scored significantly higher in concentration (p = 0.01) and body awareness (p = 0.03), but lower in avoidance (p = 0.01) than U-14 competitors. In conclusion, older, more experienced athletes revealed more positive athletic and pain coping skills than younger, less experienced athletes, although athletes in skill positions requiring spontaneous decision-making skills and split-second adjustment in a constantly changing sport environment (forwards, midfielders) did not exhibit more positive athletic and pain coping skills than those positions requiring reaction and protection (defenders, goalkeepers).
Lesões nos jogadores de futebol profissional do Marília Atlético Clube: estudo de coorte histórico do campeonato brasileiro de 2003 a 2005 Injuries in the professional soccer players of Marília Atlético Clube: a cohort study of the Brazilian Championship, 2003 to 2005
Evandro Pereira Palacio
no-activity period. The purpose of this study was to assess, through a cohort study, the injured athletes' recovery period, facing it to the variables: age, position in game and injure pattern. METHODS: The medical reports of all professional soccer players of Marília Atlético Clube who were injured during the Brazilian Soccer Championship - 2nd Division, from January/2003 to December/2005 were assessed, with a 24 months follow-up. RESULTS: Athletes' mean age (SD was 24.5 years (4.4 years; the most frequently injured athletes were: strikers (36.8, center-backs (26.6%, center-midfielders (20%, side-midfielders (10% and goalkeepers (6.6%. The most frequent injuries were: muscular (46.8%, ligament (26.6%, bone (16.6% and meniscal (10%; the strikers have shown a mean recovery period of 28 days (78.3 days, the center-backs 26.5 days (33.9, the center-midfielders 18.5 days (66.3, the side-midfielders 17 days (129.9 and the goalkeepers 47.5 days (17.6. CONCLUSION: Statistical analysis showed that there was no correlation between athletes' age and their healing period (p/ =/ 0.31; there was no statistical difference between the healing period among the five different athletes' positions (p/ =/ 0.49; there was statistical difference between the healing period and the injury pattern (p/ 0.001 among the variables: meniscal and bone injuries, meniscal and muscular injuries, ligament and bone injuries and ligament and muscular injuries.
Cleston Alexandre dos Santos
Full Text Available Brazilian soccer teams are required to present good results inside and outside the field. The main demand is about winning titles, to present continuous and increasing profits, and, consequently, to reach economic-financial stability. The present study aims at analyzing the relationship between the ranking formed by the Brazilian Soccer Confederation (CBF and the economic-financial indicators of the Brazilian soccer teams. The sample consisted of 36 Brazilian soccer teams that belong to the series A, B and C. Such teams are linked to CBF and published their financial statements of 2014. For data analysis, we used multi-criteria decision making method VIKOR that was applied along with Kendall rank correlation. Results revealed that the majority of Brazilian soccer teams have insufficient economical liquidity; they cannot bear their own expenses; they dependent of third-party resources; and they present negative profitability. Results also showed, through VIKOR technique, that the soccer teams studied occupy different positions in CBF ranking and in the economical-financial indicators, except for Botafogo club. Kendall rank correlation revealed no correlation and no significance between the rankings. Findings seem to support the idea that there is no relationship between CBF rankings and the economical-financial indicators of Brazilian soccer teams.
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
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…
Maria Cristina Chimelo Paim
Full Text Available This study aimed to verify what were the motivational factors that made teenagers to choose ADUFSM soccer school, and to verify the difference among the groups, the performance and gain scores at soccer basis. The sample comprised 32 persons, 10 to 16 years old, that practice soccer at ADUFSM. The sample was divided in four groups. The motivational factors inventory (MFI was applied in the beginning of the semester. It was verified, through descriptive statistics, that the stronger motivation for the subjects involvement with soccer was to develop skills (78%, followed by excitation and challenge (72%; affiliation (70% and aptitude (68%. The performance level evaluation in three different phases was done through soccer basis analytical matrix (SBAM, always in game situation. Five observations per subject were made for each base listed in SBAM, and the execution mistakes were identifies. Initially, an ANOVA was used to deal with the data; later, a post-hoc test. The results showed that learning occurred and that there was a significant difference favoring GF10 in the learning gain scores after the treatment.
Liam D Harper
Full Text Available Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63% either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50% and do not (50% account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk
Harper, Liam D; Fothergill, Melissa; West, Daniel J; Stevenson, Emma; Russell, Mark
Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery
Leo, Francisco Miguel; González-Ponce, Inmaculada; Sánchez-Oliva, David; Pulido, Juan José; García-Calvo, Tomás
This investigation presents two studies with the goal of adapting and validating a short version of the Group Environment Questionnaire in the Spanish sport context with professional players. Study 1 used a sample of 377 male soccer players aged between 18 and 39 years ( M = 24.51, SD = 3.73), in a preliminary study using exploratory factor analysis. Study 2 used a sample of 604 professional male and female athletes, ages between 15 and 38 years ( M = 24.34, SD = 4.03). The data analyzed were collected at three moments of the season. For each measurement, we developed seven first- and second-order structures that were analyzed with confirmatory factor analysis. Study 1 indicated appropriate factorial validity (> .60) and internal consistency (> .70), with only Item 3 presenting a low factor loading (.11), so its drafting was modified in the next study. Study 2 revealed that the Spanish version of the GEQ has high levels of internal consistency (> .70) and acceptable fit index values in its original four first-order factor structure in all three measurements ( χ²/df = 4.39, CFI = .95, IFI = .95, RMSEA = .07, SRMR = .04, AIC = 271.09). Discriminant validity (from r = .45 to r = .72) and concurrent validity (from r = .21 to r = .60) also presented appropriate values. Lastly, we conducted analysis of invariance, confirming that the models established in the different measurements were invariant. The short 12-item adaptation of the GEQ to Spanish is a valid and reliable instrument to measure team cohesion in professional male and female 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
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.
Williams, Jeremy D; Abt, Grant; Kilding, Andrew E
The aim of this study was to determine the validity and reliability of a 90-minute soccer performance test: Ball-sport Endurance and Sprint Test (BEAST90). Fifteen healthy male amateur soccer players participated and attended 5 testing sessions over a 10-day period to perform physiologic and soccer-specific assessments. This included familiarization sessions and 2 full trials of the BEAST90, separated by 7 days. The total 90-minute distance, mean percent peak heart rate (HRpeak), and estimated percent peak oxygen uptake of the BEAST90 were 8,097 ± 458 m, 85 ± 5% and 82 ± 14%, respectively. Measures obtained from trial 1 and trial 2 were not significantly different (p > 0.05). Reliability of measures over 90 minutes ranged from 0.9-25.5% (% typical error). The BEAST90 protocol replicated soccer match play in terms of time, movement patterns, physical demands (volume and intensity), distances, and mean and HRpeak values, as well as having an aerobic load similar to that observed during a soccer match. Reproducibility of key physical measures during the BEAST90 were mostly high, suggesting good reliability. The BEAST90 could be used in studies that wish to determine the effects of training or nutritional interventions on prolonged intermittent physical performance.
Justin Wai-Yuk Lee
Full Text Available The aim of this study was to investigate the match and training injury incidence, injury patterns and severity, and their monthly variation in a Hong Kong male professional football league. The study design was a prospective cohort study. Seven teams in the Hong Kong Football Association first division league and 152 players from 10 professional teams participated in this study. On a weekly basis throughout the 9-month season, time-loss injuries and individual exposure were collected from injury recorders team visits. Operational injury definitions and procedures followed the recommendations of a football consensus. The overall injury incidence was 7.4 injuries/1000 player hours and 296 injuries were recorded. The relative risk of match injury was 17 times greater than the risk of training injury [relative ratio (RR, 17.3; 95% confidence injury (CI, 11.6–25.7; p < 0.001]. Ankle sprain was the most common injury type (16.2% of all injuries and 52% of these injuries were recurrent. Thigh strain was the second most common injury type with 82% of the injuries involving the hamstring muscle and 80% of hamstring strains were noncontact injuries. During the competitive season, the relative risk of injury was highest in October (RR, 6.8; 95% CI, 6.7–6.9; p < 0.001 and February (RR, 4.7; 95% CI, 4.3–5.2; p < 0.001. This highlighted that Hong Kong professional football has a high match injury incidence. The relative risk of injury was highest at the beginning of the competitive season. A prospective multicentre epidemiological study is warranted to examine regional differences in injury risks. Coaches, players, health professionals, and researchers should join their efforts to investigate the effect on injury incidence and injury pattern associated with the duration and content of the preseason period, and the number of friendly matches held during preseason.
Full Text Available This paper describes models for detecting individual and team ball possession in soccer based on position data. The types of ball possession are classified as Individual Ball Possession (IBC, Individual Ball Action (IBA, Individual Ball Control (IBC, Team Ball Possession (TBP, Team Ball Control (TBC und Team Playmaking (TPM according to different starting points and endpoints and the type of ball control involved. The machine learning approach used is able to determine how long the ball spends in the sphere of influence of a player based on the distance between the players and the ball together with their direction of motion, speed and the acceleration of the ball. The degree of ball control exhibited during this phase is classified based on the spatio-temporal configuration of the player controlling the ball, the ball itself and opposing players using a Bayesian network. The evaluation and application of this approach uses data from 60 matches in the German Bundesliga season of 2013/14, including 69,667 IBA intervals. The identification rate was F = .88 for IBA and F = .83 for IBP, and the classification rate for IBC was κ = .67. Match analysis showed the following mean values per match: TBP 56:04 ± 5:12 min, TPM 50:01 ± 7:05 min and TBC 17:49 ± 8:13 min. There were 836 ± 424 IBC intervals per match and their number was significantly reduced by -5.1% from the 1st to 2nd half. The analysis of ball possession at the player level indicates shortest accumulated IBC times for the central forwards (0:49 ± 0:43 min and the longest for goalkeepers (1:38 ± 0:58 min, central defenders (1:38 ± 1:09 min and central midfielders (1:27 ± 1:08 min. The results could improve performance analysis in soccer, help to detect match events automatically, and allow discernment of higher value tactical structures, which is based on individual ball possession.
Leonardo Pestillo de Oliveira
Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n5p601 This study investigated the impact of performance traits on self-determined motivation in high-performance soccer athletes. Participants were professionalized and non-professionalized athletes from a soccer club of the state of Paraná, totaling 182 subjects. Data were collected using the Sport Motivation Scale and the Multidimensional Perfectionism Scale through previous scheduling and the application of research instruments occurred through direct contact with subjects during practices, which were individually answered with average duration of 35 minutes. For data analysis, Mann-Whitney, Spearman correlation and Simple Regression were conducted (p<0.05. Results showed that professional athletes had higher levels in externally controlled motivation compared to non-professionalized (p<0.05 athletes, while non-professionalized athletes were more amotivated (p=0.002. Professionalized athletes had higher scores in the adaptive perfectionism domains compared to non-professionalized athletes (p<0.05. Adaptive perfectionism had significant impact (p<0.05 on the self-determined motivation regulations in professional athletes, while maladaptive perfectionism had an effect (p<0.05 on the external regulation of non-professionalized athletes. It was concluded that for athletes who reach professional level, adaptive perfectionism is an intervening element in the development of self-determined motivation. In addition, for non-professionalized
Full Text Available In this paper the trajectories of a soccer ball for the most important kicks in the football game - a corner kick and a direct free kick are studied. The soccer ball is modelled as an ideal rigid hollow spherical body with six degrees of freedom, which performs a general motion in an immovable air environment with constant parameters. The ball 3D orientation is determined by the three Cardan angles. The aerodynamic forces and moments with which the air environment acts to the ball are taken into account. Two of the most dangerous areas of the football goal are defined. Differential equations which describe the motion of the soccer ball are solved numerically by MatLab-Simulink.
Shephard, R J
Recent literature on the biology and medicine of soccer (primarily since 1990) has been accumulated by a combination of computer searching of relevant databases and review of the author's extensive files. From a total of 9681 papers, 540 were selected for closer scrutiny and 370 are discussed in the present review. These articles cover patterns of play and the resulting energy demands, the nutritional requirements of soccer, the anthropometric, physiological, biochemical and immunological characteristics of successful players, the influence of environmental stressors (heat, cold, hypoxia and time zone shifts), special features of female and junior competitors, selected issues in training, and the incidence and prevention of injuries. The information presented has important implications for the safety and success of soccer players; the challenge is now to ensure that this information is understood and acted upon by coaches and individual team members.
Williams, A M; Reilly, T
In this review, we attempt to integrate the main research findings concerned with talent identification and development in soccer. Research approaches in anthropometry, physiology, psychology and sociology are considered and, where possible, integrated. Although some progress has been made in identifying correlates of playing success, it appears that no unique characteristics can be isolated with confidence. Both biological and behavioural scientists have indicated a strong genetic component in performance of sports such as soccer; nevertheless, the influence of systematic training and development programmes should not be underestimated. We conclude that the sport and exercise sciences have an important support role in the processes of identifying, monitoring and nurturing talented soccer players towards realizing their potential.
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
Eddosary, Melfy; Ko, Yong Jae; Sagas, Michael; Kim, Hee Youn
The purpose of this study was to identify important factors of consumers' intention to attend professional soccer events among Saudi Arabian soccer fans. To explore the decision-making process of this relatively understudied population, the theory of planned behavior was used as theoretical background. Particularly, this study measured the effect of attitude, subjective norm, perceived behavioral control (time and money), and game importance on intention to attend, and examined the moderating role of commitment. Structural equation modeling (SEM) using 231 Saudi university students (M = 21.9 yr., SD = 1.21) indicate that attitude and game importance were significantly related to attendance intention. The effect of subjective norms was significant only for the low commitment group and game importance was more important for the low than the high commitment group.
Elbin, R J; Beatty, Amanda; Covassin, Tracey; Schatz, Philip; Hydeman, Ana; Kontos, Anthony P
This study compared changes in neurocognitive performance and symptom reports following an acute bout of soccer heading among athletes with and without protective soccer headgear. A total of 25 participants headed a soccer ball 15 times over a 15-minute period, using a proper linear heading technique. Participants in the experimental group completed the heading exercise while wearing a protective soccer headband and controls performed the heading exercise without wearing the soccer headband. Neurocognitive performance and symptom reports were assessed before and after the acute bout of heading. Participants wearing the headband showed significant decreases on verbal memory (p = 0.02) compared with the no headband group, while the no headband group demonstrated significantly faster reaction time (p = 0.03) than the headband group following the heading exercise. These findings suggest that protective soccer headgear likely does not mitigate the subtle neurocognitive effects of acute soccer heading.
Results showed that the midfielders had the least (13.5 ± 3.7 %), while the goalkeepers had the highest percentage body fat (16.8 ± 2.3 %). Skinfold values were found to vary by playing positions. Goalkeepers had the highest biceps skinfold thickness (7.2 ± 2.8 mm). Supra-iliac skinfold thickness was least in the defenders ...
Esteve, Ernest; Rathleff, Michael Skovdal; Vicens-Bordas, Jordi
Background: Hip adductor muscle weakness and a history of groin injury both have been identified as strong risk factors for sustaining a new groin injury. Current groin pain and age have been associated with hip adductor strength. These factors could be related, but this has never been investigat...
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.
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.
Full Text Available Rafael Júlio de Freitas Guina Fachina,1,2 Marília dos Santos Andrade,3 Fernando Roberto Silva,4 Silas Waszczuk-Junior,4 Paulo César Montagner,1 João Paulo Borin,1 Claudio Andre Barbosa de Lira5 1Departamento de Ciência do Esporte, Faculdade de Educação Física, Universidade Estadual de Campinas (UNICAMP, Campinas, Brazil; 2Confederação Brasileira de Basketball (CBB, Rio de Janeiro, Brazil; 3Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, Brazil; 4Grêmio Barueri Futebol LTDA, Barueri, Brazil; 5Setor de Fisiologia Humana e do Exercício, Universidade Federal de Goiás, Câmpus Jataí, Jataí, Brazil Abstract: Soccer, which has a large number of participants, has a high injury incidence that causes both financial and time burdens. Therefore, knowledge about the epidemiology of soccer injuries could allow sports-medicine professionals, such as physicians and physiotherapists, to direct their work in specific preventive programs. Thus, our aim was to conduct an epidemiological survey of injuries sustained by professional soccer players from the same team who participated in the Brazilian championship premier league in 2009. To this end, we evaluated retrospectively player medical records from the team, which included name, date of birth, position, date of injury, mechanism of injury, and type of injury. In the period of study, 95 injuries were recorded: 42 (44.2% were recorded during matches, and 53 (55.8% during the training period. Injuries occurred more frequently in midfielders and strikers. All injuries happened in the lower limb, most of the injuries were muscular, and most occurred as the result of collisions with other athletes. In summary, this study demonstrates that there is a need for greater safety awareness in the training environment. Keywords: injuries, epidemiology, soccer players
Giancola, Silvio; Amine, Mohieddine; Dghaily, Tarek; Ghanem, Bernard
In this paper, we introduce SoccerNet, a benchmark for action spotting in soccer videos. The dataset is composed of 500 complete soccer games from six main European leagues, covering three seasons from 2014 to 2017 and a total duration of 764 hours. A total of 6,637 temporal annotations are automatically parsed from online match reports at a one minute resolution for three main classes of events (Goal, Yellow/Red Card, and Substitution). As such, the dataset is easily scalable. These annotations are manually refined to a one second resolution by anchoring them at a single timestamp following well-defined soccer rules. With an average of one event every 6.9 minutes, this dataset focuses on the problem of localizing very sparse events within long videos. We define the task of spotting as finding the anchors of soccer events in a video. Making use of recent developments in the realm of generic action recognition and detection in video, we provide strong baselines for detecting soccer events. We show that our best model for classifying temporal segments of length one minute reaches a mean Average Precision (mAP) of 67.8%. For the spotting task, our baseline reaches an Average-mAP of 49.7% for tolerances $\\delta$ ranging from 5 to 60 seconds.
In this paper, we introduce SoccerNet, a benchmark for action spotting in soccer videos. The dataset is composed of 500 complete soccer games from six main European leagues, covering three seasons from 2014 to 2017 and a total duration of 764 hours. A total of 6,637 temporal annotations are automatically parsed from online match reports at a one minute resolution for three main classes of events (Goal, Yellow/Red Card, and Substitution). As such, the dataset is easily scalable. These annotations are manually refined to a one second resolution by anchoring them at a single timestamp following well-defined soccer rules. With an average of one event every 6.9 minutes, this dataset focuses on the problem of localizing very sparse events within long videos. We define the task of spotting as finding the anchors of soccer events in a video. Making use of recent developments in the realm of generic action recognition and detection in video, we provide strong baselines for detecting soccer events. We show that our best model for classifying temporal segments of length one minute reaches a mean Average Precision (mAP) of 67.8%. For the spotting task, our baseline reaches an Average-mAP of 49.7% for tolerances $\\\\delta$ ranging from 5 to 60 seconds.
Beato, Marco; Jamil, Mikael; Devereux, Gavin
The Video Tracking multiple cameras system (VTS) is a technology that records two-dimensional position data (x and y) at high sampling rates (over 25 Hz). The VTS is of great interest because it can record external load variables as well as collect technical and tactical parameters. Performance analysis is mainly focused on physical demands, yet less attention has been afforded to technical and tactical factors. Digital.Stadium® VTS is a performance analysis d